Electrode assembly, cylindrical battery, and battery pack and vehicle including same

Abstract

The present invention provides an electrode assembly, a cylindrical battery, a battery pack and a vehicle. The electrode assembly comprises: a first electrode and a second electrode that are wound around one axis so as to define a core and an outer circumferential surface; and a separator interposed therebetween. The first electrode and / or the second electrode includes an uncoated portion extending in a winding direction along a long side end portion thereof. The uncoated portion includes a plurality of segment pieces that are separated by a cut groove formed in the winding direction and are independently bendable. The plurality of segment pieces are bent toward the core so as to form a bent surface area at one end of the electrode assembly. At least some of the plurality of segment pieces include a folded end portion.

Description

Electrode assembly, cylindrical battery and battery pack and vehicle including the same

[0001] The present invention relates to an electrode assembly, a cylindrical battery, and a battery pack and a vehicle including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0105883, filed on August 11, 2023, and Korean Patent Application No. 10-2024-0107867, filed on August 12, 2024, the contents of which are hereby incorporated by reference herein.

[0003] Secondary batteries, which have high applicability according to product group and electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electrical power sources.

[0004] These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency because they not only have the primary advantage of drastically reducing the use of fossil fuels, but also have the advantage of producing no byproducts from energy use.

[0005] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary batteries, i.e., unit batteries, is approximately 2.5 V to 4.5 V. Therefore, when a higher output voltage is required, multiple batteries are connected in series to form a battery pack. Furthermore, depending on the required charge / discharge capacity of the battery pack, a number of batteries are connected in parallel to form a battery pack. Therefore, the number of batteries included in the battery pack and the electrical connection type can be set in various ways depending on the required output voltage and / or charge / discharge capacity.

[0006] Meanwhile, cylindrical, prismatic, and pouch-shaped batteries are known as types of unit secondary batteries. In the case of a cylindrical battery, a separator, which is an insulator, is interposed between the positive and negative electrodes, and the separator is wound to form a jelly-roll-shaped electrode assembly, which is then inserted into a battery housing to form a battery. The battery housing is referred to in the art as a battery can. In addition, a strip-shaped electrode tab may be connected to each of the non-coated portions of the positive and negative electrodes, and the electrode tab electrically connects the electrode assembly and the electrode terminal exposed to the outside. For reference, the positive terminal is a cap of a sealing body that seals the opening of the battery housing, and the negative terminal is the battery housing. However, according to a conventional cylindrical battery having such a structure, since the current is concentrated on the strip-shaped electrode tab connected to the positive non-coated portion and / or the negative non-coated portion, there were problems such as high resistance, high heat generation, and poor current collection efficiency.

[0007] Resistance and heat generation are not major issues for small cylindrical batteries with form factors such as 1865 (diameter: 18 mm, height: 65 mm) or 2170 (diameter: 21 mm, height: 70 mm). However, increasing the form factor for cylindrical batteries for electric vehicles can lead to problems such as excessive heat generation around the electrode tabs during rapid charging, potentially leading to ignition of the cylindrical battery.

[0008] To solve these problems, a cylindrical battery (so-called tab-less cylindrical battery) was proposed, which has a structure in which a positive electrode non-conducting portion and a negative electrode non-conducting portion are located at the top and bottom of a jelly roll type electrode assembly, respectively, and a current collector is welded to these non-conducting portions to improve current collection efficiency.

[0009] Figures 1 to 3 are drawings illustrating the manufacturing process of a tab-less cylindrical battery. Figure 1 illustrates the structure of an electrode, Figure 2 illustrates the winding process of the electrode, and Figure 3 illustrates the process of welding a current collector to the folded surface area of ​​the non-conductive portion.

[0010] Referring to FIGS. 1 to 3, the positive electrode (10) and the negative electrode (11) have a structure in which an active material (21) is coated on a sheet-shaped current collector (20), and includes a non-conductive portion (22) on one long side along the winding direction (X). The long side means a side that is relatively long in a direction parallel to the X-axis.

[0011] The electrode assembly (A) is manufactured by sequentially stacking a positive electrode (10) and a negative electrode (11) together with two separators (12) as illustrated in Fig. 2, and then winding them in one direction (X) around one axis of the core (33). The stacking order of the positive electrode (10) and the negative electrode (11) may be opposite to that illustrated. The non-coated portions of the positive electrode (10) and the negative electrode (11) are arranged in opposite directions.

[0012] After the winding process, the non-coated portion (10a) of the positive electrode (10) and the non-coated portion (11a) of the negative electrode (11) are folded toward the core side. Thereafter, current collectors (30, 31) are welded to the non-coated portions (10a, 11a), respectively, to join them.

[0013] The positive electrode uncharged portion (10a) and the negative electrode uncharged portion (11a) are not connected with separate electrode tabs, the current collectors (30, 31) are connected to external electrode terminals, and the current path is formed with a large cross-sectional area along the winding axis direction of the electrode assembly (A) (see arrow), so there is an advantage in that the resistance of the battery can be reduced. This is because the resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0014] Meanwhile, the folded portion of the non-coated portion (10a, 11a) to which the current collector (30, 31) is welded is overlapped in multiple layers as illustrated in FIG. 3. Therefore, the folded surface area formed when the non-coated portion (10a, 11a) is folded has almost no gap through which the electrolyte can pass in the direction of the winding axis. This is because most of the gaps between the winding turns that existed immediately after winding disappear during the process of folding the non-coated portion (10a, 11a). Therefore, the electrode assembly manufactured with a conventional tab-less structure has a disadvantage in that the electrolyte impregnation speed is slow. This is because the folded surface area does not have sufficient gaps through which the electrolyte can move into the interior of the electrode assembly.

[0015] The present invention was created under the background of the above-described prior art, and its purpose is to provide an electrode assembly having an improved structure of the non-coated portion of the electrode so that a gap is sufficiently formed in the folded surface area of ​​the non-coated portion in which an electrolyte can be impregnated.

[0016] Another technical object of the present invention is to provide a battery including an electrode assembly of an improved structure, a battery pack including the same, and a vehicle including the battery pack.

[0017] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0018] In order to achieve the above technical task, an electrode assembly according to the present invention comprises a first electrode, a second electrode, and a separator interposed therebetween, which are wound around one axis to define a core and an outer circumferential surface, wherein at least one of the first electrode and the second electrode includes a non-coated portion extending in a winding direction along a long end portion, and the non-coated portion includes a plurality of independently foldable segments separated by a cutting groove formed along the winding direction, and the plurality of segments are folded toward the core to form a folded surface area at one end of the electrode assembly, and at least some of the plurality of segments may include a folded end portion.

[0019] The present invention defines a segment including a bend end as a bend end segment, and defines the number of uneven portions intersecting an imaginary straight line passing through the center of the bend end as the number of bends of the bend end.

[0020] The above-mentioned bending surface area may include a plurality of end bending segments.

[0021] The above-mentioned bending section has two or more bending times and can form a gap between radially adjacent segments of the electrode assembly.

[0022] The gap may have a spacing distance corresponding to the thickness of the folded end between radially adjacent segments of the electrode assembly.

[0023] The above plurality of end-bending segments can be arranged in a regular or irregular pattern along the radial or circumferential direction of the electrode assembly on the bending surface area.

[0024] The above-mentioned bending surface area may include a radial section in which the number of end bending segments arranged in the circumferential direction increases stepwise or gradually from the core to the outer surface.

[0025] The above-mentioned bending surface area may include a radius section in which the number of bends of the bending end increases stepwise or gradually from the core to the outer circumference.

[0026] The above-mentioned bending surface area may include a radius section in which the number of bends of the bending end remains the same from the core to the outer circumference.

[0027] The height of the plurality of end bending segments may increase stepwise from the core of the electrode assembly toward the outer periphery. In this case, the bending surface area may include a radius section in which the number of bendings of the bending ends also increases as the height of the end bending segments increases.

[0028] The above-mentioned bending surface area may include a radial section in which the width in the uniaxial direction of the non-woven portion forming the bending end increases stepwise or gradually from the core of the electrode assembly to the outer circumference.

[0029] The present invention defines the number of uncoated portions intersecting an imaginary line penetrating the folded surface area parallel to the axial direction at any point of the folded surface area as the number of uncoated portion layers at that point.

[0030] The above-mentioned bending surface area may include a section with an increasing number of layers and a section with a uniform number of layers.

[0031] The above-mentioned layer number increase section may be located close to the outer surface of the electrode assembly, and the layer number uniformity section may be located between the layer number increase section and the core of the electrode assembly.

[0032] The number of end bending segments included in the above-mentioned uniform number of layers section may be greater than the number of end bending segments included in the above-mentioned increased number of layers section.

[0033] The number of bendings of the bending ends included in the above-mentioned section of increasing the number of layers may be greater than the number of bendings of the bending ends included in the above-mentioned section of increasing the number of layers.

[0034] The above-mentioned folded end may have a structure folded in a jelly roll shape, a structure folded in a zigzag shape, or a structure folded randomly.

[0035] In order to achieve the above technical task, a cylindrical battery according to the present invention may include an electrode assembly comprising a first electrode, a second electrode, and a separator interposed therebetween, which are wound around one axis to define a core and an outer circumferential surface, and which includes at least one of the above-described features; a battery housing having an open end and a closed end, the electrode assembly being received through the open end, and being electrically connected to the second electrode of the electrode assembly; a sealing body sealing the open end of the battery housing; and a terminal electrically connected to the first electrode of the electrode assembly, the terminal having a surface exposed to the outside of the battery housing.

[0036] The above-mentioned bending surface area may be formed by bending a plurality of segments included in the non-conductive portion of the first electrode.

[0037] The cylindrical battery may further include a first collector plate electrically connecting the terminal and the folded surface area formed by the non-conductive portion of the first electrode.

[0038] The terminal may be installed in a through hole formed in a closed end of the battery housing so as to be insulated from the battery housing. A gasket may be interposed between the terminal and the through hole.

[0039] The terminal may include a terminal exposure portion exposed through the outer circumference of the closed end, and a terminal insertion portion extended from the terminal exposure portion and inserted into the interior of the battery housing through the through hole.

[0040] The lower edge of the terminal insertion portion may be riveted toward the inner surface of the closed end.

[0041] The sealing body may include a cap plate that seals the open end of the battery housing.

[0042] A gasket may be interposed between the edge of the cap plate and the open end of the battery housing.

[0043] The above terminal may be the above cap plate.

[0044] The above-mentioned bending surface area may be formed by bending a plurality of segments included in the non-conductive portion of the second electrode.

[0045] The cylindrical battery may further include a second collector plate electrically connecting a folded surface area formed by the non-conductive portion of the second electrode and a side wall of the battery housing.

[0046] The above battery housing may include a beaded portion formed by pressing an outer surface near the open end.

[0047] The edge of the second collector plate may be interposed between the gasket and the side wall of the battery housing.

[0048] The edge of the second collector plate may be in contact with a side wall of the battery housing, such as a beading portion.

[0049] If the side wall of the battery housing does not include a bead portion, the side wall may extend in a straight line between the closed end and the open end. In this case, the edge of the cap plate may be welded to the open end.

[0050] At least a portion of the second collector plate may be welded to the cap plate.

[0051] The above second collector plate can be electrically connected to the cap plate.

[0052] At least a portion of the inner edge area of ​​the cap plate may be welded to a folded surface area formed by the non-conductive portion of the second electrode facing the cap plate. In this case, the cap plate may replace the function of the second collector plate.

[0053] Another technical object of the present invention can be achieved by a battery pack comprising a plurality of the above-described cylindrical batteries.

[0054] Another technical object of the present invention can also be achieved by a vehicle including the battery pack.

[0055] According to the present invention, by improving the end structure of the segments, gaps used as a path for impregnating the electrolyte in the folded surface area formed by bending the segments can be sufficiently formed in the radial and / or circumferential direction, thereby shortening the impregnation time of the electrolyte.

[0056] According to another aspect of the present invention, a cylindrical battery including an electrode assembly having improved electrolyte impregnation properties, low internal resistance, and improved welding strength between a current collector and a non-conducting portion, a battery pack including the same, and a vehicle can be provided.

[0057] In addition, the present invention may have various other effects, which will be described in each embodiment, or the description of effects that can be easily inferred by a person skilled in the art will be omitted.

[0058] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0059] Figure 1 is a plan view showing the structure of an electrode used in the manufacture of a conventional tab-less cylindrical battery.

[0060] Figure 2 is a drawing showing an electrode winding process of a conventional tab-less cylindrical battery.

[0061] Figure 3 shows a process in which a current collector is welded to a folded surface area of ​​a non-conductive portion in a conventional tab-less cylindrical battery.

[0062] Figure 4 is a plan view showing the structure of an electrode according to an embodiment of the present invention.

[0063] FIG. 5 is a plan view exemplarily showing an electrode structure including a plurality of end-folded segments according to an embodiment of the present invention.

[0064] Fig. 6 is a drawing showing a cross-sectional structure of a folded end portion along line A-A' of Fig. 5.

[0065] Fig. 7 is a drawing showing another cross-sectional structure of a folded end along line A-A' of Fig. 5.

[0066] Fig. 8 is a drawing showing another cross-sectional structure of a folded end along line A-A' of Fig. 5.

[0067] Fig. 9 is a drawing showing another cross-sectional structure of a folded end along line A-A' of Fig. 5.

[0068] FIG. 10a is a perspective view showing the upper structure of an electrode assembly having a bending surface area formed according to an embodiment of the present invention.

[0069] Figure 10b is a plan view schematically showing the position of a bending end on a bending surface area according to an embodiment of the present invention with a dotted box.

[0070] Figure 10c is a cross-sectional view of a portion of a bending surface area according to an embodiment of the present invention, taken along the winding axis direction of the electrode assembly.

[0071] Fig. 11 is a cross-sectional view taken along the winding axis direction (Y) of a jelly roll type electrode assembly in which electrodes according to an embodiment of the present invention are applied to a first electrode (anode) and a second electrode (cathode).

[0072] Fig. 12 is a cross-sectional view of a cylindrical battery according to one embodiment of the present invention, taken along the winding axis direction (Y).

[0073] FIG. 13 is a cross-sectional view of a cylindrical battery according to another embodiment of the present invention, taken along the winding axis direction (Y).

[0074] FIG. 14 is a drawing schematically showing the configuration of a battery pack according to an embodiment of the present invention.

[0075] FIG. 15 is a schematic drawing of a vehicle including a battery pack according to an embodiment of the present invention.

[0076] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0077] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0078] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may have exaggerated dimensions. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0079] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 10%. Furthermore, uniformity of a parameter within a region may mean uniformity on average within that region.

[0080] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0081] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0082] Any configuration being placed "on (or below)" a component or "on (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0083] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0084] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C to D", this means C or more and D or less, unless otherwise stated.

[0085] For convenience of explanation, the direction along the longitudinal direction of the winding axis of the electrode assembly wound in the form of a jelly roll is referred to as the axial direction (Y) in this specification. In addition, the direction surrounding the winding axis is referred to as the circumferential direction or the peripheral direction (X). In addition, the direction approaching or away from the winding axis is referred to as the radial direction. Among these, the direction approaching the winding axis is referred to as the centripetal direction, and the direction away from the winding axis is referred to as the centrifugal direction.

[0086] First, an electrode assembly according to an embodiment of the present invention will be described. The electrode assembly may be a jelly roll type electrode assembly having a structure in which a first electrode and a second electrode having a sheet shape and a separator interposed therebetween are wound in one direction.

[0087] At least one of the first electrode and the second electrode includes a non-coated portion on a long side in the winding direction that is not coated with an active material. At least a portion of the non-coated portion is used as an electrode tab in its own right. The non-coated portion includes a core-side non-coated portion adjacent to the core of the electrode assembly, an outer-side non-coated portion adjacent to the outer peripheral surface of the electrode assembly, and an intermediate non-coated portion interposed between the core-side non-coated portion and the outer-side non-coated portion.

[0088] Preferably, at least one of the core-side plain part and the outer-side plain part has a relatively lower height than the middle plain part.

[0089] Figure 4 is a plan view showing the structure of an electrode (60) according to an embodiment of the present invention.

[0090] Referring to FIG. 4, the electrode (60) of the embodiment includes a current collector (41) made of a metal foil and an active material layer (42). The metal foil may be a conductive metal, such as aluminum or copper, and is appropriately selected depending on the polarity of the electrode (60). An 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 (60) includes a non-coated portion (43) at a long end in the winding direction (X). The non-coated portion (43) is a portion of the current collector (41) that is not coated with an active material.

[0091] In the electrode (60), the width of the active material portion in the short side direction of the current collector (41) may be 50 mm to 120 mm, and the length of the active material portion in the long side direction of the current collector (41) may be 3 m to 5 m.

[0092] Preferably, an insulating coating layer (44) may be formed at the boundary between the active material layer (42) and the non-coated portion (43). The insulating coating layer (44) is formed so that at least a portion overlaps the boundary between the active material layer (42) and the non-coated portion (43). The insulating coating layer (44) prevents a short circuit between two electrodes with different polarities that are opposed to each other with a separator therebetween. The insulating coating layer (44) may cover the boundary between the active material layer (42) and the non-coated portion (43) with a width of 0.3 mm to 5 mm. The insulating coating layer (44) may include a polymer resin and an inorganic filler such as SiO2 or Al2O3. The portion of the current collector (41) covered by the insulating coating layer (44) may be regarded as a non-coated portion since it is not a region coated with the active material layer.

[0093] The uncoated portion (43) includes a core-side uncoated portion (B1) adjacent to the core side of the electrode assembly, an outer-side uncoated portion (B3) adjacent to the outer-side of the electrode assembly, and an intermediate uncoated portion (B2) interposed between the core-side uncoated portion (B1) and the outer-side uncoated portion (B3).

[0094] The core-side uncoated region (B1), the outer-side uncoated region (B3), and the middle uncoated region (B3) can be defined as the uncoated region of the region adjacent to the core side, the uncoated region of the region adjacent to the outer side, and the uncoated region of the remaining region excluding these, respectively, when the electrode (40) is wound into a jelly roll type electrode assembly.

[0095] Hereinafter, the core-side plain part (B1), the outer-side plain part (B3), and the middle plain part (B2) are respectively named the first part, the second part, and the third part.

[0096] In one example, the first portion (B1) may be a non-conductive portion of an electrode region including the innermost winding turns, and the second portion (B3) may be a non-conductive portion of an electrode region including the outermost winding turns. The winding turns may be counted based on the core-side end of the electrode assembly.

[0097] In another example, the boundary of B1 / B2 may be suitably defined as a point where the height (or change pattern) of the uncoated region substantially changes from the core side of the electrode assembly to the periphery side, or as a point at a predetermined % of the radius of the electrode assembly (e.g., 5%, 10%, 15% of the radius, etc.).

[0098] The boundary of B2 / B3 can be defined as a point where the height (or change pattern) of the uncoated portion substantially changes from the outer periphery of the electrode assembly toward the core side, or a point at a predetermined percentage of the radius of the electrode assembly (e.g., 85%, 90%, 95% of the radius, etc.). Once the boundary of B1 / B2 and the boundary of B2 / B3 are specified, the third portion (B2) can be automatically specified.

[0099] If only the boundary of B1 / B2 is specified, the boundary of B2 / B3 can be appropriately selected at a point near the outer periphery of the electrode assembly. In one example, the second portion can be defined as the uncoated portion of the electrode region constituting the outermost turn. Conversely, if only the boundary of B2 / B3 is specified, the boundary of B1 / B2 can be appropriately selected at a point near the core side of the electrode assembly. In one example, the first portion (B1) can be defined as the uncoated portion of the electrode region constituting the innermost turn.

[0100] It is not excluded that another structure may be interposed between the first part (B1) and the third part (B2). Furthermore, it is not excluded that another structure may be interposed between the third part (B2) and the second part (B3).

[0101] The electrode (60) has a first portion (B1) and a second portion (B3) whose heights are greater than or equal to 0, but are relatively smaller than the third portion (B2). In addition, the heights of the first portion (B1) and the second portion (B3) may be the same or different. In the winding direction, the third portion (B2) is longer than the first portion (B1) and the second portion (B3).

[0102] Width (d) of the first part (B1) B1 ) is designed by applying the condition that the core of the electrode assembly is not covered when the non-woven part of the third part (B2) is folded toward the core side. The core refers to the cavity existing at the center of the winding of the electrode assembly. The width (d) of the first part (B1) B1 ) can increase in proportion to the bending length of the core and the most adjacent non-woven part. The width (d) of the first part (B1) B1 ) can be set to 180 mm to 350 mm depending on the diameter of the electrode assembly core and the bending length of the non-conductive region closest to the core.

[0103] The plain portion of the third part (B2) may include a plurality of independently bendable segments (61) separated by a cutting groove (63) formed along the winding direction (X).

[0104] The plurality of segments (61) may have a height that gradually increases from the core side to the outer periphery side. Alternatively, the plurality of segments (61) may have a height that remains the same from the core side to the outer periphery side.

[0105] The plurality of segments (61) have a geometric shape whose width decreases from the bottom to the top. The geometric shape may be a trapezoid. The shape of the geometric shape can be transformed into various shapes, such as a square or a parallelogram.

[0106] The plurality of segments (61) may be notched by a laser. A cutting groove (63) is formed between the segments (61) along the winding direction (X). When the shape of the segments (61) is square or trapezoidal, the cutting groove (63) may have a line shape. The plurality of segments (61) may be formed by a known metal foil cutting process such as ultrasonic cutting or punching.

[0107] At least some of the plurality of segments (61) may include a folded end portion (61a).

[0108] FIG. 5 is a plan view exemplarily showing an electrode (60) structure including a plurality of end-folded segments (61') according to an embodiment of the present invention.

[0109] Figures 6 to 9 are drawings showing various cross-sectional structures of the bend end along line A-A' of Figure 5.

[0110] Referring to FIGS. 4 to 9 together, the folded end (61a) is formed only in some of the plurality of segments (61). The segment (61) including the folded end (61a) is defined as an end folded segment (61'). The folded end (61a) is formed by folding the end of the end folded segment (61') at least once. The portion of the end folded segment (61') forming the folded end (61a) is the upper region of the dotted line (see FIG. 4). In FIG. 4, the folded end (61a) is in a state before being folded.

[0111] In the short-end bending segment (61'), the width of the portion forming the bending end (61a) may be the same or different. Here, the width is the width in the winding axis direction (Y).

[0112] In the short-end bending segment (61'), the width of the portion forming the bending end (61a) can increase or decrease stepwise or gradually from the core side to the outer circumference side of the electrode assembly.

[0113] In the short-end bending segment (61'), the width of the portion forming the bending end (61a) may change irregularly from the core side to the outer circumference side of the electrode assembly.

[0114] The bend shape of the bend end (61a) may be a jelly roll structure wound in a straight line as shown in Fig. 6. The bend end (61a) may be arranged in the direction of the core of the electrode assembly. Unlike the illustrated example, the bend end (61a) may be arranged so as to face the outer peripheral surface of the electrode assembly.

[0115] In another example, the bend shape of the bend end (61a) may be a jelly roll structure wound in an arc shape as shown in FIG. 7. The bend end (61a) may be arranged in the direction of the core of the electrode assembly. Unlike the illustrated example, the bend end (61a) may be arranged so as to face the outer peripheral surface of the electrode assembly.

[0116] In another example, the bend shape of the bend end (61a) may be a zigzag bend structure as shown in Fig. 8. The bend end (61a) may be arranged in the direction of the core of the electrode assembly. Unlike the illustrated example, the bend end (61a) may be arranged so as to face the outer peripheral surface of the electrode assembly.

[0117] In another example, the bend shape of the bend end (61a) may be a randomly bent structure as shown in Fig. 9. In this case, a part of the bend end (61a) may be arranged to face the core direction of the electrode assembly, and another part of the bend end (61a) may be arranged to face the outer peripheral surface of the electrode assembly.

[0118] The number of bending cycles can be defined for the bending end (61a).

[0119] As illustrated in FIGS. 6 to 9, the number of bends may be the number of uneven portions intersecting an imaginary straight line (L) penetrating the center (62) of the bend end (61a). The imaginary straight line (L) may be substantially perpendicular to a portion of the uneven portion excluding the bend end (61a). The center (62) of the bend end (61a) may be the center of gravity of a projected portion when the bend end (61a) is projected onto a predetermined plane. The plane on which the bend end (61a) is projected may be a plane on which the end bend segment (61') exists. The number of bends of the bend end (61a) included in the end bend segment (61') illustrated in FIGS. 6 to 9 is 4. If the structure of the bend end (61a) changes, the number of bends may also change.

[0120] When the electrode (40) is included as an electrode of an electrode assembly having a jelly roll structure, a plurality of segments (61) and a plurality of end-bent segments (61') can extend and protrude to the outside of the separator along the winding axis direction (Y) of the electrode assembly.

[0121] A plurality of segments (61) and a plurality of end-bent segments (61') can be bent in the radial direction of the electrode assembly, for example, toward the core, to form a bending surface area at one end of the electrode assembly. The bending point can be near the bottom of the cutting groove (63). The bending point can be spaced upward by a distance of 1 mm or less based on the bottom of the cutting groove (63). The bending surface area is approximately perpendicular to the winding axis direction (Y).

[0122] Fig. 10a is a perspective view showing the upper structure of an electrode assembly (JR) having a folded surface area (F) formed according to an embodiment of the present invention. Fig. 10b is a plan view schematically indicating the position of a folded end (61a) on the folded surface area (F) with a dotted box. In Fig. 10b, the structure in which the segment (61) and the end folded segment (61') overlap in the radial direction is not shown. Fig. 10c is a cross-sectional view of a portion of the folded surface area (F) taken along the winding axis direction (Y) of the electrode assembly (JR).

[0123] Referring to FIGS. 10a, 10b, and 10c, the folded end portion (61a) included in the end-bent segment (61') has two or more folds and can form a gap (G) between the segments (61) radially adjacent to the electrode assembly (JR). The gap (G) can provide a path for the electrolyte (E) to be impregnated into the interior of the electrode assembly (JR). Since there are a plurality of gaps (G) formed by the plurality of end-bent segments (61') in the folded surface area (F), the impregnation speed of the electrolyte can be increased. As a result, the electrolyte injection time can be shortened.

[0124] The gap (G) may have a distance corresponding to the thickness of the folded end (61a) between the radially adjacent segments (61) of the electrode assembly (JR). The thickness of the folded end (61a) may be defined as the maximum value among the thicknesses measured at multiple points of the folded end (61a). As the number of times the folded end (61a) is folded increases, the distance of the gap (G) increases, and the impregnation speed of the electrolyte may be improved accordingly.

[0125] Referring to FIG. 10b, a plurality of end bending segments (61') can be arranged in a regular or irregular pattern along the radial or circumferential direction of the electrode assembly (JR) on the bending surface area (F).

[0126] In another aspect, the bending surface area (F) may include a radial section in which the number of circumferentially arranged end bend segments (61') increases stepwise or gradually from the core (C) of the electrode assembly (JR) toward the outer periphery.

[0127] In another aspect, the bending surface area (F) may include a radial section in which the number of bends of the bending end (61a) increases stepwise or gradually from the core (C) of the electrode assembly (JR) to the outer periphery. That is, in the radial section, the number of bends of the bending end (61a) located closer to the core (C) may be smaller than the number of bends of the bending end (61a) located closer to the outer periphery.

[0128] In another aspect, the bending surface area (F) may include a radial section in which the number of bends of the bending end (61a) remains the same from the core (C) of the electrode assembly (JR) to the outer periphery. That is, in the radial section, the number of bends of the bending end (61a) may be the same.

[0129] In another aspect, the height of the end bend segment (61') may increase stepwise from the core (C) of the electrode assembly (JR) toward the outer periphery (see FIG. 4). In this case, the bending surface area (F) may include a radial section in which the number of bends of the bend end (61a) also increases as the height of the end bend segment (61') increases. That is, in the radial section, the number of bends of the bend end (61a) included in the end bend segment (61') having a relatively low height may be smaller than the number of bends of the bend end (61a) included in the end bend segment (61') having a relatively high height.

[0130] In another aspect, the bending surface area (F) may include a radial section in which the width in the winding axis direction (Y) of the non-woven portion forming the bending end (61a) gradually or stepwise increases from the core (C) of the electrode assembly (JR) toward the outer surface.

[0131] According to the above examples, the electrolyte impregnation speed can be improved by relatively increasing the number of end-bending segments (61') arranged in a radius section with a low electrolyte impregnation speed among the bending surface areas (F) and / or the number of bendings of the bending end portions (61a).

[0132] Referring to Fig. 10c, an arbitrary point (r) of the bending surface area (F) k ) is an imaginary straight line (L) parallel to the winding axis direction (Y) k ) when drawing an imaginary straight line (L k ) can be defined as the number of layers of the unlined portion at that point. An imaginary straight line (L k ) crosses the bending end (61a), the number of layers of the non-woven part increases by 1. The point (r) illustrated in Fig. 6 k ) The number of layers of the ignorant part is 6.

[0133] In the bending surface area (F), the number of uncoated layer layers gradually increases from the outer surface to the core side, and when it reaches a certain value, a radius section appears where the number of uncoated layer layers remains uniform. The uniform layer number section (S2) is a radius section of the electrode assembly (JR) where the number of uncoated layer layers remains substantially the same. 'Substantially the same' includes cases where a deviation of less than 10% is observed.

[0134] The folded surface area (F) may include a layer number increasing section (S1) and a layer number uniform section (S2). The layer number increasing section (S1) is located close to the outer surface of the electrode assembly (JR). The layer number uniform section (S2) is located between the layer number increasing section (S1) and the core (C) of the electrode assembly (JR). The length of the layer number uniform section (S2) is greater than the length of the layer number increasing section (S1).

[0135] In the example of Fig. 10c, in the increase section of the number of layers (S1), the number of layers in the unlined portion increases from 1 to 13. In the uniform section of the number of layers (S2), the number of layers in the unlined portion is maintained at 13. The number of layers in the unlined portion of the uniform section of the number of layers (S2) can increase to 13 or more as the lengths of the segment (61) and the end-bent segment (61') increase.

[0136] Since the number of non-laminated layers in the uniform layer count section (S2) is greater than that in the increased layer count section (S1), the electrolyte impregnation speed is slow. Therefore, the number of end-bent segments (61') included in the uniform layer count section (S2) may be greater than the number of end-bent segments (61') included in the increased layer count section (S1). Alternatively, the number of bends of the bended end portions (61a) included in the uniform layer count section (S2) may be greater than the number of bends of the bended end portions (61a) included in the increased layer count section (S1). In this case, the electrolyte impregnation speed in the uniform layer count section (S2) where the electrolyte impregnation speed is slow can be improved.

[0137] Referring again to FIGS. 4 and 5, in order to prevent damage to the active material layer (42) and / or the insulating coating layer (44) during the bending process of the non-coated portion (43), it is preferable to provide a predetermined gap between the bottom of the cutting groove between the segments (61) and the active material layer (42). This is because stress is concentrated near the bottom of the cutting groove (63) when the non-coated portion (43) is bent. The gap can be varied along the winding direction of the electrode (60). The gap is preferably 0.2 mm to 4 mm, and preferably 1.5 mm to 2.5 mm. When the gap is adjusted within the corresponding numerical range, damage to the active material layer (42) and / or the insulating coating layer (44) near the bottom of the cutting groove (63) due to stress generated during the bending process of the non-coated portion (43) can be prevented. Additionally, the gap can prevent damage to the active material layer (42) and / or the insulating coating layer (44) due to tolerance during notching or cutting of the segment (61).

[0138] The lower end of the cutting groove (63) and the insulating coating layer (44) may be spaced apart from each other by 0.5 mm to 2.0 mm. When the electrode (60) is wound, the end of the insulating coating layer (44) in the winding axis (Y) direction may be located within a 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) may prevent short circuits between two electrodes with different polarities that are positioned opposite to each other with the separator in between, and may support the bending point when the segment (61) is bent. In order to improve the short circuit prevention effect between the two electrodes, the insulating coating layer (44) may be exposed to the outside of the separator. In addition, in order to further maximize the short circuit prevention effect between the two electrodes, the width of the insulating coating layer (44) may be increased so that the end of the insulating coating layer (44) in the winding axis (Y) direction is located above the lower end of the cutting groove (63). In one embodiment, the end of the insulating coating layer (44) in the direction of the winding axis may be located within a range of -2 mm to +2 mm based on the lower end of the cutting groove (63). The thickness of the insulating coating layer (44) may be thinner than that of the active material layer. In this case, a gap may exist between the surface of the insulating coating layer (44) and the separator.

[0139] A plurality of segments (61) may form a plurality of segment groups from the core side toward the outer periphery side. At least one of the width, height, and spacing pitch of the segments belonging to the same segment group may be substantially the same. Preferably, the width, height, and spacing pitch of the segments belonging to the same segment group may be the same.

[0140] The width of the segment (61) roughly corresponds to the width of the lower portion. The width of the segment (61) may be 1 mm to 11 mm. The width of the segment (61) may increase stepwise or gradually as the radius r of the winding turns increases.

[0141] The height of the segment (61) corresponds approximately to the shortest distance between the top and bottom. The height of the segment (61) may be 2 mm to 10 mm. The height of the segment (61) may increase stepwise or gradually along the radial direction of the electrode assembly.

[0142] The separation pitch (P) of the segments (61) corresponds to the distance between the two points where a straight line passing through the lower end of the cutting groove in the winding direction intersects two straight lines extending from the side of the segments (61) on both sides of the cutting groove. The separation pitch (P) of the segments (61) may be 0.05 to 1 mm.

[0143] When the segment (61) is approximated by a trapezoid, the lower inner angle of the trapezoid can gradually or stepwise increase from the core side to the outer periphery side. When the radius of the electrode assembly increases, the radius of curvature increases. If the lower inner angle (θ) of the segment (61) increases together with the increase in the radius of the electrode assembly, the stress generated in the radial and circumferential directions when the segment (61) is bent can be relieved. In addition, when the lower inner angle (θ) increases, the area overlapping with the inner segment (61) and the number of overlapping layers also increase when the segment (61) is bent, thereby ensuring uniform welding strength in the radial and circumferential directions and forming a flat bending surface area.

[0144] Width (d) of the first part (B1) B1 ) is designed so that when the segment (61) of the third part (B2) is bent toward the core side, the core of the electrode assembly is opened to the outside by 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more based on its diameter.

[0145] In one embodiment, the width of each segment group may be designed to form the same number of turns of the electrode assembly. Here, the number of turns may be counted based on the end of the first portion (B1) when the electrode (60) is in a wound state.

[0146] In another variation, the width of each segment group can be designed to form at least one turn of the electrode assembly.

[0147] In another variation, the width and / or height and / or spacing pitch of segments (61) belonging to the same segment group may be increased or decreased gradually and / or stepwise and / or irregularly within the group or between adjacent groups.

[0148] When the number of segment groups is one, the height of the segments (61) in the third part (B2) can be uniform.

[0149] The segment structure of the third part (B2) can be extended to the second part (B3). In this case, the second part (B3) can also include a plurality of segments, just like the third part (B2). Preferably, the segment structure of the second part (B3) can be substantially identical to the group of segments located at the outermost side of the third part (B2). In this case, the segments included in the second part (B3) and the third part (B2) can have substantially the same width, height, and spacing pitch. In a modified example, the segments of the second part (B3) can have a width and / or height and / or spacing pitch greater than those of the third part (B2).

[0150] The structure of the electrode (40) described above can be applied to at least one of the first electrode and the second electrode having different polarities included in the electrode assembly having a jelly roll structure. In addition, when the electrode structure of the embodiments (variants) is applied to one of the first electrode and the second electrode, a conventional electrode structure can be applied to the other. In addition, the electrode structures applied to the first electrode and the second electrode may not be identical but may be different.

[0151] For example, when the first electrode and the second cathode are the anode and cathode, respectively, one of the embodiments (variants) may be applied to the first electrode, and a conventional electrode structure (see Fig. 1) may be applied to the second electrode.

[0152] As another example, when the first electrode and the second cathode are the anode and the cathode, respectively, one of the embodiments (variants) may be selectively applied to the first electrode, and the other of the embodiments (variants) may be selectively applied to the second electrode.

[0153] In the present invention, the positive electrode active material coated on the positive electrode and the negative electrode active material coated on the negative electrode can be used without limitation as long as they are active materials known in the art.

[0154] In one example, the positive electrode active material has the general chemical formula A[A x M y ]O 2+z (A includes at least one element selected from Li, Na, and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, 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; stoichiometric coefficients x, y, and z are selected such that the compound maintains electrical neutrality) may include an alkali metal compound represented by the following formula:

[0155] In another example, the positive electrode active material is an alkali metal compound xLiM as disclosed in US6,677,082, US6,680,143, etc. 1 O2 - (1-x)Li2M 2 O3(M 1 contains at least one element having an average oxidation state of 3; M 2 contains at least one element having an average oxidation state of 4; 0≤x≤1).

[0156] In another example, the positive electrode active material has the general chemical formula Li a M 1 x Fe 1-x M 2 y P 1-y M 3 z O 4-z (M1 Contains at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Mg and Al; M 2 contains at least one element selected from Ti, Si, Mn, Co, Fe, Cr, Mo, Ni, Nd, Mg, Al, As, Sb, Si, Ge, V and S; M 3 may be a lithium metal phosphate represented by Li3M2(PO4)3 [M comprises at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Mg and Al], wherein the compound 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 so that the compound remains electrically neutral].

[0157] Preferably, the positive electrode active material may include primary particles and / or secondary particles formed by agglomeration of primary particles.

[0158] In one example, the negative active material may be carbon, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, etc. Metal oxides such as TiO2 and SnO2 with a potential of less than 2 V can also be used as the negative active material. Carbon materials such as low-crystalline carbon and high-crystalline carbon can all be used.

[0159] The separator may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, etc., used alone or in a laminated manner. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc.

[0160] At least one surface of the membrane may include a coating layer of inorganic particles. Furthermore, the membrane itself may be formed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are bound to a binder such that an interstitial volume exists between adjacent particles.

[0161] Below, the structure of an electrode assembly according to an embodiment of the present invention is described in detail.

[0162] Fig. 11 is a cross-sectional view of a jelly roll type electrode assembly (100) in which an electrode (60) of the embodiment is applied to a first electrode (anode) and a second electrode (cathode), taken along the winding axis direction (Y).

[0163] Referring to FIG. 11, the non-conductive portion (43a) of the first electrode includes a first portion (B1) adjacent to the core of the electrode assembly (100), a second portion (B3) adjacent to the outer peripheral surface of the electrode assembly (100), and a third portion (B2) interposed between the first portion (B1) and the second portion (B3).

[0164] The height of the plain portion of the first part (B1) is lower than that of the segment (61) and the end-bent segment (61') included in the third part (B2). Therefore, when the segment (61) and the end-bent segment (61') included in the third part (B2) are bent, the plain portion of the first part (B1) is not bent.

[0165] In the third part (B2), the bending length (H) of the segment (61) or the end-bent segment (61) closest to the core (102) is equal to or less than the radial length (R) of the first part (B1). Therefore, even if the segment (61) and the end-bent segment (61) included in the third part (B2) are bent, the core (102) is opened to the outside. If the core (102) is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, the welding process of the current collector can be easily performed by inserting a welding jig through the core (102).

[0166] The length of the second part (B3) may be shorter than the length of the first part (B1). The height of the non-coated portion of the second part (B3) is lower than the segment (61) and the end-bent segment (61') included in the third part (B2). Therefore, when the beaded portion of the battery housing is pressed near the winding turn of the second part (B3), an internal short circuit can be prevented from occurring when the beaded portion and the upper edge of the electrode assembly (100) come into contact with each other. The non-coated portion of the second part (B3) is not bent when the segment (61) and the end-bent segment (61') included in the third part (B2) are bent.

[0167] The second electrode portion (43b) has the same structure as the first electrode portion (43a). In one variation, the second electrode portion (43b) may have a conventional electrode structure or an electrode structure of other embodiments (variants).

[0168] A plurality of segments (61) and a plurality of end-bent segments (61') included in the third portion (B2) of the first non-conductive portion (43a) and the second non-conductive portion (43b) can be bent toward the core (102) of the electrode assembly (100) to form a bending surface area (F of FIG. 10a). When the bending surface area (F) is formed, the end-bent segments (61') are interposed between adjacent segments (61) in the radial direction of the electrode assembly (100), so that the bending end portions (61a) form a gap (G of FIG. 10c), thereby providing an electrolyte impregnation path.

[0169] An electrode assembly according to an embodiment of the present invention can be applied to a cylindrical battery of the jelly roll type.

[0170] Preferably, the cylindrical battery may be, for example, a cylindrical battery having a form factor ratio (defined as the ratio of the diameter (Φ) to the height (H) of the cylindrical battery) greater than about 0.4. Here, the form factor refers to a value representing the diameter and height of the cylindrical battery.

[0171] The diameter of the cylindrical battery may be 35 mm or more, preferably 40 mm to 50 mm. The height of the cylindrical battery may be 70 mm or more, preferably 75 mm to 90 mm. The cylindrical battery according to one embodiment may be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 4680 battery. In the figures indicating the form factor, the first two numbers indicate the diameter of the battery, and the remaining numbers indicate the height of the battery.

[0172] When applying an electrode assembly having a tab-less structure to a cylindrical battery having a form factor ratio exceeding 0.4, the stress applied in the radial direction when bending the non-woven portion is large, making it easy for the non-woven portion to tear. Furthermore, when welding a current collector plate to the bend surface area of ​​the non-woven portion, the number of layers of the non-woven portion in the bend surface area must be sufficiently increased to ensure sufficient welding strength and reduce resistance. These requirements can be achieved by the electrode and electrode assembly according to embodiments (modified examples) of the present invention.

[0173] A battery according to one embodiment of the present invention may be a cylindrical battery having a substantially cylindrical shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0174] According to another embodiment, the battery may be a cylindrical battery having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0175] According to another embodiment, the battery may be a cylindrical battery having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.436.

[0176] According to another embodiment, the battery may be a cylindrical battery having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0177] According to another embodiment, the battery may be a cylindrical battery having a generally cylindrical shape, a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0178] The present invention is not limited by the form factor ratio described above and the diameter and height of the cylindrical battery. Accordingly, the present invention can also be applied to batteries with a form factor ratio of approximately 0.4 or less, such as 1865 batteries and 2170 batteries.

[0179] Hereinafter, a cylindrical battery according to an embodiment of the present invention will be described in detail.

[0180] FIG. 12 is a cross-sectional view of a cylindrical battery (190) according to one embodiment of the present invention, taken along the winding axis direction (Y).

[0181] Referring to FIG. 12, a cylindrical battery (190) according to one embodiment of the present invention includes an electrode assembly (110) including a first electrode, a separator, and a second electrode, a battery housing (142) that accommodates the electrode assembly (110), and a sealing body (143) that seals an open end of the battery housing (142).

[0182] The battery housing (142) is a cylindrical container with an opening formed at the top. The battery housing (142) is made of a conductive metal material, such as aluminum, steel, or stainless steel. A nickel coating layer may be formed on the surface of the battery housing (142). The battery housing (142) accommodates an electrode assembly (110) in an inner space through the upper opening, and also accommodates an electrolyte.

[0183] Electrolyte is A + B -It may be a salt having a structure similar to that of A. Here, A + is Li + , Na + , K + It includes ions composed of alkali metal cations such as and combinations thereof. And B - is 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 - , C4F9SO3 - , CF3CF2SO3 - , (CF3SO2)2N - , (FSO2)2N - ,　 CF3CF2(CF3)2CO - , (CF3SO2)2CH - , (SF5)3C - , (CF3SO2)3C - , CF3(CF2)7SO3 - , CF3CO2 - , CH3CO2 - , SCN - and (CF3CF2SO2)2N - Contains at least one anion selected from the group consisting of:

[0184] The electrolyte can also be used by dissolving it in an organic solvent. Examples of the organic solvent that can be used include 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), gamma butyrolactone, or mixtures thereof.

[0185] The electrode assembly (110) may have a jelly roll shape. The electrode assembly (110) may be manufactured by winding a laminate formed by sequentially stacking a lower separator, a first electrode, an upper separator, and a second electrode at least once, as illustrated in FIG. 2.

[0186] The first electrode and the second electrode have different polarities. That is, if one has a positive polarity, the other has a negative polarity. At least one of the first electrode and the second electrode may have an electrode structure according to the embodiments (variants) described above. In addition, the other of the first electrode and the second electrode may have a conventional electrode structure or an electrode structure according to the embodiments (variants). The number of electrode pairs included in the electrode assembly (110) is not limited to one and may be two or more.

[0187] The electrode assembly (110) may include a folded surface area (F in FIG. 10a) on the upper and lower portions. The first collector plate (144) may be welded to the folded surface area (F) of the first non-coated portion (146a), and the second collector plate (145) may be welded to the folded surface area (F) of the second non-coated portion (146b).

[0188] Preferably, more than 50% of the welding area (W) of the first collector plate (144) and the second collector plate (145) may overlap with the uniform number of plies section (S2 of Fig. 10c) of the bending surface area (F). Optionally, the remaining area of ​​the welding area (W) may overlap with the increased number of plies section (S1 of Fig. 10c) of the bending surface area (F). In terms of high welding strength, low resistance of the welding interface, and prevention of damage to the separator or active material layer, it is preferable that the entire welding area (W) overlap with the uniform number of plies section (S2 of Fig. 10c).

[0189] The core (112) of the electrode assembly (110) is not occluded by the folded surface area (F). Therefore, there is no difficulty in the electrolyte injection process, and the welding process between the second current collector (145) and the battery housing (142) can be easily performed by inserting a welding jig through the core (112).

[0190] When the width and / or height and / or spacing pitch of the segments are adjusted to satisfy the numerical range of the above-described embodiment, as shown in Fig. 10c, when the segments are bent, the segments overlap at least 10 times to sufficiently secure welding strength and do not form empty spaces (gaps) in the bending surface area (F).

[0191] The sealing member (143) may include a cap plate (143a), a first gasket (143b) that provides sealing between the cap plate (143a) and the battery housing (142) and has insulating properties, and a connecting plate (143c) that is electrically and mechanically connected to the cap plate (143a).

[0192] The cap plate (143a) is a component made of a conductive metal material and covers the upper opening of the battery housing (142). The cap plate (143a) is electrically connected to the folded surface area (F) of the first electrode and is electrically insulated from the battery housing (142) via a first gasket (143b). Therefore, the cap plate (143a) can function as a first electrode terminal (e.g., a positive electrode) of the cylindrical battery (190).

[0193] The cap plate (143a) is mounted on a beading portion (147) formed on the battery housing (142) and is fixed by a crimping portion (148). A first gasket (143b) may be interposed between the cap plate (143a) and the crimping portion (148) to ensure airtightness of the battery housing (142) and electrical insulation between the battery housing (142) and the cap plate (143a). The cap plate (143a) may have a protrusion (143d) formed to protrude upward from its center.

[0194] The battery housing (142) is electrically connected to the folded surface area (F) of the second electrode. Therefore, the battery housing (142) has the same polarity as the second electrode. If the second electrode has a negative polarity, the battery housing (142) also has a negative polarity.

[0195] The battery housing (142) has a beading portion (147) and a crimping portion (148) at the top. The beading portion (147) is formed by inward pressing the outer circumference of the battery housing (142). The beading portion (147) prevents the electrode assembly (110) accommodated inside the battery housing (142) from escaping through the upper opening of the battery housing (142), and can function as a support portion on which the sealing body (143) is secured.

[0196] The second part (B3) of the first electrode does not include a segment, and the height of the uncoated part of the second part (B3) is lower than that of the third part (B2). Therefore, even when the battery housing (142) is pressed in from the outside to form the beading part (147), the winding turns of the second part (B3) are not substantially affected. Accordingly, the winding turns of the second part (B3) are not pressed by other components such as the beading part (147). This prevents partial deformation of the electrode assembly (110), thereby preventing a short circuit inside the cylindrical battery (190).

[0197] Preferably, when the pressing depth of the beading portion (147) is defined as D1 and the radial length from the inner surface of the battery housing (142) to the boundary point between the second portion (B3) and the third portion (B2) is defined as D2, the relationship D1 ≤ D2 can be satisfied. In this case, when pressing the battery housing (142) to form the beading portion (147), damage to the winding turns formed by the second portion (B3) is substantially prevented.

[0198] The crimping portion (148) is formed on the upper portion of the beading portion (147). The crimping portion (148) has an extended and bent shape so as to surround the outer circumference of the cap plate (143a) placed on the beading portion (147) and a portion of the upper surface of the cap plate (143a).

[0199] The cylindrical battery (190) may further include a first collector plate (144) and / or a second collector plate (145) and / or an insulator (146).

[0200] The first collector plate (144) is attached to the upper portion of the electrode assembly (110). The first collector plate (144) is made of a conductive metal material such as aluminum, copper, steel, nickel, etc., and is electrically connected to the folded surface area (F) of the first electrode. The electrical connection can be made through welding. A lead (149) can be connected to the first collector plate (144). The lead (149) can extend upward from the electrode assembly (110) and be attached to the connection plate (143c) or directly attached to the lower surface of the cap plate (143a). The connection of the lead (149) to other components can be made through welding.

[0201] Preferably, the first collector plate (144) may be formed integrally with the lead (149). In this case, the lead (149) may have a long plate shape extending outward from the center or near the edge of the first collector plate (144).

[0202] The connection between the first collector plate (144) and the folded surface area (F) of the first electrode can be achieved, for example, by laser welding. Laser welding can be achieved by partially melting the collector plate base material. In a variation, welding between the first collector plate (144) and the folded surface area (F) can be achieved with solder interposed therebetween. In this case, the solder can have a lower melting point compared to the first collector plate (144) and the first non-stick portion (146a). Laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0203] A second collector plate (145) may be coupled to the lower surface of the electrode assembly (110). One side of the second collector plate (145) may be coupled to the folded surface area (F) of the second electrode by welding, and the opposite side may be coupled to the inner bottom surface of the battery housing (142) by welding. The coupling structure between the second collector plate (145) and the folded surface area (F) of the second electrode may be substantially the same as the coupling structure between the first collector plate (144) and the folded surface area (F) of the first electrode.

[0204] The insulator (146) can cover the first collector plate (144). The insulator (146) can cover the first collector plate (144) on the upper surface of the first collector plate (144), thereby preventing direct contact between the first collector plate (144) and the inner surface of the battery housing (142).

[0205] The insulator (146) has a lead hole (151) so that a lead (149) extending upward from the first collector plate (144) can be drawn out. The lead (149) is drawn upward through the lead hole (151) and is coupled to the lower surface of the connecting plate (143c) or the lower surface of the cap plate (143a).

[0206] The peripheral area of ​​the insulator (146) can be interposed between the first collector plate (144) and the beading portion (147) to fix the assembly of the electrode assembly (110) and the first collector plate (144). Accordingly, the assembly of the electrode assembly (110) and the first collector plate (144) can be restricted from moving in the height direction of the battery (190), thereby improving the assembly stability of the battery (190).

[0207] The insulator (146) may be made of an insulating polymer resin. In one example, the insulator (146) may be made of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0208] The battery housing (142) may further include a venting portion (152) formed on its lower surface. The venting portion (152) corresponds to a region of the lower surface of the battery housing (142) that has a thinner thickness than the surrounding region. The venting portion (152) is structurally weaker than the surrounding region. Therefore, if an abnormality occurs in the cylindrical battery (190) and the internal pressure increases above a certain level, the venting portion (152) may rupture, allowing gas generated inside the battery housing (142) to be discharged to the outside. The internal pressure at which the venting portion (152) ruptures is approximately 15 kgf / cm2 Up to 35 kgf / cm 2 It could be.

[0209] The venting portion (152) may be formed continuously or discontinuously in a circular pattern on the lower surface of the battery housing (142). In a modified example, the venting portion (152) may be formed in a linear pattern or other pattern.

[0210] Fig. 13 is a cross-sectional view of a cylindrical battery (200) according to another embodiment of the present invention, taken along the winding axis direction (Y).

[0211] Referring to FIG. 13, the cylindrical battery (200) is substantially the same in structure as the cylindrical battery (190) illustrated in FIG. 12 in that the structure of the electrode assembly is changed except for the structure of the remaining electrode assembly.

[0212] Specifically, the cylindrical battery (200) includes a battery housing (171) having a rivet terminal (172) installed therethrough. The rivet terminal (172) is installed through a through hole formed in a closed end of the battery housing (171). The rivet terminal (172) is riveted to the through hole of the battery housing (171) while a second gasket (173) made of an insulating material is interposed therebetween. The rivet terminal (172) is exposed to the outside in a direction opposite to the direction of gravity.

[0213] The rivet terminal (172) includes a terminal exposure portion (172a) and a terminal insertion portion (172b). The terminal exposure portion (172a) is exposed to the outside of the closed end of the battery housing (171). The terminal exposure portion (172a) may be located approximately at the center of the closed end of the battery housing (171). The maximum diameter of the terminal exposure portion (172a) may be formed to be larger than the maximum diameter of a through hole formed in the battery housing (171). The terminal insertion portion (172b) may penetrate approximately at the center of the closed end of the battery housing (171) and be electrically connected to the uncoated portion (146a) of the first electrode. The lower edge of the terminal insertion portion (172b) may be riveted onto the inner surface of the battery housing (171). That is, the lower edge of the terminal insertion portion (172b) may have a shape that is curved toward the inner surface of the battery housing (171). A flat portion (172c) is included on the inner side of the lower edge of the terminal insertion portion (172b). The maximum diameter of the lower portion of the riveted terminal insertion portion (172b) may be larger than the maximum diameter of the through hole of the battery housing (171).

[0214] The flat portion (172c) of the terminal insertion portion (172b) can be welded to the center portion of the first collector plate (144) connected to the folded surface area (F) of the first electrode. Laser welding is preferred as the welding method, but other welding methods such as ultrasonic welding can be used instead.

[0215] An insulator (174) made of an insulating material may be interposed between the first collector plate (144) and the inner surface of the battery housing (171). The insulator (174) covers the upper portion of the first collector plate (144) and the upper edge portion of the electrode assembly (110). This prevents the second portion (B3) of the electrode assembly (110) from coming into contact with the inner surface of the battery housing (171) having a different polarity, thereby causing a short circuit.

[0216] The thickness of the insulator (174) corresponds to or is slightly larger than the distance between the upper surface of the first collector plate (144) and the inner surface of the closed portion of the battery housing (171). Therefore, the insulator (174) can contact the upper surface of the first collector plate (144) and the inner surface of the closed portion of the battery housing (171).

[0217] The terminal insertion portion (172b) of the rivet terminal (172) can be welded to the first collector plate (144) through a through-hole of the insulator (174). The diameter of the through-hole formed in the insulator (174) can be larger than the diameter of the riveting portion at the bottom of the terminal insertion portion (172b). Preferably, the through-hole can expose the lower portion of the terminal insertion portion (172b) and the second gasket (173).

[0218] A second gasket (173) is interposed between the battery housing (171) and the rivet terminal (172) to prevent the battery housing (171) and the rivet terminal (172) having opposite polarities from electrically contacting each other. This allows the upper surface of the battery housing (171) having a roughly flat shape to function as a second electrode terminal (e.g., negative electrode) of the cylindrical battery (200).

[0219] The second gasket (173) includes a gasket exposure portion (173a) and a gasket insertion portion (173b). The gasket exposure portion (173a) is interposed between the terminal exposure portion (172a) of the rivet terminal (172) and the battery housing (171). The gasket insertion portion (173b) is interposed between the terminal insertion portion (172b) of the rivet terminal (172) and the battery housing (171). The gasket insertion portion (173b) can be deformed together with the terminal insertion portion (172b) when riveting so as to be in close contact with the inner surface of the battery housing (171). The second gasket (173) can be made of, for example, an insulating polymer resin.

[0220] The gasket exposure portion (173a) of the second gasket (173) may have an extended shape to cover the outer surface of the terminal exposure portion (172a) of the rivet terminal (172). When the second gasket (173) covers the outer surface of the rivet terminal (172), a short circuit can be prevented from occurring during the process of connecting an electrical connection component such as a bus bar to the upper surface of the battery housing (171) and / or the rivet terminal (172). Although not shown in the drawing, the gasket exposure portion (173a) may have an extended shape to cover not only the outer surface of the terminal exposure portion (172a) but also a portion of the upper surface.

[0221] In the case where the second gasket (173) is made of a polymer resin, the second gasket (173) can be joined to the battery housing (171) and the rivet terminal (172) by heat fusion. In this case, the sealing properties at the joining interface between the second gasket (173) and the rivet terminal (172) and at the joining interface between the second gasket (173) and the battery housing (171) can be strengthened. Meanwhile, in the case where the gasket exposure portion (173a) of the second gasket (173) has a form that extends to the upper surface of the terminal exposure portion (172a), the rivet terminal (172) can be integrally joined to the second gasket (173) by insert injection molding.

[0222] Among the upper surfaces of the battery housing (171), the remaining area (175) excluding the area occupied by the rivet terminal (172) and the second gasket (173) corresponds to a second electrode terminal having the opposite polarity to the rivet terminal (172).

[0223] The second collector plate (176) is connected to the lower portion of the electrode assembly (141). The second collector plate (176) is made of a conductive metal material such as aluminum, steel, copper, or nickel, and is electrically connected to the folded surface area (F) of the second electrode.

[0224] Preferably, the second collector plate (176) is electrically connected to the battery housing (171). To this end, at least a portion of the edge portion of the second collector plate (176) may be interposed and fixed between the inner surface of the battery housing (171) and the first gasket (178b). In one example, at least a portion of the edge portion of the second collector plate (176) may be fixed to the beading portion (180) formed at the bottom of the battery housing (171) by welding while being supported by the lower surface of the beading portion (180). In a variation, at least a portion of the edge portion of the second collector plate (176) may be directly welded to the inner wall surface of the battery housing (171).

[0225] Preferably, the second collector plate (176) and the folded surface area (F) of the second electrode can be joined, for example, by laser welding. In addition, the welding portion of the second collector plate (176) and the folded surface area (F) can be spaced apart from the inner surface of the beading portion (180) by a predetermined distance toward the core (C).

[0226] A sealing member (178) for sealing the lower open end of the battery housing (171) includes a cap plate (178a) and a first gasket (178b). The first gasket (178b) electrically separates the cap plate (178a) from the battery housing (171). A crimping member (181) secures the edge of the cap plate (178a) and the first gasket (178b) together. A vent member (179) is provided in the cap plate (178a). The configuration of the vent member (179) is substantially the same as that in the above-described embodiment (modified example). The lower surface of the cap plate (178a) may be positioned above the lower end of the crimping member (181). In this case, a space is formed at the lower portion of the cap plate (178a) to facilitate venting. In particular, it is useful when the cylindrical battery (200) is installed so that the crimping portion (181) faces the direction of gravity.

[0227] Preferably, the cap plate (178a) is made of a conductive metal material. However, since a first gasket (178b) is interposed between the cap plate (178a) and the battery housing (171), the cap plate (178a) does not have electrical polarity. The sealing body (178) mainly functions to seal the open end of the lower portion of the battery housing (171) and to discharge gas when the internal pressure of the battery (200) increases above a critical value. The critical value of the internal pressure is 15 kgf / cm 2 Up to 35 kgf / cm 2 am.

[0228] Meanwhile, in a modified example, the battery housing (171) may not include the beading portion (180) and the crimping portion (181). In this case, the side wall of the battery housing (171) may extend in a straight line, and the edge of the cap plate (178a) may be directly coupled to the open end of the battery housing (171). The edge of the cap plate (178a) may be welded to the open end of the battery housing (171). In this modified example, the first gasket (178b) may be omitted.

[0229] In one variation, at least a portion of the second collector plate (176), for example an edge portion, may be coupled to the cap plate (178a).

[0230] In another variation, at least a portion of the second collector plate (176), for example an edge portion, may be bent to face the inner surface of the side wall of the battery housing (171), and the bent portion may be joined to the inner surface of the side wall of the battery housing (171) by welding.

[0231] In another variation, the edge of the cap plate (178a), the open end of the battery housing (171) and the edge portion of the second collector plate (176) can be integrally joined by welding.

[0232] In another variation, the inner edge area of ​​the cap plate (178a) may be directly welded to the folded surface area (F) of the second electrode. In this case, the cap plate (178a) functions to electrically connect the second electrode and the battery housing (171), so the second current collector (176) may be omitted.

[0233] Preferably, the rivet terminal (172) electrically connected to the folded surface area (F) of the first electrode is used as the first electrode terminal. In addition, the portion (175) of the upper surface of the battery housing (171) electrically connected to the folded surface area (F) of the second electrode through the second collector plate (176), excluding the rivet terminal (172), is used as a second electrode terminal having a different polarity from the first electrode terminal. In this way, when the two electrode terminals are positioned on the upper portion of the cylindrical battery (200), it is possible to place electrical connection components such as bus bars on only one side of the cylindrical battery (200). This can lead to simplification of the battery pack structure and improvement of energy density. In addition, since the portion (175) used as the second electrode terminal has a substantially flat shape, a sufficient bonding area can be secured when bonding electrical connection components such as bus bars. Accordingly, the cylindrical battery (200) can lower the resistance at the joint portion of the electrical connection component to a desirable level.

[0234] The cylindrical battery described above can be used to manufacture a battery pack.

[0235] FIG. 14 is a drawing schematically showing the configuration of a battery pack according to an embodiment of the present invention.

[0236] Referring to FIG. 14, a battery pack (300) according to an embodiment of the present invention includes an assembly of cylindrical batteries (301) electrically connected thereto and a pack housing (302) accommodating the same. The cylindrical battery (301) may be any of the batteries according to the embodiments (variants) described above. In the drawing, for convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrical connection of the cylindrical batteries (301) are omitted.

[0237] The battery pack (300) may be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheeled vehicle or a two-wheeled vehicle.

[0238] FIG. 15 is a drawing for explaining a vehicle including the battery pack (300) of FIG. 14.

[0239] Referring to FIG. 15, a vehicle (V) according to one embodiment of the present invention includes a battery pack (300) according to one embodiment of the present invention. The vehicle (V) operates by receiving power from the battery pack (300) according to one embodiment of the present invention.

[0240] According to the present invention, by improving the end structure of the segments, gaps used as a path for impregnating the electrolyte in the folded surface area formed by bending the segments can be formed in the radial and / or circumferential direction, thereby shortening the impregnation time of the electrolyte.

[0241] According to another aspect of the present invention, by improving the non-beaded structure of the electrode assembly so that the inner surface of the electrode assembly and the battery housing do not interfere during the process of forming the beaded portion of the battery housing, a short circuit inside a cylindrical battery due to partial deformation of the electrode assembly can be prevented.

[0242] According to another aspect of the present invention, there is provided an electrode assembly having improved energy density and reduced resistance by applying a structure in which a collector plate is welded over a large area to a folded surface area formed by folding segments.

[0243] According to another aspect of the present invention, by improving the structure of the non-conductive portion adjacent to the core of the electrode assembly, the cavity in the core of the electrode assembly is prevented from being occluded when the non-conductive portion is bent, thereby facilitating the electrolyte injection process and the welding process of the battery housing (or rivet terminal) and the current collector plate.

[0244] According to another aspect of the present invention, a cylindrical battery having a structure in which electrolyte impregnation property is improved, internal resistance is low, internal short circuit is prevented, and welding strength between a collector plate and a non-conductive portion is improved, and a battery pack and a vehicle including the same can be provided.

[0245] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by a person having ordinary skill in the art to which the present invention pertains within the scope of the technical idea of ​​the present invention and the equivalent scope of the claims to be described below.

Claims

1. In an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around one axis to define a core and an outer surface, At least one of the first electrode and the second electrode includes a non-coated portion extending in the winding direction along the longitudinal end, The above-mentioned portion includes a plurality of independently bendable segments separated by cutting grooves formed along the winding direction, The above plurality of segments are folded toward the core to form a folded surface area at one end of the electrode assembly, An electrode assembly, wherein at least some of said plurality of segments include a folded end portion.

2. In claim 1, When defining a segment including the above-mentioned bending section as a short-bending segment, The above-mentioned bending surface area includes a plurality of short-section bending segments, An electrode assembly, wherein the number of uncut portions intersecting an imaginary straight line passing through the center of the above-mentioned bending end is defined as the number of bends of the above-mentioned bending end, the above-mentioned bending end has a number of bends of two or more, and forms a gap between adjacent segments in the radial direction of the electrode assembly.

3. In claim 2, An electrode assembly, wherein the gap has a distance corresponding to the thickness of the folded end between radially adjacent segments of the electrode assembly.

4. In claim 2, An electrode assembly, wherein the plurality of short-section bending segments are arranged in a regular or irregular pattern along the radial or circumferential direction of the electrode assembly on the bending surface area.

5. In claim 2, An electrode assembly, wherein the above-described bending surface area includes a radial section in which the number of end bending segments arranged in a circumferential direction increases stepwise or gradually from the core to the outer surface.

6. In claim 2, An electrode assembly, wherein the above-mentioned bending surface area includes a radius section in which the number of bends at the bending end gradually or stepwise increases from the core to the outer surface.

7. In claim 2, An electrode assembly, wherein the above-mentioned bending surface area includes a radius section in which the number of bends of the bending end is maintained the same from the core to the outer surface.

8. In claim 2, The height of the above multiple short-section bending segments gradually increases from the core of the electrode assembly to the outer periphery, An electrode assembly, wherein the above-mentioned bending surface area includes a radial section in which the number of bends of the bending end also increases as the height of the bending segment increases.

9. In claim 2, An electrode assembly, wherein the above-mentioned bending surface area includes a radial section in which the uniaxial width of the non-woven portion forming the bending end increases stepwise or gradually from the core of the electrode assembly to the outer surface.

10. In claim 2, When the number of uncoated portions intersecting an imaginary line penetrating the folded surface area parallel to the axial direction at any point of the folded surface area is defined as the number of uncoated portion layers at that point, The above-mentioned bending surface area includes a section of increasing number of layers and a section of uniform number of layers from the outer surface of the electrode assembly toward the core, An electrode assembly, wherein the number of short bend segments included in the above-described uniform number of layers is greater than the number of short bend segments included in the above-described increased number of layers.

11. In claim 2, When the number of uncoated portions intersecting an imaginary line penetrating the folded surface area parallel to the axial direction at any point of the folded surface area is defined as the number of uncoated portion layers at that point, The above-mentioned bending surface area includes a section of increasing number of layers and a section of uniform number of layers from the outer surface of the electrode assembly toward the core, An electrode assembly, wherein the number of bendings of a bending end included in the above-mentioned uniform number of layers is greater than the number of bendings of a bending end included in the above-mentioned increased number of layers.

12. In claim 1, An electrode assembly, wherein the above-mentioned folded end has a structure folded in a jelly roll shape, a structure folded in a zigzag shape, or a structure folded randomly.

13. An electrode assembly according to any one of claims 1 to 12; A battery housing comprising an open end and a closed end, wherein the electrode assembly is received through the open end and is electrically connected to a second electrode of the electrode assembly; A sealing body sealing the open end of the battery housing; and A cylindrical battery comprising a terminal electrically connected to a first electrode of the electrode assembly and having a surface exposed to the outside of the battery housing.

14. In claim 13, The above-mentioned folding surface area is formed by folding a plurality of segments included in the non-woven portion of the first electrode, A cylindrical battery further comprising a first collector plate electrically connecting the above-described folding surface area and the terminal.

15. In claim 13, The terminal is installed in a through hole formed in the closed end of the battery housing so as to be insulated from the battery housing, The terminal includes a terminal exposure portion exposed through the outer surface of the closed end, and a terminal insertion portion extended from the terminal exposure portion and inserted into the interior of the battery housing through the through hole. A cylindrical battery, wherein the lower edge of the terminal insertion portion is riveted toward the inner surface of the closed end.

16. In claim 13, The sealing body comprises a cap plate that seals the open end of the battery housing, The above terminal is a cylindrical battery, which is the cap plate.

17. In claim 13, The above-mentioned folding surface area is formed by folding a plurality of segments included in the non-woven portion of the second electrode, A cylindrical battery further comprising a second collector plate electrically connecting the above-described folding surface area and the side wall of the battery housing.

18. In claim 17, The sealing body comprises a cap plate covering the open end of the battery housing; and a gasket interposed between an edge of the cap plate and the open end, A cylindrical battery, wherein the edge of the second collector plate is interposed between the gasket and the side wall of the battery housing.

19. In claim 18, The above battery housing includes a beaded portion formed by pressing an outer surface near the open end, A cylindrical battery, wherein the edge of the cap plate is in contact with the beading portion.

20. In claim 13, The sealing body comprises a cap plate covering the open end of the battery housing, A cylindrical battery, wherein the edge of the cap plate is joined to the open end.

21. In claim 20, A cylindrical battery, wherein at least a portion of the cap plate is joined to a folded surface area of ​​the electrode assembly.

22. A battery pack comprising a plurality of cylindrical batteries according to any one of claims 13 to 21.

23. A vehicle comprising the battery pack of claim 22.

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