Electrode assembly, battery, battery pack and vehicle

Abstract

Electrode assembly (A; 80) comprising a first electrode (10; 11), a second electrode (10; 11) and a separator (12) arranged between them, wherein the first electrode (10; 11), the second electrode (10; 11) and the separator (12) are wound around a winding axis (Y), wherein the first electrode (10; 11) has a first active material section coated with an active material layer (42) and a first uncoated section (43; 146a) which is free of the active material layer (42), wherein the first uncoated section (43; 146a) is located at an edge of the first electrode (10; 11) which extends along a winding direction (X), wherein the first uncoated section (43; 146a) is partially formed with several separate tabs (61) which are individually bendable in a radial direction of the electrode assembly (A; 80), wherein the height of an outermost region having an outermost winding turn of the first uncoated section (43; 146a) is less than the heights of the several separate tabs (61), wherein the several separate tabs (61) are bent along the radial direction in the direction of the winding axis (Y) of the electrode assembly (A; 80) to form a bending surface area (F), and wherein the bending surface area (F) comprises an area with a uniform number of overlap layers (b1) in which the number of overlapping layers of the separate tabs (61) is 10 or more, and an area with a decreasing number of overlap layers (b2) adjacent to the area with a uniform number of overlap layers (b1) in which the number of overlapping layers of the separate tabs (61) decreases in the radial direction away from the area with a uniform number of overlap layers (b1).

Description

TECHNICAL AREA

[0001] The present disclosure relates to an electrode assembly, a battery and a battery pack and a vehicle incorporating these. STATE OF THE ART

[0002] Secondary batteries, which are easily applicable to various product groups and have electrical properties such as high energy density, are universally used not only for portable devices but also for electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by an electric drive source.

[0003] These secondary batteries are attracting attention as a new energy source to improve environmental friendliness and energy efficiency because they have the primary advantage of being able to drastically reduce the use of fossil fuels, as well as the secondary advantage of not producing any byproducts from the use of energy.

[0004] Secondary batteries, which are currently widely used in technology, include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and the like. A secondary battery unit, or standard battery, has an operating voltage of approximately 2.5 V to 4.5 V. Therefore, if a higher output voltage is required, a battery pack can be designed by connecting several batteries in series. Additionally, several batteries can be connected in parallel to form a battery pack according to the required charge / discharge capacity. Accordingly, the number of batteries contained in the battery pack and the form of the electrical connection can be adjusted according to the required output voltage and / or charge / discharge capacity.

[0005] Meanwhile, cylindrical, rectangular, and pouch-shaped batteries are known types of secondary battery units. In the case of a cylindrical battery, a separator, acting as an insulator, is positioned between a positive and a negative electrode, and they are wound to form an electrode assembly in the form of a jelly-roll structure. This assembly is inserted into a battery casing to create the battery. Additionally, a strip-shaped electrode tab may be connected to an uncoated section of each of the positive and negative electrodes. This electrode tab electrically connects the electrode assembly to an electrode terminal exposed to the outside. For example, the positive electrode terminal could be a cap of a sealing body that seals the opening of the battery casing, and the negative electrode terminal could be the battery casing itself.However, according to the conventional cylindrical battery with such a structure, the current collection efficiency is not good due to the high resistance and high heat generation, as current is concentrated in the strip-shaped electrode tab that is coupled to the uncoated section of the positive electrode and / or the uncoated section of the negative electrode.

[0006] For small cylindrical batteries with a form factor of 1865 (diameter: 18 mm, height: 65 mm) or 2170 (diameter: 21 mm, height: 70 mm), resistance and heat are not a major concern. However, when the form factor is increased to allow the cylindrical battery to be used in electric vehicles, the battery can ignite if a significant amount of heat is generated around the electrode tab during a fast-charging process.

[0007] To solve this problem, a cylindrical battery (so-called tabless cylindrical battery) is provided in which the uncoated section of the positive electrode and the uncoated section of the negative electrode are designed to be positioned at the top and bottom, respectively, of the jelly roll electrode assembly, and the current collector is welded to the uncoated section to improve current collection efficiency. DESCRIPTION

[0008] Fig. 1 to Fig. Figure 3 shows a manufacturing process for a tabless cylindrical battery. Fig. Figure 1 shows the structure of an electrode, Fig. Figure 2 shows a winding process of the electrode and Fig. Figure 3 shows a welding process of a current collector to a curved surface area of ​​an uncoated section.

[0009] With reference to Fig. 1 to Fig. 3. A positive electrode 10 and a negative electrode 11 have a structure in which a plate-shaped current collector 20 is coated with an active material 21, and an uncoated section 22 has on one long side along the winding direction X. The long side is a direction parallel to the x-axis direction, which means: a side with a relatively long length.

[0010] An electrode assembly A is produced by stacking the positive electrode 10 and the negative electrode 11 sequentially together with two plates of separators 12, as shown in Fig. 2 is shown, and they are then wound in one direction X. Meanwhile, the uncoated sections of the positive electrode 10 and the negative electrode 11 are oriented in opposite directions.

[0011] After the winding process, the uncoated section 10a of the positive electrode 10 and the uncoated section 11a of the negative electrode 11 are bent towards the core. Then, current collectors 30 and 31 are welded and coupled to the uncoated sections 10a and 11a, respectively.

[0012] An electrode tab is not separately coupled to the uncoated section 10a of the positive electrode and the uncoated section 11a of the negative electrode; the current collectors 30, 31 are connected to external electrode terminals, and a current path with a large cross-sectional area is formed along the winding axis direction of the electrode assembly A (see arrow), which has the advantage of reducing the resistance of the battery. This is because the resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0013] In the case of the tabless cylindrical battery, in order to improve the welding properties of the uncoated sections 10a, 11a and the current collectors 30, 31, strong pressure must be applied to the welding area of ​​the uncoated sections 10a, 11a in order to bend the uncoated sections 10a, 11a as flat as possible.

[0014] However, if the weld area of ​​the uncoated sections 10a and 11a is bent, their shapes can become irregularly distorted and deformed. In this case, the deformed section can come into contact with an electrode of opposite polarity, causing an internal short circuit or microcracks in the uncoated sections 10a and 11a. Furthermore, because the uncoated section 32, which borders the core of electrode assembly A, is bent, all or a significant portion of the cavity 33 in the core of electrode assembly A is blocked. This causes a problem in the electrolyte injection process. That is, cavity 33 in the core of electrode assembly A serves as a passage through which an electrolyte is injected. However, if this passage is blocked, electrolyte injection becomes difficult.Furthermore, while an electrolyte injector is being inserted into cavity 33, the electrolyte injector may disturb the uncoated section 32 near the core, which may cause the uncoated section 32 to rupture.

[0015] Furthermore, the curved sections of the uncoated sections 10a, 11a, to which the current collectors 30, 31 are welded, should be overlapped in several layers, and no empty spaces (gaps) should be present. In this way, sufficient weld strength can be obtained, and even with the latest technology, such as laser welding, it can be prevented that the laser penetrates the electrode assembly A and melts the separator or the active material.

[0016] In contrast, in the conventional tabless cylindrical battery, the uncoated section 10a of the positive electrode is formed entirely on the upper portion of the electrode assembly A. Therefore, when the outer circumference of the top of the battery case is pressed inward to form a beaded section, an upper edge region 34 of the electrode assembly A is compressed by the battery case. This compression can cause partial deformation of the electrode assembly A, which can rupture the separator 12 and cause an internal short circuit. If a short circuit occurs within the battery, it can cause the battery to overheat or explode. TECHNICAL TASK

[0017] The present disclosure is designed to solve the problems of the prior art, and therefore the present description is directed to providing an electrode assembly with an improved structure of the uncoated section in order to relieve stresses exerted on the uncoated section when the uncoated section exposed at both ends of the electrode assembly is bent.

[0018] The present disclosure is also directed to providing an electrode assembly in which an electrolyte injection passage is not blocked, even if the uncoated section is bent.

[0019] The present disclosure is also directed to providing an electrode assembly which includes a structure which can prevent an upper edge of the electrode assembly from touching an inner surface of a battery housing when the top of the battery housing is crimped.

[0020] The present disclosure is also directed to providing an electrode assembly that improves the physical properties of a welding area by applying a segment structure to the uncoated section of the electrode and by optimizing the dimensions (width, height, parting line) of the segments to sufficiently increase the number of overlapping layers of the segments in an area used as a predetermined welding area.

[0021] The present disclosure is also directed to providing an electrode assembly with improved energy density and reduced resistance by applying a structure in which a current collector is welded over a large area to a bending surface area formed by bending the segments.

[0022] The present disclosure is also directed to providing a battery which includes a terminal and a current collector with an improved design for carrying out electrical wiring on an upper section thereof.

[0023] The present disclosure is also directed to the provision of a battery comprising the electrode assembly with an improved structure, a battery pack comprising the battery, and a vehicle comprising the battery pack.

[0024] The technical problems to be solved by the present disclosure are not limited to those above, and other problems not mentioned here will be clearly understood by those skilled in the art from the following disclosure. TECHNICAL SOLUTION

[0025] The present invention is defined by the subject matter of the independent claims. Specific examples of the present invention are defined by the features of the dependent claims. Furthermore, any of the features described above may also be included in the claimed subject matter, provided that this is not inappropriate.

[0026] An electrode assembly can comprise a first electrode, a second electrode, and a separator. The separator can be positioned between the first and second electrodes. The first electrode, the second electrode, and the separator can be wound around a winding axis. The first electrode can comprise a first active material section and a first uncoated section. The first active material layer can be coated with an active material (active material layer). The first uncoated section can be free of the active material layer. The first uncoated section can be formed at an edge of the first electrode, with the edge extending along a winding direction of the electrode assembly. The first uncoated section can be configured to provide an electrical connection to the first electrode.The first uncoated section can comprise a first section, a second section, and a third section. The third section can be positioned between the first and second sections. The height of the first section and / or the second section can be less than the height of the third section. The heights can be defined in a winding axis direction parallel to the winding axis of the electrode assembly. The height of the first uncoated section can be defined as its dimension in the winding direction relative to the boundary of the active material section or to an area where the (first) active material is deposited.

[0027] The electrode assembly can have a (generally approximately) cylindrical shape and, accordingly, a cylindrical geometry. The outer circumference of the wound first and second electrodes and the separator positioned between them can generally have a cylindrical shape. The cylindrical geometry can define an axial direction, a radial direction, and a circumferential (tangential) direction according to basic mathematics. The winding axis of the electrode assembly can be parallel to the axial direction. The axial direction can be the same as the winding axis direction of the electrode assembly. The winding direction can be perpendicular to the winding axis direction. The winding direction can be approximately the same as the circumferential direction of the electrode assembly. Here, a height in the axial direction (i.e., the winding axis) can be specified unless otherwise stated.Here, a width in the winding or circumferential direction can be specified, unless otherwise stated.

[0028] The wound first and second electrodes and the separator between them may have a cross-section corresponding to a spiral shape. A core may refer to a generally cylindrical cavity and may be described as a hollow core section. The description "generally cylindrical," as used here with reference to the wound first and second electrodes and the separator between them, is to be understood as referring to the inner and / or outer cylindrical surface, which may have a step-like transition at the terminal inner or outer winding edge with respect to the penultimate winding. The terminal winding edge may extend (generally approximately) parallel to the winding axis. The terminal winding edge may alternatively be described as a short side end.The other side ends, which connect between the short side ends, can be called long side ends. The edge that extends in the winding direction and where the uncoated section is located can be a long side end of the first electrode.

[0029] In an unwound view (i.e., without winding or coiling) of the electrode assembly, each of the first electrode, the second electrode, and the separator can extend axially between any two long end pieces. The first electrode, the second electrode, and the separator can also extend axially between any two short end pieces. In some examples, each of the long end pieces can be longer than each of the short end pieces. The long end piece of each of the first and second electrodes and the separator can correspond to a longer or longest end piece of each of the plate-shaped first and second electrodes and the separator.For example, for a first electrode, a second electrode, or a separator that has a substantially rectangular shape before being rolled to form the battery's electrode assembly, an edge of the rectangle formed by the unrolled separator corresponding to the longer side of the rectangle may correspond to the respective "long side end." The long side end of each of the first and second electrodes and the separator may therefore be perpendicular to a vertical direction of the battery. In the direction perpendicular to the battery's height, the first uncoated portion of the first electrode may protrude from and / or extend beyond the separator. Alternatively, the terms "long" and "short" may be nominal values ​​only, and each of the short side ends may be longer than the long side ends. Each of the long side ends may be linear, curved, or patterned (e.g.,with segments as described below) or a combination thereof.

[0030] The first electrode can be a sheet, plate, or film onto which the active material is deposited. Generally, the first electrode can be a positive or a negative electrode. An area of ​​the first electrode on which the active material is deposited (coated with the active material) can be referred to as the first active material section. The first electrode can be coated with the active material along its edge (which can be one of the long sides, as described above), except for the uncoated section. Here, an edge can refer to an end face, a terminal edge, or a boundary of the respective component.

[0031] The electrode assembly can have any of the features of an electrode assembly as disclosed herein. Both the first electrode, the second electrode, and the separator can have any of the respective features as described below.

[0032] The first uncoated section can be made of a conductive material to provide an electrical connection with the first electrode. The first uncoated section can be a portion of a sheet, plate, or film of the first electrode. The first uncoated section can be dimensioned and arranged to provide an electrical connection with the first electrode. In particular, the first uncoated section can be designed to electrically connect a terminal to the first electrode. Thus, the first uncoated section can act as a tab for the first electrode. Since the first uncoated section is part of the first electrode, the first electrode itself can act as a tab.

[0033] The first, second, and third sections of the first uncoated section can be adjacent to each other in the winding direction. The first, second, and third sections can have different sizes (i.e., overall widths) in the winding direction. In the wound electrode assembly, the first uncoated section, or any one of the first, second, and third sections, can be bent radially to the winding axis (i.e., inward) or outward. Unless otherwise inappropriate or specified, terms such as "inward," "inward(outward)," and "innermost" are used toward a center of volume of the (wound) electrode assembly. Correspondingly, terms such as "outward," "outward(outward)," and "outermost" are used to indicate a direction or a direction away from the center of volume of the (wound) electrode assembly.

[0034] In the wound electrode assembly, the first uncoated section of the first electrode can protrude in the winding axis direction above and between the end faces of the second electrode and the separator. These end faces can be collectively referred to as one end face of the electrode assembly, based on their cylindrical geometry. Accordingly, the wound electrode assembly can have two end faces and a lateral surface extending between them.

[0035] The first, second, and third sections of the first uncoated section of the first electrode of the electrode assembly can be dimensioned and arranged, particularly with respect to their respective heights, to provide an optimized contact area with the first electrode. Specifically, the uncoated section can be used to provide a contact area for a current collector, as described below. The first uncoated section can be used to increase the contact area compared to conventional arrangements, especially for larger battery cell assemblies. The height of any one or all of the first, second, and third sections can be defined as a specific dimension in the winding direction from the boundary of the active material section or from an area where the (first) active material is deposited.

[0036] In one aspect, an electrode assembly is provided in which a first electrode, a second electrode, and an intermediate separator are wound around a winding axis to define a core and an outer circumference, wherein the first electrode has a first active material section coated with an active material layer and a first uncoated section that is not coated with an active material layer along a winding direction, wherein at least a portion of the first uncoated section is defined as an electrode tab, and wherein the first uncoated section has a first section adjacent to the core of the electrode assembly, a second section adjacent to the outer circumference of the electrode assembly, and a third section that is arranged between the first section and the second section.and wherein the first section or the second section has a lower height in the winding axis direction than the third section.

[0037] In one example, the second section, when bent along the radial direction of the electrode assembly, can be defined as the electrode tab. Additionally or alternatively, the third section, when bent along the radial direction of the electrode assembly, can also be defined as the electrode tab. In general, an electrode tab can refer to a structure that provides an electrical connection to a particular electrode, especially for an external load or a battery cell connection.

[0038] In another example, the second section and the third section can be defined as the electrode tab in a state bent along a radial direction of the electrode assembly.

[0039] For example, the third section can be formed, at least partially, into several separate tabs. These separate tabs can be bendable, for instance, in the radial direction. Alternatively or additionally, at least a portion of the third section can be divided into a multitude of segments that are independently bendable. Here, the terms "separate tab" and "segment" can be used interchangeably. Furthermore, the separate tabs can also be referred to as foil tabs, tab fingers, various parts, separating parts, cut sections, or the like.

[0040] All or some of the separate tabs may have a polygonal shape, in particular a quadrilateral shape with an inner surface (i.e., a base) adjacent to a continuous (strip-shaped) portion of the first uncoated section. Each of the separate tabs may extend from the inner surface in the axial direction (winding axis direction) to an outer surface. All or some of the separate tabs may have a lateral surface extending between the inner and outer surfaces. The separate tabs may be provided sequentially along the edge of the first electrode to which the first uncoated section is attached. As specified below, the separate tabs may have identical shapes and / or dimensions, either individually or in groups. The separate tabs may exhibit any of the features described below.

[0041] For example, each of the multiple separate tabs (segments) can have a geometric shape in which one or more straight lines, one or more curves, or a combination thereof are joined. For example, each of the separate tabs can have a non-polygonal shape, with at least one of the outer and lateral sides not being straight. In general, any two-dimensional shape seen from a top view can be considered for the separate tabs.

[0042] In one example, the third section can be formed, at least partially, into several separate tabs that are individually bendable. All or some of the separate tabs can be designed to be bent. In particular, the separate tabs can be shaped (e.g., individually and / or according to a pattern) and / or dimensioned (e.g., in terms of height, width, thickness) such that they can be bent individually by applying an external force. Each, every, or all of the separate tabs can be bent in a state in which the electrode assembly is wound.

[0043] As stated above, the width can be fixed in the winding direction. For example, the width of one or more, or each of the multiple separate tabs, can decrease away from the active material layer in the winding axis direction. Alternatively, the width of one or more, or each of the multiple separate tabs, can decrease away from the active material layer in the winding axis direction and then increase. Alternatively, the width of one or more, or each of the multiple separate tabs, can increase away from the active material layer in the winding axis direction and then decrease. Alternatively, the width of one or more, or each of the multiple separate tabs, can increase away from the active material layer in the winding axis direction and then remain constant. Alternatively, the width of one or more, or each of the multiple separate tabs, can decrease away from the active material layer in the winding axis direction and then remain constant.Alternatively, the width of one or more or each of the several separate tabs along the winding axis direction can remain unchanged.

[0044] In one example, in any of the multitude of segments, the width of a lower section can be greater than the width of an upper section.

[0045] In one example, in each of the multitude of segments, the width of a lower section can be identical to the width of an upper section.

[0046] In one example, each of the multitude of segments can have a width that gradually decreases from a lower section to an upper section.

[0047] In one example, each of the multitude of segments can have a width that gradually decreases from a lower section to an upper section and then increases.

[0048] In one example, each of the multitude of segments can have a width that gradually increases from a lower section to an upper section and then decreases.

[0049] In one example, each of the multitude of segments can have a width that gradually increases from a lower section to an upper section and is then kept constant.

[0050] In one example, each of the multitude of segments can have a width that gradually decreases from a lower section to an upper section and is then kept constant.

[0051] In one example, the width of at least one of several separate tabs in the winding axis direction can be smaller at an outermost point than at an innermost point. Alternatively, the width of at least one of the several separate tabs in the winding axis direction can be equal to the width at an outermost point and at an innermost point. Thus, the width of each or any one of the separate tabs can vary along the winding axis direction. This can be used to optimize a contact surface, a tab arrangement, or the electrical connection.

[0052] For example, each of the multitude of segments can have a side formed by one or more straight lines, one or more curves, or a combination thereof.

[0053] In one example, each of the multitude of segments can have a side that is convex outwards or convex inwards.

[0054] In another example, a corner of an upper section of each of the multitude of segments can have a rounded shape.

[0055] In one example, the multiple separate tabs can be shaped to form internal angles proximal to the active material layer, increasing individually or in groups in the winding direction. The internal angles can be formed between the inner and lateral sides of a given separate tab in one view (in a thickness direction of the first electrode plate or in the radial direction of the wound electrode assembly). The internal angle can also be referred to as the lower angle. For example, the plurality of segments can have a lower internal angle that increases individually or in groups in a direction parallel to the winding direction.

[0056] In one example, the (lower) inside angle of the multitude of segments can increase individually or in groups in the range of 60 to 85 degrees in a direction parallel to the winding direction. For example, the range can be 45 to 90 degrees, or 45 degrees or greater, 55 degrees or greater, 60 degrees or greater, 65 degrees or greater, or 70 degrees or greater and 90 degrees or less, 85 degrees or less, 80 degrees or less, or 75 degrees or less.

[0057] In one example, the width of one or more, or each of the several separate tabs, decreases away from the active material layer in the winding axis direction. A lower inside angle θ of a separate tab located at a position corresponding to a radial distance r from the winding axis of the electrode assembly satisfies the formula below. cos−1(0.5∗Dr)≤θ≤tan−1(2∗H∗tanθrefer2∗H−p∗tanθrefer)

[0058] Here, D is a segment width in the winding direction; r is a radius of the winding turn containing the segment; H is a segment height; p is a segment pitch. Additionally or alternatively, each of the plurality of segments can have a geometric shape with a width that gradually decreases from a lower section to an upper section, and a lower interior angle (θ) of a segment located in a winding turn with a radius (r) based on the core of the electrode assembly can fall within an angular range of the formula above. The radial distance can be determined in the radial direction. The pitch can imply a regular spacing and refer to a distance between repeating positions of the pitch tabs.

[0059] In one example, each of the multitude of segments has a side formed by one or more straight lines, one or more curves, or a combination thereof.

[0060] In one example, each of the multitude of segments has a side that is either convex outwards or convex inwards. The side can refer to any of the outer and lateral faces described above.

[0061] In one example, one or more, or each of the multiple separate tabs, can have a rounded corner on one of its outermost sides. In other words, a corner of the upper section of each of the multiple segments has a rounded shape. The corner can be located between the outer surface and one of the lateral sides of the respective separate tab.

[0062] For example, a cut groove can be formed between each of the separate tabs that are adjacent in the winding direction. The corners of the cut groove can be rounded. In other words, a cut groove can be arranged between segments that are adjacent to each other along the winding direction, and a lower section of the cut groove can have a bottom section and a rounded section for connecting both ends of the bottom section to sides of the segments on either side of the cut groove. The cut groove can refer to a cavity that extends inward from the edge of the first electrode in the winding axis direction. Thus, a cut groove can separate two separate tabs that are adjacent along the winding direction. The cut groove can also be referred to as a notch, a recess, or the like.

[0063] In one example, the corners of the cut groove can be rounded with a radius of curvature of 0 to 0.1 mm or 0.01 mm to 0.05 mm. In other words, the rounded section can have a radius of curvature greater than 0 and less than or equal to 0.1 mm, preferably 0.01 mm to 0.05 mm. The radius of curvature can be 0.02 to 0.04 mm.

[0064] In one example, the inside (lower section) of the cut groove can be flat. Flat can refer to an essentially straight linear shape in a view in the radial direction (or the thickness direction).

[0065] In one example, the multiple separate tabs are spaced apart in the winding direction by a separation distance that can be from 0.05 to 1.00 mm. In other words, a separation distance, defined as the interval between two points where lines extending from the sides of two segments located on either side of the cut groove meet a line extending from the bottom section of the cut groove, can be from 0.05 mm to 1.00 mm.

[0066] In one example, the multitude of segments can be formed from an aluminum foil. A separation distance, defined as the interval between two points where lines extending from the sides of two segments located on either side of the cut groove meet a line extending from the bottom section of the cut groove, can be 0.5 mm to 1.00 mm.

[0067] For example, the inner side of the cut groove can be spaced a certain distance from the active material layer. In other words, the lower section of the cut groove can be offset from the active material layer by a predetermined distance.

[0068] For example, the specified distance (a separation distance) between the lower section of the cut groove and the active material layer can be from 0.2 mm to 4 mm.

[0069] For example, one or more, or each of the multiple separate tabs, may be bent at a point located on an inside face of the adjacent cut groove, or offset outwards from an inside face of the adjacent cut groove by 1 mm or less. In other words, a bending area of ​​the plurality of segments is located in a radial direction of the electrode assembly in the range of 0 to 1 mm above a lower end of the cut groove.

[0070] In one example, one or more, or each of the multiple separate tabs, can have a lateral face that defines the boundary of the respective separate tab in the winding direction. Optionally, the lateral face can be provided such that, after the respective separate tab is bent at the winding axis of the electrode assembly, it forms a central angle of 45 degrees or less. In other words, in each of the multiple segments, the circumferential angle of an arc formed by a lower end of the segment based on a core center of the electrode assembly can be 45 degrees or less. Furthermore, optionally, the lateral face can be provided such that, after the respective separate tab is bent at the winding axis of the electrode assembly, it forms a central angle that remains constant.

[0071] For example, for one or more or each of the several separate tabs D(r), the following formula can be satisfied, where r is a distance of the respective separate tab from the winding axis of the electrode assembly in the radial direction and D(r) is a width of the respective separate tab in the winding direction. 1≤D(r)≤(2⋅π⋅r / 360°)⋅45°.

[0072] In other words, in each of the multitude of segments, assuming that a radius of a winding turn containing the segment based on a core center of the electrode assembly is r and a width of the segment (segment width) in the winding direction is D(r), D(r) can satisfy the above formula.

[0073] In examples, D(r) can increase continuously or stepwise as r increases. Alternatively, D(r) can decrease continuously or stepwise as r increases. Alternatively, D(r) can increase continuously or stepwise and then decrease as r increases.

[0074] In other words, in each of the multitude of segments, as the radius (r) of the winding turn, where the segment is located based on the core center of the electrode assembly, increases, the width D(r) in the winding direction can gradually or stepwise increase, or vice versa.

[0075] In an example where, in each of the multitude of segments, while the radius (r) of the winding turn increases, where the segment is based on the core center of the electrode assembly, the width D(r) in the winding direction gradually or stepwise increases and then gradually or stepwise decreases, or vice versa.

[0076] In one example, the circumferential angle with respect to the core center of the electrode assembly can be essentially the same in the multitude of segments.

[0077] In examples, the widths of the multiple separate tabs can increase at a constant rate in the winding direction of the electrode assembly. Alternatively or additionally, the widths of the multiple separate tabs can increase in the radial direction depending on a distance r from the winding axis of the electrode assembly. Alternatively or additionally, the widths of the multiple separate tabs can vary within a range of 1 mm to 11 mm.

[0078] In one example, the widths of the multitude of segments in the winding direction along a direction parallel to the winding direction of the electrode assembly can increase at essentially the same rate.

[0079] For example, in each of the multitude of segments where the segment is based on the core center of the electrode assembly, while the radius (r) of the winding turn increases, the width in the winding direction can gradually or stepwise increase within the range of 1 mm to 11 mm.

[0080] In one example, the height of the first uncoated section, particularly of its multiple separate tabs, can change continuously or stepwise in the winding direction in at least a sub-region of the second and / or third section of the first uncoated section. Specifically, the heights of the multiple separate tabs can differ in two distinct regions. In other words, the height of the third section can change gradually or stepwise in the winding axis direction along a direction parallel to the winding direction in at least a sub-region of the third section.

[0081] For example, in at least one sub-section of the third section, the height in the winding axis direction can change gradually or stepwise along a direction parallel to the winding direction.

[0082] For example, the third section is subdivided into several areas along the winding direction. The height of the first uncoated section can differ in two distinct areas. The third section, and optionally the second section, can be subdivided into a multitude of areas with varying heights along a direction parallel to the winding direction, and the height of the uncoated section within these multiple areas can increase gradually or stepwise along a direction parallel to the winding direction.

[0083] In one example, in a height-variable area, the heights of the separate tabs can be stepwise from a first height (h1) to an (N-1)th height h N -1 increase, where N is a height index and a natural number of 2 or more, in particular 2 to 30. A uniform height range in which the heights of the separate tabs at an N-th height h n remain unchanged, whereby h n greater than h N -1. In other words, the first uncoated section can include a height-variable region in which the height of the segment gradually increases from a first height (h1) to an N-1th height (h1). N -1, N is a height index and a natural number of 2 or more) increases, and a uniform height range in which the height of the segment is defined as an N-th height (h n , greater than h N-1). The height of one or each of the separate tabs can be determined as a respective size in the winding direction from a continuous (rod-shaped) section of the first uncoated section, i.e. from a point where the separate tabs are structurally different.

[0084] For example, N can be a natural number from 2 to 30.

[0085] In one example, separate tabs of the same height hk are arranged in the same winding turn around the winding axis. In other words, the height hk (k is a natural number from 1 to N) can be assigned to a plurality of segments, and the plurality of segments with height hk can be arranged in at least one winding turn.

[0086] In one example, at least 90% of a hollow core section of the electrode assembly, with respect to a radial dimension, can remain uncovered in the radial direction after bending by the separate tabs. In other words, if a starting radius of a winding turn, which is the segment with height h, k (k is a natural number from 1 to N) includes, as r k As defined, the core of the electrode assembly cannot be separated for at least 90% or more of its diameter by a curved section of the segment that is located at the r k The hollow core section can refer to a cylindrical cavity around the winding axis of the electrode assembly, around which the first electrode, the second electrode, and the separator located between them are wound. Hereinafter, the hollow core section can also be referred to as a core.

[0087] In one example, where r kspecifies a distance from the winding axis in a radial direction and r c specifies a radius of a central hollow section of the electrode assembly and h k indicates the height of separate tabs that are located at r k are located, where h k and r k can be such that they fulfill the following: 2 mm≤hk≤rk−α⋅rc(α is 0.90 to 1).

[0088] In other words, if a starting radius of a winding turn is r k is defined as the segment with height h k (k is a natural number from 1 to N) and a radius of the kernel r. c is, the height h k of the segment that fulfill the above formula.

[0089] For example, the electrode assembly can include a tab-skipping region, a variable-height region, and a uniform-height region. The tab-skipping region can also be called a segment-skipping region and may not have separate tabs. The first section can correspond to the tab-skipping region. In the variable-height region, the separate tabs may have variable heights. In the uniform-height region, the separate tabs may have a uniform height in a radial direction or in the winding direction. The multiple separate tabs arranged in the variable-height region and the uniform-height region may be bent in the radial direction to form a bending surface region.In other words, the electrode assembly can include a segment-skipping region which has no segment, a height-variable region in which segments have variable heights, and a height-uniform region in which segments have a uniform height along a radial direction based on a cross-section along the winding axis direction, and the plurality of segments can be arranged in the height-variable region and the height-uniform region and bent along the radial direction of the electrode assembly to form a bending surface region.

[0090] In one example, the third section can correspond to the height-variable area and the height-uniform area. Alternatively, the height-variable area and the height-uniform area correspond to the second and third sections, respectively. In other examples, the first section may not be subdivided into segments, and the segment-skipping area may correspond to the first section.

[0091] In one example, the third section can be divided into a multitude of segments that are independently bendable, and the height-variable area and the height-uniform area can correspond to the third section.

[0092] In one example, the second section and the third section can be subdivided into a multitude of segments that are independently bendable, and the height-variable area and the height-uniform area can correspond to the second section and the third section.

[0093] For example, a maximum height h can be defined in the height-variable area and the height-uniform area. max The segments must satisfy the following formula: hmax≤Wfoil−Wscrap,min−Wmargin,min−Wgap where W foil a width of a current collector foil before segments are formed; W scrap,min a width that corresponds to a minimal offcut margin when segments are formed by cutting the current collector foil; W margin,min a width that corresponds to a minimal meandering edge of the separator; and W gap The width corresponds to an insulation gap between one end of the separator and one end of the second electrode, which faces the first electrode, with the separator positioned between them. The parameters used herein may be as shown in the drawings.

[0094] For example, the first electrode is a positive electrode and the insulation gap can be in the range of 0.2 mm to 6 mm or 2 mm or more, 3 mm or more or 4 mm or more and 6 mm or less, 5.5 mm or less or 5 mm or less.

[0095] For example, the first electrode is a negative electrode and the insulation gap can be in the range of 0.1 mm to 2 mm or 0.1 mm or more, 0.2 mm or more, 0.5 mm or more or 1 mm or more and 2 mm or less, 1.8 mm or less, 1.5 mm or less or 1.2 mm or less.

[0096] For example, the minimum cutting waste margin can range from 1.5 mm to 8 mm, or 1.5 mm or more, or 1.8 mm or more, or 2 mm or more, or 2.5 mm or more, and 8 mm or less, or 6 mm or less, or 3 mm or less.

[0097] For example, the minimum meander edge can range from 0 to 1 mm, or 1 mm or less, or 0.8 mm or less, or 0.5 mm or less, or 0.2 mm or less. With modification, the minimum trimming waste edge can be zero.

[0098] For example, the heights of the separate tabs (segments) arranged in the height-variable area can increase gradually or stepwise within the range of 2 mm to 10 mm or 2 mm or more, 3 mm or more, 4 mm or more or 5 mm or more and 10 mm or less, 8 mm or less, 6 mm or less or 5 mm or less.

[0099] For example, the ratio of a radial size in the radial direction (radial length) of the segment skip area to a radius of the electrode assembly, excluding the core, in the radial direction of the electrode assembly can be 10% to 40%, or 10% or more, 15% or more, 20% or more, or 25% or more, and 40% or less, 35% or less, 30% or less, or 25% or less.

[0100] For example, the ratio of a radial size of the height-variable area to a radial size corresponding to the height-variable area and the height-unitary area in the radial direction of the electrode assembly may be 1% to 50%, or 1% or more, 5% or more, 10% or more, 20% or more, or 30% or more, and 50% or less, 40% or less, 35% or less, or 30% or less.

[0101] For example, the ratio of the length of an electrode area corresponding to the segment skip area (segment skip region) to the total length of the first electrode in the winding (or radial) direction can be 1% to 30%, or 1% or more, 5% or more, 10% or more, 15% or more, or 20% or more, and 50% or less, 40% or less, 30% or less, or 25% or less.

[0102] For example, the ratio of the length of an electrode area corresponding to the height-variable region to the total length of the first electrode in the winding (or radial) direction can be 1% to 40%, or 1% or more, 5% or more, 10% or more, or 20% or more, and 40% or less, 35% or less, or 30% or less, or 25% or less.

[0103] For example, the ratio of the length of an electrode area corresponding to the height-unit area to the total length of the first electrode in the winding (or radial) direction can be 50% to 90%, or 50% or more, 60% or more, or 70% or more, and 90% or less, 80% or less, or 70% or less.

[0104] For example, the widths of the multiple separate tabs in the winding direction and / or the heights of the multiple separate tabs in the winding axis direction (i.e., the widths of the multiple segments in the winding direction and / or their heights in the winding axis direction) can gradually or stepwise increase along a direction parallel to the winding direction.

[0105] In one example, the widths of the multiple separate tabs in the winding direction and / or the heights of the multiple separate tabs in the winding axis direction (i.e., the widths of the multiple segments in the winding direction and / or their heights in the winding axis direction) can gradually or stepwise increase and then gradually or stepwise decrease along a direction parallel to the winding direction, or vice versa (i.e., decrease and then increase).

[0106] In one example, the multiple separate tabs along a direction parallel to the winding direction of the electrode assembly can form several tab groups. Separate tabs belonging to one of the tab groups can have the same width in the winding direction and / or the same height in the winding axis direction. Alternatively or additionally, separate tabs belonging to another of the tab groups can have increasing widths and / or increasing heights in the winding direction. Alternatively or additionally, three successive tab groups can have widths W1, W2, and W3 respectively in the winding direction, where the ratio W3 / W2 is smaller than the ratio W2 / W1.

[0107] In other words, the multitude of segments along a direction parallel to the winding direction of the electrode assembly can form a multitude of segment groups, and segments belonging to the same segment group can be essentially the same with respect to a width in the winding direction and a height in the winding axis direction.

[0108] For example, at least one of the widths of the segments belonging to the same segment group can increase stepwise in the winding direction and their heights in the winding axis direction along a direction parallel to the winding direction of the electrode assembly.

[0109] For example, if three segment groups that are consecutively adjacent to each other in a direction parallel to the winding direction of the electrode assembly have widths in the winding direction of W1, W2 and W3 respectively, a combination of segment groups in which W3 / W2 is smaller than W2 / W1 may be included.

[0110] In one example, the first section and / or the second section may not be formed into separate tabs (i.e., they may not have any) and may not be bent along a radial direction of the electrode assembly. For example, the first section may not be subdivided into segments, and the first section may not be bent along a radial direction of the electrode assembly.

[0111] For example, the second section cannot be divided into segments and the second section cannot be bent along a radial direction of the electrode assembly.

[0112] For example, an insulating coating layer, such as a polymer resin with an inorganic filler dispersed in the polymer resin, can be formed at a boundary between the active material layer and the first uncoated section. In other words, an insulating coating layer can be formed at a boundary between the active material layer and an area of ​​an uncoated section provided in a section where the bottom section of the cut groove and the active material layer are separated.

[0113] In one example, the insulating coating layer can comprise a polymer resin and an inorganic filler dispersed in the polymer resin.

[0114] In another example, the insulating coating layer can be formed to cover a boundary section of the active material layer and the first uncoated section along the winding direction.

[0115] In yet another example, the insulating coating layer can be formed to cover the boundary section of the active material layer and the first uncoated section along the winding axis direction for a width of 0.3 mm to 5 mm.

[0116] In yet another example, one end of the insulation coating layer can be positioned within the range of -2 mm to 2 mm along the winding axis direction based on one end of the separator.

[0117] For example, the insulating coating layer may be exposed by (from) the separator. In other words, the insulating coating layer may be partially uncovered or not overlapped by the separator in one viewing direction in the radial direction (thickness direction).

[0118] For example, the inside of a cut groove formed in the first uncoated section and the insulation coating layer can be spaced from 0.5 mm to 2 mm apart. In other words, the inside (i.e., the bottom end) of the cut groove formed in the insulation coating layer can be spaced from 0.5 mm to 2 mm apart.

[0119] For example, one end of the insulation coating layer can be positioned in the winding axis direction within the range of -2 mm to +2 mm with respect to (based on) the inside (bottom end) of the cut slot.

[0120] For example, the second electrode can be coated with an active material layer in a second active material section. One end of the second active material section, in the winding axis direction, can overlap the insulating coating layer in one viewing direction in the radial direction. In other words, the second electrode can have a second active material section coated with an active material layer along the winding axis direction, and one end of the second active material section can be positioned between an upper end and a lower end of the insulating coating layer in the winding axis direction. The active material of the second electrode can differ from the active material of the first electrode. In particular, the active material of the second electrode can be designed to provide a different electrochemical potential than the active material of the first electrode.

[0121] In yet another example, the third section and / or the second section can each be formed into several separate tabs that are independently bendable. The electrode assembly can have a bending surface area formed by bending the multiple separate tabs along a radial direction of the electrode assembly. In other words, the third section and optionally the second section can be divided into a plurality of segments that are independently bendable, and the electrode assembly can have a bending surface area formed by bending the plurality of segments along a radial direction of the electrode assembly.

[0122] For example, the number of segments that intersect a virtual line parallel to the winding axis direction at any radial location within the bending surface area, relative to the winding axis (based on a core center) of the electrode assembly, can be defined as the number of overlapping layers of segments at that radial location. Here, the bending surface area can have a uniform overlap layer count region, where the number of overlapping layers of segments is constant along a radial direction (e.g., away from the winding axis towards an outer circumference or vice versa), and a decreasing overlap layer count region located outside the uniform overlap layer count region, where the number of overlapping layers of segments decreases continuously (gradually) in the radial direction, e.g., towards an outer circumference.

[0123] In one example, the radial size of the area with a uniform number of overlap layers and the area with a decreasing number of overlap layers can correspond to the radial size of an area in which the multiple separate tabs are formed. In other words, the radial size (radial length) of the area with a uniform number of overlap layers and the area with a decreasing number of overlap layers, based on the core center of the electrode assembly, can correspond to the radial length of a radial area in which winding turns, comprising the plurality of segments, are arranged.

[0124] In another example, the electrode assembly can optionally include, in the following order: a segment-skipping region with no separate tabs (segments), a height-variable region where the separate tabs (segments) have variable heights, and a height-uniform region where separate tabs (segments) have a uniform height along the radial direction. A radius from the winding axis of the electrode assembly, or a radial location where the area with a uniform number of overlap layers begins, can correspond to a radius where the height-variable region begins.

[0125] For example, in the area with a uniform number of overlapping layers, the number of overlapping layers of the segments can be 10 to 35, or 10 or more, 12 or more, or 15 or more and 35 or less, 30 or less, 25 or less, or 20 or less.

[0126] In one example, the first electrode can be a positive electrode, and in the area with a uniform number of overlap layers, the overlap thickness of the segments can be in the range of 100 µm to 875 µm, or 100 µm or more, 200 µm or more, 400 µm or more, or 500 µm or more, and 875 µm or less, 650 µm or less, or 500 µm or less.

[0127] In another example, the first electrode can be a negative electrode, and in the area with a uniform number of overlap layers, the overlap thickness of segments can be in the range of 50 µm to 700 µm, or 50 µm or more, 100 µm or more, 200 µm or more, or 350 µm or more, and 700 µm or less, 600 µm or less, 500 µm or less, or 400 µm or less.

[0128] In yet another example, the ratio of a radial size (radial length) of the area with a uniform number of overlapping layers to a radial size (radial length) of the area with a uniform number of overlapping layers and the area with a decreasing number of overlapping layers can be 30% to 85%, or 30% or more, 40% or more, or 50% or more and 85% or less, 70% or less, or 60% or less.

[0129] For example, the electrode assembly may also include a current collector welded to the bending surface area. A welded area of ​​the current collector may overlap the area with a uniform number of overlap layers in the radial direction of the electrode assembly by at least 50%. In other words, a welded area of ​​the current collector may overlap the area with a uniform number of overlap layers by at least 50% in the radial direction of the electrode assembly.

[0130] In one example, the welding area of ​​the current collector can extend in such a way that it also overlaps the area with a decreasing number of overlap layers. In other words, a portion of the current collector's welding area that does not overlap the area with a uniform number of overlap layers can, in the radial direction of the electrode assembly, overlap the area with a decreasing number of overlap layers.

[0131] In another example, an edge of the current collector can be positioned at the bending surface area to cover one end of a bent section of the outermost separate tabs in the radial direction of the electrode assembly. In other words, an edge of the current collector can be positioned at the bending surface area to cover one end of a bent section of the outermost segment in the radial direction of the electrode assembly and welded to the bending surface area.

[0132] For example, the current collector is welded to the bending surface area in such a way that it has a weld strength of 2 kgf / cm². 2 or more or 4 kgf / cm² 2 or more, 6 kgf / cm² 2 or more or 10 kgf / cm² 2 or more. In other words, the weld strength of the current collector can be adjusted to the welding area 2 kgf / cm². 2 or more, or as specified.

[0133] Preferably, the weld strength of the current collector can be adjusted to a welding area of ​​4 kgf / cm². 2 or more, or as specified.

[0134] In yet another example, the first uncoated section can be made of a metal foil. The metal foil can have an elongation of 1.5% to 3.0% and a tensile strength of 25 kgf / mm². 2 up to 35 kgf / mm 2 exhibit. The elongation can be measured according to the standard ASTM E8 / E8M - 16a.

[0135] For example, the metal foil could be aluminum foil.

[0136] For example, the first electrode may have a curvature length of less than 20 mm. The curvature length can be measured according to US 4,794,773 A.

[0137] For example, in the first active material section, the ratio of the length of a short side along (parallel to) the winding axis direction to the length of a long side along (parallel to) the winding axis direction can be 1% to 4%, or 2% or more, or 3% or more and 4% or less.

[0138] In one example, the height of the second section can decrease continuously (gradually) or stepwise in the radial direction or in the winding direction, e.g. from the core to the outer circumference of the electrode assembly.

[0139] In one example, the second and third sections can be formed (subdivided) into several separate tabs (a multitude of segments) that are individually (independently) bendable. The widths and / or heights of the separate tabs in the second section can be greater than those of the separate tabs in the third section. In other words, the segments contained in the second section can be larger than the segments contained in the third section with respect to a width in the winding direction and / or a height in the winding axis direction.

[0140] In one example, the third section may include a tab-skipping area (segment-skipping area) that does not have separate tabs (segments) along the winding direction of the electrode assembly.

[0141] For example, the third section can include multiple tab-skipping areas (a multitude of segment-skipping areas) in the winding direction (i.e., along a direction parallel to the winding direction).

[0142] In one example, the multiple tab-skipping areas can have widths that increase or decrease along the winding direction. In other words, the multitude of segment-skipping areas can have widths that gradually increase or decrease along a direction parallel to the winding direction.

[0143] For example, the height of the tab-skipping area can be equal to the height of the first section or the second section. In other words, the height of an uncoated section of the segment-skipping area can be essentially equal to the height of an uncoated section of the first section or an uncoated section of the second section.

[0144] For example, the multitude of segments can be located within a circumferential angle range that is preset based on a core center of the electrode assembly.

[0145] In one example, the multitude of segments can be located in at least two sectoral or polygonal areas arranged in a circumferential direction based on a core center of the electrode assembly.

[0146] For example, the multiple separate tabs on the winding axis of the electrode assembly can be located within a preset central angle, which might be 20 degrees or more. In other words, the sectoral area can have a circumferential angle of 20 degrees or more. The central angle can refer to an angle on the winding axis corresponding to a sector of a circle and can also be called the circumferential angle. The preset central angle can be 25 degrees or more, 30 degrees or more, or 40 degrees or more.

[0147] In one example, the second electrode can have a second active material section coated with a different active material (active material layer) and a second uncoated section. The second uncoated section can be free of the other active material (active material layer) (i.e., not coated with the active material layer). The second uncoated section can be located at an edge of the second electrode that extends along the winding direction. The second uncoated section can be designed to provide an electrical connection with the first electrode (i.e., at least part of the second uncoated section can itself be defined as an electrode tab). The second uncoated section can be partially subdivided into several separate tabs that are individually bendable (i.e.,The second uncoated section can have an area divided into a multitude of segments that are individually (independently) bendable. The multiple separate tabs can be bent along a radial direction of the electrode assembly to form a bending surface area; that is, the multitude of segments can be bent along a radial direction of the electrode assembly to form a bending surface area.

[0148] The electrode assembly, as described above, may include any of the features of an electrode assembly specified below, particularly with reference to the drawings, provided this is not technically inappropriate. The first electrode and the second electrode may be a positive electrode and a negative electrode, respectively. Alternatively, the first electrode and the second electrode may be a negative electrode and a positive electrode, respectively.

[0149] According to one aspect, an electrode assembly can comprise a first electrode, a second electrode, and a separator positioned between them. The first electrode, the second electrode, and the separator can be wound around a winding axis. The first electrode can have a first active material section coated with an active material layer and a first uncoated section free of the active material layer. The first uncoated section can be located at an edge of the first electrode extending along a winding direction. The first uncoated section can be partially formed into several separate tabs, each individually bendable in a radial direction of the electrode assembly. The multiple separate tabs can be bent along the radial direction to the winding axis of the electrode assembly to form a bending surface area.The bending surface area can have an area with a uniform number of overlap layers, in which the number of overlapping layers of the separate tabs can be 10 or more, and an area adjacent to the area with a uniform number of overlap layers with a decreasing number of overlap layers, in which the number of overlapping layers of the separate tabs can decrease in the radial direction away from the area with a uniform number of overlap layers.

[0150] Accordingly, an electrode assembly can be provided in which a first electrode, a second electrode, and an intermediate separator are wound relative to a winding axis to define a core and an outer circumference, wherein the first electrode has a first active material section coated with an active material layer and a first uncoated section not coated with an active material layer along a winding direction, wherein the first uncoated section has a region subdivided into a plurality of segments that are bendable towards the outer circumference of the electrode assembly independently of the core, wherein the plurality of segments are bent along a radial direction of the electrode assembly to form a bending surface region, and the bending surface region has a region with a uniform number of overlapping layers.in which the number of overlapping layers of the segments is 10 or more, and has an area with a decreasing number of overlapping layers arranged next to the area with a uniform number of overlapping layers, such that the number of overlapping layers of the segments gradually decreases along the radial direction away from the area with a uniform number of overlapping layers.

[0151] For example, the electrode assembly can have a tab-skipping region with no separate tabs, a height-variable region where the separate tabs have heights that increase incrementally along the radial direction of the electrode assembly, and a height-uniform region where the separate tabs have a uniform height along the radial direction of the electrode assembly. From a winding axis of the electrode assembly, a radial location where the area with a uniform number of overlap layers begins corresponds to a radial location where the height-variable region begins. The tab-skipping region, the height-variable region, and the height-uniform region can be as described above.

[0152] The electrode assembly according to the above aspect may include any of the features of an electrode assembly specified above and below, in particular with reference to the drawings, provided that this is not technically inappropriate.

[0153] In particular, the electrode assembly can implement any of the following features according to the aspect above. An innermost region of the first uncoated section may not be formed into separate tabs. The ratio of the radial size of the region with a uniform number of overlap layers to the radial size of the region with a uniform number of overlap layers and the region with a decreasing number of overlap layers may be 30% to 85% or any other value specified above. The ratio of the length of an electrode area in the winding direction corresponding to the tab-skipping region to the total length of the first electrode in the winding direction may be 1% to 30% or any other value specified above.The ratio of the length of an electrode area in the winding direction, corresponding to the height-variable region, to the total length of the first electrode in the winding direction can be 1% to 40% or any other value specified above. The ratio of the length of an electrode area in the winding direction, corresponding to the height-uniform region, to the total length of the first electrode in the winding direction can be 50% to 90% or any other value specified above. In the region subdivided into multiple separate tabs, the widths of the separate tabs in the winding direction, their heights in the winding axis direction, and / or a lower internal angle can increase stepwise along a direction parallel to the winding direction.The height of the innermost region or the outermost region of the first uncoated section may be less than the heights of the multiple separate tabs. The multiple separate tabs may be curved towards the winding axis of the electrode assembly. At least 90% or more, based on a radial dimension, of a central cylindrical region surrounded by the electrode assembly may be uncovered by the curved portion of the separate tabs.

[0154] According to another aspect, an electrode assembly can have a positive electrode, a negative electrode, and a separator positioned between them. The positive electrode, the negative electrode, and the separator can be wound around a winding axis. The positive electrode can have a positive active material section coated with a positive active material and a first uncoated section free of the positive active material. The first uncoated section can be located at an edge of the positive electrode extending along one winding direction of the electrode assembly. The first uncoated section can be designed to provide an electrical connection with the positive electrode. The first uncoated section can have several separate tabs that are individually bendable in a radial direction of the electrode assembly.The multiple separate tabs can be bent towards the winding axis to form a bending surface area. This bending surface area can include a uniform overlap layer area, where the number of overlapping layers of the separate tabs is consistent, and an adjacent area with a decreasing overlap layer number, where the number of overlapping layers of the separate tabs decreases in a direction away from the uniform overlap layer area. The combined thickness of the overlapping layers of the separate tabs in the uniform overlap layer area ranges from 100 µm to 875 µm.

[0155] Accordingly, an electrode assembly can be provided in which a positive electrode, a negative electrode, and an intermediate separator are wound around a winding axis to define a core and an outer circumference, wherein the positive electrode has a first active material section coated with an active material layer and a first uncoated section not coated with an active material layer along a winding direction, wherein at least a portion of the first uncoated section itself is used as an electrode tab, and wherein the first uncoated section has a plurality of segments that are bendable towards the outer circumference of the electrode assembly independently of the core, the plurality of segments being bent along a radial direction of the electrode assembly and overlapping in multiple layers to form a bending surface area.wherein the bending surface area has a region with a uniform number of overlapping layers, in which the number of overlapping layers of the segments is uniform, and a region with a decreasing number of overlapping layers, which is arranged adjacent to the region with a uniform number of overlapping layers, such that the number of overlapping layers of the segments gradually decreases along the radial direction away from the region with a uniform number of overlapping layers, and wherein in the region with a uniform number of overlapping layers there is an overlap thickness of segments between 100 µm and 875 µm.

[0156] The electrode assembly according to the above aspect may also include any of the features of an electrode assembly specified above and below, in particular with reference to the drawings, provided that this is not technically inappropriate.

[0157] For example, the electrode assembly may further include a current collector welded to the area with a uniform number of overlapping layers, such that at least part of a welded area of ​​the current collector overlaps the area with a uniform number of overlapping layers and the overlapping layers of segments in the welded area have a thickness in the range of 100 µm to 875 µm or any other value specified here.

[0158] According to another aspect, an electrode assembly can comprise a positive electrode, a negative electrode, and a separator positioned between them. The positive electrode, the negative electrode, and the separator can be wound around a winding axis. The negative electrode can have a negative active material section coated with a negative active material and an uncoated section free of the negative active material. The uncoated section can be located at an edge of the negative electrode extending along a winding direction. The uncoated section can be designed to provide an electrical connection with the negative electrode. The uncoated section can have multiple separate tabs that are individually bendable in a radial direction. The multiple separate tabs can be bent toward the winding axis to form a bending surface area.The bending surface area can have a region with a uniform number of overlap layers, where the number of overlapping layers of the separate tabs is uniform, and an adjacent region with a decreasing number of overlap layers, where the number of overlapping layers of the separate tabs decreases in a direction away from the region with a uniform number of overlap layers. The combined thickness of the overlapping layers of the separate tabs in the region with a uniform number of overlap layers can range from 50 µm to 700 µm.

[0159] Accordingly, an electrode assembly can be provided in which a positive electrode, a negative electrode, and an intermediate separator are wound around a winding axis to define a core and an outer circumference, wherein the negative electrode has a first active material section coated with a layer of active material and a first uncoated section not coated with a layer of active material along a winding direction, wherein at least a portion of the first uncoated section is used as an electrode tab, and wherein the first uncoated section has a plurality of segments that are bendable towards the outer circumference of the electrode assembly independently of the core, the plurality of segments being bent along a radial direction of the electrode assembly and overlapping into multiple layers.to form a bending surface area, wherein the bending surface area has an area with a uniform number of overlapping layers, in which the number of overlapping layers of the segments is uniform, and has an area arranged next to the area with a uniform number of overlapping layers with a decreasing number of overlapping layers, such that the number of overlapping layers of the segments gradually decreases along the radial direction away from the area with a uniform number of overlapping layers, and in the area with a uniform number of overlapping layers there is an overlap thickness of segments between 50 µm and 700 µm.

[0160] The electrode assembly according to the above aspect may also include any of the features of an electrode assembly specified above and below, in particular with reference to the drawings, provided that this is not technically inappropriate.

[0161] For example, the electrode assembly may further include a current collector welded to the area with a uniform number of overlapping layers, such that at least part of a welded area of ​​the current collector overlaps the area with a uniform number of overlapping layers and the overlapping layers of segments in the welded area have a thickness in the range of 50 µm to 700 µm or any other value specified here.

[0162] According to another aspect, a battery is provided. The battery can include any of the aspects of an electrode assembly as described above. Furthermore, the battery's electrode assembly can include any of the features specified above.

[0163] The battery may further comprise a battery housing, a sealing body, and a terminal. The battery housing may have an open first end face and a second end face opposite the first end face, wherein the electrode assembly is housed within the battery housing and the battery housing is electrically connected to either the first or the second electrode of the electrode assembly. The sealing body may be configured to seal the open first end face of the battery housing. The terminal may be electrically connected to either the first or second electrode, and the terminal may have a surface exposed to the outside of the battery housing.

[0164] For example, a battery can be provided comprising: an electrode assembly in which a first electrode, a second electrode, and an intermediate separator are wound based on a winding axis to define a core and an outer circumference, wherein the first electrode comprises a first active material section coated with a layer of active material and a first uncoated section not coated with a layer of active material along a winding direction, wherein at least a portion of the first uncoated section itself is defined as an electrode tab, and wherein the first uncoated section comprises a first section adjacent to the core of the electrode assembly, a second section adjacent to the outer circumference of the electrode assembly, and a third section arranged between the first section and the second section.and wherein the first section or the second section has a lower height than the third section in the winding axis direction; a battery casing having an open end and a bottom section opposite it, wherein the electrode assembly is housed in a space between the open end and the bottom section and the battery casing is electrically connected to the first electrode or the second electrode to have a first polarity; a sealing element designed to seal the open end of the battery casing; and a terminal electrically connected to the other of the first or second electrode to have a second polarity, and designed to have a surface exposed to the outside.

[0165] In one example, the height of the second section can be less than the height of the third section, with the heights determined in the winding axis direction. The battery casing can have a beaded section that is pressed inwards in a region adjacent to the first end face, with the beaded section faces and the second section spaced apart by a predetermined distance. In other words, the second section can have a smaller height than the third section in the winding axis direction, the battery casing can have a beaded section that is pressed inwards in a region adjacent to the open end, and an inner circumference of the beaded section facing a top edge of the electrode assembly, and the second section can be spaced apart by a predetermined distance.

[0166] The term "ribbed section" can be used figuratively and can refer to a circumferential recess, groove, or notch formed on a side wall of the battery housing. The ribbed section can be located near (close to, proximal to, adjacent to) the end face of the battery housing. The ribbed section can have any of the features described below, particularly with reference to the drawings.

[0167] For example, an indentation depth (D1) of the corrugated section is greater than or equal to a distance (D2) from the inner circumference of the battery housing to a boundary between the second and third sections. In other words, an indentation depth (D1) of the corrugated section and a distance (D2) from the inner circumference of the battery housing to a boundary between the second and third sections can satisfy a formula D1 : < D2.

[0168] In another example, the battery may further include a current collector electrically coupled to the third section; and an insulator designed to cover the current collector and having an edge positioned and fixed between the inner circumference of the corrugated section and the current collector.

[0169] For example, the diameter of the current collector may be smaller than a minimum inner diameter of the inner circumference of the corrugated section, and the diameter of the current collector may be greater than or equal to an outermost diameter of the third section.

[0170] In another example, the current collector can be positioned higher in the winding axis direction than the bead section.

[0171] In one example, the sealing body can comprise a cap designed to seal the open end of the battery housing, a gasket positioned between an edge of the cap and the open end of the battery housing, and a crimp section that is bent and extends into the battery housing and is designed to surround and hold the edge of the cap together with the gasket. The terminal can be the cap. The terminal can have a second polarity. The cap, the gasket, and the crimp section can have any of the respective features as described below, particularly with reference to the drawings.

[0172] In one example, the battery may further include a first current collector that is electrically connected to the first uncoated section. The connection may be a feedthrough terminal inserted into a perforation formed in the second end face of the battery casing. The feedthrough terminal may be insulated from the battery casing and electrically connected to the first current collector, for example, by an insulator placed between an inner surface of the bottom section of the battery casing and an upper surface of the first current collector, in order to electrically isolate the inner surface of the bottom section of the battery casing and the first current collector.In other words, the connection can be a riveted connection installed in a perforated hole formed in the bottom section of the battery housing to be insulated from it, and electrically connected to the first current collector to have the second polarity.

[0173] In one example, the battery may further include an insulator arranged between an inner surface of the bottom section of the battery housing and an upper surface of the first current collector to electrically isolate the inner surface of the bottom section of the battery housing and the first current collector.

[0174] For example, the insulator may have a thickness corresponding to a distance between the inner surface of the bottom section of the battery housing and the upper surface of the first current collector, and be in close contact with the inner surface of the bottom section of the battery housing and the upper surface of the first current collector.

[0175] In one example, the connection may include a flat section at its lower end, the insulator may have an opening to expose the flat section, and the flat section may be welded to the first current collector through the opening.

[0176] In one example, the second electrode can have a second active material section coated with an active material layer and a second uncoated section that is not coated with an active material layer along the winding direction, wherein the second electrode can have the first polarity, and wherein at least part of the second uncoated section can be defined as an electrode tab on its own, and the battery can further comprise a second current collector that is electrically connected to the second uncoated section and has an edge that is at least partially coupled to a side wall of the battery casing.

[0177] In one example, the second electrode can have a second active material section coated with a second active material and a second uncoated section free of the second active material, the second uncoated section being located at an edge of the second electrode extending along the winding direction. The second uncoated section can provide an electrical connection to the second electrode. The battery can further include a second current collector that is electrically connected to the second uncoated section and has an edge that is electrically coupled to a side wall of the battery casing extending between the first end face and the second end face. The first current collector can have an outer diameter greater than or equal to that of the second current collector.

[0178] In other words, the second electrode can have a second active material section coated with an active material layer and a second uncoated section that is not coated with an active material layer along the winding direction, wherein the second electrode can have the first polarity, and wherein at least part of the second uncoated section can be defined as an electrode tab on its own, wherein the battery can further comprise a second current collector that is electrically connected to the second uncoated section and has an edge that is at least partially coupled to a side wall of the battery housing, and wherein the first current collector can have an outer diameter that is greater than or equal to that of the second current collector.

[0179] For example, the first current collector and the second current collector can each be welded to the first uncoated section and the second uncoated section along a radial direction of the electrode assembly to form a respective weld pattern. One length of the weld pattern of the first current collector can be longer than one length of the weld pattern of the second current collector. The weld pattern can refer to the shape of an area where the parts are welded together in a respective top view (e.g., in a direction perpendicular to the area).

[0180] In other words, the first current collector and the second current collector can each be welded to the first uncoated section and the second uncoated section along a radial direction of the electrode assembly to form weld patterns, and one length of the weld pattern of the first current collector can be longer than one length of the weld pattern of the second current collector.

[0181] For example, the welding pattern of the first current collector and the welding pattern of the second current collector may be located at essentially the same distance from a core center of the electrode assembly.

[0182] For example, the battery housing may have a corrugated section that is pressed inwards adjacent to the first end face of the battery housing (i.e., its open end) (pressed inwards against an inner wall). The edge of the second current collector may be electrically connected to the corrugated section, for example, by welding.

[0183] For example, an area of ​​the second current collector that is in electrical contact with the second uncoated section may be located further inwards than an inner circumference of the corrugated section.

[0184] In yet another example, the battery can have a cap with an edge supported by the beaded section and lacking polarity, a gasket positioned between the cap's edge and the open end of the battery casing, and a crimped section that is bent and extends into the open end of the battery casing, designed to surround and hold the cap's edge along with the gasket. For example, the edge of the second current collector can be positioned and secured between the beaded section and the gasket by the crimped section.

[0185] For example, the edge of the second pantograph can be welded to the corrugated section.

[0186] In another aspect of the present disclosure, a battery is also provided comprising: an electrode assembly in which a first electrode, a second electrode, and an intermediate separator are wound based on a winding axis to define a core and an outer circumference, wherein the first electrode comprises a first active material section coated with an active material layer and a first uncoated section not coated with an active material layer along a winding direction, wherein the first uncoated section comprises an area subdivided into several segments that are bendable independently of the core to the outer circumference of the electrode assembly, the several segments being bent along a radial direction of the electrode assembly to form a bending surface area.and the bending surface area comprises a uniform overlap layer count area in which the number of overlapping layers of the segments is 10 or more, and a decreasing overlap layer count area adjacent to the uniform overlap layer count area such that the number of overlapping layers of the segments gradually decreases away from the uniform overlap layer count area along the radial direction; a battery housing having an open end and a bottom section opposite the open end, wherein the electrode assembly is housed in a space between the open end and the bottom section, and the battery housing is electrically connected to the first electrode or the second electrode to have a first polarity; a sealing body configured to seal the open end of the battery housing; and a terminal,which is electrically connected to the other of the first and second electrodes to have a second polarity, and is configured to have an outwardly exposed surface.

[0187] The battery, as described above, may also include any of the battery features specified above and below, particularly with reference to the drawings, provided this is not technically inappropriate. The battery may also include any of the aspects of an electrode assembly as described above. Furthermore, the battery's electrode assembly may include any of the features specified above.

[0188] In another aspect of the present disclosure, a battery is also provided which comprises: an electrode assembly in which a positive electrode, a negative electrode and an intermediate separator are wound on the basis of a winding axis to define a core and an outer circumference, wherein the positive electrode has a first active material section coated with a layer of active material and a first uncoated section not coated with a layer of active material along a winding direction, wherein at least a part of the first uncoated section itself is used as an electrode tab, wherein the first uncoated section has a plurality of segments that are bendable independently of the core in the direction of the outer circumference of the electrode assembly.wherein the plurality of segments are bent along a radial direction of the electrode assembly and overlap in several layers to form a bending surface area, wherein the bending surface area has a region with a uniform number of overlapping layers, in which the number of overlapping layers of the segments is uniform, and a region with a decreasing number of overlapping layers, which is adjacent to the region with a uniform number of overlapping layers, such that the number of overlapping layers of the segments gradually decreases away from the region with a uniform number of overlapping layers along the radial direction, and in the region with a uniform number of overlapping layers, the overlapping thickness of the segments is between 100 µm and 875 µm; a battery casing having an open end and a bottom section opposite it,wherein the electrode assembly is accommodated in a space between the open end and the bottom section and the battery casing is electrically connected to one of the first electrodes and the second electrode to provide a first polarity; a sealing element designed to seal the open end of the battery casing; and a terminal electrically connected to the other of the first electrodes and the second electrode to provide a second polarity, and designed to have an outwardly exposed surface.

[0189] The battery, as described above, may also include any of the battery features specified above and below, particularly with reference to the drawings, provided this is not technically inappropriate. The battery may also include any of the aspects of an electrode assembly as described above. Furthermore, the battery's electrode assembly may include any of the features specified above.

[0190] For example, the battery may further include a current collector welded to the area with a uniform number of overlapping layers, such that at least part of a welded area of ​​the current collector overlaps the area with a uniform number of overlapping layers and the overlapping layers of segments in the welded area have a thickness in the range of 100 µm to 875 µm.

[0191] In another aspect of the present disclosure, a battery is also provided which comprises: an electrode assembly in which a positive electrode, a negative electrode and an intermediate separator are wound based on a winding axis to define a core and an outer circumference, wherein the negative electrode has a first active material section coated with an active material layer and a first uncoated section not coated with an active material layer along a winding direction, wherein at least a part of the first uncoated section itself is used as an electrode tab, wherein the first uncoated section has a plurality of segments that are bendable independently of the core in the direction of the outer circumference of the electrode assembly.wherein the plurality of segments are bent along a radial direction of the electrode assembly and overlap in several layers to form a bending surface region, wherein the bending surface region has an overlap-layer-number-uniform region in which the number of overlapping layers of the segments is uniform, and an overlap-layer-number-decreasing region which is arranged adjacent to the overlap-layer-number-uniform region, such that the number of overlapping layers of the segments gradually decreases away from the overlap-layer-number-uniform region along the radial direction, and in the overlap-layer-number-uniform region, the overlap thickness of segments is between 50 µm and 700 µm; a battery casing having an open end and a bottom section opposite it,wherein the electrode assembly is accommodated in a space between the open end and the bottom section, and the battery casing is electrically connected to one of the first electrodes and the second electrode to provide a first polarity; a sealing element designed to seal the open end of the battery casing; and a terminal electrically connected to the other of the first electrodes and the second electrode to provide a second polarity, and designed to have an externally exposed surface.

[0192] The battery, as described above, may also include any of the battery features specified above and below, particularly with reference to the drawings, provided this is not technically inappropriate. The battery may also include any of the aspects of an electrode assembly as described above. Furthermore, the battery's electrode assembly may include any of the features specified above.

[0193] For example, the battery may further include a current collector welded to the area with a uniform number of overlapping layers, such that at least part of a welded area of ​​the current collector overlaps the area with a uniform number of overlapping layers and the overlapping layers of segments in the welded area have a thickness in the range of 50 µm to 700 µm.

[0194] In another aspect of the present disclosure, a battery pack is also provided, comprising a plurality of batteries described above. Accordingly, the battery pack may include any of the battery features specified above and below, particularly with reference to the drawings, provided this is not technically inappropriate. Each or every component of the battery pack may include any aspect of an electrode assembly as described above. Furthermore, the electrode assembly included in the battery pack may include any of the features specified above.

[0195] For example, the ratio of the battery's diameter to its height can be greater than 0.4 or greater than 0.42, greater than 0.44 or greater than 5 and less than 10, less than 8 or less than 6.

[0196] For example, the battery can have a form factor of 46110, 4875, 48110, 4880 or 4680.

[0197] For example, the battery can have a resistance of 4 milliohms or less. The resistance of the battery cell can be at least 0.5 mΩ or at least 1.0 mΩ and / or 3.8 mΩ or less, 3.5 mΩ or less, or 3 mΩ or less.

[0198] For example, in a battery pack, the multitude of batteries can be arranged in a predetermined number of columns, such that an electrode terminal of each battery and an outer surface of a bottom section of each battery casing face upwards.

[0199] According to another example, the battery pack can also include several busbars designed to connect the multitude of batteries in series and parallel.

[0200] For example, the plurality of busbars may be arranged on an upper section of the plurality of batteries, and each of the busbars may have a body section designed to extend between the terminals of adjacent batteries; several first busbar terminals designed to extend from one side of the body section and electrically couple to an electrode terminal of a battery located on one side; and several second busbar terminals designed to extend from the other side of the body section and electrically couple to an outer surface of the bottom of the battery casing of a battery located on the other side.

[0201] In another aspect of the present disclosure, a vehicle is also provided that includes the battery pack. BENEFICIAL EFFECTS

[0202] According to one example, since the uncoated sections that protrude from the upper and lower sections of the electrode assembly are used as electrode tabs, it is possible to reduce the internal resistance of the battery and increase the energy density.

[0203] According to another example, it is possible to prevent a short circuit in the cylindrical battery caused by partial deformation of the electrode assembly by improving the structure of the uncoated section of the electrode assembly so that the electrode assembly does not disturb the inner circumference of the battery during the process of forming the bead section of the battery casing.

[0204] According to yet another example, it is possible to prevent the uncoated section from tearing when the uncoated section is bent, and the number of overlapping layers of the uncoated sections is sufficiently increased to improve the weld strength of the current collector, as the structure of the uncoated section of the electrode assembly is improved.

[0205] According to yet another example, it is possible to improve the physical properties of an area where the current collector is welded by applying a segmented structure to the uncoated section of the electrode and by optimizing the dimensions (width, height, spacing) of the segments to sufficiently increase the number of overlapping segment layers in the area used as the welding target. As mentioned above, the multitude of segments can also be referred to as multiple separate tabs.

[0206] According to yet another example, it is possible to provide an electrode assembly with improved energy density and reduced resistance by applying a structure in which a current collector is welded over a large area to a bending surface area formed by bending the segments.

[0207] According to yet another example, it is possible to provide a cylindrical battery with an improved design to allow for electrical wiring on an upper section of it.

[0208] According to another example, because the structure of the uncoated section adjacent to the core of the electrode assembly is improved, it is possible to prevent the cavity in the core of the electrode assembly from becoming blocked when the uncoated section is bent. Thus, the electrolyte injection process and the welding process of the battery casing (or terminal) and the current collector can be carried out easily.

[0209] According to yet another example, it is possible to provide a cylindrical battery with a structure that has a low internal resistance, prevents an internal short circuit and improves the weld strength of the current collector and the uncoated section, and a battery pack as well as a vehicle that incorporates the cylindrical battery.

[0210] In particular, the present disclosure may provide a cylindrical battery with a diameter-to-height ratio of 0.4 or more and a resistance of 4 milliohms (mΩ) or less, and a battery pack and a vehicle incorporating therein. The resistance of the battery cell may be at least 0.5 mΩ or at least 1.0 mΩ and / or 3.8 mΩ or less, 3.5 mΩ or less, or 3 mΩ or less.

[0211] In addition, the present disclosure may have several other effects, and such effects are described in each example, or any description which can be easily derived by a person skilled in the art is omitted for one effect. FIGURE DESCRIPTION

[0212] The accompanying drawings illustrate a preferred representation and, together with the preceding disclosure, serve to provide a further understanding of the technical features of the present disclosure, and thus the present disclosure is not to be interpreted as being limited to the drawing. Fig. Figure 1 is a top view showing the structure of an electrode used to manufacture a conventional tabless cylindrical battery. Fig. Figure 2 is a diagram showing an electrode winding process of the conventional tabless cylindrical battery. Fig. Figure 3 is a diagram showing a welding process of a current collector to a curved surface area of ​​an uncoated section in the conventional tabless cylindrical battery. Fig. Figure 4 is a top view showing the structure of an electrode according to the first. Fig. Figure 5 is a top view showing the structure of an electrode according to the second. Fig. Figure 6 is a top view showing the structure of an electrode according to the third. Fig. Figure 7a is a top view showing a structure of an electrode according to the fourth. Fig. Figure 7b is a diagram showing the definitions of width, height, and separation distance of a segment according to an example. As mentioned above, the plurality of segments can also be referred to here as multiple separate tabs. The term "segments" is used consistently hereafter and can refer to the separate tabs as specified in the claims. Fig. Figure 7c is a diagram showing an arc formed by a lower end of a segment, defining a width of the segment based on a core center of an electrode assembly when the electrode is wound according to an example. Fig. 7d is a diagram that shows a relationship between the heights h1, h2, h3, h4 of the segments, a kernel radius (r) c ) and radii r1, r2, r3, r4 of a winding turn shows where the segments appear, according to an example in the present disclosure. Fig. 7e is a diagram for determining a maximum value (h max ) the height (H) of the segments in a height-variable area of ​​the segments. Fig. Figure 7f is a schematic diagram illustrating a formula for determining a lower interior angle (θ) of the segment. Fig. Figure 7g is a top view showing a modified structure of the electrode according to the fourth. Fig. Figure 7h is a top view showing an independent area where a plurality of segments may be located if the electrode is wound as an electrode assembly according to the modification of the present disclosure. Fig. Figure 8a is a top view showing the structure of an electrode according to the fifth. Fig. Figure 8b is a diagram showing the definitions of width, height, and separation distance of a segment according to another example. Fig. Figure 8c is a top view showing a modified structure of the electrode according to the fifth. Fig. Figure 9 is a diagram showing segment structures according to various modifications of the present disclosure. Fig. Figure 10a is a diagram showing a cross-section of a bending surface area formed by bending the segment towards the core of the electrode assembly. Fig. Figure 10b is a perspective top view schematically showing an electrode assembly in which the bending surface area is formed. Fig. Figure 10c is a diagram showing results obtained by counting the number of overlapping layers of segments along a radial direction in a bending surface area of ​​a positive electrode formed on an upper section of the electrode assemblies, according to Examples 1-1 to 1-7 and a comparison example. Fig. Figure 10d is a diagram showing results obtained by counting the number of overlapping layers of segments along the radial direction in a bending surface region of a positive electrode formed on an upper section of the electrode assemblies, according to Examples 2-1 to 2-5, Examples 3-1 to 3-4, Examples 4-1 to 4-3 and Examples 5-1 and 5-2. Fig. Figure 10e is a diagram showing results obtained by counting the number of overlapping layers of segments along the radial direction in a bending surface region of a positive electrode formed on an upper section of the electrode assemblies according to Examples 6-1 to 6-6 and Examples 7-1 to 7-6. Fig. Figure 10f is a top view of the electrode assembly showing a uniform area b1 of the number of overlapping layers and a decreasing area b2 of the number of overlapping layers in the bending surface area of ​​the segment according to an example. Fig. Figure 11 is a sectional view showing a jelly roll type electrode assembly in which the electrode of the first example is applied to a first electrode (a positive electrode) and a second electrode (a negative electrode) along the Y-axis direction (winding axis direction). Fig. Figure 12 is a sectional view showing a jelly roll type electrode assembly in which the electrode of the second example is applied to the first electrode (the positive electrode) and the second electrode (the negative electrode) along the Y-axis direction (winding axis direction). Fig. Figure 13 is a sectional view showing a jelly-roll type electrode assembly in which any one of the electrodes of the third to fifth examples (modifications thereof) is applied to the first electrode (the positive electrode) and the second electrode (the negative electrode) along the Y-axis direction (winding axis direction). Fig. Figure 14 is a sectional view showing an electrode assembly along the Y-axis direction (winding axis direction) according to yet another example. Fig. Figure 15 is a sectional view showing an electrode assembly along the Y-axis direction (winding axis direction) according to yet another example. Fig. Figure 16 is a sectional view showing an electrode assembly along the Y-axis direction (winding axis direction) according to yet another example. Fig. Figure 17 is a sectional view showing a cylindrical battery according to an example along the Y-axis direction. Fig. Figure 18 is a sectional view showing a cylindrical battery according to another example along the Y-axis direction. Fig. Figure 19 is a sectional view showing a cylindrical battery along the Y-axis direction, as in yet another example. Fig. Figure 20 is a sectional view showing a cylindrical battery along the Y-axis direction, as in yet another example. Fig. Figure 21 is a sectional view showing a cylindrical battery along the Y-axis direction, as in yet another example. Fig. Figure 22 is a sectional view showing a cylindrical battery along the Y-axis direction, as in yet another example. Fig. Figure 23 is a sectional view showing a cylindrical battery along the Y-axis direction, as in yet another example. Fig. Figure 24 is a sectional view showing a cylindrical battery along the Y-axis direction, as in yet another example. Fig. Figure 25 is a sectional view showing a cylindrical battery along the Y-axis direction, as in yet another example. Fig. Figure 26 is a top view showing the structure of a first pantograph according to an example. Fig. Figure 27 is a top view showing the structure of a second pantograph according to an example. Fig. Figure 28 is a top view showing a state in which several cylindrical batteries are electrically connected. Fig. 29 is a partially enlarged view of Fig. 28. Fig. Figure 30 is a diagram that schematically shows a battery pack according to an example. Fig. Figure 31 is a diagram that schematically shows a vehicle that includes the battery pack according to an example. EXAMPLES

[0213] Preferred examples of the present disclosure are described in detail below with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the description and the attached claims should not be interpreted as being limited to general and literal meanings, but rather should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure, on the basis of the principle that the inventor is permitted to define terms appropriately for the best possible explanation.

[0214] Therefore, the description proposed here is only a preferred example for illustrative purposes only, which is not intended to limit the scope of the disclosure, so that it is understood that other equivalents and modifications could be made to it without deviating from the scope of the disclosure.

[0215] Additionally, to facilitate understanding of the invention, some components in the accompanying drawings may not be drawn to scale, and their dimensions may be exaggerated. Furthermore, the same components may be assigned the same reference numerals in different examples.

[0216] When two tasks are described as "identical," this means that they are "essentially identical." Accordingly, essentially identical tasks can include variations that are considered minor in engineering, for example, variations within 5%. Similarly, when certain parameters are described as uniform within a range, this can mean that the parameters are uniform with respect to an average within that range.

[0217] First, an electrode assembly is described according to an example. The electrode assembly can be a jelly-roll type electrode assembly in which a first electrode and a second electrode with a sheet shape and an intermediate separator are wound in one direction. However, the present invention is not limited to a specific type of electrode assembly.

[0218] For example, at least one of the first electrodes and the second electrode has an uncoated section that is not coated with an active material at one long side end in the winding direction. At least part of the uncoated section is used as an electrode tab. The uncoated section has a core-side uncoated section adjacent to a core of the electrode assembly, a circumferential uncoated section adjacent to an outer circumference of the electrode assembly, and an uncoated intermediate section located between the core-side uncoated section and the circumferential uncoated section.

[0219] For example, at least one of the core-side uncoated section and the surrounding uncoated section has a relatively lower height than the uncoated intermediate section.

[0220] Fig. Figure 4 is a top view showing a structure of an electrode 40 according to the first.

[0221] Referring to Fig. In the first example, the electrode 40 has a current collector 41 formed from a metal foil and an active material layer 42. The metal foil can be a conductive metal, for example, aluminum or copper, and is selected appropriately according to the polarity of the electrode 40. The active material layer 42 is formed on at least one surface of the current collector 41. The active material layer 42 is formed along the winding direction X. The electrode 40 has an uncoated section 43 at its long end in the winding direction X. The uncoated section 43 is a portion of the current collector 41 where it is not coated with active material. The portion of the current collector 41 where the active material is formed can be referred to as an active material section.

[0222] In the electrode 40, the width of the active material section in one direction along a short side of the current collector 41 can be 50 mm to 120 mm, and the length of the active material section in one direction along a long side of the current collector 41 can be 3 m to 5 m. Accordingly, the ratio of the short side to the long side of the active material section can be 1% to 4%.

[0223] For example, in electrode 40, the width of the active material section in one direction along a short side of the current collector 41 can be 60 mm to 70 mm, and the length of the active material section in one direction along a long side of the current collector 41 can be 3 m to 5 m. Accordingly, the ratio of the short side to the long side of the active material section can be 1.2% to 2.3%.

[0224] The ratio of the short side to the long side of the active material section is significantly smaller than the ratio of the short side to the long side of an active material section in the electrode used in a cylindrical battery with a form factor of 1865 or 2170, which is 6% to 11%.

[0225] For example, the pantograph 41 can withstand an elongation of 1.5% to 3.0% and a tensile strength of 25 kgf / mm². 2 up to 35 kgf / mm 2The elongation and tensile strength can be measured according to the measurement method of IPC-TM-650. The electrode 40 is manufactured by forming an active material layer 42 on the current collector 41 and then compressing it. During compression, an area of ​​the uncoated section 43 and an area of ​​the active material layer 42 exhibit different elongations. Therefore, swelling occurs on the electrode 40 after compression, and the swelling is greater because the electrode 40 is longer.

[0226] Optimizing the elongation and tensile strength of the current collector 41 reduces the warping length after compression to less than 20 mm when the electrode 40 is approximately 4 m long. The warping length is the maximum amount of deflection of the electrode 20 in the winding direction X when the swollen electrode 20 is coiled. The maximum amount of deflection can be measured at one end of the circumference. The electrode 40, with optimized elongation and tensile strength, exhibits a small warping length, thus preventing meandering defects during notching of the uncoated section 43 or winding of the electrode 40.

[0227] The current collector 41 is prone to breakage due to its low elongation. If the elongation of the current collector 41 is less than 1.5%, the rolling process efficiency of the current collector 41 deteriorates, and thus, when the electrode 40 coated with the active material layer 42 is compressed onto the current collector 41, separation may occur in the current collector 41. Meanwhile, if the elongation of the current collector 41 exceeds 3.0%, the active material section of the electrode 40 is stretched more, and consequently, the curvature length increases significantly. If the tensile strength of the current collector 41 is less than 25 kgf / mm², the following applies: 2 or more than 35 kgf / mm 2 If the electrode process efficiency of electrode 40 is lower, it will deteriorate.

[0228] The warping phenomenon is particularly problematic in a current collector with a positive electrode made of aluminum foil. According to the present disclosure, if an aluminum foil has an elongation of 1.5% to 3.0% and a tensile strength of 25 kgf / mm² 2 up to 35 kgf / mm 2 When used as a current collector, the warping phenomenon is suppressed. It is preferred that an active material layer is formed on the current collector to serve as a positive electrode.

[0229] For example, an insulating coating layer 44 can be formed at the boundary between the active material layer 42 and the uncoated section 43. The insulating coating layer 44 is formed such that at least a portion of it overlaps the boundary between the active material layer 42 and the uncoated section 43. The insulating coating layer 44 prevents a short circuit between two electrodes with opposite polarities facing each other with a separator arranged between them. The insulating coating layer 44 has a width of 0.3 mm to 5 mm and can thus cover the boundary section of the active material layer 42 and the uncoated section 43. The width of the insulating coating layer 44 can vary in one winding direction of the electrode 40. The insulating coating layer 44 contains a polymer resin and may contain inorganic fillers such as Al₂O₃.The section of the current collector 41 that is covered by the insulating coating layer 44 is not an area coated with an active material layer and can therefore be considered an uncoated section.

[0230] The uncoated section 43 can have a core-side uncoated section B1 adjacent to the core side of the electrode assembly, a circumferential uncoated section B3 adjacent to the outer circumferential side of the electrode assembly and an uncoated intermediate section B2 located between the core-side uncoated section B1 and the circumferential uncoated section B3.

[0231] The core-side uncoated section B1, the circumferential uncoated section B3 and the uncoated intermediate section B3 can be defined as an uncoated section of a region adjacent to the core, an uncoated section of a region adjacent to the outer circumference or an uncoated section of a remaining region excluding the foregoing, when the electrode 40 is wound to form a jelly-roll type electrode assembly.

[0232] In the following, the core-side uncoated section B1, the circumferential uncoated section B3 and the uncoated intermediate section B2 are referred to as a first section, a second section and a third section respectively.

[0233] In one example, the first section B1 can be an uncoated section of the electrode area with an innermost winding turn, and the second section can be an uncoated section of the electrode area with an outermost winding turn.

[0234] In another example, the boundary of B1 / B2 may be appropriately defined as a location where the height (or change pattern) of the uncoated section changes substantially from the core of the electrode assembly to the outer circumference, or a location with a certain percentage (%) based on the radius of the electrode assembly (e.g., 5% location, 10% location, 15% location of the radius, etc.).

[0235] The B2 / B3 boundary is a location where the height (or change pattern) of the uncoated section substantially changes from the outer circumference of the electrode assembly to the core, or a location with a specific percentage (%) based on the radius of the electrode assembly (e.g., 85% site, 90% site, 95% site of the radius, etc.). If the B1 / B2 and B2 / B3 boundaries are specified, the third section, B2, can be specified automatically.

[0236] If only the boundary of B1 / B2 is specified, the boundary of B2 / B3 can be suitably selected at a location near the perimeter of the electrode assembly. For example, the second section could be defined as an uncoated portion of the electrode area forming an outermost winding turn. Conversely, if only the boundary of B2 / B3 is specified, the boundary of B1 / B2 can be suitably selected at a location near the core of the electrode assembly. For example, the first section could be defined as an uncoated portion of the electrode area forming an innermost winding turn.

[0237] In the first example, the height of the uncoated section 43 is not constant, and there is a relative difference in the winding direction X. That is, the height (length in the Y-axis direction) of the second section B3 is relatively smaller than that of the first section B1 and the third section B2.

[0238] Fig. Figure 5 is a top view showing a structure of electrode 45 according to the second.

[0239] With reference to Fig. 5 The electrode 45 of the second example differs from that of the first example only in that the height of the second section B3 gradually decreases towards the outer circumference and the other configuration is essentially the same.

[0240] In one modification, the second section B3 can be transformed into a stepped shape (see dotted lines) in which the height decreases stepwise.

[0241] Fig. Figure 6 is a top view showing a structure of an electrode 50 according to the third.

[0242] With reference to Fig. In electrode 50 of the third example, the heights of the first section B1 and the second section B3 are 0 or more and relatively smaller than those of the third section B2. Additionally, the heights of the first section B1 and the second section B3 can be the same or different from each other.

[0243] For example, the height of the third section B2 can have a stepped shape, increasing gradually from the core to the outer perimeter.

[0244] Patterns 1 through 7 classify the third section B2 based on the position where the height of the uncoated section 43 changes. For example, the number of patterns and the height (length in the Y-axis direction) and width (length in the X-axis direction) of each pattern can be adjusted to distribute the stress as much as possible during the bending process of the uncoated section 43. This stress distribution is intended to prevent the uncoated section 43 from tearing when it is bent towards the core of the electrode assembly.

[0245] The width (d B1 The first section B1 is designed by applying a condition that the core of the electrode assembly is not covered when the patterns of the third section B2 are bent towards the core. The core is a cavity present at the winding center of the electrode assembly.

[0246] In one example, the width (d B1 The bend length of the first section B1 increases proportionally to the bend length of pattern 1. The bend length corresponds to the height of the pattern based on the bend point of the pattern.

[0247] For example, the width (d B1 ) of the first section B1 is adjusted such that the radial width of the winding turns formed by the first section B1 is greater than or equal to the bend length of pattern 1. In a modified example, the width (d B1 ) of the first section B1 shall be adjusted such that the value obtained by subtracting the radial width of the winding turns formed by the first section B1 from the bending length of pattern 1 is less than 0 or less than or equal to 10% of the radius of the core.

[0248] In a specific example, if electrode 60 is used to manufacture an electrode assembly for a cylindrical battery with a form factor of 4680, the width (d) B1 ) of the first section B1 is set to 180 to 350 mm according to the diameter of the core of the electrode assembly and the bending length of sample 1.

[0249] In one example, the width of each pattern can be designed to form one or more winding turns of the electrode assembly.

[0250] In one modification, the height of the third section B2 can have a stepped shape that increases from the core to the outer circumference and then decreases.

[0251] In another modification, the second section B3 can be modified to have the same structure as the second example.

[0252] In yet another modification, the pattern structure applied to the third section B2 can be extended to the second section B3 (see a dotted line).

[0253] Fig. Figure 7a is a top view showing a structure of an electrode 60 according to the fourth.

[0254] With reference to Fig. 7a In electrode 60 of the fourth example, the heights of the first section B1 and the second section B3 in the winding axis direction (Y) are 0 or more and relatively smaller than those of the third section B2. Additionally, the height of the first section B1 and the second section B3 in the winding axis direction (Y) can be the same or different.

[0255] For example, at least a sub-area of ​​the third section B2 can have a plurality of segments 61. As mentioned above, the plurality of segments can also be referred to here as several separate tabs. In the following, the term segments is used consistently and can refer to the separate tabs as specified in the claims. The plurality of segments 61 can increase in height stepwise from the core to the outer circumference. The plurality of segments 61 has a geometric shape in which the width gradually decreases from bottom to top. For example, the geometric shape is a trapezoid. As will be explained later, the shape of the geometric figure can be modified in various ways.

[0256] Segment 61 can be formed by laser notching. Segment 61 can be formed by a known metal foil cutting process, such as ultrasonic cutting or punching.

[0257] To prevent damage to the active material layer 42 and / or the insulating coating layer 44 during bending of the uncoated section 43, it is preferred in the fourth example to have a predetermined gap between a base G (see Fig. 7b) to provide a cut groove 63 between the segments 61 and the active material layer 42. This is because stress is concentrated near the bottom of the cut groove 63 when the uncoated section 43 is bent. The gap is preferably 0.2 mm to 4 mm, more preferably 1.5 mm to 2.5 mm. The gap can also vary along a winding direction of the electrode 60. Setting the gap within the appropriate numerical range prevents the active material layer 42 and / or the insulating coating layer 44 near the bottom of the cut groove 63 from being damaged by the stress generated during the bending of the uncoated section 43. Additionally, the gap prevents the active material layer 42 and / or the insulating coating layer 44 from being damaged due to tolerances during the notching or cutting of the segments 61.The lower end of the cut groove 63 and the insulating coating layer 44 can be separated by 0.5 mm to 2.0 mm. If the electrode 60 is wound, the end of the insulating coating layer 44 can be positioned in the winding axis direction (Y) in the range of -2 mm to 2 mm along the winding axis direction with respect to the end of the separator. The insulating coating layer 44 can prevent a short circuit between two electrodes of opposite polarities facing each other with an interposed separator and can support the bending point when the segments 61 are bent. To improve the short-circuit prevention effect between the two electrodes, the insulating coating layer 44 can be exposed from the separator.Additionally, to further maximize the effect of preventing a short circuit between the two electrodes, the width of the insulating coating layer 44 can be increased so that its end is positioned higher in the winding axis direction (Y) than the lower end of the cut slot 63. For example, the end of the insulating coating layer 44 can be positioned within the range of -2 mm to +2 mm in the winding axis direction with respect to the lower end of the cut slot 63.

[0258] The multitude of segments 61 can form a multitude of segment groups from the core to the outer perimeter. The multitude of segments belonging to the same segment group can be substantially the same with respect to at least one of their width, height, and separation distance. The width, height, and separation distance of segments belonging to the same segment group can be the same.

[0259] Fig. Figure 7b is a diagram showing the definitions of width (D), height (H) and separation distance (P) of the trapezoidal segment 61.

[0260] With reference to Fig. 7b the width (D), height (H) and separation distance (P) of segment 61 are designed to prevent abnormal deformation of the uncoated section 43, while sufficiently increasing the number of overlapping layers to prevent the uncoated section 43 from breaking near the bending point during bending of the uncoated section 43, and to improve sufficient weld strength of the uncoated section 43.

[0261] Segment 61 is bent along a line G that passes through the lower end of the cutting groove 63 or above line G. The cutting groove 63 facilitates the smooth and easy bending of segment 61 in a radial direction along the electrode assembly.

[0262] The width (D) of segment 61 is defined as the length between two points where two straight lines extending from both sides 63b of segment 61 intersect a straight line extending from the lower section 63a of the cutting groove 63. The height (H) of segment 61 is defined as the shortest distance between the top side of segment 61 and a straight line extending from the lower section 63a of the cutting groove 63. The separation distance (P) of segment 61 is defined as the length between two points where a straight line extending from the lower section 63a of the cutting groove 63 intersects straight lines extending from two sides 63b connected to the lower section 63a.If page 63b and / or the lower section 63a is curved, the straight line can be replaced by a tangent line extending from page 63b and / or the lower section 63a at the point of intersection where page 63b and the lower section 63a meet.

[0263] For example, the width (D) of segment 61 is at least 1 mm. If D is less than 1 mm, an area where segment 61 does not overlap sufficiently to ensure weld strength, or an empty space (gap) may occur if segment 61 is bent towards the core.

[0264] For example, the width (D) of segment 61 can be adaptively adjusted according to the radius of the winding turn where segment 61 is located, so that segment 61 slightly overlaps in the radial direction when segment 61 is bent towards the core of the electrode assembly.

[0265] Fig. 7c is a diagram showing an arc (A1A2) passing through the lower end (line segment Dab of Fig. 7b) of segment 61 is formed where the width (D) of segment 61 is defined when the electrode 60 is wound according to an example based on the core center O of the electrode assembly.

[0266] With reference to Fig. 7c The arc (A1A2) has a length equal to the width (D) of segment 61 and has a circumferential angle (Φ) with respect to the core center of the electrode assembly. The circumferential angle (Φ) can be defined as an angle between two line segments connecting both ends of the arc (A1A2) and the core center O on a plane perpendicular to the winding axis passing through the arc (A1A2).

[0267] If the length of the arc (A1A2) of segment 61 is constant, the circumferential angle (Φ) decreases as the radius (r) of the winding turn where segment 61 is located increases. Conversely, if the circumferential angle (Φ) of segment 61 is constant, the length of the arc (A1A2) increases proportionally as the radius (r) of the winding turn where segment 61 is located increases.

[0268] The circumferential angle (Φ) influences the bending quality of segment 61. In the drawing, a solid arrow indicates the direction of a force applied to bend segment 61, and a dotted arrow indicates the direction in which segment 61 is bent. The bending direction is towards the core center O.

[0269] The circumferential angle (Φ) of segment 61 can preferably be 45 degrees or less and more preferably 30 degrees or less, depending on a radius (r) of a winding turn on which segment 61 is located, in order to improve the uniformity of the bending and to prevent the occurrence of cracks.

[0270] In one aspect, the circumferential angle (Φ) of segment 61 can gradually or stepwise increase or decrease along a radial direction of the electrode assembly within the numerical range above. In another aspect, the circumferential angle (Φ) of segment 61 can gradually or stepwise increase and then gradually or stepwise decrease along a radial direction of the electrode assembly within the numerical range above, or vice versa. In yet another aspect, the circumferential angle (Φ) of segment 61 can be essentially constant along a radial direction of the electrode assembly within the numerical range above.

[0271] According to the experiment, if the circumferential angle (Φ) of segment 61 exceeds 45 degrees, the bending shape of segment 61 is not uniform. The force applied to a central part of segment 61 differs significantly from the force applied to a side part, so that segment 61 is not compressed uniformly in the circumferential direction. Additionally, if the compressive force is increased to achieve uniformity of the bend, there is a possibility that cracks may occur in the uncoated section 43 near the cut groove 63.

[0272] In one example, the circumferential angle (Φ) of the segments 61 contained in the electrode 60 is essentially the same, and the width of segment 61 can be increased proportionally as the radius (r) of the winding turn where segment 61 is located increases. The term "essentially identical" means that they are completely identical or that there is a deviation of less than 5%.

[0273] For example, if the radius of the electrode assembly is 22 mm, the radius of the core is 4 mm, and segment 61 begins to be positioned from the winding turn located at a point where the radius is 7 mm, and if the circumferential angle (Φ) of segment 61 is constant at 28.6 degrees, the width (D) of segment 61 can be increased proportionally according to the radius (r) of the winding turn where segment 61 is located, as shown in Table 1 below. That is, the width of segment 61 can be increased by 0.5 mm at essentially the same rate when the radius (r) of the winding turn increases by 1 mm.

[0274] For example, the width D(r) of segment 61, which is located in a winding turn with a radius of r with respect to the core center O of the electrode assembly, can be determined in a region that satisfies the formula 1 below. 1≤D(r)≤(2⋅π⋅r / 360°)⋅45°

[0275] For example, as each of the multitude of segments 61 increases, while the radius (r) of the winding turn, where the segment is located based on the core center of the electrode assembly, increases, the width D(r) in the winding direction gradually or stepwise increases or vice versa.

[0276] In another aspect, as the radius (r) of the winding turn, where the segment is based on the core center of the electrode assembly, increases, each of the multiple segments 61 gradually or stepwise increases the width D(r) in the winding direction within the range of 1 mm to 11 mm or vice versa.

[0277] In another aspect, as the radius (r) of the winding turn increases where the segment is based on the core center of the electrode assembly, the width D(r) in the winding direction gradually or stepwise increases and then gradually or stepwise decreases or vice versa.

[0278] In another aspect, each of the multitude of segments 61, while the radius (r) of the winding turn, where the segment is located based on the core center of the electrode assembly, increases, the width D(r) in the winding direction gradually or stepwise increases and then gradually or stepwise within the range of 1 mm to 11 mm or vice versa.

[0279] In another aspect, the variation ratio of D(r) can be essentially the same or different depending on the radius (r) of the winding turn where the segment is located based on the core center of the electrode assembly.

[0280] In another aspect, the variation ratio of D(r) can be essentially the same or different depending on the radius (r) of the winding turn, where the segment is based on the core center of the electrode assembly, depending on the radius (r) within the range of 1 mm to 11 mm.

[0281] With renewed reference to Fig. 7b The height (H) of segment 61 can be 2 mm or more. If D2 is less than 2 mm, an area where segment 61 does not overlap sufficiently to ensure weld strength, or an empty space (gap) may occur if segment 61 is bent towards the core.

[0282] The height (H) of segment 61 can be determined by applying the condition that segment 61 does not cover the core when bent towards the core. For example, the height (H) of segment 61 can be set such that the core can be opened outwards by 90% or more of its diameter.

[0283] For example, the height (H) of segment 61 can gradually increase from the core to the outer circumference, depending on the radius of the core and the radius of the winding turn where segment 61 is located.

[0284] In one example, assuming that the height (H) of segment 61 is gradually increased over N steps from h1 to h1 n increases when the radius of the winding increases, when a k-th height of the segment 61 h k is (k is a natural number from 1 to N), a starting radius of the winding turn that includes segment 61 with height hk, r k is and the radius of the kernel r cis the height h1 to h n of segment 61 to satisfy formula 2 below. 2 mm≤hk≤rk−α⋅rc(preferably α is 0.90 to 1)

[0285] If the height (h k ) of segment 61, if formula 2 is satisfied, 90% or more of the diameter of the core can be opened outwards, even if segment 61 is bent towards the core.

[0286] In one example, the total winding turn radius of electrode 60 is 22 mm. The height of segment 61 starts at 3 mm and increases successively to 3 mm, 4 mm, 5 mm, and 6 mm whenever the radius of the winding turn containing segment 61 increases by 1 mm. The height of segment 61 can be kept essentially constant at 6 mm in the remaining winding turn. That is, among the radii of all winding turns, the radial directional width of a height-variable region of segment 61 is 3 mm, and the remaining radial region corresponds to a height-uniform region.

[0287] In this case, according to the radius (r) c) of the core of the electrode assembly the starting radius r1, r2, r3, r4 of the winding turn which includes the segment 61 with the height of 3 mm, 4 mm, 5 mm and 6 mm, as shown in Table 2 below, when α is 1 and the condition of like sign is applied in a correct inequality of the above formula. Table 2 Segmenthöhe (mm) Element 3 (h1) 4 (h2) 5 (h3) 6 (h4) core radius (r c )(mm) 2 5 (r1) 6 (r2) 7 (r3) 8 (r4) 2,5 5,5 (r1) 6,5 (r2) 7,5 (r3) 8,5 (r4) 3 6 (r1) 7 (r2) 8 (r3) 9 (r4) 3,5 6,5 (r1) 7,5 (r2) 8,5 (r3) 9,5 (r4) 4 7 (r1) 8 (r2) 9 (r3) 10 (r4)

[0288] When segment 61 is positioned at the radial location shown in Table 2, the core is not covered by segment 61, even if segment 61 is bent towards the core. Meanwhile, r1, r2, r3, r4, shown in Table 2, can be shifted towards the core according to the α value. For example, if α is 0.90, r1, r2, r3, r4 can be shifted towards the core by 10% of the core radius. In this case, if segment 61 is bent towards the core, 10% of the core radius is covered by segment 61. r1, r2, r3, r4, shown in Table 2, are the limiting values ​​of the starting point of segment 61. Accordingly, the position of segment 61 can be shifted further towards the outer circumference by a predetermined distance from the radius shown in Table 1.

[0289] Fig. 7d is a diagram that schematically shows the relationship between the heights h1, h2, h3, h4 of the segment, the kernel radius (r) c) and the radius r1, r2, r3, r4 of the winding turn, where segment 61 begins to appear.

[0290] Referring to Table 2 and Fig. 7d together, if for example the radius (r cIf the core C is 3 m, the starting radius r1, r2, r3, and r4 of the winding turn containing segment 61 with heights of 3 mm (h1), 4 mm (h2), 5 mm (h3), and 6 mm (h4) can be 6 mm, 7 mm, 8 mm, and 9 mm, respectively, and the height of segment 61 can be maintained as 6 mm from the 9 mm radius to the last winding turn. Furthermore, a winding turn with a radius of less than 6 mm (r1) can omit segment 61. Since, in this example, the segment 61 with a height of 3 mm (h1), which is closest to the core C, is located from the winding turn with a radius of 6 mm, even when the segment 61 is bent towards the core C, the segment 61 only covers the radial area from 3 mm to 6 mm, and the core C is essentially not shielded. According to the α-value of formula 2, the position of segment 61 can be within 10% of the core radius (r). c ) are shifted towards kernel C.

[0291] In another aspect, the height of segment 61, when the starting radius (r) of the winding turn, where segment 61 is located based on the core center of the electrode assembly, increases, may increase essentially at the same rate or differently depending on the radius (r).

[0292] For example, the height (H) of segment 61 can satisfy formula 2 and at the same time the maximum height of the segment can be limited.

[0293] Fig. 7e is a conceptual diagram for determining the maximum value (h). max ) for the height (H) of segment 61 in the height-variable area of ​​segment 61.

[0294] With reference to Fig. In the winding structure of the electrode assembly, electrode 7e (E1) has segment 61 facing an electrode (E2) of opposite polarity with a separator S arranged radially between them. Both surfaces of electrode 7e are coated with an active material layer (E). 1,active ) coated, and both surfaces of the electrode (E2) are also coated with an active material layer (E 2,active ) coated. end ) of the separator S by a length which corresponds to the insulation gap (W gap ) corresponds to the end (E 2,end ) of the electrode (E2) extend further outwards. Additionally, the end of the electrode (E1) for electrical insulation does not extend further outwards towards the end of the electrode (E2). Therefore, an area that leads to the insulation gap (W) must gap) corresponds to being secured at the lower end of the uncoated section 43. When the electrodes (E1, E2) and the separator S are wound up, the end (S) also causes end ) of separator S forms a meander. Therefore, to expose segment 61 from separator S, a section (W) must be margin,min ), which corresponds to the minimal meandering edge of the separator S, is assigned to the uncoated section 43. In order to cut segment 61, an additional minimal offcut margin (W) must be added. scrap,min ) can be assigned to the end of the pantograph foil. Therefore, the maximum height (h) can be max The value of segment 61 in the height-variable area of ​​segment 61 can be determined by the following formula 3. In formula 3, W corresponds to... foil to the width of the current collector foil before the current collector foil is cut. hmax=Wfoil−Wscrap,min−Wmargin,min−Wgap

[0295] For example, the insulation gap (Wgap ) in the range of 0.2 mm to 6 mm if the first electrode is a positive electrode, and in the range of 0.1 mm to 2 mm if the first electrode is a negative electrode.

[0296] For example, the minimum trimming waste margin (W scrap,min ) in the range of 1.5 mm to 8 mm. The minimum kerf (W scap,min ) cannot be taken into account depending on the process of cutting segment 61. For example, the cutting groove 63 can be formed such that the top surface of segment 61 coincides with that of the current collector foil. In this case, W scrap,min Formula 3 should be zero.

[0297] For example, the minimal meander edge (W margin,min ) in the range of 0 to 1 mm.

[0298] In one example, the minimum trimming waste margin (W) scap,min ) 1.5 mm and the minimum meander edge (W margin,minThe diameter (W) of the separator S can be 0.5 mm. Under these conditions, if the width (W) foil the current collector foil before forming segment 61 is 8 mm to 12 mm and the insulation gap (W gap ) 0.6 mm, 0.8 mm and 1.0 mm, is the result of the calculation of the maximum height (h) max ) of segment 61 using formula 3 as shown in Table 3 below. Table 3 Element Separator ⇔ negativer Elektrodenspalt (mm) 0,6 0,8 1 StromabnehmerFolienbreite(mm) 8 5.4 5.2 5 9 6.4 6.2 6 10 7.4 7.2 7 11 8.4 8.2 8 12 9.4 9.2 9

[0299] Taking Table 3 into account, the maximum height (h) can be determined. max The height of segment 61 in the height-variable area of ​​segment 61 can be set to 10 mm. Therefore, in the height-variable area of ​​segment 61, the height of segment 61 fulfills formula 2 and can be increased simultaneously stepwise or gradually along the radial direction of the electrode assembly in the range of 2 mm to 10 mm.

[0300] With renewed reference to Fig. 7b The separation distance (P) of segment 61 can be set in the range of 0.05 to 1 mm. If the separation distance (P) is less than 0.05 mm, cracks may occur in the uncoated section 43 near the lower end of the cut groove 63 due to stress when the electrode 60 moves during a winding process or the like. Meanwhile, if the separation distance (P) exceeds 1 mm, an empty space (gap) or an area where the segments 61 do not overlap sufficiently to ensure adequate weld strength may occur if the segment 61 is bent.

[0301] Meanwhile, if the current collector 41 of the electrode 60 is made of aluminum, the separation distance (P) is preferably set to 0.5 mm or more. If the separation distance (P) is 0.5 mm or more, it is possible to prevent cracks from forming in the lower section of the cut groove 63, even if the electrode 60 moves at a speed of 100 mm / s or more under a voltage of 300 gf or more during the winding process or the like.

[0302] According to the test results, if the current collector 41 of the electrode 60 is an aluminum foil with a thickness of 15 µm and the separation distance (P) is 0.5 mm or more, no cracks occur in the lower section of the cut groove 63 when the electrode 60 moves under the above conditions.

[0303] As in Fig. As shown in Figure 7b, the cut groove 63 is arranged between two segments 61 that are adjacent to each other in the winding direction X. The cut groove 63 corresponds to the space created when the uncoated section 43 is removed. For example, the two ends of the lower section of the cut groove 63 have a rounded shape. That is, the cut groove 63 comprises a substantially flat lower section 63a and a rounded section 63c. The rounded section 63c connects the lower section 63a and the side 63b of the segment 61. In a modified example, the lower section 63a of the cut groove 63 can be replaced by an arc shape. In this case, the sides 63b of the segments 61 can be smoothly connected by the arc shape of the lower section 63a.

[0304] The radius of curvature of the round section 63c can preferably be in the range of 0 to 0.5 mm, more preferably in the range of 0 to 0.1 mm, or more preferably in the range of 0.01 mm to 0.05 mm. If the radius of curvature of the round section 63c meets the above numerical range, it is possible to prevent cracks from forming in the lower section of the cut groove 63 while the electrode 60 is moving during the winding process or the like.

[0305] In the multitude of segments 61, a lower interior angle (θ) can increase from the core to the outer circumference. The lower interior angle (θ) is the angle between a straight line extending from the lower section 63a of the cutting groove 63 and a straight line extending from the side section 53b of the segment 61. If the segment 61 is symmetrical in the left and right directions, the lower interior angles (θ) on the left and right sides are essentially equal.

[0306] As the radius of the electrode assembly increases, so does the radius of curvature. As the lower internal angle (θ) of segment 61 increases with the radius of the electrode assembly, the stresses generated in the radial and circumferential directions when segment 61 is bent can be reduced. Furthermore, as the lower internal angle (θ) increases when segment 61 is bent, its area overlapping with the segment 61 located on an inner side, and the number of overlapping layers, also increase. This ensures uniform weld strength in the radial and circumferential directions and forms a flat bending surface area.

[0307] For example, the lower internal angle (θ) can be determined by the radius of the winding turn where segment 61 is located and the width (D) of segment 61.

[0308] Fig. Figure 7f is a schematic diagram to explain a formula for determining the lower interior angle (θ) of segment 61.

[0309] With reference to Fig. 7f the side of segment 61 coincides identically with a line segment AE and a line segment DE, which connect the core center (E) with both endpoints A and D of a line segment AD that corresponds to the width (D) of segment 61.

[0310] If the side of segment 61 extends in the most ideal direction, assuming that line segment EF is approximately equal to line segment AE and line segment DE, the lower internal angle (θrefer) of segment 61 can be determined approximately from the width (D) of segment 61 and the radius (r) of the winding turn where segment 61 is located, using formula 4 below. θrefer=cos−1(0.5∗Dr)

[0311] The angle in Formula 4 is an ideal criterion angle for the lower internal angle (θrefer) of segment 61. Meanwhile, a separation distance (P) exists between adjacent segments 61 located in the same winding turn. The length of the separation distance (P) is given by p. Because of the separation distance (P) between adjacent segments 61, a tolerance of 50% of the separation distance (P) can be given to the lower internal angle (θ). That is, the width of the top surface BC of segment 61 can be increased by a maximum of p / 2 relative to the top surface B'C'. The lower internal angle (θ') that represents the tolerance can be expressed by Formula 5 below. The lower internal angle (θrefer) is the ideal criterion angle BAG, and the lower internal angle (θ') is the angle B'AG' that represents the tolerance according to the separation distance (P). In formula 5, H corresponds to the height of segment 61, and p corresponds to the separation distance. θ'=tan−1(2∗H∗tanθrefer2∗H−p∗tanθrefer)

[0312] For example, the lower internal angle (θ) of the segment 61 located at each winding turn of the electrode assembly can satisfy the formula 6 below. Then, when the segments 61 are bent towards the core center of the electrode assembly, the circumferentially adjacent segments 61 do not interfere with each other and are bent smoothly. cos−1(0.5∗Dr)≤θ≤tan−1(2∗H∗tanθrefer2∗H−p∗tanθrefer)

[0313] For example, if the electrode 60 forms a winding structure with a diameter of 22 mm and a core radius of 4 mm, the lower internal angle of the segment 61 can gradually increase in the range of 60 degrees to 85 degrees in the height-variable range.

[0314] Meanwhile, the lower interior angles of segment 61 on the left and right sides may differ. Nevertheless, at least one of the lower interior angles on the left and right sides of segment 61 can be configured such that it satisfies formula 6.

[0315] With renewed reference to Fig. 7a will be the width (d B1 ) of the first section B1 is designed such that the core of the electrode assembly opens outwards by 90% or more based on the diameter of the core when segment 61 of the third section B2 is bent towards the core. The width (d B1The width (d) of the first section B1 can increase proportionally to the bending length of segment 61 of group 1. The bending length corresponds to a length from the bending point to the top side of segment 61. For example, if electrode 60 is used to manufacture an electrode assembly for a cylindrical battery with a form factor of 4680, the width (d) can be increased proportionally to the bending length of segment 61. B1 ) of the first section B1 shall be adjusted to 180 mm to 350 mm according to the diameter of the core of the electrode assembly and the height of the segment 61 contained in group 1.

[0316] The bending point of segment 61 can be set on a line passing through the lower end of the cutting groove 63 or at a point spaced upwards from the line by a predetermined distance. When the segments 61 are bent towards the core at a point spaced a predetermined distance from the lower end of the cutting groove 63, the segments can overlap more easily in the radial direction. When the segments 61 are bent, a segment located on an outside surface based on the center of the core pushes a segment on an inside surface. Meanwhile, when the bending point is spaced a predetermined distance from the lower end of the cutting groove 63, a segment on an inside surface is pushed by a segment on an outside surface in the winding axis direction, so that the segments overlap better. For example, the separation distance of the bending point can be 1 mm or less.The minimum height of segment 61 is 2 mm, and therefore the ratio of the separation distance to the minimum height of segment 61 can be 50% or less.

[0317] In one example, the width of each segment group can be designed to form the same winding turn of the electrode assembly. Here, the winding turn can be counted based on the end of the first section B1 when electrode 60 is in a wound state.

[0318] In another modified example, the width of each segment group can be designed to form at least one winding turn of the electrode assembly.

[0319] In yet another modification, the width and / or height and / or separation distance of segment 61, which belongs to the same segment group, can be gradually and / or stepwise and / or irregularly increased or decreased within the group or between the adjacent groups.

[0320] Groups 1 to 8 are just one example of segment groups included in the third section B2. The number of groups, the number of segments 61 contained in each group, and the width of each group can be adjusted to allow the segments 61 to overlap in multiple layers, thereby distributing stress as much as possible during the bending process of the uncoated section 43 and ensuring sufficient weld strength with a current collector.

[0321] In another modification, the height of the second section B3 can be gradually or stepwise reduced, as in the first example and the second example.

[0322] In yet another modification, the segment structure of the third section B2 can be extended to the second section B3 (see dotted line). In this case, the second section B3 can also contain a multitude of segments, just like the third section B2. For example, the segment structure of the second section B3 can be essentially the same as the segment group at the outermost edge of the third section B2. In this case, the segments contained in the second section B3 and the third section B2 can be essentially the same in terms of width, height, and spacing. In one modification, the segment of the second section B3 can have a width and / or height and / or spacing that is greater than that of the third section B2.

[0323] In the third section B2, the area (groups 1 to 7) in which the height of segment 61 increases stepwise based on the winding direction of electrode 60 is defined as a height-variable area of ​​the segment, and the segment group at the last (group 8) can be defined as a height-uniform area in which the height of the segment is kept uniform.

[0324] That is, if in the third section B2 the height of segment 61 gradually increases from h1 to h n The area in which segments 61 with a height from h1 to h is increased corresponds to the area in which segments 61 have a height of h1 to h N -1 (N is a height index and a natural number of 2 or more) are arranged in a height-variable area, and the area in which segments 61 with a height of h nThe arrangement corresponds to a uniform height area. The relationship between the variable height area and the uniform height area to the length of electrode 60 in the winding direction will be described later with reference to specific examples.

[0325] When the electrode plate 60 is used to manufacture an electrode assembly for a cylindrical battery with a form factor of 4680, the width (d B1) of the first section B1 may be 180 to 350 mm. The width of group 1 may be 35 to 40% of the width of the first section B1. The width of group 2 may be 130 to 150% of the width of group 1. The width of group 3 may be 120 to 135% of the width of group 2. The width of group 4 may be 85 to 90% of the width of group 3. The width of group 5 may be 120 to 130% of the width of group 4. The width of group 6 may be 100 to 120% of the width of group 5. The width of group 7 may be 90 to 120% of the width of group 6. The width of group 8 may be 115 to 130% of the width of group 7. The width (d B3 ) of the second section B3 can be 180 to 350 mm, like the width of the first section B1.

[0326] The reason the widths of groups 1 to 8 do not show a constant increase or decrease pattern is that while the segment width gradually increases from group 1 to group 8, the number of segments in each group is limited to an integer, and the electrode thickness exhibits a slight variation along one winding direction. Consequently, the number of segments in a specific segment group can be reduced. Therefore, the widths of the groups can show an irregular pattern of change, as in the example above from the core to the outer circumference.

[0327] That is, assuming that the width in the winding direction for each of the three segment groups that are successively adjacent to each other in the circumferential direction of the electrode assembly is W1, W2 and W3 respectively, it is possible to include a combination of segment groups in which W3 / W2 is smaller than W2 / W1.

[0328] In this specific example, groups 4 to 6 correspond to the case above. The width ratio of group 5 to group 4 is 120 to 130%, and the width ratio of group 6 to group 5 is 100 to 120%, which is less than 120 to 130%.

[0329] According to another modification, if the uncoated section 43 of the electrode 60 has a segmented structure, the electrode 60 can include a segment-skipping region 64 in which some of the multitude of segments are regularly or irregularly omitted, as in Fig. 7g shown.

[0330] For example, the segment skip area 64 can be provided multiple times. In one example, the width of the segment skip area 64 can be constant from the core to the outer perimeter. In another example, the width of the segment skip area 64 can increase or decrease regularly or irregularly from the core to the outer perimeter. For example, the height of the uncoated section present in the segment skip area 64 can correspond to the height of the first section B1 and / or the second section B3.

[0331] The number of segments 61 that exist between the segment-skipping areas 64 can be at least one. As in Fig. As shown in Figure 7g, the electrode 60 can have an uncoated section in which the number of segments 61 that are present between the segment skipping regions 64 increases from the core to the outer circumference.

[0332] For example, the width of the segment skip area 64 can be set such that, when the electrode 60 is as in Fig. As shown in Figure 7h, segments located in each winding turn can be situated in a preset independent area 66 with respect to the core center C of the electrode assembly 65.

[0333] This means that the multitude of segments 61 can be located within a multitude of independent regions 66 with respect to the core center C when the electrode assembly 65 is viewed in the winding axis direction. The number of independent regions 66 can be changed to 2, 3, 4, 5, or the like.

[0334] For example, the independent region 66 may have a sectoral shape. In this case, the angle between the independent regions 66 may be essentially the same. Additionally, the inscribed angle (δ) of the independent region 66 may be 20 degrees or more, optionally 25 degrees or more, optionally 30 degrees or more, optionally 35 degrees or more, or optionally 40 degrees or more.

[0335] In a modified example, the independent region 66 can have a geometric shape, such as a square, a rectangle, a parallelogram, a trapezoid, or the like.

[0336] In the present disclosure, the form of segment 61 can be modified in different ways.

[0337] Fig. Figure 8a is a top view showing the structure of an electrode 70 according to the fifth.

[0338] With reference to Fig. 8a The electrode 70 of the fifth example has essentially the same configuration as that of the first example, except that the shape of segment 61' is different. Therefore, unless otherwise stated, the configuration of the fourth example can be applied equally to the fifth example.

[0339] Segment 61' has a geometric shape with essentially the same width at the top and bottom. For example, segment 61' can have a rectangular shape.

[0340] Fig. Figure 8b is a diagram showing the definition of the width, height and separation distance of the rectangular segment 61'.

[0341] With reference to Fig. 8b The width (D), height (H), and separation distance (P) of segment 61' can be adjusted to prevent abnormal deformation of the uncoated section 43, while sufficiently increasing the number of overlapping layers of the uncoated section 43 to prevent tearing during bending and to improve weld strength with a current collector. Abnormal deformation means that the uncoated section below the bending point does not maintain a straight state and collapses and deforms irregularly.

[0342] The width (D) of segment 61' is defined as the length between two points where two straight lines extending from both sides of segment 61' intersect a straight line extending from the lower section 63a of the cutting groove 63. The height (H) of segment 61' is defined as the shortest distance between the top side of segment 61' and the straight line extending from the lower section 63a of the cutting groove 63. The separation distance (P) of segment 61' is defined as the length between two points where the straight line extending from the lower section 63a of the cutting groove 63 intersects straight lines extending from two sides 63b connected to the lower section 63a.If page 63b and / or the lower section 63a is curved, the straight line can be replaced by a tangent line extending from page 63b and / or the lower section 63a at the point of intersection where page 63b and the lower section 63a meet.

[0343] For example, the conditions regarding the width (D), height (H), and separation distance (P) of segment 61' are essentially the same as those of the fourth example and are therefore not described again. However, since segment 61' has a rectangular shape, the lower interior angle of segment 61' can be constant at 90 degrees.

[0344] Similar to electrode 60 in the fourth example, electrode 70 according to the fifth example can also include a segment-skipping region 64 in which some of the multitude of segments are regularly or irregularly omitted, as in Fig. 8c shown.

[0345] Additionally, if the electrode 70, which includes the segment-skipping region 64, is wound in an electrode assembly, the segments can be located within a plurality of independent regions 66, as in Fig. Shown at 7h.

[0346] As in the fourth and fifth examples, if the third section B2 and the second section B3 contain a multitude of segments 61, 61', the shape of each segment 61, 61' can be modified differently.

[0347] For example, the segment can be deformed into different shapes as long as at least one of the following conditions is met.

[0348] Condition 1: The width of the lower section is greater than the width of the upper part.

[0349] Condition 2: The width of the lower section and the width of the upper part are the same.

[0350] Condition 3: The width remains the same from bottom to top.

[0351] Condition 4: The width decreases from bottom to top.

[0352] Condition 5: The width decreases and then increases from bottom to top.

[0353] Condition 6: The width increases and then decreases from bottom to top.

[0354] Condition 7: The width increases from bottom to top and remains constant.

[0355] Condition 8: The width decreases from bottom to top and remains constant.

[0356] Condition 9: The interior angle of one side of the lower section and the interior angle of the other side are equal.

[0357] Here, the interior angle can be defined as an angle formed by the side segment of the segment based on the latitude direction of the lower segment. If the side segment is curved, the interior angle is defined as the angle between a tangent line drawn at the bottom of the curve and the latitude direction of the lower segment.

[0358] Condition 10: The interior angle of one side of the lower section and the interior angle of the other side are different from each other.

[0359] Condition 11: The interior angle of one side of the lower section and the interior angle of the other side of the lower section are acute, right, or obtuse, respectively.

[0360] Condition 12: Symmetrical left and right with respect to the winding axis direction.

[0361] Condition 13: Left and right asymmetrical with respect to the winding axis direction.

[0362] Condition 14: The page section has a straight line shape.

[0363] Condition 15: The side section is curved.

[0364] Condition 16: The side segment is convex outwards.

[0365] Condition 17: The side section is convex inwards.

[0366] Condition 18: The corner of the upper section and / or the lower section has a structure where one straight line meets another straight line.

[0367] Condition 19: The corner of the upper section and / or the lower section has a structure where a straight line meets a curve.

[0368] Condition 20: The corner of the upper section and / or the lower section has a structure where one curvature meets another curvature.

[0369] Condition 21: The corner of the upper section and / or the lower section has a rounded structure.

[0370] Fig. Figure 9 is a diagram illustrating the shapes of segments according to modified examples from the present revelation.

[0371] As shown in the drawing, the segment can have various geometric shapes, with a dotted line connecting the lower sections of the cut grooves on both sides as the basis. The geometric figure has a structure in which one or more straight lines, one or more curves, or a combination thereof are connected. In one example, the segment can have a polygonal shape, a round shape, or various shapes combined with these.

[0372] In particular, the segment can have a left-right symmetrical trapezoidal shape (ⓐ); a left-right asymmetrical trapezoidal shape (ⓑ); a parallelogram shape (ⓒ); a triangular shape (ⓛ); a pentagonal shape (ⓚ); an arc shape (ⓔ); or an elliptical shape (ⓕ).

[0373] Since the shape of the segment does not correspond to the one in Fig. The shape shown in 9 is limited; it can be transformed into other polygonal shapes, other round shapes, or a combination thereof to satisfy at least one of the conditions 1 to 21 described above.

[0374] In the polygonal shapes ⓐ, ⓑ, ⓒ, ⓚ and ⓛ of the segment, the corner of the upper section and / or the lower section can be a shape where a straight line meets a straight line, or a round shape (see the enlarged view of the corner of the upper section and the lower section of shape ⓐ).

[0375] In the polygonal forms ⓐ, ⓑ, ⓒ, ⓚ, and ⓛ of the segment and the curved forms ⓔ and ⓕ of the segment, the interior angle (θ1) on one side of the lower section and the interior angle (θ2) on the other side can be equal or different, and the interior angle (θ1) on one side of the lower section and the interior angle (θ2) on the other side can be any acute angle, right angle, or obtuse angle, respectively. An interior angle is an angle at which the base and side of a geometric figure meet. If the side is a curve, the straight line can be replaced by a tangent line extending through the point where the base and side meet.

[0376] The shape of the side section of the segment with a polygonal shape can be modified in various ways.

[0377] In one example, the side section of the segment shape ⓐ can be transformed into an outwardly convex curve as in the shape ⓓ or into a curve embedded in the segment as in the shape ⓖ or ⓙ.

[0378] In another example, the side section of segment shape ⓐ can be transformed into a curved straight line inset into the segment, as in shape ⓗ or ⓘ. Although not shown, the side section of segment shape ⓐ can also be transformed into a curved straight line that is convex outwards.

[0379] In the segment shapes ⓓ, ⓖ, ⓙ, ⓗ and ⓘ, in which the side segment is modified differently, the interior angle (θ1) on one side of the lower segment and the interior angle (θ2) on the other side of it can be the same or different from each other, and the interior angle (θ1) of one side of the lower segment and the interior angle (θ2) on the other side of it can be any acute angle, right angle or obtuse angle.

[0380] The width of the segment can exhibit different change patterns from bottom to top.

[0381] In one example, the segment width can be kept constant from bottom to top (shape ⓒ). In another example, the segment width can gradually decrease from bottom to top (shapes ⓐ, ⓑ, ⓓ, ⓔ, ⓕ, and ⓖ). In yet another example, the segment width can gradually decrease from bottom to top and then increase (shapes ⓘ and ⓙ). In another example, the segment width can gradually increase from bottom to top and then decrease (shape ⓚ). In yet another example, the segment width can gradually decrease from bottom to top and then be kept constant (shape ⓗ). Although not shown, the segment width can gradually increase from bottom to top and then be kept constant.

[0382] Meanwhile, among the forms of the in Fig. The nine segments shown are polygonal shapes with a flat top that can be rotated 180 degrees. In one example, if the segment shape ⓐ, ⓑ, ⓓ, or ⓖ is rotated 180 degrees, the width of the segment can gradually increase from bottom to top. In another example, if the segment shape ⓗ is rotated 180 degrees, the width of the segment can be kept constant from bottom to top and then gradually increase.

[0383] In the above examples (modifications), according to another aspect of the present disclosure, it is possible to modify the shapes of segments 61, 61' differently depending on the region of the third section B2. In one example, a circular shape (e.g., semicircle, ellipse, etc.) that is advantageous for the stress distribution is applied to a region where the stress is concentrated, and a polygonal shape (e.g., a rectangle, trapezoid, parallelogram, etc.) with the largest area can be applied to a region where the stress is relatively low.

[0384] In the examples above (modifications), the segment structure of the third section B2 can also be applied to the first section B1. However, if the segment structure is applied to the first section B1, when segments 61, 61' of the third section B2 are bent according to the radius of curvature of the core, the end of the first section B1 can be bent towards the outer circumference, a phenomenon known as inversion forming. Therefore, the first section B1 does not have a segment, or even if the segment structure is applied to the first section B1, it is desirable to control the width and / or height and / or separation distance of segments 61, 61' as small as possible, taking into account the radius of curvature of the core, so that no inversion forming occurs.

[0385] According to yet another aspect of the present disclosure, the segments exposed at the upper and lower sections of the electrode assembly can be overlapped in several layers along the radial direction of the electrode assembly after the electrode 60, 70 has been wound into an electrode assembly to form a bending surface area.

[0386] Fig. Figure 10a is a schematic diagram showing a cross-section of the bending surface area F formed when segment 61 is bent towards the core C of the electrode assembly 80. Fig. Figure 10a is shown only on the left side of the cross-section of the bending surface area F with respect to the winding axis of the electrode assembly 80. The bending surface area F can be formed on both the upper and lower sections of the electrode assembly 80. Fig. Figure 10b is a perspective top view schematically showing the electrode assembly 80, on which the bending surface area F is formed.

[0387] With reference to Fig. 10a and Fig. In Figure 10b, the bending surface region F has a structure in which the segments 61 overlap in several layers along the winding axis direction. The overlap direction is the winding axis direction (Y). Region ① is a segment-skipping region (the first section B1) that does not contain a segment, and regions ② and ③ are regions containing the winding turn that encompasses the segment 61. Region ② is a height-variable region in which the height of the segment 61 is variable, and region ③ is a height-uniform region in which the height of the segment is kept uniform with respect to the outer circumference of the electrode assembly. As will be described later, the radial lengths of region ② and region ③ can be variable. Meanwhile, the uncoated section (the second section B3), which is contained in at least one winding turn with the outermost winding turn, cannot contain a segment structure.In this case, the second section B3 may be excluded from area ③.

[0388] In area ②, the heights of segments 61 can be gradually increased from the minimum height h1 (= hmin) to the maximum height h n (= h max ) in the radius range from r1 to r n The electrode assembly 80 can be modified. The height-variable range, in which the heights of the segments 61 are variable, is r1 to r n . From radius r n Up to the radius R of the electrode assembly 80, the heights of the segments 61 are uniform at h n maintained. Uniform height means that the height deviation is within 5%.

[0389] At any radial point in region 2 and region 3, the number of overlapping layers of segments 61 varies depending on the radial point. Additionally, the number of overlapping layers of segments 61 can be determined based on the width of region 2, the minimum height (h1), and the maximum height (h). N -1) the segments in the height-variable area of ​​segment 61 and the height change amount (Δh) of segments 61 vary. The number of overlapping layers of segments 61 is the number of segments that intersect a virtual line when the virtual line is drawn in the winding axis direction at any radial location of the electrode assembly 80.

[0390] For example, the number of overlapping layers of segments 61 at each position of the bending surface area F can be optimized to suit the required weld strength of the current collector by adjusting the height, width and separation distance of segment 61 according to the radius of the winding turn containing segment 61.

[0391] First, if the minimum height (h1) of the segment in the height-variable area (②) of segment 61 is the same, specific examples are given to describe how the number of overlapping layers of segments 61 along the radial direction of the bending surface area F is changed according to the change in the maximum height III of segment 61.

[0392] The electrode assemblies of Examples 1-1 to 1-7 are manufactured. The electrode assemblies of these examples have a radius of 22 mm and a core diameter of 4 mm. The positive and negative electrodes contained in the electrode assembly have the properties shown in Fig. The electrode structure shown in Figure 7a is as follows. That is, the segment has a trapezoidal shape. The second section B3 of the positive and negative electrodes has no segment. The length of the second section B3 is 2% to 4% of the total electrode length. The positive electrode, the negative electrode, and the separator are connected by the structure shown in Figure 7a. Fig. The two described methods are wound. The number of winding turns ranges from 48 to 56, while the winding turns in these examples are 51. The thicknesses of the positive electrode, the negative electrode, and the separator are 149 µm, 193 µm, and 13 µm, respectively. The thickness of the positive and negative electrodes includes the thickness of the active material layer. The thickness of the current collector plate of the positive electrode and the current collector plate of the negative electrode are 15 µm and 10 µm, respectively. The lengths of the positive and negative electrodes in the winding direction are 3948 mm and 4045 mm, respectively.

[0393] In each example, the minimum height of segment 61 is set to 3 mm, so the height-variable area (②) of segment 61 starts at a radius of 5 mm. Furthermore, in each example, the height of segment 61 is increased by 1 mm for every 1 mm increase in radius, and the maximum height of segment 61 is varied from 4 mm to 10 mm.

[0394] Specifically, in Example 1-1, the height-variable range (②) of segment 61 is 5 mm to 6 mm, and the height of segment 61 is variable with a radius of 3 mm to 4 mm. In Example 1-2, the height-variable range (②) of segment 61 is 5 mm to 7 mm, and the height of segment 61 is variable from 3 mm to 5 mm. In Example 1-3, the height-variable range (②) of segment 61 is 5 mm to 8 mm, and the height of segment 61 is variable from 3 mm to 6 mm. In Example 1-4, the height-variable range (②) of segment 61 is 5 mm to 9 mm, and the height of segment 61 is variable from 3 mm to 7 mm. In Example 1-5, the height-variable range (②) of segment 61 is 5 mm to 10 mm, and the height of segment 61 is variable from 3 mm to 8 mm. In Example 1-6, the height-variable range (②) of segment 61 is 5 mm to 11 mm, and the height of segment 61 is variable from 3 mm to 9 mm.In Example 1-7, the height-variable range (②) of segment 61 is 615 mm to 12 mm, and the height of segment 61 is variable from 3 mm to 10 mm. In Examples 1-1 to 1-7, the height of segment 61 is uniform from the radius corresponding to the upper limit of the height-variable range (②) to the outer circumference. In one example, in Example 1-7, the height of segment 61, which is located within a radius of 12 mm to 22 mm, is a uniform 10 mm. Meanwhile, in the electrode assembly of the comparison example, the height of segment 61 is maintained at a single height of 3 mm from the radius of 5 mm to the radius of 22 mm.

[0395] Fig. Figure 10c is a diagram showing the results of counting the number of overlapping layers of the segments along the radial direction in the flexural area F of the positive electrode formed on the upper section of the electrode assemblies, according to Examples 1-1 to 1-7 and the comparison example. The flexural area of ​​the negative electrode shows essentially the same result. The horizontal axis of the diagram is the radius based on the core center, and the vertical axis of the diagram is the number of overlapping layers counted at each radius point, and it is the same in the Fig. 10d and Fig. 10e, which will be explained later.

[0396] With reference to Fig. 10c is the uniform area b1 of the number of overlapping layers of the segment, usually shown in Examples 1-1 to 1-7 and Comparative Example 1. The uniform area b1 of the number of overlapping layers is a radial portion of a flat area in each diagram. The length of the uniform area b1 of the number of overlapping layers increases as the maximum height of the segment decreases, and the uniform area (b1') of the number of overlapping layers in Comparative Example 1 is the longest. Meanwhile, the number of overlapping layers of the segments increases as the maximum height III of the segment increases. That is, as the maximum height III of the segment increases, thus increasing the width of the height-variable area (②) of the segment, the number of overlapping layers of the segments increases, but the width of the uniform area b1 of the number of overlapping layers decreases.On the outer side of region b1 with a uniform number of overlapping layers, region b2 with a decreasing number of overlapping layers appears, in which the number of overlapping layers decreases as the radius increases. Region b2 with a decreasing number of overlapping layers is a radial region in which the number of overlapping layers decreases as the radius of the electrode assembly increases. Region b1 with a uniform number of overlapping layers and region b2 with a decreasing number of overlapping layers are radially adjacent and complementary. That is, if the length of one region increases, the length of the other region decreases. Furthermore, the magnitude of the decrease in the number of overlapping layers in region b2 with a decreasing number of overlapping layers is proportional to the distance it is from region b1 with a uniform number of overlapping layers.

[0397] From the perspective of the number of overlapping layers of the segments, in Examples 1-1 to 1-7, the number of overlapping layers of the segments is 10 or more in region b1 with a uniform number of overlapping layers. A region in which the number of overlapping layers of segments is 10 or more can be set as a preferred welding target region. The welding target region is a region in which at least part of the current collector can be welded.

[0398] In examples 1-1 to 1-7, the area b1 with a uniform number of overlapping layers begins at a radius point where the height-variable area (②) of the segment begins. That is, the height-variable area (②) starts at a radius of 5 mm and extends to the outer circumference.

[0399] The following Table 4 shows, in examples 1-1 to 1-7 and comparison example 1 for the positive electrode, calculation results of a ratio of the length of the segment jump region (c, ① in Fig. 10a) to the radius (ba) of the electrode assembly excluding the core, a ratio (e / f) of the length of the uniform area b1 of the number of overlapping layers to the length (f) from the radius point (5 mm) where the uniform area of ​​the number of overlapping layers begins to an outermost point of the electrode assembly (22 mm), a ratio (d / f) of the length of the height-variable area (d) of segment (d) to the length (f) from the radius point (5 mm) where the uniform area of ​​the number of overlapping layers begins to the outermost point (22 mm) of the electrode assembly, a ratio (h) of the length of the electrode area corresponding to the segment jump area (first section B1) to the total length of the electrode, a ratio (i) of the length of the electrode area corresponding to the height-variable area to the total length of the electrode, a ratio (j) of the electrode area corresponding to the height-uniform area,regarding the total length of the electrode and the like.

[0400] Except that the negative electrode has a difference of 0.1 to 1.2% with respect to parameter h, the remaining parameters are essentially the same as for the positive electrode. The sum of the components h, i, and j differs slightly from 100%. This is because there is a region that lacks a segment in the second section B3, corresponding to the outer circumferential uncoated section of the electrode. For example, in Example 1-1, there is no segment in the second section B3, which corresponds to approximately 4% of the total electrode length. In Table 4, a to f are parameters based on the length in the radial direction, and h, i, and j are parameters based on the length in the longitudinal direction of the electrode before it is wound into an electrode assembly. Additionally, the parameters corresponding to the ratio (%) are values ​​rounded to one decimal place.These points are essentially the same as those in Tables 5 and 6, which will be explained later.

[0401] As can be seen in Examples 1-1 to 1-7 of Table 4, the number of overlapping layers of segments ranges from 11 to 26, and the ratio (d / f) of the height-variable area (d) to the radius area (f) containing the segment ranges from 6% to 41%. Furthermore, the ratio (e / f) of the area (e) with a uniform number of overlapping layers to the radius area (f) containing the segment ranges from 47% to 82%. Additionally, the ratio (c / (ba)) of the segment-skipping area (c, ① in Fig. 10a) to the radius (ba) of the electrode assembly, excluding the core, is 15%. Furthermore, the ratio of the length of the electrode area corresponding to the segment-skipping region (first section B1) to the total length of the electrode is 6%, the ratio of the length of the electrode area corresponding to the height-variable region to the total length of the electrode is 3% to 32%, and the ratio of the length of the electrode area corresponding to the height-uniform region to the total length of the electrode is 59% to 87%.

[0402] The number of overlapping layers (g) in the uniform overlap layer count area is 10 or more for all examples 1-1 to 1-7. The uniform overlap layer count area (e) decreases as the variable height area (d) of the segment increases, but the number of overlapping layers (g) of the segments increases in the uniform overlap layer count area (e). For example, the uniform overlap layer count area (e) where the number of overlapping layers (g) of the segments is 10 or more can be set as a weld target area.

[0403] In the cylindrical battery with form factors of 1865 and 2170, the radius of the electrode assembly is approximately 9 mm to 10 mm. Therefore, for a conventional cylindrical battery, the radial length of the segment region (f) cannot be guaranteed at a height of 17 mm as in Examples 1-1 to 1-7, and the length of the region (e) with a uniform number of overlapping layers, where the number of overlapping layers of the segments is 10 or more, cannot be guaranteed at a height of 8 mm to 14 mm. This is because, in the conventional cylindrical battery, if the core radius is 2 mm, which is the same as in Examples 1-1 to 1-7, the radial area in which the segments can be arranged is essentially only 7 mm to 8 mm. Furthermore, in the conventional cylindrical battery, the electrode length in the winding direction is 600 mm to 980 mm.Such a short electrode length is only about 15% to 24% of the length of the electrode used in Examples 1-1 to 1-7 (the positive electrode of 3948 mm, the negative electrode of 4045 mm). Accordingly, the numerical ranges for the parameters h, i, and j cannot be easily derived from the design specifications of the conventional cylindrical battery.

[0404] Next, concrete examples will explain how the number of overlapping layers of the segments in the radial direction of the bending surface area F changes according to the change in the minimum height (h1) of the segment when the maximum height (h) N ) of the segment in the height-variable area of ​​the segment is equal (② in Fig. 10a).

[0405] The electrode assemblies of Examples 2-1 to 2-5 have a radius of 22 mm and the core C has a diameter of 4 mm. In the height-variable area of ​​segment 61 (② in Fig. 10a) the minimum height (h1) is equal to 4 mm and the maximum height (h N ) is changed by 1 mm from 6 mm to 10 mm. Therefore, in the electrode assemblies of Examples 2-1 to 2-5, the width of the height-variable area (② in Fig. 10a) of the segment 2 mm, 3 mm, 4 mm, 5 mm or 6 mm and the segment skip area (① of Fig. 10a) is a radial area with a radius of 2 mm to 6 mm.

[0406] The electrode assemblies of Examples 3-1 to 3-4 have a radius of 22 mm and the core C has a diameter of 4 mm. In the height-variable area (② of Fig. 10a) of segment 61 the minimum height (h1) is equal to 5 mm and the maximum height (h N ) is changed by 1 mm from 7 mm to 10 mm. Therefore, in the electrode assemblies of Examples 3-1 to 3-4, the width of the height-variable area (② in Fig. 10a) of the segment 2 mm, 3 mm, 4 mm or 5 mm and the segment skip area (① in Fig. 10a) is a radial area with a radius of 2 mm to 7 mm.

[0407] The electrode assemblies of Examples 4-1 to 4-3 have a radius of 22 mm and the core C has a diameter of 4 mm. In the height-variable area (② in Fig. 10a) of segment 61, the minimum height (h1) is 6 mm and the maximum height (h) is changed by 1 mm from 8 mm to 10 mm. Therefore, in the electrode assemblies of Examples 4-1 to 4-3, the width of the height-variable area ② is Fig. 10a) of the segment 2 mm, 3 mm or 4 mm and the segment skip area (① in Fig. 10a) is a radius range with a radius of 2 mm to 8 mm.

[0408] The electrode assemblies of Examples 5-1 to 5-2 have a radius of 22 mm and the core C has a diameter of 4 mm. In the height-variable area (② in Fig. 10a) of segment 61 the minimum height (h1) is equal to 7 mm and the maximum height (hN ) is changed by 1 mm from 9 mm to 10 mm. Therefore, in the electrode assemblies of Examples 5-1 to 5-2, the width of the height-variable area ② is Fig. 10a) of the segment 2 mm or 3 mm and the segment skip area (① in Fig. 10a) is a radius range with a radius of 2 mm to 9 mm.

[0409] Fig. Figure 10d is a diagram showing the results of counting the number of overlapping layers of segments along the radial direction in the flexural area F of the positive electrode formed on the upper section of the electrode assemblies of Examples 2-1 to 2-5, Examples 3-1 to 3-4, Examples 4-1 to 4-3, and Examples 5-1 to 5-2. The flexural area of ​​the negative electrode also shows essentially the same results.

[0410] In Fig. 10d shows diagram (a) the result of counting the number of overlapping layers of the segments along the radial direction in the bending surface area F for examples 2-1 to 2-5, diagram (b) shows the result for examples 3-1 to 3-4, diagram (c) shows the result for examples 4-1 to 4-3 and diagram (d) shows the result for examples 5-1 to 5-2.

[0411] With reference to Fig. In 10d, the uniform area b1 of the number of overlapping layers of the segment appears common in all examples. The uniform area b1 of the number of overlapping layers is a radial region of a flat area in the diagram. The length of the uniform area b1 of the number of overlapping layers increases as the maximum height (h) NThe length of the segment decreases when the minimum height (h1) of the segment is the same. Furthermore, the length of the uniform area b1 increases with the number of overlapping layers when the minimum height (h1) of the segment decreases when the maximum height (h) is the same. N ) of the segment is equal. Meanwhile, in the uniform area b1, the number of overlapping layers of the segments increases when the maximum height (h) N ) of the segment increases. Furthermore, in the examples, area b2 with a decreasing number of overlap layers appears next to area b1 with a uniform number of overlap layers.

[0412] In the examples, the number of overlapping layers of the segments in area b1 with a uniform number of overlapping layers is always 10 or more. For example, the area in which the number of overlapping layers of segments is 10 or more can be set as a preferred weld target area.

[0413] In the examples, area b1 begins with a uniform number of overlapping layers at a radial point where the height-variable area (② in Fig. 10a) of the segment begins. In examples 2-1 to 2-5, the height-variable area (② in Fig. 10a) of the segment at 6 mm and extends to the outer circumference. In examples 3-1 to 3-4, the height-variable area (② in Fig. 10a) of the segment at 7 mm and extends to the outer circumference. In examples 4-3 to 4-3, the height-variable area (② in Fig. 10a) of the segment at 8 mm and extends to the outer circumference. In examples 5-1 to 5-2, the height-variable area (② in Fig. 10a) of the segment at 9 mm and extends to the outer circumference.

[0414] The following Table 5 shows the results of calculating various parameters, such as a ratio (e / f) of the length of the uniform area of ​​the number of overlapping layers to the length from the radius point (6 mm, 7 mm, 8 mm, 9 mm) where the uniform area of ​​the number of overlapping layers begins to the outermost point (22 mm) of the electrode assembly, a ratio (d / f) of the length of the height-variable area (②) to the length from the radius point (6 mm, 7 mm, 8 mm, 9 mm) where the uniform area of ​​the number of overlapping layers begins to the outermost point (22 mm) of the electrode assembly, and the like for Examples 2-1 to 2-5, Examples 3-1 to 3-4, Examples 4-1 to 4-3 and Examples 5-1 to 5-2.

[0415] See Example 2-5, Example 3-4, Example 4-3 and Example 5-2 from Table 5 together with the Fig. 10a and Fig. 10d, is the maximum height (h N The length (h1) of the segment in the height-variable area (②) of the segment is 10 mm, but the minimum height (h1) of the segment increases by 1 mm to 4 mm, 5 mm, 6 mm, and 7 mm, and the length of the height-variable area (②) decreases by 1 mm to 6 mm, 5 mm, 4 mm, and 3 mm. In the four examples, the ratio (e / f) of the uniform area to the number of overlapping layers is the maximum in example 2-5 (69%) and the minimum in example 5-2 (38%), and the number of overlapping layers in the uniform area is the same in all examples.

[0416] From the results shown in Table 5, when the maximum height (h NSince the length (h1) of the segment is constant and the minimum height (h1) of the segment decreases, it follows that the width of the uniform area increases proportionally to the number of overlapping layers as the width of the height-variable area (②) of the segment increases. This is because, when the minimum length (h1) of the segment is smaller, the radial point where the segment begins is closer to the core, so the area where the segments are stacked extends towards the core.

[0417] As shown in Table 5, the number of overlapping layers of segments ranges from 16 to 26, the ratio (d / f) of the height-variable area (②) of the segment ranges from 13% to 38%, and the ratio (e / f) of the area with a uniform number of overlapping layers ranges from 31% to 69%. Furthermore, the ratio (c / (ba)) of the segment-skipping area (①) to the radius (ba) of the electrode assembly, excluding the core, ranges from 20% to 35%. Furthermore, the ratio of the length of the electrode area corresponding to the segment-skipping region (①) to the total length of the electrode is 10% to 20%, the ratio of the length of the electrode area corresponding to the height-variable region (②) to the total length of the electrode is 6% to 25%, and the ratio of the length of the electrode area corresponding to the height-uniform region (③) to the total length of the electrode is 62% to 81%.

[0418] For the cylindrical battery form factors of 1865 and 2170, the electrode assembly radius is approximately 9 mm to 10 mm. Therefore, it is impossible to ensure the radial length of the segment region (f) at a height of 13 mm to 16 mm, as in the examples, and it is impossible to ensure the length of the segment-skipping region (c, ①) at a height of 4 mm to 7 mm, while ensuring the length of the region (e) with a uniform number of overlapping layers, where the number of overlapping layers of the segments is 10 or more, at a height of 5 mm to 11 mm. This is because, in the conventional cylindrical battery, if the core radius is 2 mm, which is the same as in the examples, the radial area in which the segments can be arranged is essentially only 7 mm to 8 mm. Furthermore, in a conventional cylindrical battery, the length of the electrode in the winding direction is 600 mm to 980 mm.In the examples, such a short electrode length is only about 15% to 24% of the total electrode length (the positive electrode being 3948 mm, the negative electrode 4045 mm). Accordingly, the numerical ranges for the parameters h, i, and j cannot be easily derived from the design specifications of the conventional cylindrical battery.

[0419] Next, specific examples will explain how the number of overlapping layers of the segments is changed according to the diameter of the core C of the electrode assembly along the radial direction of the bending surface area F when the minimum height (h1) and the maximum height (h) N ) of the segment in the height-variable area (②) of the segment are equal.

[0420] The electrode assemblies of Examples 6-1 to 6-6 have a radius of 22 mm, and core C has a radius of 4 mm. In the height-variable region (②) of segment 61, the minimum height (h1) of the segment is 3 mm, and the maximum height (h) N The width of the segment is changed by 1 mm from 5 mm to 10 mm. Therefore, in the electrode assemblies of Examples 6-1 to 6-6, the width of the height-variable area (②) of the segment is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 7 mm, respectively, and the segment-skipping area (①) is a radial area with a radius of 4 mm to 7 mm.

[0421] The electrode assemblies of Examples 7-1 to 7-6 have a radius of 22 mm, and core C has a radius of 2 mm. In the height-variable region (②) of segment 61, the minimum height (h1) of the segment is 3 mm, and the maximum height (h) NThe width of the segment is changed by 1 mm from 5 mm to 10 mm. Therefore, in the electrode assemblies of Examples 7-1 to 7-6, the width of the height-variable area (②) of the segment is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 7 mm respectively, and the segment-skipping area (①) is a radial area with a radius of 2 mm to 5 mm.

[0422] Fig. Figure 10e is a diagram showing the results of counting the number of overlapping layers of the segments along the radial direction in the flexural area F of the positive electrode formed on the upper section of the electrode assembly for Examples 6-1 to 6-6 and Examples 7-1 to 7-6. Essentially the same results are shown in the flexural area of ​​the negative electrode.

[0423] In Fig. 10e shows diagram (a) the results of counting the number of overlapping layers of segments along the radial direction in the bending surface area F for examples 6-1 to 6-6 and diagram (b) shows the results for examples 7-1 to 7-6.

[0424] With reference to Fig. 10e The uniform area b1 of the number of overlapping layers of the segment appears common in all examples. The uniform area b1 of the number of overlapping layers is a radial region of a flat area in the diagram. The radial length of the uniform area b1 of the number of overlapping layers increases as the maximum height (h) N The number of overlapping layers of the segment decreases when the minimum height (h1) of the segment is equal to the minimum height (h1). Meanwhile, in the uniform area b1, the number of overlapping layers of the segments increases when the maximum height (h1) is equal to the minimum height (h1). NThe number of overlapping layers in the segment increases. In the examples, area b2 with a decreasing number of overlapping layers appears next to area b1 with a uniform number of overlapping layers.

[0425] In the examples, the number of overlapping layers of the segments in area b1 with a uniform overlap layer count is 10 or more for all examples. For instance, an area where the number of overlapping layers of segments is 10 or more can be set as a preferred weld target area.

[0426] In the examples, area b1 with a uniform number of overlapping layers begins at a radius point where the height-variable area (②) of the segment begins. In examples 6-1 to 6-6, the radius at which the area (②) with variable segment height begins is 7 mm, and in examples 7-1 to 7-6, the radius at which the area (②) with variable segment height begins is 5 mm.

[0427] The following Table 6 shows the results of the calculation of various parameters, including a ratio (e / f) of the length of the area with a uniform number of overlapping layers to the length from the radius point (7 mm, 5 mm) where the area with a uniform number of overlapping layers begins to the outermost point (22 mm) of the electrode assembly, a ratio (d / f) of the length of the height-variable area (②) to the length from the radius point (7 mm, 5 mm) where the area with a uniform number of overlapping layers begins to the outermost point (22 mm) of the electrode assembly, for Examples 6-1 to 6-6 and Examples 7-1 to 7-6 and the like.

[0428] Taking into account examples 6-6 and 7-6 in Table 6 together with Fig. 10a are the minimum height (h1) and the maximum height (h NThe radius of the segment in the height-variable area (②) of the segment is 3 mm or 10 mm, respectively. However, in Example 6-6, the radius of the core is 2 mm larger compared to that of Example 7-6. Therefore, in Example 6-6, the uniform area (e) of the number of overlapping layers and the segment area (f) are 2 mm smaller compared to those of Example 7-6, and the number of overlapping layers of the segments in the uniform area is the same. These results are derived from the difference in the radius of the core. From the results shown in Table 6, it is clear that when the width of the height-variable area (②) of the segment is the same because the radius (a) of the core is smaller, the ratio (d / f) of the height-variable area (②) decreases, while the ratio (e / f) of the uniform area of ​​the number of overlapping layers increases.

[0429] As shown in Table 6, the number of overlapping layers of segments ranges from 13 to 26, the ratio (d / f) of the height-variable area (②) ranges from 12% to 47%, and the ratio (e / f) of the length of the area with a uniform number of overlapping layers ranges from 40% to 76%. Furthermore, the ratio (c / (ba)) of the segment-skipping area (①) to the radius (ba) of the electrode assembly, excluding the core, ranges from 15% to 17%. Furthermore, the ratio of the length of the electrode area corresponding to the segment-skipping region (①) to the total length of the electrode is 6%, the ratio of the length of the electrode area corresponding to the height-variable region (②) to the total length of the electrode is 7% to 32%, and the ratio of the length of the electrode area corresponding to the height-uniform region (③) to the total length of the electrode is 59% to 83%.

[0430] For cylindrical batteries with form factors of 1865 and 2170, the electrode assembly radius is approximately 9 mm to 10 mm. Therefore, it is impossible to ensure the radial length of the segment region (f) at a height of 15 mm to 17 mm, the length of the segment overlap region (①) at a height of approximately 3 mm, and simultaneously ensure the length of the region (e) with a uniform number of overlapping layers, where the number of overlapping segment layers is 10 or more, at a height of 6 mm to 13 mm, as in the examples. This is because, in a conventional cylindrical battery, when the core radius is 2 mm to 4 mm, which is the same as in the examples, the radial area in which the segments can be arranged is essentially only 5 mm to 8 mm. Furthermore, in a conventional cylindrical battery, the length of the electrode in the winding direction is 600 mm to 980 mm.In the examples, such a short electrode length is only about 15% to 24% of the total electrode length (the positive electrode being 3948 mm, the negative electrode 4045 mm). Accordingly, the numerical ranges for the parameters h, i, and j cannot be easily derived from the design specifications of the conventional cylindrical battery.

[0431] Taking into full consideration the data in Tables 4 to 6, the number of overlapping layers of the segments in the uniform area can range from 11 to 26. Furthermore, the ratio (d / f) of the height-variable area (②) of the segment can range from 6% to 47%. Additionally, the ratio (e / f) of the area with a uniform number of overlapping layers can range from 31% to 82%. Furthermore, the ratio (c / (ba)) of the length of the segment-skipping area (①) to the radius of the electrode assembly, excluding the core, can range from 15% to 35%. Finally, the ratio of the length of the electrode area corresponding to the segment-skipping area (①) to the total length (in the winding direction) of the electrode can range from 6% to 20%. Furthermore, the ratio of the length of the electrode area corresponding to the height-variable area (②) of the segment to the total length of the electrode can be 3% to 32%.Furthermore, the ratio of the length of the electrode area corresponding to the height unit area (③) of the segment to the total length of the electrode can be 59% to 87%.

[0432] Meanwhile, the parameters described in Tables 4 to 6 can be varied according to design factors, including the radius (a) of the core; the radius (b) of the electrode assembly; the minimum height (h1) and the maximum height (h2). N ) in the height-variable area (②) of the segment; the amount of change (Δh) of the height of the segment per 1 mm increase in radius; the thickness of the positive electrode, the negative electrode and the separator; and the like.

[0433] Therefore, within the uniform range of overlapping layers of the segment, the number of overlapping layers can be increased to 10 to 35. The ratio (d / f) of the height-variable area (②) of the segment can be increased to 1% to 50%. Furthermore, the ratio (e / f) of the area with a uniform number of overlapping layers can be increased to 30% to 85%. Additionally, the ratio (c / (ba)) of the length of the segment-skipping area (①) to the radius of the electrode assembly, excluding the core, can be increased to 10% to 40%. Finally, the ratio of the length of the electrode area corresponding to the segment-skipping area (①) to the total length (in the winding direction) of the electrode can be increased to 1% to 30%. Furthermore, the ratio of the length of the electrode area corresponding to the height-variable area (②) of the segment to the total length of the electrode can be increased to 1% to 40%.Furthermore, the ratio of the length of the electrode area corresponding to the height-unit region (③) of the segment to the total electrode length can be increased to 50% to 90%. In the examples above, the height index N is located at the maximum height (h). N ) of the segment in the height-variable region (②) and the height-united region (③) in the range of 2 to 8. For example, the height index N for Examples 1-1 and 1-7, with reference to Table 4, is 2 and 8, respectively. However, the height index N can vary according to the amount of height change (“h”) of the segment in a radial direction of the electrode assembly. If the radial length of the height-variable region (②) is fixed, the height index N increases accordingly, and conversely, if the amount of height change (“h”) of the segment decreases. For example, the height index N can be extended to the range of 2 to 20 and optionally further to the range of 2 to 30.

[0434] In the bending surface area F, which is formed on the top and bottom of the electrode assembly, the area with a uniform number of overlap layers can be used as a welding target area of ​​the current collector.

[0435] For example, the welding area of ​​the current collector overlaps the area with a uniform number of overlap layers in the radial direction of the electrode assembly by at least 50%. A higher overlap ratio is preferred here.

[0436] For example, the remaining area of ​​the current collector's welding area that does not overlap the area with a uniform number of overlap layers may overlap the area with a decreasing number of overlap layers next to the area with a uniform number of overlap layers in the radial direction.

[0437] Preferably, the remaining area of ​​the current collector's welding area, which does not overlap the area with a uniform number of overlapping layers, can overlap an area of ​​the area with a decreasing number of overlapping layers, in which the number of overlapping layers of segments is 10 or more.

[0438] When the current collector is welded to an area where the number of overlapping segment layers is 10 or more, this method is preferable with regard to weld strength and preventing damage to the separator or active material layer during welding. It is particularly advantageous when welding the current collector using a high-power laser with high penetration properties.

[0439] When the area with a uniform number of overlapping layers, in which 10 or more segments are stacked, is laser-welded to the current collector, even if the laser power is increased to improve the weld quality, the area with the uniform number of overlapping layers absorbs most of the laser energy to form weld beads, thus preventing damage to the separator and the active material layer under the bending surface area F by the laser.

[0440] Additionally, in the laser-irradiated area, the number of overlapping segment layers is 10 or more, ensuring the formation of weld beads with sufficient volume and thickness. Consequently, adequate weld strength can be guaranteed, and the resistance of the weld interface can be reduced to a level suitable for fast charging.

[0441] When welding the current collector, the laser power can be determined by the desired weld strength between the bending surface area F and the current collector. The weld strength increases proportionally to the number of overlapping segment layers. This is because, with an increasing number of overlapping layers, the volume of weld beads formed by the laser also increases. These weld beads are formed when the current collector material and the segment material fuse together. Therefore, a larger volume of weld beads results in a stronger coupling between the current collector and the bending surface area, and the contact resistance of the weld interface is reduced.

[0442] For example, the weld strength can be 2 kgf / cm². 2 or more, preferably 4 kgf / cm² 2or more. The maximum weld strength can depend on the power of a laser welding device. As an example, the weld strength can preferably be set to 8 kgf / cm². 2 or less, preferably 6 kgf / cm² 2 or less, but the present invention is not limited to that.

[0443] If the weld strength meets the above numerical range, the physical properties of the weld interface will not deteriorate, even if strong vibrations act on the electrode assembly along the winding axis direction and / or the radial direction, whereby the resistance of the weld interface may also be reduced due to the sufficient volume of the weld beads.

[0444] The laser power required to meet the weld strength requirement varies depending on the laser equipment and can be appropriately adjusted in the range of 250 W to 320 W or 40% to 100% of the maximum laser power specification provided by the respective equipment.

[0445] Weld strength can be expressed as tensile strength per unit area (kgf / cm²). 2The weld strength of the current collector is defined as the point at which the current collector begins to detach from the bending surface area F. Specifically, after the current collector is fully welded, a tensile force can be applied to the current collector, but the magnitude of the tensile force can be gradually increased. When the tensile force exceeds a threshold, the segment begins to detach from the weld interface. At this point, the value obtained by dividing the tensile force applied to the current collector by the area of ​​the current collector corresponds to the weld strength.

[0446] In the bending surface area F, segments are stacked in multiple layers, and according to the examples above, the number of overlapping layers of segments can be increased from a minimum of 10 sheets to a maximum of 35 sheets.

[0447] The thickness of the current collector with the positive electrode (foil), which forms an uncoated section 43, can range from 10 µm to 25 µm, and the thickness of the current collector with the negative electrode (foil), which forms an uncoated section 43, can range from 5 µm to 20 µm. Therefore, the bending area F of the positive electrode can encompass a range in which the total overlap thickness of the segments is 100 µm to 875 µm. Furthermore, the bending area F of the negative electrode can encompass a range in which the total overlap thickness of the segments is 50 µm to 700 µm.

[0448] Fig. Figure 10f is a top view showing an electrode assembly in which the uniform area b1 of the number of overlapping layers and the decreasing area b2 of the number of overlapping layers in the bending surface area F of segments 61, 61' are shown according to an example.

[0449] With reference to Fig. 10f corresponds to the area between two circles indicated by thick solid lines, the bending area area F of the segment, and the area between two circles indicated by dashed lines corresponds to the uniform area b1 of the number of overlapping layers, in which the number of overlapping layers of the segments is 10 or more, and the outer area of ​​the uniform area b1 of the number of overlapping layers corresponds to the decreasing area b2 of the number of overlapping layers.

[0450] In one example, when the current collector (Pc) is welded to the bending surface area F, a weld pattern (Wp) is formed on the surface of the current collector (Pc). The weld pattern (Wp) can be a line pattern or a dot pattern. The weld pattern (Wp) corresponds to the weld area and can overlap the area with a uniform overlap layer count b1 of the segment by 50% or more along the radial direction. Accordingly, part of the weld pattern (Wp) can be contained within the area b1 with a uniform overlap layer count, and the remainder of the weld pattern (Wp) can be contained within the area b1 with a decreasing overlap layer count outside the area b1 with a uniform overlap layer count. Naturally, the entire weld pattern (Wp) can overlap the area with a uniform overlap layer count b1 to maximize weld strength and reduce resistance in the weld area.

[0451] The area of ​​the bending surface region F can be defined as the sum of the area of ​​the region with a uniform number of overlap layers b1 of the segment and the area of ​​the region with a decreasing number of overlap layers b2. Since the ratio (e / f) of the region with a uniform number of overlap layers b1 is 30% to 85%, preferably 31% to 82%, the ratio of the area of ​​the region with a uniform number of overlap layers b1 to the area of ​​the bending surface region F can be 9% (302 / 1002) to 72% (852 / 1002), preferably 10% (312 / 1002) to 67% (822 / 1002).

[0452] For example, the edge of the section where the current collector (Pc) contacts the bending surface area F can cover the end of the segments 61, 61' that are bent towards the core C in the last winding turn of the uniform height area (③). Since a weld pattern (Wp) is formed in this case in a state where the segments 61, 61' are pushed by the current collector (Pc), the current collector (Pc) and the bending surface area F are strongly coupled. As a result, the segments 61, 61', which are stacked in the winding axis direction, adhere tightly to one another, thereby reducing the resistance at the weld interface and preventing the segments 61, 61' from lifting.

[0453] Meanwhile, the bending direction of the segment can be opposite to that described above. That is, the segment can be bent from the core towards the outer circumference. In this case, the pattern in which the height of the segment changes along the winding direction (X-axis direction) can be the opposite of that in the previous examples (modified examples). For example, the height of the segment can be gradually reduced from the core towards the outer circumference. Furthermore, the structure applied to the first section B1 and the structure applied to the second section B3 can be interchanged.For example, the height change pattern of the segment can be designed such that the height of the segment gradually decreases from the core side to the outer circumferential side, but the end of the segment is not exposed from the outer circumference of the electrode assembly when the segment closest to the outer circumference of the electrode assembly is bent towards the outer circumference.

[0454] The electrode structure of the above examples (modifications) can be applied to at least one of the first and second electrodes with different polarities contained in the jelly-roll type electrode assembly or any other type of electrode assembly known in the art. Furthermore, if the electrode structure of the above examples (modifications) is applied to any one of the first and second electrodes, the conventional electrode structure can also be applied to the other. Additionally, the electrode structures applied to the first and second electrodes can be different from each other.

[0455] For example, if the first electrode and the second electrode are a positive electrode and a negative electrode respectively, any of the above examples (modifications) can be applied to the first electrode, and the conventional electrode structure (see Fig. 1) can be applied to the second electrode.

[0456] As another example, if the first electrode and the second electrode are a positive electrode and a negative electrode respectively, any one of the above examples (modifications) can be selectively applied to the first electrode, and any one of the above examples (modifications) can be selectively applied to the second electrode.

[0457] In the present disclosure, an active material of the positive electrode, which is coated onto the positive electrode, and an active material of the negative electrode, which is coated onto the negative electrode, can use any active material which is known in the art without restriction.

[0458] In one example, the active material of the positive electrode can comprise an alkali metal compound, which can be described by a general formula A[A x M y ]O 2+z is expressed (A includes at least one element from Li, Na and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru and Cr; x ≥ 0, 1 ≤ x+y ≤ 2, 0,1 ≤ z ≤ 2; and the stoichiometric moduli x, y and z are selected such that the compound retains electrical neutrality).

[0459] In another example, the active material of the positive electrode can be an alkali metal compound xLiM. 1 O2-(1-x)Li2M 2 O3, which is disclosed in US6,677,082, US6,680,143, et al., wherein M 1 includes at least one element with an average oxidation state of 3; M 2 includes at least one element with an average oxidation state of 4; and 0 ≤ x ≤ 1).

[0460] In yet another example, the active material of the positive electrode can be lithium metal phosphate, which can be described by the general formula Li a M 1 x Fe 1-x M 2 y P 1-y M 3 z O 4-z is expressed (M 1 includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M 2includes at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V and S; M 3 comprises a halogen element, optionally including F; 0 a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y 1, 0 ≤ z 1; the stoichiometric coefficients a, x, y and z are selected such that the compound retains electrical neutrality), or Li3M2(PO4)3 (M comprises at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al).

[0461] For example, the active material of the positive electrode may contain primary particles and / or secondary particles in which the primary particles are aggregated.

[0462] In one example, the active material of the negative electrode can be carbon, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, or the like. Metal oxides such as TiO₂ and SNO₂ with a potential of less than 2 V can also be used as the active material of the negative electrode. The carbon material can be either low-crystalline or high-crystalline carbon, or the like.

[0463] The separator can use a porous polymer film, for example, a porous polymer film made from a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, or the like, or laminates thereof. Alternatively, the separator can use a conventional porous nonwoven fabric, for example, a nonwoven fabric made from high-melting-point glass fiber, polyethylene terephthalate fiber, or the like.

[0464] A coating layer of inorganic particles can be present on at least one surface of the separator. It is also possible that the separator itself is made from a coating layer of inorganic particles. Particles in the coating layer can be bonded with a binder, resulting in an interstitial volume between adjacent particles.

[0465] The inorganic particles can be made from an inorganic material with a dielectric constant of 5 or higher. As a non-restrictive example, the inorganic particles can comprise at least one material selected from the group consisting of Pb(Zr,Ti)O3 (PZT), Pb 1-x La x Zr 1-y Ti y O3 (PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMN-PT), BaTiO3, Hafnium oxide (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0466] The structure of the electrode assembly is described in detail below, using an example.

[0467] Fig. Figure 11 is a sectional view showing a jelly-roll type electrode assembly 80 in which the electrode 40 of the first example is applied to the first electrode (the positive electrode) and the second electrode (the negative electrode) along the Y-axis direction (winding axis direction).

[0468] The electrode assembly 80 can be described by reference to Fig. The winding methods described in section 2 are used to produce the components. For the sake of simplicity, the structures of the first uncoated section 43a and the second uncoated section 43b extending from the separator are illustrated in detail, while the winding structures of the first electrode, the second electrode, and the separator are not shown. The first uncoated section 43a, which projects upwards, extends from the first electrode, and the second uncoated section 43b, which projects downwards, extends from the second electrode.

[0469] The patterns in which the heights of the first and second uncoated sections 43a, 43b change are illustrated schematically. That is, the height of the uncoated section can vary irregularly depending on the position where the cross-section is cut. For example, in a cross-section where the sides of the trapezoidal segments 61, 61' or the cutting slots 63 are cut, the height of the uncoated section in the cross-section is lower than the height H of the segments 61, 61'. Accordingly, it is understood that the heights of the uncoated sections shown in the drawings depicting the cross-section of the electrode assembly are the average of the heights (H in Fig. 7b and Fig. 8b) of the uncoated section contained in each winding turn.

[0470] With reference to Fig. 11 The first uncoated section 43a has a first section B1 adjacent to the core of the electrode assembly 80, a second section B3 adjacent to the outer circumference of the electrode assembly 80 and a third section B2 which is arranged between the first section B1 and the second section B3.

[0471] The height (length in the Y-axis direction) of the second section B3 is relatively smaller than the height of the third section B2. Accordingly, an internal short circuit can be prevented because the corrugated section and the second section B3 are in contact with each other, while the corrugated section of the battery casing is pressed against the second section B3.

[0472] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure from other examples (modifications).

[0473] The ends 81 of the first uncoated section 43a and the second uncoated section 43b may be bent in the radial direction of the electrode assembly 80, for example from the outer circumference towards the core. At this point, the second section B3 may not be significantly bent.

[0474] Fig. Figure 12 is a sectional view showing a jelly-roll type electrode assembly 90 in which the electrode 45 of the second example is applied to the first electrode (the positive electrode) and the second electrode (the negative electrode) along the Y-axis direction (winding axis direction).

[0475] With reference to Fig. 12 The first uncoated section 43a has a first section B1 adjacent to the core of the electrode assembly 90, a second section B3 adjacent to the outer circumference of the electrode assembly 90 and a third section B2 which is arranged between the first section B1 and the second section B3.

[0476] The height of the second section B3 is relatively smaller than the height of the third section B2 and decreases gradually or stepwise from the core to the outer circumference. Accordingly, an internal short circuit can be prevented because the beaded section and the second section B3 are in contact with each other, while the beaded section of the battery casing is pressed against the second section B3.

[0477] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure from other examples (modifications).

[0478] The ends 91 of the first uncoated section 43a and the second uncoated section 43b can be bent in the radial direction of the electrode assembly 90, for example from the outer circumference to the core. At this point, the outermost section 92 of the second section B3 can not be substantially bent.

[0479] Fig. Figure 13 is a sectional view showing an electrode assembly 100 of the jelly roll type in which any one of the electrodes 50, 60, 70 of the third to fifth example (modifications thereof) is applied to the first electrode (the positive electrode) and the second electrode (the negative electrode) along the Y-axis direction (winding axis direction).

[0480] With reference to Fig. 13 the first uncoated section 43a has a first section B1 adjacent to the core of the electrode assembly 100, a second section B3 adjacent to the outer circumference of the electrode assembly 100 and a third section B2 which is arranged between the first section B1 and the second section B3.

[0481] The height of the first section B1 is relatively smaller than the height of the third section B2. Additionally, the bend length of the uncoated section 43a, located on the innermost side of the third section B2, is less than or equal to the radial length (R) of the first section B1. The bend length (H) corresponds to the distance from the bend point of the uncoated section 43a to the top surface of the uncoated section 43a. In a modified example, the bend length (H) can be less than the sum of the radial length (R) of the first section B1 and 10% of the radius of the core 102.

[0482] Therefore, the core 102 of the electrode assembly 100 is open to the outside by 90% or more of the diameter of the core 102, even if the third section B2 is bent. The core 102 is a cavity in the center of the electrode assembly 100. If the core 102 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding device through the core 102, the welding process can be easily carried out between the current collector of the negative electrode (or the positive electrode) and the battery casing (or the terminal).

[0483] The height of the second section B3 is relatively smaller than the height of the third section B2. Accordingly, it prevents the corrugated section and the second section B3 from touching each other, while the corrugated section of the battery casing is pressed near the second section B3 to cause an internal short circuit.

[0484] In one modification, the height of the second section B3 can be gradually or stepwise reduced, unlike in Fig. 13 shown. Also in Fig. 13 Although the height of the third section B2 is partially the same in one circumferential direction, the height of the third section B2 can gradually or stepwise increase from the boundary between the first section B1 and the third section B2 to the boundary between the third section B2 and the second section B3. If the third section B2 is subdivided into a plurality of segments, an area where the height of the uncoated section 43a changes corresponds to the height-variable area (② in Fig. 10a) of the segment.

[0485] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure from other examples (modifications).

[0486] The ends 101 of the first uncoated section 43a and the second uncoated section 43b can be bent in the radial direction of the electrode assembly 100, for example from the outer circumference to the core. At this point, the first section B1 and the second section B3 are not significantly bent.

[0487] If the third section B2 contains a large number of segments, the bending stress can be reduced to prevent the uncoated section 43a from tearing or deforming abnormally near the bend point. Additionally, if the width and / or height and / or separation distance of the segment is set according to the numerical range of the example above, the segments will be bent towards the core and overlap in multiple layers to ensure sufficient weld strength, and no void (gap) will be formed in the bent surface area.

[0488] Fig. Figure 14 is a sectional view showing an electrode assembly 110 according to yet another example along the Y-axis direction (winding axis direction).

[0489] With reference to Fig. 14. The electrode assembly 110 is essentially the same as the electrode assembly 100 from Fig. 13, except that the height of the second section B3 is essentially the same as the height of the outermost side of the third section B2.

[0490] The second section B3 can contain a multitude of segments. The configuration of the multitude of segments is essentially the same as described in the fourth and fifth examples (modifications) with respect to electrodes.

[0491] In electrode assembly 110, the height of the first section B1 is relatively smaller than the height of the third section B2. Furthermore, the bending length (H) of the uncoated section located on the innermost side of the third section B2 is less than or equal to the radial length (R) of the first section B1. For example, the first section B1 could be the segment-skipping region, which does not contain a segment (① in Fig. 10a). In a modified example, the bending length (H) can be less than the sum of the radial length (R) of the first section B1 and 10% of the radius of the core 102.

[0492] Therefore, the core 112 of the electrode assembly 110 is open to the outside by at least 90% or more of the diameter of the core 112, even if the third section B2 is bent. If the core 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding device through the core 112, the welding process can be easily carried out between the current collector of the negative electrode (or the positive electrode) and the battery housing (or the terminal).

[0493] In one modification, the structure, in which the height of the third section B2 gradually or stepwise increases from the core to the outer circumference, can be extended to the second section B3. In this case, the height of the uncoated section 43a can gradually or stepwise increase from the boundary between the first section B1 and the third section B2 to the outermost surface of the electrode assembly 110.

[0494] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure from other examples (modifications).

[0495] The ends 111 of the first uncoated section 43a and the second uncoated section 43b can be bent in the radial direction of the electrode assembly 110, for example from the outer circumference towards the core. At this point, the first section B1 is not significantly bent.

[0496] If the third section B2 and the second section B3 contain a large number of segments, the bending stress can be reduced to prevent the uncoated sections 43a, 43b from tearing or abnormally deforming near the bend point. Additionally, if the width and / or height and / or separation distance of the segment is set according to the numerical range of the example above, the segments will be bent towards the core and overlap in multiple layers to ensure sufficient weld strength, and no void (gap) will be formed in the bent surface area.

[0497] Fig. Figure 15 is a sectional view showing an electrode assembly 120 according to yet another example along the Y-axis direction (winding axis direction).

[0498] With reference to Fig. The electrode assembly 120 is essentially the same as the electrode assembly 100 from 15. Fig. 13, except that the height of the third section B2 has a pattern that increases and then gradually or stepwise decreases. The radial area in which the height of the third section B2 changes can be called the height-variable area (② in Fig. 10a) of the segment. Even in this case, the height-variable area of ​​the segment can be designed such that the area with a uniform number of overlapping layers, in which the number of overlapping layers of segments is 10 or more, appears in the preferred numerical range described above in the bending surface area F formed by bending the third section B2.

[0499] This change in the height of the third section B2 can be achieved by using the step pattern (see Fig. 6) or adjusting the height of segments (see Fig. 7a or Fig. 8a), which are contained in the third section B2, will be implemented.

[0500] In electrode assembly 120, the height of the first section B1 is relatively smaller than the height of the third section B2. Furthermore, the bending length (H) of the uncoated section located on the innermost side of the third section B2 is less than or equal to the radial length (R) of the first section B1. The area corresponding to the first section B1 is the segment skip area, which does not include any segment (① in Fig. 10a). In a modified example, the bending length (H) can be less than the sum of the radial length (R) of the first section B1 and 10% of the radius of the core 102.

[0501] Therefore, the core 122 of the electrode assembly 120 is open outwards by at least 90% or more of its diameter, even if the third section B2 is bent towards the core. If the core 122 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding device through the core 122, the welding process can be easily carried out between the current collector of the negative electrode (or the positive electrode) and the battery casing (or the terminal).

[0502] Furthermore, the height of the second section B3 is relatively smaller than the height of the third section B2, and preferably no segment can be formed in the second section B3. Accordingly, an internal short circuit can be prevented, since the corrugated section and the second section B3 are in contact with each other, while the corrugated section of the battery casing is pressed near the second section B3. In one modification, the height of the second section B3 can decrease gradually or stepwise towards the outer circumference.

[0503] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure from other examples (modifications).

[0504] The ends 121 of the first uncoated section 43a and the second uncoated section 43b can be bent from the outer circumference of the electrode assembly 120 towards the core. At this point, the first section B1 and the second section B3 are not significantly bent.

[0505] If the third section B2 contains a large number of segments, the bending stress can be reduced to prevent the uncoated sections 43a, 43b from tearing or abnormally deforming. Additionally, if the width and / or height and / or separation distance of the segment is set according to the numerical range of the example above, the segments will be bent towards the core and overlap in multiple layers to ensure sufficient weld strength, and no void (gap) will be formed in the bent surface area.

[0506] Fig. Figure 16 is a sectional view showing an electrode assembly 130 according to yet another example along the Y-axis direction (winding axis direction).

[0507] With reference to Fig. 16. The electrode assembly 130 is essentially the same as the electrode assembly 120 from Fig. 15, except that the height of the second section B3 has a pattern that gradually or stepwise decreases from the boundary point of the second section B3 and the third section B2 to the outermost surface of the electrode assembly 130.

[0508] This change in the height of the second section B3 can be achieved by extending the step pattern (see Fig. 6), which is contained in the third section B2, can be implemented in the second section B3, while at the same time the height of the pattern gradually or stepwise decreases towards the outer perimeter. Additionally, in another modification, the change in the height of the second section B3 can be implemented by extending the segment structure of the third section B2 to the second section B3, while at the same time the height of the segments gradually or stepwise decreases towards the outer perimeter.

[0509] In electrode assembly 130, the height of the first section B1 is relatively smaller than the height of the third section B2. Furthermore, in the third section B2, the bending length (H) of the innermost uncoated section is less than or equal to the radial length (R) of the first section B1. The first section B1 corresponds to the segment skip region, which does not contain a segment (① in Fig. 10a). In a modified example, the bending length (H) can be less than the sum of the radial length (R) of the first section B1 and 10% of the radius of the core 102.

[0510] Accordingly, the core 132 of the electrode assembly 130 is open to the outside by at least 90% or more of its diameter, even if the third section B2 is bent towards the core. If the core 132 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding device through the core 132, the welding process can be easily carried out between the current collector of the negative electrode (or the positive electrode) and the battery casing (or the terminal).

[0511] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure from other examples (modifications).

[0512] The ends 131 of the first uncoated section 43a and the second uncoated section 43b can be bent from the outer circumference of the electrode assembly 130 towards the core. At this point, the first section B1 is not significantly bent.

[0513] If the third section B2 and the second section B3 contain a large number of segments, the bending stress can be reduced to prevent the uncoated sections 43a, 43b from tearing or abnormally deforming near the bend point. Additionally, if the width and / or height and / or separation distance of the segment is set according to the numerical range of the example described above, the segments will be bent towards the core and overlap in multiple layers to ensure sufficient weld strength, and no void (gap) will be formed in the bent surface area.

[0514] Meanwhile, in the earlier examples (modified examples), the ends of the first uncoated section 43a and the second uncoated section 43b can be bent from the core towards the outer circumference. In this case, it is preferred that the second section B3 be designed as the segment-skipping region, which does not contain a segment (① in Fig. 10a) and is not bent towards the outer circumference. Additionally, the width of the second section B3 in the radial direction may be greater than or equal to the length by which the outermost uncoated section (or segment) of the third section B2 is bent. Only if the outermost uncoated section (or segment) of the third section B2 is bent towards the outer circumference will the end of the bent section not project beyond the outer circumference of the electrode assembly to the inner surface of the battery casing. Also, the change pattern of the segment structure may be the opposite of the previous examples (modified examples). For example, the height of the segment may increase stepwise or gradually from the core to the outer circumference. That is, by arranging the segment skip region (① of Fig. 10a), of the height-variable area (② of Fig. 10a) of the segment and the height-unit area (③ of Fig. 10a) of the segment from the outer circumference of the electrode assembly to the core in the sequence, the area with a uniform number of overlap layers, in which the number of overlap layers of segments is 10 or more, can appear in a desired numerical range in the bending surface area.

[0515] Various electrode assembly structures, as shown in one example, can be applied to a cylindrical battery.

[0516] For example, a cylindrical battery can be a cylindrical battery whose form factor ratio (defined as a value obtained by dividing the diameter of the cylindrical battery by its height, namely a ratio of height (H) to diameter (Φ)) is greater than approximately 0.4. Here, the form factor means a value that specifies the diameter and height of a cylindrical battery.

[0517] For example, a cylindrical battery can have a diameter of 40 mm to 50 mm and a height of 60 mm to 130 mm. The form factor of a cylindrical battery, for example, could be 46110, 4875, 48110, 4880, or 4680. In the numerical value representing the form factor, the first two numbers indicate the diameter of the battery, and the remaining numbers indicate the height.

[0518] When an electrode assembly with a tabless structure is applied to a cylindrical battery with a form factor ratio greater than 0.4, the stress applied in the radial direction when the uncoated section is bent is high, so that the uncoated section can easily tear. Furthermore, when welding the current collector to the bent surface area of ​​the uncoated section, it is necessary to sufficiently increase the number of overlapping layers of the uncoated section on the bent surface area to ensure adequate weld strength and reduce resistance. This requirement can be met by the electrode and electrode assembly according to the examples (modifications) of this disclosure.

[0519] For example, a battery can be a cylindrical battery with an approximately cylindrical shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0520] According to another example, a battery can be a cylindrical battery with a substantially cylindrical shape, a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0521] According to yet another example, a battery can be a cylindrical battery with an approximately cylindrical shape, a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.436.

[0522] According to yet another example, a battery can be a cylindrical battery with an approximately cylindrical shape, a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0523] According to yet another example, a battery can be a cylindrical battery with an approximately cylindrical shape, a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0524] Traditionally, batteries with a form factor ratio of approximately 0.4 or less were used. That is, traditionally, 1865 batteries, 2170 batteries, and so on were used. The 1865 battery has a diameter of approximately 18 mm, a height of approximately 65 mm, and a form factor ratio of 0.277. The 2170 battery has a diameter of approximately 21 mm, a height of approximately 70 mm, and a form factor ratio of 0.300.

[0525] The cylindrical battery is described in detail below using an example.

[0526] Fig. Figure 17 is a sectional view showing a cylindrical battery 140 according to an example along the Y-axis direction.

[0527] With reference to Fig. 17 The cylindrical battery 140 according to an example comprises an electrode assembly 141 with a first electrode, a separator and a second electrode, a battery housing 142 for receiving the electrode assembly 141 and a sealing body 143 for sealing an open end of the battery housing 142.

[0528] The battery housing 142 is a cylindrical container with an opening at the top. The battery housing 142 is made of a conductive metal material, such as aluminum, steel, or stainless steel. A nickel plating may be applied to the surface of the battery housing 142. The battery housing 142 accommodates the electrode assembly 141 inside through the top opening and also holds the electrolyte.

[0529] The electrolyte can be a salt with a structure like A+B-. Here, A+ comprises an alkali metal cation, such as Li+, Na+ or K+, or a combination thereof. and B- comprises at least one anion selected from the group consisting of F-, Cl-, Br-, I-, NO3-, N(CN)2-, BF4-, Clo4-, Alo4-, Alcl4-, PF6-, Sbf6-, Asf6-, BF2C2O4-, BC4O8-, (CF3)2PF4-, (CF3)3PF3-, (CF3)4PF2-, (CF3)5PF-, (CF3)6P-, CF3SO3-, C4F9SP3-, CF3CF2SO3-, (CF3)2N-, (FSO2)2N-, CF3CF2 (CF3)2CO-, (CF3)2SO2CH-, (SF5)C-, (CF3)3C-, CF3SO3-, (CF3)7SO3-, CF3CO-, CH2CO-, SCN3- and (CF3)2SO2N-.

[0530] The electrolyte can also be dissolved in an organic solvent. The organic solvent can be propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.

[0531] The electrode assembly 141 can have a jelly roll shape, but the present invention is not limited thereto. The electrode assembly 141 can be produced by winding a laminate formed by successively laminating a lower separator, a first electrode, an upper separator, and a second electrode at least once based on the winding axis of the core C, as shown in Fig. 2 shown.

[0532] The first and second electrodes have opposite polarities. That is, if one has a positive polarity, the other has a negative polarity. At least one of the first and second electrodes can have an electrode structure according to the examples (modifications) above. Furthermore, the other of the first and second electrodes can have a conventional electrode structure or an electrode structure according to the examples (modifications). The electrode pair contained in electrode assembly 141 is not limited to one pair; it can also contain two or more pairs.

[0533] A first uncoated section 146a of the first electrode and a second uncoated section 146b of the second electrode each project from the upper and lower sections of the electrode assembly 141, respectively. The first electrode has the electrode structure of the first example (modification). Accordingly, in the first uncoated section 146a, the height of the second section B3 is less than the height of the uncoated section of the other region. The second section B3 is spaced a predetermined distance from the inner circumference of the battery housing 142, in particular from the corrugated section 147. Therefore, the second section B3 of the first electrode does not come into contact with the battery housing 142, which is electrically connected to the second electrode, thus preventing an internal short circuit of the battery 140.

[0534] The second uncoated section 146b of the second electrode can have the same structure as the first uncoated section 146a. In another modification, the second uncoated section 146b can optionally have the structure of the uncoated section of the electrode according to the examples (modifications).

[0535] The sealing body 143 can comprise a cap 143a with a plate shape, a first seal 143b to provide airtightness between the cap 143a and the battery housing 142 and with insulating properties, and a connecting plate 143c that is electrically and mechanically coupled to the cap 143a.

[0536] The cap 143a is a component made of a conductive metal material and covers the upper opening of the battery housing 142. The cap 143a is electrically connected to the uncoated section 146a of the first electrode and is electrically insulated from the battery housing 142 by means of the first seal 143b. Accordingly, the cap 143a can function as a first electrode terminal (for example, the positive electrode) of the cylindrical battery 140.

[0537] The cap 143a is placed on the corrugated section 147 formed on the battery housing 142 and is secured by a crimp section 148. The first seal 143b can be arranged between the cap 143a and the crimp section 148 to ensure the airtightness of the battery housing 142 and the electrical insulation between the battery housing 142 and the cap 143a. The cap 143a can have a projection 143d extending upwards from its center.

[0538] The battery casing 142 is electrically connected to the second uncoated section 146b of the second electrode. Therefore, the battery casing 142 has the same polarity as the second electrode. If the second electrode has negative polarity, the battery casing 142 also has negative polarity.

[0539] The battery housing 142 has the beaded section 147 and the crimped section 148 on its upper surface. The beaded section 147 is formed by pressing in the circumference of the outer perimeter of the battery housing 142. The beaded section 147 prevents the electrode assembly 141 housed in the battery housing 142 from escaping through the upper opening of the battery housing 142 and can act as a support section on which the sealing body 143 is placed.

[0540] The inner circumference of the bead section 147 is spaced a predetermined distance from the second section B3 of the first electrode. Specifically, the lower end of the inner circumference of the bead section 147 is spaced a predetermined distance from the second section B3 of the first electrode. Since the second section B3 has a low height, it is not significantly affected even when the battery housing 142 is pressed in from the outside to form the bead section 147. Accordingly, the second section B3 is not compressed by other components such as the bead section 147, thus preventing partial deformation of the shape of the electrode assembly 141 and preventing a short circuit in the cylindrical battery 140.

[0541] For example, if the indentation depth of the corrugated section 147 is defined as D1 and the radial length from the inner circumference of the battery housing 142 to the boundary point of the second section B3 and the third section B2 is defined as D2, the formula D1 ≤ D2 can be satisfied. In this case, damage to the second section B3 is essentially prevented when the battery housing 142 is pressed in to form the corrugated section 147.

[0542] The crimp section 148 is formed on the bead section 147. The crimp section 148 has an extended and curved shape to cover the outer circumference of the cap 143a, which is arranged on the bead section 147, and part of the upper surface of the cap 143a.

[0543] The cylindrical battery 140 may further comprise a first current collector 144 and / or a second current collector 145 and / or an insulator 146.

[0544] The first current collector 144 is coupled to the upper section of the electrode assembly 141. The first current collector 144 is made of a conductive metal material, such as aluminum, copper, steel, or nickel, and is electrically connected to the uncoated section 146a of the first electrode. The electrical connection can be made by welding. A conductor 149 can be connected to the first current collector 144. The conductor 149 can extend upwards above the electrode assembly 141 and be coupled to the connecting plate 143c, or it can be directly coupled to the lower surface of the cap 143a. The conductor 149 can be connected to other components by welding.

[0545] For example, the first pantograph 144 can be formed integrally with the conductor 149. In this case, the conductor 149 can have an elongated plate shape extending outwards from near the center of the first pantograph 144.

[0546] The first current collector 144 can have a variety of bumps (not shown) formed radially on its lower surface. When the radial bump is provided, the bump can be pressed into the first uncoated section 146a of the first electrode by pressing the first current collector 144.

[0547] The first pantograph 144 is coupled to the end of the first uncoated section 146a. The first uncoated section 146a and the first pantograph 144 can be coupled, for example, by laser welding. The laser welding can be performed in such a way that a base material of the pantograph 144 partially melts. In a modification, the first pantograph 144 and the first uncoated section 146a can be welded with a solder joint between them. In this case, the solder can have a lower melting point compared to the first pantograph 144 and the first uncoated section 146a. The laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, or similar methods.

[0548] The second current collector 145 can be coupled to the lower surface of the electrode assembly 141. One side of the second current collector 145 can be coupled to the second uncoated section 146b by welding, and the other side can be coupled to the inner bottom surface of the battery housing 142 by welding. The coupling structure between the second current collector 145 and the second uncoated section 146b can be essentially the same as the coupling structure between the first current collector 144 and the first uncoated section 146a.

[0549] The uncoated sections 146a, 146b are not limited to the illustrated structure. Accordingly, the uncoated sections 146a, 146b can selectively adopt not only a conventional uncoated section structure, but also the uncoated section structure of the electrode, as shown in the examples (modifications).

[0550] The insulator 146 can cover the first pantograph 144. The insulator 146 can cover the upper surface of the first pantograph 144, thus preventing direct contact between the first pantograph 144 and the inner circumference of the battery housing 142.

[0551] The insulator 146 has a conductor hole 151, allowing the conductor 149, which extends upwards from the first current collector 144, to be pulled out through it. The conductor 149 is pulled upwards through the conductor hole 151 and coupled to the lower surface of the connecting plate 143c or the lower surface of the cap 143a.

[0552] A circumferential region of the edge of the insulator 146 can be arranged between the first current collector 144 and the beaded section 147 to secure the coupled body of the electrode assembly 141 and the first current collector 144. Accordingly, the movement of the battery 140 in the winding axis direction Y can be restricted within the coupled body of the electrode assembly 141 and the first current collector 144, thereby improving the mounting stability of the battery 140.

[0553] The insulator 146 can be made from an insulating polymer resin. For example, the insulator 146 can be made from polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0554] The battery casing 142 may further comprise a vent section 152 formed on its lower surface. The vent section 152 corresponds to a region of lesser thickness compared to the perimeter of the lower surface of the battery casing 142. The vent section 152 is structurally weaker compared to the surrounding area. Consequently, if an anomaly occurs in the cylindrical battery 142 and the internal pressure increases to a predetermined level or higher, the vent section 152 may rupture, allowing the gas generated inside the battery casing 142 to escape to the outside. The internal pressure at which the vent section 152 ruptures may be approximately 15 kgf / cm². 2 up to 35 kgf / cm² 2 be.

[0555] The vent section 152 can be formed continuously or discontinuously by drawing a circle on the lower surface of the battery casing 142. In one modification, the vent section 152 can be formed in a straight pattern or other patterns.

[0556] Fig. Figure 18 is a sectional view showing a cylindrical battery 150 according to another example along the Y-axis direction.

[0557] With reference to Fig. The cylindrical battery 150 is essentially the same as the cylindrical battery 140 from [reference missing]. Fig. 17, except that the electrode structure of the second example (modification) is used in the first uncoated section 146a of the first electrode.

[0558] With reference to Fig. 18 The first uncoated section 146a of the first electrode can have a shape in which the height of the second section B3 gradually or stepwise decreases towards the inner circumference of the battery casing 142. For example, the virtual line connecting the upper end of the second section B3 can have the same or a similar shape to the inner circumference of the beaded section 147.

[0559] The second section B3 forms an inclined surface. Accordingly, when the battery housing 142 is pressed in to form the corrugated section 147, the second section B3 is prevented from being compressed and damaged by the corrugated section 147. Additionally, it is possible to suppress the phenomenon of the second section B3 coming into contact with the battery housing 142 with an opposite polarity, thus preventing an internal short circuit.

[0560] The remaining components of the cylindrical battery 150 are essentially the same as the example described above (modification).

[0561] The uncoated sections 146a, 146b are not limited to the illustrated structure. Accordingly, the uncoated sections 146a, 146b can selectively exhibit not only a conventional uncoated section structure, but also the uncoated section structure of the electrode, as shown in the examples (modifications).

[0562] Fig. Figure 19 is a sectional view showing a cylindrical battery 160 according to yet another example along the Y-axis direction.

[0563] With reference to Fig. 19 The cylindrical battery 160 is essentially the same as the cylindrical batteries 140, 150 described above, except that the line 149, which is connected to the first current collector 144, is directly connected to the cap 143a of the sealing body 143 through the line hole 151 of the insulator 146, and the insulator 146 and the first current collector 144 have a structure in close contact with the lower surface of the cap 143a.

[0564] In the cylindrical battery 160, the diameter of the first current collector 144 and the outermost diameter of the third section B2 are smaller than the minimum inner diameter of the battery housing 142. Furthermore, the diameter of the first current collector 144 can be greater than or equal to the outermost diameter of the third section B2.

[0565] In particular, the minimum inner diameter of the battery housing 142 can correspond to the inner diameter of the battery housing 142 at the position where the corrugated section 147 is formed. At this point, the outermost diameter of the first current collector 144 and the third section B2 is smaller than the inner diameter of the battery housing 142 at the position where the corrugated section 147 is formed. Furthermore, the diameter of the first current collector 144 can be greater than or equal to the outermost diameter of the third section B2. The circumferential region of the edge of the insulator 146 can be arranged in a downward-bent position between the second section B3 and the corrugated section 147 to secure the coupled body of the electrode assembly 141 and the first current collector 144.

[0566] For example, the insulator 146 can comprise a section covering the second section B3 and a section covering the first pantograph 144, and a section connecting these two sections can have a curved shape corresponding to the curved shape of the corrugated section 147. The insulator 146 can insulate the second section B3 and the inner circumference of the corrugated section 147, and simultaneously insulate the first pantograph 144 and the inner circumference of the corrugated section 147.

[0567] The first current collector 144 can be positioned higher than the lower end of the corrugated section 147 and can be coupled to the first section B1 and the third section B2. At this point, the indentation depth D1 of the corrugated section 147 is less than or equal to the distance D2 from the inner circumference of the battery housing 142 to the boundary between the second section B3 and the third section B2. Accordingly, the first section B1, the third section B2, and the coupled first current collector 144 can be positioned higher than the lower end of the corrugated section 147. The lower end of the corrugated section 147 represents a bending point (B) between the section of the battery housing 142 containing the electrode assembly 141 and the corrugated section 147.

[0568] Since the first section B1 and the third section B2 occupy the interior of the corrugated section 147 in the radial direction, the empty space between the electrode assembly 141 and the cap 143a can be minimized. Additionally, the connecting plate 143c, which is located in the empty space between the electrode assembly 141 and the cap 143a, is omitted. Consequently, the conductor 149 of the first current collector 144 can be directly coupled to the lower surface of the cap 143a. According to the above structure, the empty space in the battery can be reduced, and the energy density can be maximized accordingly.

[0569] In the case of the cylindrical battery 160, the first current collector 144 and the second current collector 145 can be welded to the ends of the first and second uncoated sections 146a, 146b in the same way as in the example above.

[0570] The uncoated sections 146a, 146b are not limited to the illustrated structure. Accordingly, the uncoated sections 146a, 146b can selectively exhibit not only a conventional uncoated section structure, but also the uncoated section structure of the electrode, as shown in the examples (modifications).

[0571] Fig. Figure 20 is a sectional view showing a cylindrical battery 170 along the Y-axis, as in yet another example.

[0572] According to Fig. 20 The structure of the electrode assembly of the cylindrical battery 170 is essentially the same as that of the cylindrical battery 140. Fig. 17, and the other structure, with the exception of the electrode assembly, is modified.

[0573] In particular, the cylindrical battery 170 has a battery housing 171 through which a terminal 172 is installed. The terminal 172 is installed through a perforation hole formed in the closed surface (the upper surface in the drawing) of the battery housing 171. The terminal 172 is riveted to the perforation hole of the battery housing 171 in such a way that a second seal 173, made of an insulating material, is positioned between them. The terminal 172 is exposed to the outside in a direction opposite to the direction of gravity.

[0574] The terminal 172 has a terminal exposure section 172a and a terminal insertion section 172b. The terminal exposure section 172a is exposed to the outside of the closed surface of the battery housing 171. The terminal exposure section 172a may be located approximately at the midpoint of the closed surface of the battery housing 171. The maximum diameter of the terminal exposure section 172a may be larger than the maximum diameter of the perforation hole formed in the battery housing 171. The terminal insertion section 172b may be electrically connected to the uncoated section 146a of the first electrode through approximately the midpoint of the closed surface of the battery housing 171. The bottom edge of the terminal insertion section 172b may be riveted to the inner surface of the battery housing 171.This means that the bottom edge of the terminal insertion section 172b can have a shape that is curved towards the inner surface of the battery housing 171. A flat section 172c is contained within the bottom edge of the terminal insertion section 172b. The maximum diameter of the riveted lower section of the terminal insertion section 172b can be larger than the maximum diameter of the perforation hole in the battery housing 171.

[0575] The flat section 172c of the connection insertion section 172b can be welded to the center of the first current collector 144, which is connected to the first uncoated section 146a of the first electrode. Laser welding is the preferred welding method, but other welding methods, such as ultrasonic welding, can be used.

[0576] An insulator 174, made of an insulating material, can be arranged between the first current collector 144 and the inner surface of the battery housing 171. The insulator 174 covers the upper section of the first current collector 144 and the upper edge of the electrode assembly 141. Accordingly, it is possible to prevent the second section B3 of the electrode assembly 141 from contacting the inner surface of the battery housing 171 with a different polarity and thus causing a short circuit.

[0577] The thickness of the insulator 174 corresponds to the distance between the upper surface of the first current collector 144 and the inner surface of the closed section of the battery housing 171, or is slightly greater than this distance. Accordingly, the insulator 174 can be in contact with both the upper surface of the first current collector 144 and the inner surface of the closed section of the battery housing 171.

[0578] The terminal insert section 172b of the terminal 172 can be welded to the first current collector 144 through the perforation hole of the insulator 174. The diameter of the perforation hole formed in the insulator 174 can be larger than the diameter of the riveted section at the lower end of the terminal insert section 172b. For example, the perforation hole can expose the lower section of the terminal insert section 172b and the second seal 173.

[0579] The second seal 173 is arranged between the battery housing 171 and the terminal 172 to prevent the battery housing 171 and the terminal 172 from making electrical contact with each other if they have opposite polarities. Accordingly, the upper surface of the battery housing 171, which has an approximately flat shape, can function as a second electrode terminal (for example, the negative electrode) of the cylindrical battery 170.

[0580] The second seal 173 has a seal exposure section 173a and a seal insertion section 173b. The seal exposure section 173a is located between the terminal exposure section 172a of the terminal 172 and the battery housing 171. The seal insertion section 173b is located between the terminal insertion section 172b of the terminal 172 and the battery housing 171. The seal insertion section 173b can be deformed together with the terminal insertion section 172b when it is riveted to ensure close contact with the inner surface of the battery housing 171. The second seal 173 can, for example, be made of an insulating polymer resin.

[0581] The seal exposure section 173a of the second seal 173 can have an extended shape to cover the outer circumference of the terminal exposure section 172a of the terminal 172. When the second seal 173 covers the outer circumference of the terminal 172, it is possible to prevent a short circuit from occurring while an electrical connecting part, such as a busbar, is coupled to the upper surface of the battery housing 171 and / or the terminal 172. Although not shown in the drawings, the seal exposure section 173a can have an extended shape to cover not only the outer circumferential surface of the terminal exposure section 172a, but also a portion of its upper surface.

[0582] If the second seal 173 is made of a polymer resin, it can be thermally fused to the battery housing 171 and the terminal 172. In this case, the airtightness at the coupling interface between the second seal 173 and the terminal 172, and at the coupling interface between the second seal 173 and the battery housing 171, can be improved. Furthermore, if the seal exposure section 173a of the second seal 173 has a shape that extends to the upper surface of the terminal exposure section 172a, the terminal 172 can be integrally coupled to the second seal 173 by insert injection molding.

[0583] In the upper surface of the battery housing 171, a remaining area 175, which differs from the area occupied by the terminal 172 and the second seal 173, corresponds to the second electrode terminal with a polarity opposite to that of the terminal 172.

[0584] The second current collector 176 is coupled to the lower section of the electrode assembly 141. The second current collector 176 is made of a conductive metal material, such as aluminum, steel, copper, or nickel, and is electrically connected to the second uncoated section 146b of the second electrode.

[0585] For example, the second current collector 176 is electrically connected to the battery housing 171. For this purpose, at least one section of the edge of the second current collector 176 can be arranged and fastened between the inner surface of the battery housing 171 and a first seal 178b. In one example, at least one section of the edge of the second current collector 176 can be attached to the corrugated section 180 by welding in such a way that it is supported on the bottom surface of the corrugated section 180 formed on the bottom of the battery housing 171. In another modification, at least one section of the edge of the second current collector 176 can be welded directly to the inner wall surface of the battery housing 171.

[0586] The second pantograph 176 can have a plurality of irregularities (not shown) formed radially on a surface facing the second uncoated section 146b. When the irregularity is formed, it can be pressed into the second uncoated section 146b by pressing the second pantograph 176 into it.

[0587] For example, the second current collector 176 and the ends of the second uncoated section 146b can be coupled by welding, for example, laser welding. Furthermore, the welded sections of the second current collector 176 and the second uncoated section 146b can be spaced apart from the core C by a predetermined distance based on the inner circumference of the corrugated section 180.

[0588] A sealing body 178 for sealing the lower open end of the battery housing 171 comprises a cap 178a with a plate shape and a first seal 178b. The first seal 178b electrically isolates the cap 178a and the battery housing 171. A crimp section 181 holds the edge of the cap 178a and the first seal 178b together. The cap 178a has a vent section 179. The configuration of the vent section 179 is essentially the same as in the example above (modification). The lower surface of the cap 178a may be positioned higher than the lower end of the crimp section 181. In this case, a space is formed under the cap 178a, ensuring smooth venting. This is particularly useful when the cylindrical battery 170 is installed such that the crimp section 181 faces the direction of gravity.

[0589] For example, cap 178a is made of a conductive metal material. However, since the first seal 178b is located between cap 178a and battery housing 171, cap 178a has no electrical polarity. The sealing body 178 primarily seals the open end of the lower section of battery housing 171 and serves to discharge gas when the internal pressure of battery 170 exceeds a critical value. The critical internal pressure is 15 kgf / cm². 2 up to 35 kgf / cm² 2 .

[0590] For example, terminal 172, which is electrically connected to the first uncoated section 146a of the first electrode, is used as the first electrode terminal. Additionally, on the upper surface of the battery housing 171, which is electrically connected to the second uncoated section 146b of the second electrode via the second current collector 176, a portion 175, excluding terminal 172, is used as the second electrode terminal, having a different polarity than the first electrode terminal. With two electrode terminals located on the upper section of the cylindrical battery 170 as described above, it is possible to arrange electrical connection components, such as busbars, on only one side of the cylindrical battery 170. This can simplify the battery pack structure and improve energy density.Additionally, since part 175, which serves as the second electrode connection, has an approximately flat shape, a sufficient contact area can be ensured for connecting electrical connection components such as busbars. Accordingly, the cylindrical battery 170 can reduce the resistance at the connection point of the electrical connection components to a desired level.

[0591] Meanwhile, the structure of the uncoated section and the structure of the electrode assembly 141 are not limited to those shown in the drawings and can be replaced by the structures of the above examples (modifications).

[0592] Fig. Figure 21 is a sectional view showing a cylindrical battery 180 along the Y-axis, as in yet another example.

[0593] With reference to Fig. 21 The structure of the electrode assembly 141 of the cylindrical battery 180 is essentially the same as that of the one in Fig. 18 illustrated cylindrical battery 150, and the other components besides the electrode assembly 141 are essentially the same as those in Fig. 20 cylindrical battery 170 shown.

[0594] Accordingly, the configuration of the example (modification) with regard to the cylindrical batteries 150, 170 can be applied equally to the cylindrical battery 180.

[0595] In addition, the structure of the electrode assembly 141 and the structure of the uncoated section are not limited to those shown in the drawing and can be replaced by the structures of the above examples (modifications).

[0596] Fig. Figure 22 is a sectional view showing a cylindrical battery 190 along the Y-axis, as in yet another example.

[0597] With reference to Fig. 22 includes the cylindrical battery 190 which is in Fig. Electrode assembly 110 is illustrated in section 14, and the other components besides electrode assembly 110 are essentially the same as those in Fig. 17 illustrated cylindrical battery 140. Accordingly, the with reference to the Fig. 14 and Fig. The configuration described in point 17 can be applied to this example in essentially the same way.

[0598] With reference to the Fig. 10a and Fig. 22 the first and the second uncoated section 146a, 146b of the electrode assembly 110 are bent in the radial direction of the electrode assembly 110, for example from the outer circumference to the core, to form a bending surface area F.

[0599] The first section B1 has a lower height than the other sections and corresponds to the segment-skipping region a1, which has no segment, so it is not bent towards the core.

[0600] For example, the bending surface area F can include a segment-skipping area a1, a height-variable area a2 of the segment and a height-uniform area a3 of the segment from the core to the outer circumference.

[0601] As in the Fig. 10c, Fig. 10d and Fig. As shown in Figure 10e, the bending surface area F includes an area b1 with a uniform number of overlapping layers next to the segment skipping area a1, in which the number of overlapping layers of segments is 10 or more.

[0602] The bending surface area F can also include an area b2 with a decreasing number of overlap layers adjacent to the outer circumference of the electrode assembly 110, in which the number of overlapping layers of segments gradually decreases towards the outer circumference. For example, area b1 with a uniform number of overlap layers can be set as the welding target area.

[0603] In the bending surface area F, the preferred numerical ranges of the ratio (a2 / c), which is a ratio of the height-variable area a2 to the radius area c containing segments, the ratio (b1 / c) of the area b1 with a uniform number of overlap layers to the radius area c containing segments, and the ratio of the area of ​​the area b1 with a uniform number of overlap layers to the area of ​​the bending surface area F have already been described above and are therefore not described again.

[0604] The first pantograph 144 can be laser-welded to the bending surface area F of the first uncoated section 146a, and the second pantograph 145 can be laser-welded to the bending surface area F of the second uncoated section 146b. The welding process can be replaced by ultrasonic welding, resistance welding, spot welding, or the like.

[0605] For example, 50% or more of the weld area W of the first current collector 144 and the second current collector 145 can overlap the area with a uniform number of overlap layers b1 of the bending surface area F. Optionally, the remaining area of ​​the weld area W can overlap the area with a decreasing number of overlap layers b2 of the bending surface area F. With regard to high weld strength, low resistance of the weld interface, and prevention of damage to the separator or the active material layer, it is further preferred that the entire weld area W overlaps the area with a uniform number of overlap layers b1.

[0606] For example, in area b1 with a uniform number of overlapping layers, which overlaps the welding area W, and optionally in area b2 with a decreasing number of overlapping layers, the number of overlapping layers can be from 10 to 35 segments.

[0607] Optionally, if the number of overlapping layers of segments in area b2 with decreasing overlap layer count, which overlaps the welding area W, is less than 10, the laser power for welding area b2 with decreasing overlap layer count can be reduced below that of area b1 with a uniform overlap layer count. That is, if the welding area W overlaps area b1 with a uniform overlap layer count and area b2 with decreasing overlap layer count simultaneously, the laser power can be varied according to the number of overlapping layers of segments. In this case, the weld strength of area b1 with a uniform overlap layer count can be greater than the weld strength of area b2 with decreasing overlap layer count.

[0608] In the bending surface area F formed on the upper and lower sections of the electrode assembly 110, the radial length of the segment-skipping area a1 and / or the height-variable area a2 of the segment and / or the height-uniform area a3 of the segment can be the same or different from each other.

[0609] In electrode assembly 110, the height of the first section B1 is relatively smaller than that of the other sections. Furthermore, as in Fig. Figure 14 shows that the bending length (H) of the uncoated section located on the innermost side of the third section B2 is less than a value obtained by adding the radial length (R) of the first section B1 and 10% of the radius of the core 112.

[0610] Accordingly, the core 112 of the electrode assembly 110 can be opened outwards by at least 90% or more of its diameter, even if the first uncoated section 146a is bent towards the core. If the core 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding device through the core 112, the welding process between the second current collector 145 and the battery housing 142 can be easily carried out.

[0611] If the uncoated sections 146a, 146b have a segmented structure, if the width and / or height and / or separation distance of the segments are adjusted to meet the numerical ranges of the above example, the segments overlap in several layers to ensure sufficient weld strength when the segments are bent, and no empty space (gap) is formed in the bent surface area F.

[0612] For example, the first pantograph 144 and the second pantograph 145 can have an outer diameter that corresponds to the ends of the segments 61, 61' (see Fig. 10f) covered, which are bent in the last winding turn of the height-unitary region a3 of the first electrode and the second electrode. In this case, welding can be carried out in a condition in which the segments forming the bending area F are pressed uniformly through the current collector, and the tightly stacked state of the segments can be well maintained even after welding. The tightly stacked state means a condition in which there is essentially no gap between the segments, as in Fig. Figure 10a shows that the densely stacked state helps to reduce the resistance of the cylindrical battery 190 to a level suitable for fast charging (e.g., 4 milliohms) or below. The resistance can be at least 0.5 mΩ or at least 1.0 mΩ and / or 3.8 mΩ or less, 3.5 mΩ or less, or 3 mΩ or less.

[0613] The structures of the uncoated sections 146a and 146b can be modified to the structures shown in the examples above. Furthermore, a conventional uncoated section structure can be applied to any of the uncoated sections 146a and 146b without restriction.

[0614] Fig. Figure 23 is a sectional view showing a cylindrical battery 200 along the Y-axis, as in yet another example.

[0615] With reference to Fig. 23 includes the cylindrical battery 200 which is in Fig. Electrode assembly 110 is illustrated in section 14, and the other components besides the electrode assembly 110 are essentially the same as those in the Fig. 21 illustrated cylindrical battery 180. Accordingly, the one with reference to the Fig. 14 and Fig. The configuration described in section 21 can be applied to this example in essentially the same way.

[0616] With reference to the Fig. 10a and Fig. 23 the first and the second uncoated section 146a, 146b of the electrode assembly 110 are bent in the radial direction of the electrode assembly 110, for example from the outer circumference to the core, to form a bending surface area F.

[0617] The first section B1 has a lower height than the other sections and corresponds to the segment-skipping region a1, which has a segment, so that it is not bent towards the core.

[0618] For example, the bending surface area F can include a segment-skipping area a1, a height-variable area a2 of the segment and a height-uniform area a3 of the segment from the core to the outer circumference.

[0619] As in the Fig. 10c, Fig. 10d and Fig. As shown in Figure 10e, the bending surface area F includes an area b1 with a uniform number of overlapping layers next to the segment skipping area a1, in which the number of overlapping layers of segments is 10 or more.

[0620] The bending surface area F can also include an area b2 with a decreasing number of overlap layers adjacent to the outer circumference of the electrode assembly 110, in which the number of overlapping layers of segments decreases towards the outer circumference. For example, area b1 with a uniform number of overlap layers can be set as the welding target area.

[0621] In the bending surface area F, the preferred numerical ranges of the ratio (a2 / c), which is a ratio of the height-variable area a2 to a radius area c that includes segments, the ratio (b1 / c) of the area b1 with a uniform number of overlap layers to the radius area c that includes segments, and the ratio of the area of ​​the area b1 with a uniform number of overlap layers to the area of ​​the bending surface area F have already been described above and are therefore not described again.

[0622] The first pantograph 144 can be laser-welded to the bending surface area F of the first uncoated section 146a, and the second pantograph 176 can be laser-welded to the bending surface area F of the second uncoated section 146b. The welding process can be replaced by ultrasonic welding, resistance welding, spot welding, or the like. The weld area W of the second pantograph 176 and the second uncoated section 146b can be spaced a predetermined distance from the inner surface of the corrugated section 180.

[0623] For example, 50% or more of the weld area W of the first current collector 144 and the second current collector 176 can overlap the area with a uniform number of overlap layers b1 of the bending surface area F. Optionally, the remaining area of ​​the weld area W can overlap the area with a decreasing number of overlap layers b2 of the bending surface area F. With regard to high weld strength, low resistance of the weld interface, and prevention of damage to the separator or the active material layer, it is preferred that the entire weld area W overlaps the area with a uniform number of overlap layers b1.

[0624] For example, in area b1 with a uniform number of overlapping layers, which overlaps the welding area W, and optionally in area b2 with a decreasing number of overlapping layers, the number of overlapping layers can be from 10 to 35 segments.

[0625] Optionally, if the number of overlapping layers of segments in area b2 with decreasing overlap layer count, which overlaps the welding area W, is less than 10, the laser power for welding area b2 with decreasing overlap layer count can be reduced below that of area b1 with a uniform overlap layer count. That is, if the welding area W overlaps area b1 with a uniform overlap layer count and area b2 with decreasing overlap layer count simultaneously, the laser power can be varied according to the number of overlapping layers of segments. In this case, the weld strength of area b1 with a uniform overlap layer count can be greater than the weld strength of area b2 with decreasing overlap layer count.

[0626] In the bending surface area F formed on the upper and lower sections of the electrode assembly 110, the radial length of the segment-skipping area a1 and / or the height-variable area a2 of the segment and / or the height-uniform area a3 of the segment can be the same or different from each other.

[0627] In electrode assembly 110, the height of the first section B1 is relatively smaller than that of the other sections. Furthermore, as in Fig. Figure 14 shows that the bending length (H) of the uncoated section located on the innermost side of the third section B2 is less than a value obtained by adding the radial length (R) of the first section B1 and 10% of the radius of the core 112.

[0628] Therefore, the core 112 of the electrode assembly 110 can be opened outwards by at least 90% or more of its diameter, even if the uncoated section 146a is bent towards the core. If the core 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Furthermore, by inserting a welding device through the core 112, the welding process between the first current collector 144 and the terminal 172 can be easily carried out.

[0629] If the first and second uncoated sections 146a, 146b have a segmented structure, if the width and / or height and / or separation distance of the segments are adjusted to meet the numerical ranges of the above example, the segments overlap in several layers to ensure sufficient weld strength when the segments are bent, and no empty space (gap) is formed in the bent surface area F.

[0630] For example, in the first pantograph 144 and the second pantograph 176, the areas that contact the first and second uncoated sections 146a, 146 can have an outer diameter that corresponds to the ends of the segments 61, 61' (see Fig. 10f) covered, which are bent in the last winding turn of the height-unitary region a3 of the first electrode and the second electrode. In this case, welding can be carried out in a condition in which the segments forming the bending area F are pressed uniformly through the current collector, and the tightly stacked state of the segments can be well maintained even after welding. The tightly stacked state means a condition in which there is essentially no gap between the segments, as in Fig. Figure 10a shows that the densely stacked state helps to reduce the resistance of the cylindrical battery 190 to a level suitable for fast charging (e.g., 4 milliohms) or below. The resistance can be at least 0.5 mΩ or at least 1.0 mΩ and / or 3.8 mΩ or less, 3.5 mΩ or less, or 3 mΩ or less.

[0631] The structures of the uncoated sections 146a and 146b can be modified to the structures shown in the examples above. Furthermore, a conventional uncoated section structure can be applied to any of the uncoated sections 146a and 146b without restriction.

[0632] Fig. Figure 24 is a sectional view showing a cylindrical battery 210 along the Y-axis according to yet another example.

[0633] With reference to Fig. 24 includes the cylindrical battery 210 which is in Fig. Electrode assembly 100 was illustrated in Figure 13, and the other configuration besides electrode assembly 100 is essentially the same as that shown in Figure 13. Fig. 17 illustrated cylindrical battery 140. Therefore, the reference to the Fig. 13 and Fig. The configuration described in this example (17) can be applied essentially identically.

[0634] For example, the first and second uncoated sections 146a, 146b of the electrode assembly 100 are subdivided into a plurality of segments, and the plurality of segments is bent in a radial direction of the electrode assembly 100, for example, from the outer circumference towards the core. At this point, the first section B1 and the second section B3 of the first uncoated section 146a have a lower height than the other sections and do not have a segment, and thus they are not substantially bent. This is the same for the second uncoated section 146b.

[0635] In this example as well, the bending surface area F can include a segment-skipping area a1, a height-variable area a2 of the segment, and a height-uniform area a3 of the segment from the core to the outer circumference. However, since the second section B3 is not bent, the radial length of the bending surface area F can be shorter than that of the first example.

[0636] As in the Fig. 10c, Fig. 10d and Fig. As shown in Figure 10e, the bending surface area F includes an area b1 with a uniform number of overlapping layers next to the segment skipping area a1, in which the number of overlapping layers of segments is 10 or more.

[0637] The bending surface area F can also include an area b2 with a decreasing number of overlap layers adjacent to the second section B3 of the electrode assembly 110, in which the number of overlapping layers of segments gradually decreases towards the outer circumference. For example, area b1 with a uniform number of overlap layers can be set as the welding target area.

[0638] In the bending surface area F, the preferred numerical ranges of the ratio (a2 / c), which is a ratio of the height-variable area a2 to a radius area containing segments (c), the ratio (b1 / c) of the area b1 with a uniform number of overlap layers to the radius area containing segments (c), and the ratio of the area of ​​the area b1 with a uniform number of overlap layers to the area of ​​the bending surface area F have already been described above and are therefore not described again.

[0639] The first pantograph 144 can be welded to the bending surface area F of the first uncoated section 146a and the second pantograph 145 can be welded to the bending surface area F of the second uncoated section 146b.

[0640] The overlap relationship of area b1 with uniform number of overlap layers and area b2 with decreasing number of overlap layers with the welding area W, the outer diameter of the first current collector 144 and the second current collector 145, the configuration in which the first section B1 does not close the core by at least 10% or more of its diameter, and the like are essentially the same as described above.

[0641] Meanwhile, the second section B3 has no segment and a height lower than that of the third section B2. Accordingly, when the first uncoated section 146a is bent, the second section B3 is essentially not bent. Since the second section B3 is sufficiently spaced from the corrugated section 147, it is also possible to solve the problem of the second section B3 being damaged while the corrugated section 147 is being pressed in.

[0642] The structures of the uncoated sections 146a and 146b can be modified to the structures shown in the examples above. Furthermore, a conventional uncoated section structure can be applied to any of the uncoated sections 146a and 146b without restriction.

[0643] Fig. Figure 25 is a sectional view showing a cylindrical battery 220 along the Y-axis, as in yet another example.

[0644] With reference to Fig. 25 includes the cylindrical battery 220 which is in Fig. 24 illustrated electrode assembly 100, and the other configuration besides electrode assembly 100 is essentially the same as that in Fig. 21 illustrated cylindrical battery 180. Therefore, with reference to the Fig. 21 and Fig. The configuration described in this example (24) can be applied essentially identically.

[0645] For example, the first and second uncoated sections 146a, 146b of the electrode assembly 100 are divided into a plurality of segments, and the plurality of segments is curved from the outer circumference towards the core. At this point, the first section B1 and the second section B3 of the first uncoated section 146a have a lower height than the other sections and do not have a segment, and thus they are not substantially curved. This is the same for the second uncoated section 146b.

[0646] Therefore, the bending surface area F in this example can be similar to the example of Fig. 24 includes a segment-skipping region a1, a height-variable region a2 of the segment, and a height-uniform region a3 of the segment from the core to the outer circumference. However, since the second section B3 is not curved, the radial length of the bending surface region F can be shorter than that of the first example.

[0647] As in the Fig. 10c, Fig. 10d and Fig. As shown in Figure 10e, the bending surface area F includes an area b1 with a uniform number of overlapping layers next to the segment skipping area a1, in which the number of overlapping layers of segments is 10 or more.

[0648] The bending surface area F can also include an area b2 with a decreasing number of overlap layers adjacent to the second section B3 of the electrode assembly 110, in which the number of overlapping layers of segments gradually decreases towards the outer circumference. For example, area b1 with a uniform number of overlap layers can be set as the welding target area.

[0649] In the bending surface area F, the preferred numerical ranges of the ratio (a2 / c), which is a ratio of the height-variable area a2 to a radius area containing segments (c), the ratio (b1 / c) of the area b1 with a uniform number of overlap layers to the radius area (c) containing segments, and the ratio of the area of ​​the area b1 with a uniform number of overlap layers to the area of ​​the bending surface area F have already been described above and are therefore not described again.

[0650] The first pantograph 144 can be welded to the bending surface area F of the first uncoated section 146a and the second pantograph 176 can be welded to the bending surface area F of the second uncoated section 146b.

[0651] The overlap relationship of area b1 with a uniform number of overlap layers and area b2 with a decreasing number of overlap layers with the welding area W, the outer diameter of the first current collector 144 and the second current collector 176, the configuration in which the first section B1 does not close the core by at least 10% or more of its diameter, and the like are essentially the same as described above.

[0652] The structures of the uncoated sections 146a and 146b can be modified to the structures according to the earlier examples (modifications). Furthermore, the conventional uncoated section structure can be applied to any of the uncoated sections 146a and 146b without restriction.

[0653] In the earlier examples (modified examples), the first pantograph 144 and the second pantograph 176, which are included in the cylindrical battery 170, 180, 200, 220, which includes the terminal 172, may have an improved structure, as shown in Fig. 26 and Fig. 27 shown.

[0654] The improved structure of the first pantograph 144 and the second pantograph 176 can help to reduce the resistance of the cylindrical battery, improve vibration resistance, and increase energy density. In particular, the first pantograph 144 and the second pantograph 176 are more effective when used in a large cylindrical battery where the diameter-to-height ratio is greater than 0.4.

[0655] Fig. Figure 26 is a top view showing the structure of the first pantograph 144 according to an example.

[0656] Referring to Fig. 23 and Fig. 26 Together, the first current collector 144 can comprise an edge section 144a, a first coupling section 144b of the uncoated section, and a connection coupling section 144c. The edge section 144a is arranged on the electrode assembly 110. The edge section 144a can have a substantially edge shape with a void formed therein (S openThe drawings of the present disclosure illustrate only one case in which the edge section 144a has a substantially circular border shape, but the present disclosure is not limited to this. The edge section 61 may have a substantially rectangular border shape, a hexagonal border shape, an octagonal border shape, or other border shapes, in contrast to the one illustrated. The number of edge sections 144a may be increased to two or more. In this case, another edge section in a border shape may be provided on the inside of the edge section 144a.

[0657] The connection coupling section 144c can have a diameter greater than or equal to the diameter of the flat section 172c formed on the bottom surface of the connection 172 to provide a welding area for coupling with the flat section 172c formed on the bottom surface of the connection 172.

[0658] The coupling section 144b of the first uncoated section extends inwards from the edge section 144a and is welded to the uncoated section 146a. The connection coupling section 144c is spaced apart from the coupling section 144b of the first uncoated section and is positioned within the edge section 144a. The connection coupling section 144c may be welded to the connection 172. The connection coupling section 144c may, for example, be located approximately in the middle of the interior (S openThe connection coupling section 144c is located within the core C of the electrode assembly 110, surrounded by the edge section 144a. The connection coupling section 144c can be positioned corresponding to the hole formed in the core C of the electrode assembly 110. The connection coupling section 144c can be designed to cover the hole formed in the core C of the electrode assembly 110, so that the hole is not exposed by the connection coupling section 144c. For this purpose, the connection coupling section 144c can have a larger diameter or width than the hole formed in the core C of the electrode assembly 110.

[0659] The coupling section 144b of the first uncoated section and the connecting coupling section 144c can be arranged not directly, but rather spaced apart and indirectly connected by the edge section 144a. Since the first pantograph 144 has a structure in which the coupling section 144b of the first uncoated section and the connecting coupling section 144c are not directly connected, but rather connected by the edge section 144c as described above, it is possible, when a shock and / or vibration occurs on the cylindrical battery 200, to distribute the shock exerted on the coupling section between the coupling section 144b of the first uncoated section and the first uncoated section 146a, and on the coupling section between the connecting coupling section 144c and the terminal 172.The drawings in the present disclosure illustrate only one case in which four coupling sections 144b of the first uncoated section are provided, but the present disclosure is not limited to this. The number of coupling sections 144b of the first uncoated section can be determined taking into account the manufacturing difficulty according to the complexity of the shape, electrical resistance, and space (p. open ) within edge section 144a, taking into account electrolyte impregnation and the like, may be determined differently.

[0660] The first current collector 144 can further comprise a bridge section 144d extending inwards from the edge section 144a and connected to the connecting coupling section 144c. At least a portion of the bridge section 144d can have a smaller cross-sectional area compared to the coupling section 144b of the first uncoated section and the edge section 144a. For example, at least a portion of the bridge section 144d can be configured to have a smaller width and / or thickness compared to the coupling section 144b of the first uncoated section. In this case, the electrical resistance in the bridge section 144d increases. As a result, if a current flows through the bridge section 144d, the relativ...

Claims

[1] Electrode assembly (A; 80) comprising a first electrode (10; 11), a second electrode (10; 11) and a separator (12) arranged between them, wherein the first electrode (10; 11), the second electrode (10; 11) and the separator (12) are wound around a winding axis (Y), wherein the first electrode (10; 11) has a first active material section coated with an active material layer (42) and a first uncoated section (43; 146a) which is free of the active material layer (42), wherein the first uncoated section (43; 146a) is located at an edge of the first electrode (10; 11) which extends along a winding direction (X), wherein the first uncoated section (43; 146a) is partially formed with several separate tabs (61) which are individually bendable in a radial direction of the electrode assembly (A; 80), wherein the height of an outermost region having an outermost winding turn of the first uncoated section (43; 146a) is less than the heights of the several separate tabs (61), wherein the several separate tabs (61) are bent along the radial direction in the direction of the winding axis (Y) of the electrode assembly (A; 80) to form a bending surface area (F), and wherein the bending surface area (F) comprises an area with a uniform number of overlap layers (b1) in which the number of overlapping layers of the separate tabs (61) is 10 or more, and an area with a decreasing number of overlap layers (b2) adjacent to the area with a uniform number of overlap layers (b1) in which the number of overlapping layers of the separate tabs (61) decreases in the radial direction away from the area with a uniform number of overlap layers (b1). [2] Electrode assembly (A; 80) according to claim 1, wherein the electrode assembly (A; 80) comprises a tab-skipping region (①) which does not have separate tabs (61), a height-variable region (②) in which the separate tabs (61) have heights which increase stepwise along the radial direction of the electrode assembly (A; 80), and a height-uniform region (②) in which the separate tabs (61) have a uniform height along the radial direction of the electrode assembly (A; 80), wherein, from a winding axis (Y) of the electrode assembly (A; 80), a radial position at which the region with a uniform number of overlap layers (b1) begins corresponds to a radial position at which the height-variable region (②) begins. [3] Electrode assembly (A; 80) according to claim 2, wherein an innermost area of ​​the first uncoated section (43; 146a) is not formed into separate tabs (61); and / or wherein the ratio of a radial size of the area with a uniform number of overlapping layers (b1) to a radial size of the area with a uniform number of overlapping layers (b1) and the area with a decreasing number of overlapping layers (b2) is 30% to 85%; and / or wherein the ratio of the length of an electrode region in the winding direction (X), corresponding to the tab-skipping region (①), to the total length of the first electrode (10; 11) in the winding direction (X) is 1% to 30%; and / or wherein the ratio of the length of an electrode region in the winding direction (X), corresponding to the height-variable region (②), to the total length of the first electrode (10; 11) in the winding direction (X) is 1% to 40%; and / or wherein the ratio of the length of an electrode region in the winding direction (X), corresponding to the height-unitary region (③), to the total length of the first electrode (10; 11) in the winding direction (X) is 50% to 90%. [4] Electrode assembly (A; 80) according to one of claims 1 to 3, wherein in the area divided into the several separate tabs (61) at least one, which is selected from widths of the separate tabs (61) in the winding direction (X), heights thereof in the winding axis direction and a lower internal angle (θ) thereof, increases stepwise along a direction parallel to the winding direction (X); and / or wherein the height of the innermost region of the first uncoated section (43; 146a) or of an outermost region of the first uncoated section (43; 146a) is less than the heights of the several separate tabs (61); and / or wherein the multiple separate tabs (61) are bent in the direction of the winding axis (Y) of the electrode assembly (A; 80) and at least 90% or more, based on a radial size, of a mean cylindrical area surrounded by the electrode assembly (A; 80) is not covered by the bent section of the separate tabs (61). [5] Electrode assembly (A; 80) according to claim 1, wherein the first uncoated section (43; 146a) has a first section (B1) comprising an innermost winding turn, a second section (B3) corresponding to the outermost region, and a third section (B2) arranged between the first section (B1) and the second section (B3). [6] Electrode assembly (A; 80) according to claim 5, wherein the height of the first section (B1) is less than the height of the third section (B2). [7] Electrode assembly (A; 80) according to claim 5 or 6, wherein the second section (B3) in a state bent along a radial direction of the electrode assembly (A; 80) is defined as the electrode tab; and / or wherein the third section (B2) is defined as the electrode tab in a state bent along a radial direction of the electrode assembly (A; 80). [8] Electrode assembly (A; 80) according to one of claims 5 to 7, wherein the third section (B2) is at least partially formed with several separate tabs (61) which are individually bendable. [9] Electrode assembly (A; 80) according to claim 8, wherein a width in the winding direction (X) is determined, wherein the width of one or more or each of the several separate tabs (61): decreases in the winding axis direction away from the active material layer (42); or in the winding axis direction away from the active material layer (42) decreases and then increases; or in the winding axis direction away from the active material layer (42) increases and then decreases; or along the winding axis direction away from the active material layer (42) increases and then remains constant; or decreases along the winding axis direction away from the active material layer (42) and then remains constant; or remains unchanged along the winding axis direction. [10] Electrode assembly (A; 80) according to claim 8 or 9, wherein the width of at least one of the several separate tabs (61) at an outermost position is smaller than at an innermost position in the winding axis direction; or the width of at least one of the several separate tabs (61) at an outermost position is equal to that at an innermost position in the winding axis direction. [11] Electrode assembly (A; 80) according to one of claims 8 to 10, wherein the multiple separate tabs (61) are shaped such that they form internal angles proximal to the active material layer (42), which increase individually or in groups in the winding direction (X); and / or wherein the interior angles of the several separate tabs (61) increase individually or in groups in the range of 60 to 85 degrees in a direction parallel to the winding direction (X), wherein the interior angle (θ) is an angle between a straight line extending from a bottom section (63a) of a cut groove (63) and a straight line extending from a side section (63b) of the tab (61). [12] Electrode assembly (A; 80) according to claim 8 or claim 10, wherein the width of one or more or each of the several separate tabs (61) decreases in the winding axis direction away from the active material layer (42), wherein an internal angle θ of a separate tab (61) located at a position corresponding to a radial distance r from the winding axis (Y) of the electrode assembly (A; 80) satisfies the following: cos−1(0.5∗Dr)≤θ≤tan−1(2∗H∗tanθrefer2∗H−p∗tanθrefer) where D is a width of the separate tab (61) in the winding direction (X), r is a radial distance from the winding axis (Y) of a respective separate tab (61), H is a height of the separate tab (61) and p is a separation distance of the separate tab (61). [13] Electrode assembly (A; 80) according to one of claims 8 to 12, wherein one or more or each of the several separate tabs (61) has a side (63b) that is convex outwards or convex inwards; and / or wherein one or more or each of the several separate tabs (61) has a rounded corner on a respective outer side. [14] Electrode assembly (A; 80) according to any one of claims 8 to 13, wherein the cutting groove (63) is formed between each of the separate tabs (61) that are adjacent in the winding direction (X), the corners of the cut groove (63) are rounded. [15] Electrode assembly (A; 80) according to claim 14, wherein the corners of the cutting groove (63) are rounded with a radius of curvature of 0 to 0.1 mm or 0.01 mm to 0.05 mm. [16] Electrode assembly (A; 80) according to claim 14 or 15, wherein an inside of the cutting groove (63) between the corners is flat; and / or wherein an inner side of the cut groove (63) is spaced away from the active material layer (42) by a fixed distance, in particular by 0.2 mm to 4 mm. [17] Electrode assembly (A; 80) according to one of claims 14 to 16, wherein the several separate tabs (61) are spaced apart from each other in the winding direction (X) by a separation distance (P), where the separation distance (P) is 0.05 mm to 1.00 mm. [18] Electrode assembly (A; 80) according to one of claims 14 to 17, wherein the multiple separate tabs (61) are made of aluminum foil. [19] Electrode assembly (A; 80) according to one of claims 14 to 18, wherein one or more or each of the several separate tabs (61) are bent at a position which is located on an inside of the adjacent cut groove (63) or is offset outwards from an inside of the adjacent cut groove (63) by 1 mm or less. [20] Electrode assembly (A; 80) according to any one of claims 8 to 19, wherein one or more or each of the several separate tabs (61) have lateral sides which define boundaries of the respective separate tab (61) in the winding direction (X), where: the lateral sides are provided such that, after bending the respective separate tab (61), they form a central angle of 45 degrees or less at the winding axis (Y) of the electrode assembly (A; 80); and / or the lateral sides are provided in such a way that, after bending the respective separate tab (61), they form central angles on the winding axis (Y) of the electrode assembly (A; 80) which remain constant. [21] Electrode assembly (A; 80) according to one of claims 8 to 20, wherein for one or more or each of the several separate tabs (61) D(r) the following formula is satisfied: 1≤D(r)≤(2⋅π⋅r / 360°)⋅45° where r is a distance of the respective separate tab (61) from the winding axis (Y) of the electrode assembly (A; 80) in the radial direction and D(r) is a width of the respective separate tab (61) in the winding direction (X). [22] Electrode assembly (A; 80) according to claim 21, where D(r) increases continuously or stepwise as r increases; or where D(r) decreases continuously or stepwise as r increases; or where D(r) increases continuously or stepwise and then decreases as r increases. [23] Electrode assembly (A; 80) according to any one of claims 8 to 22, wherein the widths of the multiple separate tabs (61) increase at a constant rate in the winding direction (X) of the electrode assembly (A; 80); and / or wherein the widths of the several separate tabs (61) increase in the radial direction depending on a distance r from the winding axis (Y) of the electrode assembly (A; 80); and / or the widths of the several separate tabs (61) vary within a range of 1 mm to 11 mm. [24] Electrode assembly (A; 80) according to any one of claims 5 to 23, wherein in at least one sub-area of ​​the second section (B3) and / or the third section (B2) of the first uncoated section (43; 146a) the height of the first uncoated section (43; 146a), in particular of the several separate tabs (61) thereof, changes continuously or stepwise in the winding direction (X). [25] Electrode assembly (A; 80) according to any one of claims 5 to 24, wherein the third section (B2) is subdivided into several areas along the winding direction (X), wherein the height of the first uncoated section (43; 146a) differs in two different areas, and in particular the heights of the several separate tabs (61) differ in two different areas. [26] Electrode assembly (A; 80) according to one of claims 8 to 25, wherein the first uncoated section (43; 146a) comprises: a height-variable area (②) in which the heights of the separate tabs (61) are stepwise from a first height (h1) to an (N-1)th height h N-1 increase, where N is an altitude index and a natural number of 2 or more, in particular 2 to 30; and a height-uniform area (②) in which the heights of the separate tabs (61) remain unchanged at an N-th height h N be held, whereby h N greater than h N-1 is. [27] Electrode assembly (A; 80) according to claim 26, wherein separate tabs (61) of the same height hk are arranged in the same winding turn around the winding axis (Y); and / or wherein at least 90% of a hollow core section of the electrode assembly (A; 80), with respect to a size in the radial direction, remains uncovered after bending by the separate tabs (61); and / or where rk specifies a distance from the winding axis (Y) in a radial direction and r c a radius of a central hollow section of the electrode assembly (A; 80) and hk indicates the height of separate tabs (61) located at rk, hk and rk being such that they satisfy the following: 2 mm≤hk≤rk−α⋅rc where α is between 0.90 and 1. [28] Electrode assembly (A; 80) according to any one of claims 8 to 27, wherein the electrode assembly (A; 80) comprises: a tab-skipping area (②), for example the first section (B1) which does not have separate tabs (61); a height-variable area (②) in which the separate tabs (61) have variable heights; and a height-uniform area (②) in which the separate tabs (61) have a uniform height in a radial direction or in the winding direction (X), wherein the multiple separate tabs (61) arranged in the height-variable region (②) and the height-uniform region (③) are bent in the radial direction to form the bending surface region (F). [29] Electrode assembly (A; 80) according to claim 28, where the third section (B2) corresponds to the variable-height area (②) and the uniform-height area (③); or where the height-variable area (②) and the height-uniform area (③) correspond to the second section (B3) and the third section (B2), respectively. [30] Electrode assembly (A; 80) according to claim 28 or 29, wherein in the height-variable region (②) and the height-uniform region (③) a maximum height h max the following formula is satisfied for the separate tabs (61): hmax≤Wfoil−Wscrap,min−Wmargin,min−Wgap where W foil a width of a current collector film before separate tabs (61) are formed; W scrap,mina width that corresponds to a minimal offcut margin when separate tabs (61) are formed by cutting the current collector foil; W margin,min a width corresponding to a minimal meander edge of the separator (12); and W gap a width which corresponds to an insulating gap between one end of the separator (12) and one end of the second electrode (10; 11) which faces the first electrode (10; 11), with the separator (12) positioned between them. [31] Electrode assembly (A; 80) according to claim 30, wherein the first electrode (10; 11) is a positive electrode (10) and the insulating gap (W gap ) in the range of 0.2 mm to 6 mm; and / or wherein the first electrode (10; 11) is a negative electrode (11) and the insulating gap (W gap ) in the range of 0.1 mm to 2 mm. [32] Electrode assembly (A; 80) according to claim 30 or 31, wherein: the minimum trimming waste margin (W scrap,min ) zero or in the range of 1.5 mm to 8 mm; and / or the minimal meander edge (W margin,min ) is in the range of 0 to 1 mm; and / or [33] Electrode assembly (A; 80) according to one of claims 28 to 32, wherein: the heights of the separate tabs (61) arranged in the height-variable area (②) gradually or stepwise increase within the range of 2 mm to 10 mm; and / or a ratio of a radial size of the tab-overlap area (①) to a radius of the electrode assembly (A; 80) with the exception of a hollow core section in the radial direction of the electrode assembly (A; 80) is 10% to 40%; and / or a ratio of a radial size of the height-variable area (②) to a radial size corresponding to the height-variable area (②) and the height-uniform area (③) in the radial direction of the electrode assembly (A; 80) is 1% to 50%; and / or a ratio of the length of an electrode area corresponding to the tab-skipping area (①) to the total length of the first electrode (10; 11) in the winding direction (X) is 1% to 30%; and / or a ratio of the length of an electrode area corresponding to the height-variable area (②) to the total length of the first electrode (10; 11) in the winding direction (X) is 1% to 40%; and / or wherein the ratio of the length of an electrode area corresponding to the height-unit area (③) to the total length of the first electrode (10; 11) in the winding direction (X) is 50% to 90%. [34] Electrode assembly (A; 80) according to any one of claims 8 to 33, wherein widths in the winding direction (X) and / or heights in the winding axis direction of the several separate tabs (61): continuously or gradually increase in the winding direction (X); and / or increase in the winding direction (X) and then decrease; and / or decrease in the winding direction (X) and then increase. [35] Electrode assembly (A; 80) according to any one of claims 8 to 34, wherein the several separate tabs (61) form several tab groups along a direction parallel to the winding direction (X) of the electrode assembly (A; 80), wherein: separate tabs (61) belonging to one of the tab groups have the same width in the winding direction (X) and / or the same height in the winding axis direction; and / or separate tabs (61) belonging to a different tab group have increasing widths in the winding direction (X) and / or increasing heights in the winding direction (X); and / or three successive tab groups each have widths W1, W2 and W3 in the winding direction (X), where a ratio W3 / W2 is smaller than a ratio W2 / W1. [36] Electrode assembly (A; 80) according to any one of claims 5 to 35, wherein the first section (B1) and / or the second section (B3) is not formed into separate tabs (61) and is not bent along a radial direction of the electrode assembly (A; 80). [37] Electrode assembly (A; 80) according to one of claims 5 to 36, wherein an insulating coating layer, for example a polymer resin and an inorganic filler dispersed in the polymer resin, is formed at a boundary between the active material layer (42) and the provided first uncoated section (43; 146a). [38] Electrode assembly (A; 80) according to claim 37, wherein: the insulating coating layer is formed to cover a boundary section of the active material layer (42) and the first uncoated section (43; 146a) along the winding direction (X); and / or the insulating coating layer is formed to cover the boundary section of the active material layer (42) and the first uncoated section (43; 146a) along the winding axis direction with a width of 0.3 mm to 5 mm; and / or one end of the insulation coating layer is arranged within the range of -2 mm to 2 mm along the winding axis direction with respect to one end of the separator (12); and / or the insulating coating layer is exposed by the separator (12); and / or an inner side of a cut groove (63) formed in the first uncoated section (43; 146a) and the insulating coating layer are spaced apart by a distance of 0.5 mm to 2 mm; and / or one end of the insulation coating layer is arranged in the winding axis direction within the range of -2 mm to +2 mm with respect to a lower end of the cut groove (63) formed in the first uncoated section (43; 146a). [39] Electrode assembly (A; 80) according to claim 38, wherein the second electrode (10; 11) is coated with an active material layer (42) in a second active material section and an end of the second active material section overlaps the insulation coating layer in a radial direction in a viewing direction in the winding axis direction. [40] Electrode assembly (A; 80) according to any one of claims 5 to 39, wherein the third section (B2) and / or the second section (B3) are each formed with several separate tabs (61) which are individually bendable. [41] Electrode assembly (A; 80) according to claim 40, wherein the number of separate tabs (61) intersecting a virtual line parallel to the winding axis direction at any radial location of the bending surface area (F) based on a core center of the electrode assembly (A; 80) is defined as the number of overlapping layers of the separate tabs (61) at the corresponding radial location. [42] Electrode assembly (A; 80) according to claim 41, wherein a radial size of the area with a uniform number of overlap layers (b1) and of the area with a decreasing number of overlap layers (b2) corresponds to a radial size of an area in which the multiple separate tabs (61) are formed. [43] Electrode assembly (A; 80) according to claim 41 or 42, wherein the electrode assembly (A; 80) comprises a tab-skipping region (①) which has no separate tabs (61), a height-variable region (②) in which separate tabs (61) have variable heights, and a height-uniform region (③) in which separate tabs (61) have a uniform height in sequence along the radial direction; and / or wherein a radial position from the winding axis (Y) of the electrode assembly (A; 80) at which the area with uniform number of overlap layers (b1) begins corresponds to a radial position at which the height-variable area (②) begins. [44] Electrode assembly (A; 80) according to one of claims 41 to 43, wherein the first electrode (10; 11) is a positive electrode (10) and in the region with a uniform number of overlap layers (b1) the overlap thickness of the separate tabs (61) is between 100 µm and 875 µm; and / or wherein the first electrode (10; 11) is a negative electrode (11) and in the area with uniform number of overlap layers (b1) the overlap thickness of the separate tabs (61) is between 50 µm and 700 µm. [45] Electrode assembly (A; 80) according to claim 41, wherein a ratio of a radial size of the area with a uniform number of overlapping layers (b1) to a radial size of the area with a uniform number of overlapping layers (b1) and of the area with a decreasing number of overlapping layers (b2) is 30% to 85%. [46] Electrode assembly (A; 80) according to one of claims 40 to 45, further comprising: a current collector (41) which is welded to the bending surface area (F), wherein a welding area (W) of the current collector (41) overlaps the area with a uniform number of overlap layers (b1) by at least 50% in the radial direction of the electrode assembly (A; 80). [47] Electrode assembly (A; 80) according to claim 46, wherein the welding area (W) of the current collector (41) extends such that it also overlaps the area with decreasing number of overlap layers (b2). [48] ​​Electrode assembly (A; 80) according to claim 46 or 47, wherein an edge of the current collector (41) is arranged on the bending surface area (F) to cover one end of a bent section of outermost separate tabs (61) in the radial direction of the electrode assembly (A; 80). [49] Electrode assembly (A; 80) according to claim 47 or 48, wherein the current collector (41) is welded to the bending surface area (F), in particular such that it has a weld strength of 196 kPa (2 kgf / cm²). 2 ) or more or 392 kPa (4 kgf / cm²) 2 ) or more. [50] Electrode assembly (A; 80) according to any one of claims 5 to 49, wherein the first uncoated section (43; 146a) is made of a metal foil, in particular an aluminum foil, the metal foil has an elongation of 1.5% to 3.0% and a tensile strength of 245 MPa (25 kgf / mm²). 2 ) up to 343 MPa (35 kgf / mm²) 2 ) exhibits. [51] Electrode assembly (A; 80) according to claim 50, wherein the first electrode (10; 11) has a curvature length of less than 20 mm. [52] Electrode assembly (A; 80) according to any one of claims 5 to 51, wherein the first active material section has a short side along the winding axis direction and a long side along the winding direction (X), where the size ratio of the short side to the long side is between 1% and 4%. [53] Electrode assembly (A; 80) according to one of claims 5 to 52, wherein the height of the second section (B3) decreases continuously or stepwise in the radial direction or winding direction (X). [54] Electrode assembly (A; 80) according to any one of claims 5 to 53, wherein the second section (B3) and the third section (B2) are formed with several separate tabs (61) which are individually bendable, wherein the widths and / or heights of the separate tabs (61) in the second section (B3) are greater than those of the separate tabs (61) in the third section (B2). [55] Electrode assembly (A; 80) according to any one of claims 7 to 54, wherein the third section (B2) comprises a tab-skipping area (①) which does not have separate tabs (61). [56] Electrode assembly (A; 80) according to claim 55, wherein: the third section (B2) comprises several tab-skipping areas (①) which optionally have widths that increase or decrease along the winding direction (X); and / or a height of the tab-over area (①) is equal to a height of the first section (B1) or the second section (B3); and / or the several separate tabs (61) are arranged within a preset central angle, for example 20 degrees or more, on the winding axis (Y) of the electrode assembly (A; 80); and / or the several separate tabs (61) are arranged in at least two circular sectoral areas or polygonal areas, which are arranged in a top view in the winding axis direction of the electrode assembly (A; 80). [57] Electrode assembly (A; 80) according to any one of claims 5 to 56, wherein the second electrode (10; 11) has a second active material section coated with another active material layer (42) and a second uncoated section (145) that is free from the other active material layer (42) at an edge of the second electrode (10; 11) extending along the winding direction (X), wherein the second uncoated section (145) is designed to provide an electrical connection with the first electrode (10; 11), wherein the second uncoated section (145) is partially subdivided into several separate tabs (61) which can be bent individually. [58] Battery, comprising: the electrode assembly (A; 80) according to one of claims 1 to 57; a battery housing (142) with an open end and a bottom section opposite it, wherein the electrode assembly (A; 80) is housed in the battery housing (142), wherein the battery housing (142) is electrically connected to the first electrode (10; 11) and the second electrode (10; 11); a sealing body (143) designed to seal the open first end face of the battery housing (142); and a terminal (172) which is electrically connected to the other of the first electrode (10; 11) and the second electrode (10; 11) and has a surface which is exposed to the outside of the battery housing (142). [59] Battery according to claim 58, wherein the first uncoated section (43; 146a) has a first section (B1) having an innermost winding turn, a second section (B3) corresponding to the outermost region, and a third section (B2) arranged between the first section (B1) and the second section (B3), wherein the battery housing (142) has a corrugated section (147) which is pressed inwards at an area adjacent to the first end surface, wherein the surface of the corrugated section (147) and the second section (B3) are spaced apart from each other by a predetermined distance. [60] Battery according to claim 59, wherein an indentation depth (D1) of the corrugated section (147) is equal to or greater than a distance (D2) from the inner circumference of the battery housing (142) to a boundary between the second section (B3) and the third section (B2). [61] Battery according to claim 58 or 59, further comprising: a pantograph (41) which is electrically coupled to the third section (B2); and an insulator (146) configured to cover the pantograph (41) and having an edge positioned and fixed between the inner circumference of the corrugated section (147) and the pantograph (41). [62] Battery according to claim 61, wherein a diameter of the current collector (41) is smaller than a minimum inner diameter of the inner circumference of the corrugated section (147) and a diameter of the current collector (41) is equal to or larger than an outermost diameter of the third section (B2); and / or wherein the current collector (41) is arranged higher than the bead section (147) in the winding axis direction. [63] Battery according to any one of claims 58 to 62, wherein the sealing body (143) comprises a cap (143a) forming, for example, the terminal (172) designed to seal the open first end of the battery housing (142), a seal (143b; 178b) arranged between an edge of the cap (143a) and the open end of the battery housing (142), and a crimp section (148) which is bent and extends into the battery housing (142) and is designed to surround and hold the edge of the cap (143a) together with the seal (143b; 178b). [64] Battery according to claims 58 to 63, further comprising: a first current collector (144) which is electrically connected to the first uncoated section (43; 146a), wherein the connection (172) is a through-connection which is inserted into a perforation hole which is formed in the second end face of the battery housing (142), wherein the connection is isolated from the battery housing (142) and electrically connected to the first current collector (144), for example by an insulator (146) arranged between an inner surface of a lower section of the battery housing (142) and an upper surface of the first current collector (144) to electrically isolate the inner surface of the lower section of the battery housing (142) and the first current collector (144). [65] Battery according to claim 64, wherein the insulator (146) has a thickness corresponding to the distance between the inner surface of the lower section of the battery housing (142) and the upper surface of the first current collector (144) and is in close contact with the inner surface of the lower section of the battery housing (142) and the upper surface of the first current collector (144); and / or wherein the connection (172) includes a flat section (172c) at a lower end thereof, the insulator (146) has an opening for exposing the flat section (172c) and the flat section (172c) is welded through the opening to the first current collector (144). [66] Battery according to any one of claims 58 to 64, wherein the second electrode (10; 11) has a second active material section coated with an active material layer (42) and a second uncoated section (145) which is not coated with an active material layer (42) along the winding direction (X), the second electrode (10; 11) has a first polarity, at least a part of the second uncoated section (145) is defined as an electrode tab and the battery further includes a second current collector (145; 176) which is electrically connected to the second uncoated section (145) and has an edge which is at least partially coupled to a side wall of the battery housing (142). [67] Battery according to any one of claims 64 to 66, wherein the second electrode (10; 11) has a second active material section coated with a second active material and a second uncoated section (145) that is free of the second active material, wherein the second uncoated section (145) is located at an edge of the second electrode (10; 11) extending along the winding direction (X), wherein the second uncoated section (145) provides an electrical connection with the second electrode (10; 11), wherein the battery further includes a second current collector (145; 176) which is electrically connected to the second uncoated section (145) and has an edge which is electrically coupled to a side wall of the battery housing (142) which extends between the first end face and the second end face, wherein the first pantograph (144) has an outer diameter that is equal to or greater than that of the second pantograph (145; 176). [68] Battery according to claim 67, wherein the first current collector (144) and the second current collector (145; 176) are each welded to the first uncoated section (43; 146a) and the second uncoated section (145) along a radial direction of the electrode assembly (A; 80) to form a respective welding pattern, wherein a length of the welding pattern of the first pantograph (144) is longer than a length of the welding pattern of the second pantograph (145; 176). [69] Battery according to claim 68, wherein the welding pattern of the first current collector (144) and the welding pattern of the second current collector (145; 176) are arranged at substantially the same distance from the winding axis (Y) of the electrode assembly (A; 80). [70] Battery according to any one of claims 67 to 69, wherein the battery housing (142) has a corrugated section (147) which is pressed inwards adjacent to the first end face, wherein the edge of the second current collector (145; 176) is electrically connected to the corrugated section (147), in particular welded. [71] Battery according to claim 70, wherein a region of the second current collector (145; 176) in electrical contact with the second uncoated section (145) is surrounded by the beaded section (147) in a top view in the winding axis direction. [72] Battery according to claim 70 or 71, wherein the battery has a cap (143a) with an edge supported by the beaded section (147) and having no polarity, a seal (143b; 178b) arranged between the edge of the cap (143a) and the open end of the battery housing (142), and a crimp section (148) which is bent and extends into the open end of the battery housing (142) and is designed to surround and hold the edge of the cap (143a) together with the seal (143b; 178b), and the edge of the second current collector (145; 176) is arranged and secured between the beaded section (147) and the seal (143b; 178b) by the crimp section (148). [73] Battery according to any one of claims 58 to 72, wherein the battery further comprises a current collector (41) which includes a welded area (W) which is welded to an area with a uniform number of overlap layers (b1) of the first uncoated area, and wherein the first electrode (10; 11) is a positive electrode (10) and the overlapping layers of the separate tabs (61) in the welding area (W) have a thickness in the range of 100 µm to 875 µm; or wherein the first electrode (10; 11) is a negative electrode (11) and the overlap layers of the separate tabs (61) in the welding area (W) have a thickness in the range of 50 µm to 700 µm. [74] Battery pack (300) comprising several batteries (301) according to any one of claims 58 to 73. [75] Battery pack (300) according to claim 74, wherein the ratio of diameter to height of the battery is greater than 0.

4. [76] Battery pack (300) according to claim 74 or 75, wherein the battery has a form factor of 46110, 4875, 48110, 4880 or 4680. [77] Battery pack (300) according to one of claims 74 to 76, wherein the multiple batteries (301) are arranged in a predetermined number of columns such that a terminal (172) of each battery and an outer surface of a bottom section of a battery housing (142) of each battery face upwards. [78] Battery pack (300) according to claim 77, further comprising: several busbars (210) configured to connect the multiple batteries (301) in series and parallel, wherein the multiple busbars (21) are arranged on an upper section of the multiple batteries (301), and Each of the busbars (210) includes a body section (211) configured to extend between the terminals (172) of adjacent batteries; several first busbar terminals (213) configured to extend from one side of the body section (211) and electrically coupled to a terminal (172) of a battery located on one side; and several second busbar terminals (213) configured to extend from the other side of the body section (211) and electrically coupled to an outer surface of the bottom of the battery housing (142) of a battery located on the other side. [79] Vehicle (V) comprising the battery pack (300) according to any one of claims 74 to 78.

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