Electrode assembly, battery and battery pack and vehicle

Abstract

Having an electrode arrangement: a first electrode; a second electrode; and a separator arranged between the first electrode and the second electrode, wherein the first electrode, the second electrode and the separator are wound around a winding axis in one winding direction and thus define a core and an outer circumference of the electrode arrangement, wherein the first electrode has a first active material section coated with an active material layer along the winding direction and a first uncoated section not coated with an active material layer and exposed beyond the separator, wherein the first uncoated section comprises a first section adjacent to the core of the electrode arrangement, a second section adjacent to the outer circumference of the electrode arrangement, and a third section between the first section and the second section, wherein the third section has several segments spaced apart along the winding direction by forming a cutting groove in several along the winding axis direction, and The height of the first section is relatively smaller than the height of the uncoated section on the underside of the cut groove.

Description

TECHNICAL AREA

[0001] The present disclosure relates to an electrode arrangement, a battery and a battery pack, as well as a vehicle that may contain the aforementioned.

[0002] The present application claims priority from Korean patent application 10-2022-0089945, which was filed in the Republic of Korea on July 20, 2022, and the disclosures of which are incorporated herein by reference. STATE OF THE ART

[0003] Secondary batteries, which are easily applicable to various product groups and have electrical properties such as high energy density, are universally used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by an electric drive source.

[0004] These secondary batteries are attracting attention as a new energy source to improve environmental friendliness and energy efficiency, as they have the primary advantage of being able to dramatically reduce the use of fossil fuels, as well as the secondary advantage of not producing any byproducts through the use of energy.

[0005] Secondary batteries, which are currently widely used in technology, include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and the like. A standard secondary battery has an operating voltage of approximately 2.5 V to 4.5 V. If a higher output voltage is required, a battery pack can be created by connecting several batteries in series. Additionally, several batteries can be connected in parallel to form a battery pack according to the required charge / discharge capacity. Thus, the number of batteries contained in the battery pack and the form of the electrical connection can be adjusted according to the required output voltage and / or charge / discharge capacity.

[0006] Cylindrical, rectangular, and pouch batteries are known types of standard secondary batteries. In the case of a cylindrical battery, a separator, acting as an insulator, is positioned between a positive and a negative electrode. These electrodes are wound to form a jellyroll-shaped electrode assembly, which is inserted into a battery case to complete the battery. Additionally, a strip-shaped electrode tab can be connected to an uncoated section of both the positive and negative electrodes. This electrode tab electrically connects the electrode assembly to an externally exposed electrode terminal. For example, the positive electrode terminal might be a cap of a sealing body that tightly closes the opening of the battery case, and the negative electrode terminal might be the battery case itself.However, in the conventional cylindrical battery with such a structure, current is concentrated in the strip-shaped electrode tab that is coupled to the uncoated section of the positive electrode and / or the uncoated section of the negative electrode, so that the current collection efficiency may not be satisfactory due to the high resistance and high heat generation.

[0007] For small cylindrical batteries with a form factor of 1865 (i.e., a diameter of 18 mm and a height of 65 mm) or a form factor of 2170 (i.e., a diameter of 21 mm and a height of 70 mm), resistance and heat do not pose any particular problems. However, if the form factor is increased to use the cylindrical battery in an electric vehicle, the cylindrical battery can ignite if a lot of heat is generated at the electrode tab during the fast-charging process.

[0008] To address this problem, a cylindrical battery (in particular a so-called tabless ("tabless") cylindrical battery) is provided in which the uncoated section of the positive electrode and the uncoated section of the negative electrode are designed to be positioned on the top and bottom of the jellyroll electrode assembly, respectively, and the current collector is welded to the uncoated section to improve current collection efficiency.

[0009] Fig. 1, Fig. 2 to Fig. Figure 3 shows a process for manufacturing a tabless cylindrical battery. Fig. Figure 1 shows the structure of an electrode, Fig. 2 shows a process for winding the electrode and Fig. Figure 3 shows a process for welding a current collector to a bending surface area of ​​an uncoated section.

[0010] With reference to Fig. 1, Fig. 2 to Fig. 3 have a positive electrode 10 and a negative electrode 11, each having a structure in which a sheet-shaped current collector 20 is coated with an active material layer 21, and they have an uncoated section 22 on a longitudinal side along the winding direction X. The longitudinal side refers to a side of relatively large length in a direction parallel to the X-axis direction.

[0011] An electrode arrangement A is formed by successively stacking the positive electrode 10 and the negative electrode 11 together with two sheets of separators 12, as shown in Fig. 2 shown, and subsequent winding of the same in one direction X. At this point, the uncoated sections of the positive electrode 10 and the negative electrode 11 are arranged in opposite directions.

[0012] After the winding process, the uncoated section 10a of the positive electrode 10 and the uncoated section 11a of the negative electrode 11 are bent towards the core. Then, current collectors 30 and 31 are welded together and each coupled to the uncoated sections 10a and 11a, respectively.

[0013] An electrode tab is not separately coupled to the uncoated section 10a of the positive electrode and the uncoated section 11a of the negative electrode; the current collectors 30, 31 are connected to external electrode terminals; and a current path with a large cross-sectional area is formed along the winding axis direction of the electrode arrangement A (see arrow), which has the advantage of reducing the resistance of the battery. This is because the resistance is inversely proportional to the cross-sectional area of ​​the path through which the current flows.

[0014] In the tabless cylindrical battery, to improve the welding properties between the uncoated sections 10a, 11a and the current collectors 30, 31, strong pressure should be applied to the welding areas of the uncoated sections 10a, 11a to bend the uncoated sections 10a, 11a as flat as possible.

[0015] However, when bending the weld areas of the uncoated sections 10a and 11a, their shape can become distorted and irregularly deformed. In this case, the deformed part can come into contact with an electrode of opposite polarity, causing an internal short circuit or fine cracks in the uncoated sections 10a and 11a. Furthermore, if the uncoated sections 10a and 11a are bent while the uncoated section 32, which borders the core of the electrode assembly A, is also bent, all or a substantial part of the cavity 33 in the core of the electrode assembly A will be blocked. Additionally, the core of the electrode assembly A may not retain its original shape and could collapse. In this case, it causes a problem in the electrolyte injection process. That is, the cavity 33 in the core of the electrode assembly A is used as a passage through which an electrolyte is injected.However, if the corresponding passage is blocked, electrolyte injection becomes more difficult. Furthermore, while an electrolyte injector is being inserted into cavity 33, the injector may disturb the uncoated section 32 near the core, potentially causing it to rupture.

[0016] Furthermore, the curved sections of the uncoated sections 10a, 11a, to which the current collectors 30, 31 are welded, should overlap in several layers, and no voids (cavities) should be present. In this way, sufficient weld strength can be obtained, and even with the latest technology such as laser welding, it is possible to prevent a laser from penetrating the electrode assembly A and melting the separator or the active material.

[0017] In a conventional tabless cylindrical battery, an uncoated section 10a of the positive electrode is formed entirely on the upper portion of the electrode assembly A. Therefore, when the outer circumference of the top of the battery casing is pressed inward to form the beaded section, the upper edge region 34 of the electrode assembly A is forced through the battery casing. This pressure can cause partial deformation of the electrode assembly A, and in the process, the separator 12 may rupture, potentially causing an internal short circuit. If a short circuit occurs within the battery, it can lead to heat generation or even battery explosion. Disclosure Technique Task

[0018] The present disclosure is designed to address the problems of the prior art, and therefore the present disclosure is directed to provide an electrode arrangement with an improved structure of the uncoated section in order to relieve stress exerted on the uncoated section when the uncoated sections exposed at both ends of the electrode arrangement are bent.

[0019] The present disclosure is also directed to provide an electrode arrangement in which an electrolyte injection passage is not blocked even if the uncoated section is bent.

[0020] The present disclosure is also directed to provide an electrode arrangement with a structure that can prevent the upper edge of the electrode arrangement from touching the inner surface of the battery housing when a bead is formed on the top of the battery housing.

[0021] The present disclosure is also aimed at providing an electrode arrangement in which the properties of the welding area are improved by applying a segment structure to the uncoated section of the electrode and optimizing the dimensions (width, height, pitch) of the segments to sufficiently increase the number of segment stacks in the area used as the welding target area.

[0022] The present disclosure is also directed to provide an electrode arrangement in which the notch quality of the cut groove is improved by optimizing the lower structure of the cut groove by forming multiple segments by repeatedly forming a cut groove along the winding direction in the uncoated section of the electrode.

[0023] The present disclosure is also directed to provide an electrode arrangement in which the core shape does not coincide by adjusting the height of the uncoated section at the bottom (at the base) of the cut groove and the height of the uncoated section of an area adjacent to the core of the electrode arrangement relatively by forming several segments by repeatedly forming a cut groove along the winding direction in the uncoated section of the electrode.

[0024] The present disclosure is also aimed at providing an electrode arrangement with improved energy density and reduced resistance by applying a structure in which a current collector is welded to a wide area of ​​the bending surface area formed by bending the segments.

[0025] The present disclosure is also aimed at providing a battery with an improved terminal design so that electrical wiring can be carried out on its upper section.

[0026] The present disclosure is also directed to provide a battery containing the electrode arrangement with an improved structure, a battery pack containing the battery, and a vehicle containing the battery pack.

[0027] The technical problems to be solved by the present disclosure are not limited to those mentioned above, and other problems not mentioned here will be clearly understandable to the person skilled in the art from the following disclosure. TECHNICAL SOLUTION

[0028] In one aspect of the present disclosure, an electrode arrangement is provided comprising a first electrode, a second electrode, and a separator arranged between the first electrode and the second electrode, wherein the first electrode, the second electrode, and the separator are wound around a winding axis, thus defining a core and an outer circumference, wherein the first electrode has a first active material section coated with an active material layer along a winding direction, and a first uncoated section not coated with an active material layer and exposed beyond the separator, wherein the first uncoated section has a first section adjacent to the core of the electrode arrangement, a second section adjacent to the outer circumference of the electrode arrangement, and a third section between the first section and the second section.wherein the third section has several segments spaced apart along the winding direction by forming a cutting groove in a plurality along the winding axis direction, and wherein the height of the first section is relatively lower than the height of the uncoated section at a bottom of the cutting groove.

[0029] In the present disclosure, the difference in height refers to a relative difference. The reference point for measuring heights can, in principle, be chosen arbitrarily.

[0030] In one aspect, the reference point for measuring heights can be the end of the active material layer.

[0031] An insulating coating layer can be provided at the boundary between the first uncoated section and the active material layer.

[0032] In another aspect, the reference point for measuring heights can be the end of the insulating coating layer.

[0033] With respect to the end of the active material layer or the insulating coating layer, the height of the first section can be 0% to 95% of the height of the uncoated section at the bottom of the cut groove.

[0034] With respect to the end of the active material layer or the insulating coating layer, the height of the first section can be 37.5% to 62.5% of the height of the uncoated section at the bottom of the cut groove.

[0035] The height of the second section can be relatively smaller than the height of the uncoated section at the bottom of the cut groove.

[0036] With respect to the end of the active material layer or the insulating coating layer, the height of the second section can be 0% to 95% of the height of the uncoated section at the bottom of the cut groove.

[0037] With reference to the end of the active material layer or the insulating coating layer, the height of the second section can be 37.5% to 62.5% of the height of the uncoated section at the bottom of the cut groove.

[0038] A current collector of the first electrode can be thinner than a current collector of the second electrode.

[0039] The current collector of the first electrode can be a copper foil, and the current collector of the second electrode can be an aluminum foil.

[0040] The first electrode can be a negative electrode.

[0041] In a further aspect of the present disclosure, a battery is provided which comprises: an electrode arrangement having at least one of the above features; a battery housing with an open end and a base opposite the open end, configured to accommodate the electrode arrangement in the space between the open end and the base, and electrically connected to one of the first electrode and the second electrode, thus having a first polarity; a sealing element configured to tightly close the open end of the battery housing; and a terminal having a surface exposed to the outside, and electrically connected to another of the first electrode and the second electrode, thus having a second polarity.

[0042] The sealing body can include a cap plate configured to tightly seal the open end of the battery housing, and a gasket configured to surround the edge of the cap plate and crimped to the open end of the battery housing, and the terminal with the second polarity can be the cap plate.

[0043] The battery may further comprise a current collector electrically connected to the uncoated section of the first electrode carrying the first polarity, and having an edge that is at least partially coupled to a side wall of the battery casing. In this case, the sealing body may include a cap plate and a gasket configured to surround the edge of the cap plate and crimped to the open end of the battery casing. The battery casing may also include a rivet terminal insulated within a perforated hole formed in the center of the base, electrically connected to the second electrode, thus carrying the second polarity.

[0044] The cap plate may not have polarity.

[0045] In yet another aspect of the present disclosure, a battery pack with a plurality of the batteries described above, or a vehicle with such a battery pack, is provided. BENEFICIAL EFFECTS

[0046] According to one aspect of the present disclosure, the internal resistance of the battery can be reduced and the energy density increased by using the uncoated section itself, which protrudes from the upper and lower sections of the electrode arrangement, as an electrode tab.

[0047] According to another aspect of the present disclosure, it is possible to prevent a short circuit within the cylindrical battery due to partial deformation of the electrode arrangement by improving the structure of the uncoated section of the electrode arrangement so that the electrode arrangement and the inner circumference of the battery casing do not interfere with the process of forming the corrugated section of the battery casing.

[0048] According to yet another aspect of the present disclosure, it is possible to prevent the uncoated section from tearing when bent by improving the structure of the uncoated section of the electrode arrangement, and it is possible to improve the weld strength of the current collector by sufficiently increasing the number of overlapping layers of the uncoated section.

[0049] According to yet another aspect of the present disclosure, it is possible to improve the properties where the current collector is welded by providing a segment structure in the uncoated section of the electrode and optimizing the dimensions (width, height, pitch) of the segments to sufficiently increase the number of segment stacks in the area used as the welding target area.

[0050] According to yet another aspect of the present disclosure, where several segments are formed by repeatedly forming a cutting groove along the winding direction in the uncoated section of the electrode, the quality of the cutting grooves can be improved by optimizing a lower structure of the individual cutting groove.

[0051] According to yet another aspect of the present disclosure, when several segments are formed by repeatedly forming a cutting groove along the winding direction in the uncoated section of the electrode, it is possible to prevent the core shape from collapsing by adjusting the height of the uncoated section at a bottom of the cutting groove and the height of the uncoated section of an area adjacent to the core of the electrode arrangement relatively.

[0052] According to yet another aspect of the present disclosure, an electrode arrangement with improved energy density and reduced resistance can be provided by using a structure in which a current collector is welded to a wide area of ​​the bending surface area formed by bending the segments.

[0053] According to yet another aspect of the present disclosure, a cylindrical battery can be provided with a design in which the electrical contacting on its upper section is improved.

[0054] According to a further embodiment of the present disclosure, improving the structure of the uncoated section adjacent to the core of the electrode assembly prevents the cavity in the core of the electrode assembly from becoming blocked when the uncoated section is bent. This improves the electrolyte injection process and the welding process of the battery casing (or terminal) and the current collector.

[0055] According to yet another aspect of the present disclosure, it is possible to provide a cylindrical battery with a structure in which the internal resistance is low, an internal short circuit is prevented and the weld strength between the current collector and the uncoated section is improved, and a battery pack and a vehicle containing the cylindrical battery.

[0056] In particular, the present disclosure may provide a cylindrical battery having a diameter-to-height ratio of 0.4 or more and a resistance of 4 milliohms or less, and a battery pack and a vehicle containing the cylindrical battery.

[0057] Furthermore, the present disclosure may have several other effects, and such effects are described in relation to the embodiments, while descriptions of effects that a person skilled in the art can easily deduce are omitted. DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings illustrate a preferred embodiment of the present disclosure and, together with the preceding disclosure, serve to provide a further understanding of the technical features of the present disclosure, and thus the present disclosure is not to be construed as being limited to the drawing. Fig. Figure 1 is a top view showing the structure of an electrode used to manufacture a conventional tabless cylindrical battery. Fig. Figure 2 is a diagram showing an electrode winding process of the conventional tabless cylindrical battery. Fig. Figure 3 is a diagram showing a process for welding a current collector to a bending surface area of ​​an uncoated section in the conventional tabless cylindrical battery. Fig. Figure 4 is a top view showing the structure of an electrode according to an embodiment of the present disclosure. Fig. Figure 5a is a diagram showing definitions of width, height and pitch of a segment according to one embodiment of the present disclosure. Fig. Figure 5b is a partially enlarged view showing the lower structure of the cutting groove according to an embodiment of the present disclosure. Fig. Figure 5c is a partial top view showing the structure of the electrode, wherein the height of the uncoated section near the core of the electrode arrangement is adjusted to be smaller than the height of the uncoated section at the bottom of the cut groove according to an embodiment of the present disclosure. Fig. Figure 5d is a partial top view showing the structure of the electrode, wherein the height of the uncoated section near the outer circumference of the electrode arrangement is adjusted to be less than the height of the uncoated section at the bottom (at the base) of the cut groove according to an embodiment of the present disclosure. Fig. 5e is a photograph showing that the core shape of the electrode arrangement coincides when the height of the uncoated section near the core of the electrode arrangement is substantially equal to the height of the uncoated section at the bottom of the cut groove according to the comparative example of the present disclosure. Fig. Figure 5f is a photograph showing that the core shape of the electrode arrangement can be properly maintained if the height of the uncoated section near the core of the electrode arrangement is less than the height of the uncoated section at the bottom of the cut groove according to an embodiment of the present disclosure. Fig. Figure 6a is a diagram showing an arc formed by a lower end of the segment, wherein the width of the segment is defined in relation to the center of the core of the electrode arrangement when the electrode is wound according to an embodiment of the present disclosure. Fig. Figure 6b is a diagram schematically showing the relationship between the heights h1, h2, h3, h4 of segments, the core radius rc and the radii r1, r2, r3, r4 of winding turns at which segments begin to appear, according to an embodiment of the present disclosure. Fig. 6c is a conceptual diagram for determining a maximum value (hmax) for the height (H) of the segment in a segment-height-variable area. Fig. Figure 6d is a schematic diagram to explain the formula that determines a lower angle (θ) of the segment. Fig. Figure 7a is a top view showing the structure of the electrode according to another embodiment of the present disclosure. Fig. Figure 7b is a top view showing an independent area in which several segments can be arranged if the in Fig. 7a shows the electrode being wound into an electrode arrangement. Fig. Figure 8a is a top view showing the structure of an electrode according to another embodiment of the present disclosure. Fig. Figure 8b is a diagram showing definitions of width, height and pitch of a segment according to another embodiment of the present disclosure. Fig. Figure 8c is a partially enlarged view showing the lower structure of the cutting groove according to another embodiment of the present disclosure. Fig. Figure 8d is a partial top view showing the structure of an electrode in which the height of the uncoated section near the core of the electrode arrangement is adjusted to be smaller than the height of the uncoated section at the bottom of the cut groove according to another embodiment of the present disclosure. Fig. Figure 8e is a partial top view showing the structure of an electrode in which the height of the uncoated section near the outer circumference of the electrode arrangement is adjusted to be smaller than the height of the uncoated section at the bottom of the cut groove according to another embodiment of the present disclosure. Fig. Figure 8f is a top view showing a modified structure of the electrode according to yet another embodiment of the present disclosure. Fig. Figure 9 is a diagram showing a segment structure according to various modifications of the present disclosure. Fig. Figure 10a is a schematic diagram showing a cross-section of a bending surface area formed by bending the segment towards the core of the electrode arrangement according to an embodiment of the present disclosure. Fig. Figure 10b is a perspective top view schematically showing an electrode arrangement in which a bending surface area is formed according to an embodiment of the present disclosure. Fig. Figure 11a shows graphs showing the results of counting the number of stacked segments along a radial direction in the bending surface area of ​​a positive electrode formed on the upper section of the electrode arrangements according to embodiments 1-1 to 1-7 and the comparative example. Fig. Figure 11b shows graphs showing the results of counting the number of stacked segments along the radial direction in the bending surface area of ​​the positive electrode formed on the upper section of the electrode arrangements according to embodiments 2-1 to 2-5, embodiments 3-1 to 3-4, embodiments 4-1 to 4-3 and embodiments 5-1 to 5-2. Fig. Figure 11c shows graphs showing the results of counting the number of stacked segments along the radial direction in the bending surface area of ​​the positive electrode formed on the upper section of the electrode arrangement according to embodiments 6-1 to 6-6 and embodiments 7-1 to 7-6. Fig. Figure 12 is a top view of the electrode arrangement showing a stack number uniformity region b1 and a stack number decrease region b2 in the bending surface region of the segment according to an embodiment of the present disclosure. Fig. Figure 13 is a cross-sectional view of an electrode arrangement of the jellyroll type according to an embodiment of the present disclosure along the Y-axis direction (winding axis direction). Fig. Figure 14 is a cross-sectional view of an electrode arrangement of the jellyroll type according to another embodiment of the present disclosure along the Y-axis direction (winding axis direction). Fig. Figure 15 is a cross-sectional view of an electrode arrangement of the jellyroll type according to yet another embodiment of the present disclosure along the Y-axis direction (winding axis direction). Fig. Figure 16 is a cross-sectional view of an electrode arrangement of the jellyroll type according to yet another embodiment of the present disclosure along the Y-axis direction (winding axis direction). Fig. Figure 17 is a sectional view showing a cylindrical battery according to an embodiment of the present disclosure along the Y-axis direction. Fig. Figure 18 is a sectional view showing a cylindrical battery according to another embodiment of the present disclosure along the Y-axis direction. Fig. Figure 19 is a sectional view showing a cylindrical battery according to yet another embodiment of the present disclosure along the Y-axis direction. Fig. Figure 20 is a sectional view showing a cylindrical battery according to yet another embodiment of the present disclosure along the Y-axis direction. Fig. Figure 21 is a top view showing a structure of a first current collector according to an embodiment of the present disclosure. Fig. Figure 22 is a perspective view showing a structure of a second current collector according to an embodiment of the present disclosure. Fig. Figure 23 is a top view showing a state in which several cylindrical batteries are electrically connected. Fig. 24 is a partially enlarged view of Fig. 23. Fig. Figure 25 is a diagram schematically showing a battery pack according to an embodiment of the present disclosure. Fig. Figure 26 is a diagram schematically showing a vehicle that includes the battery pack according to an embodiment of the present disclosure. EXECUTION FORMS

[0059] Preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. Prior to the description, it should be understood that the terms used in the description and the accompanying claims should not be interpreted as being limited to general and dictionary-like meanings, but rather should be interpreted based on the meanings and concepts that correspond to the technical aspects of the present disclosure, on the basis of the principle that the inventor is permitted to define terms appropriately for the best possible explanation.

[0060] Therefore, the description proposed herein is only a preferred example for illustrative purposes and is not intended to limit the scope of the disclosure, so that it is understood that other equivalents and modifications could be made to it without deviating from the scope of the disclosure.

[0061] To facilitate understanding of the present disclosure, the accompanying drawings are not drawn to scale and the dimensions of some components may be exaggerated. Additionally, identical or related reference numerals may be assigned to the same or corresponding components in different embodiments.

[0062] To state that two objects being compared are "equal" means that they are "essentially the same." Therefore, the term "essentially the same" can encompass a deviation considered minor in engineering, for example, a deviation of less than 5%. Furthermore, the uniformity of a parameter within a range can mean that, from an average perspective, the parameter is consistent across that range.

[0063] Although the terms first, second, or similar are used to describe different elements, these terms are not to be interpreted restrictively. These terms are used to distinguish one element from another, and unless otherwise specified, a first element can be a second element.

[0064] In the entire description, unless otherwise stated, each element can be given in singular or plural.

[0065] When an element is located “above” or “on” (or “below”) another element, the element may be located directly on a top (or bottom) surface of the other element, or an intermediate element may be located between the said element and the other element (above or below).

[0066] When an element is described as being “connected”, “coupled”, or “linked” to another element, the element may additionally be directly connected or coupled to the other element, while anticipating that an intermediate element may exist between each element, or that the elements may be “connected”, “coupled”, or “linked” to each other through another element.

[0067] Throughout this description, “A and / or B” refers to either A or B or both A and B, unless expressly stated otherwise, and “C to D” refers to C or greater and D or lesser, unless expressly stated otherwise.

[0068] For the sake of simplicity, a direction running along a longitudinal axis of a winding axis of an electrode arrangement wound in a coil form is referred to herein as an axis direction Y. Furthermore, a direction around the winding axis is referred to herein as a circumferential direction X. A direction towards or away from the winding axis is also referred to as a radial direction. Specifically, the direction pointing towards the winding axis is referred to as the centripetal direction, and the direction pointing away from the winding axis is referred to as the centrifugal direction.

[0069] First, an electrode arrangement according to one embodiment of the present disclosure is described. The electrode arrangement can be a jellyroll-type electrode arrangement with a structure in which a first electrode and a second electrode are wound in one direction with a foil form and an intermediate separator. However, the present disclosure is not limited to the type of electrode arrangement.

[0070] Preferably, at least one of the first electrode and the second electrode has an uncoated section at a long side end in the winding direction, which is not coated with an active material. The uncoated section comprises a core-side uncoated section adjacent to the core of the electrode arrangement, an outer-circumference-side uncoated section adjacent to the outer circumference of the electrode arrangement, and an uncoated intermediate section located between the core-side uncoated section and the outer-circumference-side uncoated section.

[0071] Preferably, at least one of the core-side uncoated section and the outer-circumference-side uncoated section has a relatively lower height than the uncoated intermediate section.

[0072] Fig. Figure 4 is a top view showing a structure of an electrode 60 according to an embodiment of the present disclosure.

[0073] Referring to Fig. In one embodiment, the electrode 60 has a current collector 41 made of a metal foil and an active material layer 42. The metal foil can be a conductive metal, such as aluminum or copper, and is selected appropriately according to the polarity of the electrode 60. The active material layer 42 is formed on at least one surface of the current collector 41. The electrode 60 has an uncoated section 43 at its long end in the winding direction X. The uncoated section 43 is a portion of the current collector 41 that is not coated with the active material. The portion of the current collector 41 in which the active material layer 42 is formed can be referred to as the active material section.

[0074] In electrode 60, the width of the active material section in the short-side direction of the current collector 41 can be 50 mm to 120 mm, and the length of the active material section in the long-side direction of the current collector 41 can be 3 m to 5 m. Therefore, the ratio of the short side to the long side of the active material section can be 1.0% to 4.0%.

[0075] Preferably, in the electrode 60, the width of the active material section in the short-side direction of the current collector 41 can be 60 mm to 70 mm, and the length of the active material section in the long-side direction of the current collector 41 can be 3 m to 5 m. Therefore, the ratio of the short side to the long side of the active material section can be 1.2% to 2.3%.

[0076] The ratio of the short side to the long side of the active material section is significantly less than 6% to 11%, that is, the ratio of the short side to the long side of the active material section of an electrode used in a cylindrical battery with a form factor of 1865 or 2170.

[0077] Preferably, an insulating coating layer 44 can be formed at a boundary between the active material layer 42 and the uncoated section 43. The insulating coating layer 44 is designed such that at least a portion of it overlaps the boundary between the active material layer 42 and the uncoated section 43. The insulating coating layer 44 prevents a short circuit between two electrodes with opposite polarities facing each other with a separator arranged between them. The insulating coating layer 44 can cover a boundary between the active material layer 42 and the uncoated section 43 with a width of 0.3 mm to 5 mm. The width of the insulating coating layer 44 can vary along the winding direction of the electrode 60. The insulating coating layer 44 can comprise a polymer resin and an inorganic filler such as SiO2 or Al2O3.Since the section of the current collector 41 that is covered by the insulating coating layer 44 is not an area coated with an active material layer, it can be considered an uncoated section.

[0078] The uncoated section 43 has a core-side uncoated section B1 adjacent to the core of the electrode arrangement, an outer-circumference-side uncoated section B3 adjacent to the outer circumference of the electrode arrangement, and an uncoated intermediate section B2 located between the core-side uncoated section B1 and the outer-circumference-side uncoated section B3.

[0079] The core-side uncoated section B1, the outer-circumference-side uncoated section B3 and the uncoated intermediate section B2 can be defined as an uncoated section in a region adjacent to the core, an uncoated section in a region adjacent to the outer circumference, or an uncoated section of the remaining area excluding the above areas, respectively, when the electrode 60 is wound to form a jellyroll-type electrode arrangement.

[0080] In the following, the core-side uncoated section B1, the outer-circumference-side uncoated section B3 and the uncoated intermediate section B2 are referred to as a first section, a second section and a third section respectively.

[0081] In one example, the first section B1 can be an uncoated section of an electrode region encompassing the innermost winding turn, and the second section B3 can be an uncoated section of an electrode region encompassing the outermost winding turn. The winding turn can be counted based on the core-side end of the electrode assembly.

[0082] In another example, the boundary of B1 / B2 may be appropriately defined as a point at which the height (or pattern of change) of the uncoated section substantially changes as it moves from the core of the electrode array to the outer circumference, or as a point of a predetermined % based on the radius of the electrode array (e.g., 5% point, 10% point, 15% point, or the like of the radius).

[0083] The boundary of B2 / B3 can be defined as a point where the height (or change pattern) of the uncoated section substantially changes as it moves from the outer circumference of the electrode array to the core, or as a point of a predetermined percentage based on the radius of the electrode array (e.g., 85% point, 90% point, 95% point, or the like). If the boundaries of B1 / B2 and B2 / B3 are specified, the third section, B2, can be specified automatically.

[0084] If only the boundary of B1 / B2 is specified, the boundary of B2 / B3 can be suitably chosen at a point near the outer circumference of the electrode assembly. For example, the second section can be defined as an uncoated portion of a region of the electrode forming the outermost winding turn. Conversely, if only the boundary of B2 / B3 is specified, the boundary of B1 / B2 can be suitably chosen at a point near the core of the electrode assembly. For example, the first section B1 can be defined as an uncoated portion of a region of the electrode forming the innermost winding turn.

[0085] It is possible that another structure is arranged between the first section B1 and the third section B2. Furthermore, it is possible that another structure is arranged between the third section B2 and the second section B3.

[0086] The height of the uncoated section 43 is not constant, and there is a relative difference in the winding direction X. That is, the height (length in the Y-axis direction) of the second section B3 is 0 or more, but can be relatively smaller than those of the first section B1 and / or the third section B2. Here, the height of each section can be an average height or a maximum height, which is applied in the same way below. In the winding direction, the third section B2 is longer than the first section B1 and the second section B3.

[0087] In electrode 60, the heights of the first section B1 and the second section B3 are 0 or more, but are relatively smaller than those of the third section B2. Furthermore, the heights of the first section B1 and the second section B3 can be the same or different.

[0088] The width (dB1) of the first section B1 is selected by applying the condition that the core of the electrode assembly is not covered when the uncoated section of the third section B2 is bent towards the core. The core refers to a cavity present in the winding center of the electrode assembly.

[0089] In one example, the width (dB1) of the first section B1 can increase proportionally to the bending length of the uncoated section closest to the core.

[0090] Preferably, the width (dB1) of the first section B1 can be adjusted such that the width in the radial direction of the winding turns formed by the first section B1 is equal to or greater than the bending length of the uncoated section closest to the core. In a modification, the width (dB1) of the first section B1 can be adjusted such that the value obtained by subtracting the radial width of the winding turns formed by the first section B1 from the bending length of the uncoated section closest to the core is less than 0 or 10% or less of the radius of the core.

[0091] In a specific example, if the electrode 60 is used to manufacture an electrode assembly of a cylindrical battery with a form factor of 4680, the width (dB1) of the first section B1 can be adjusted to between 180 mm and 350 mm depending on the diameter of the core of the electrode assembly and the bending length of the uncoated section closest to the core.

[0092] At least a portion of the uncoated section of the third section B2 can have several segments 61. The heights of the several segments 61 can increase stepwise from the core to the outer circumference. Alternatively, the heights of the several segments 61 can be kept constant from the core to the outer circumference. The several segments 61 have a geometric shape in which the width decreases from bottom to top. Preferably, the geometric shape is a trapezoid. As will be described later, the shape of the geometric shape can be modified in various ways, for example, into a rectangular or parallelogram shape.

[0093] Segment 61 can be formed by laser notching. Segment 61 can also be formed by a known metal foil cutting process, such as ultrasonic cutting or punching.

[0094] To prevent damage to the active material layer 42 and / or the insulating coating layer 44 during bending of the uncoated section 43, it is preferable to have a predetermined gap between the underside (a section that is in Fig. 5a (designated with G) of the cut groove between the segments 61 and the active material layer 42. This is because the stress is concentrated near the bottom of the cut groove 63 when the uncoated section 43 is bent. The gap can be varied along the winding direction of the electrode 60. The gap is 0.2 mm to 4 mm, preferably 1.5 mm to 2.5 mm. If the gap is set within the appropriate numerical range, it is possible to prevent the active material layer 42 and / or the insulating coating layer 44 near the bottom of the cut groove 63 from being damaged by the stress generated during the bending of the uncoated section 43. The gap can prevent the active material layer 42 and / or the insulating coating layer 44 from being damaged due to tolerances during the notching or cutting of the segment 61.In a direction parallel to the winding direction, the gap can be essentially the same or it can vary. In the latter case, the gaps of the multiple segments can be varied individually, in a group unit, or in two or more group units along a direction parallel to the winding direction. The lower end of the cut groove 63 and the insulating coating layer 44 can be spaced apart by 0.5 mm to 2.0 mm. In a direction parallel to the winding direction, the pitch between the lower end of the cut groove 63 and the insulating coating layer 44 can be essentially the same or it can vary. In the latter case, the pitches of the multiple segments can be varied individually, in a group unit, or in two or more group units along a direction parallel to the winding direction.When the electrode 60 is wound, the end of the insulating coating layer 44 can be located in the winding axis Y-direction within a range of -2 mm to 2 mm along the winding axis direction, relative to the end of the separator. The insulating coating layer 44 can prevent a short circuit between two electrodes of opposite polarities facing each other with an interposed separator and can support a bending point when the segment 61 is bent. To improve the short-circuit prevention effect between the two electrodes, the insulating coating layer 44 can be exposed to the outside of the separator.Additionally, to further maximize the short-circuit prevention effect between the two electrodes, the width of the insulating coating layer 44 can be increased so that its end is located above the lower end of the cut groove 63 in the winding axis Y-direction. In one embodiment, the end of the insulating coating layer 44 can be located in a range of -2 mm to +2 mm relative to the lower end of the cut groove 63 in the winding axis direction. The thickness of the insulating coating layer 44 can be less than the thickness of the active material layer 42. In this case, a gap may be present between the surface of the insulating coating layer 44 and the separator.

[0095] In one aspect, the multiple segments can form several segment groups extending from the core to the outer perimeter. The width and / or height and / or pitch of segments belonging to the same segment group can be essentially the same.

[0096] Preferably, the width, height, and pitch of the segments belonging to the same segment group can be essentially the same.

[0097] In another aspect, the divisions (pitches) of the multiple segments in one group or in two or more groups can gradually or stepwise increase from the core to the outer perimeter, or vice versa.

[0098] In yet another aspect, the divisions (pitches) of the multiple segments in one group or in two or more groups can gradually or stepwise increase from the core to the outer perimeter and then gradually or stepwise decrease, or vice versa.

[0099] In yet another aspect, the gap between the underside of the cut groove 63 and the insulating coating layer 44 or the active material layer 42 can gradually or stepwise increase from the core to the outer circumference or vice versa in the several segments.

[0100] In yet another aspect, in the several segments the gap between the underside of the cut groove 63 and the insulating coating layer 44 or the active material layer 42 can gradually or stepwise increase from the core to the outer circumference and then gradually or stepwise decrease or vice versa.

[0101] Fig. Figure 5a is a diagram showing the definitions of width (D), height (H) and pitch (P) of a trapezoidal segment 61 according to an embodiment of the present disclosure, Fig. Figure 5b is a partially enlarged view showing the lower structure of the cutting groove 63.

[0102] With reference to Fig. 5a and Fig. 5b the width (D), height (H) and pitch (P) of segment 61 are designed to prevent the uncoated section 43 from tearing near the bending point during bending of the uncoated section 43 and to prevent abnormal deformation of the uncoated section 43, while sufficiently increasing the number of overlapping layers of the uncoated section 43 to ensure adequate weld strength.

[0103] Segment 61 is bent along line G, which runs through the underside of the cut groove 63 or along its upper side. The cut groove 63 allows for smooth and easy bending of segment 61 in the radial direction of the electrode assembly.

[0104] The segments 61 are arranged on both sides of the cutting groove 63. The cutting groove 63 has a side section 63a and a rounded section 63b of segment 61. The side section 63a extends in a straight line. The side section 63a forms an acute angle with the winding direction. The rounded section 63b may have a radius of curvature. Both ends of the rounded section 63b are smoothly connected to the side section 63a.

[0105] The width (D) of segment 61 is defined as the length between two points where two straight lines extending from the side section 63a of segment 61 meet a straight line G extending in the winding direction through the bottom of the round section 63b.

[0106] The height (H) of segment 61 is defined as the shortest distance between the top of segment 61 and a straight line extending in the winding direction through the bottom of the circular section 63b.

[0107] As in Fig. As shown in Figure 5b, the pitch (P) of segment 61 is defined as the length between two points where a straight line (L1), connecting both ends of the round section 63b, and straight lines (L2), extending from the side sections 63a on both sides of the cut groove 63, intersect. In other words, the distance between two points where the radius of curvature begins to change in the lower sections of the side sections 63 on both sides of the cut groove 63 corresponds to the pitch (P).

[0108] The pitch (P) of segment 61 can be from 0.05 mm to 2.0 mm, preferably from 0.5 mm to 1.0 mm.

[0109] The circular section 63b can be essentially a circle with the pitch (P) as its diameter. Alternatively, the circular section 63b can approximate the shape of a circle with the pitch (P) as its diameter. Alternatively, the circular section 63b can connect the side sections of the segments 61 located on both sides of the cutting groove 63, and the radius of curvature of the circular section 63b can gradually increase and then gradually decrease from the side section of segment 61 on one side to the side section of segment 61 on the other side.

[0110] If the round section 63b, which is essentially identical to a circle with the pitch (P) as its diameter, the round section 63b which approximately follows the circle, or the round section 63b in which the radius of curvature gradually increases and then gradually decreases, is provided at the bottom of the cutting groove 63, the notch quality can be improved during the process of notching the segment 61.

[0111] In the present disclosure, the fact that the round section 63b approximately follows a circle means that the round section 63b gently connects the lower ends of the side sections 63a on both sides of the cutting groove 63, as the radius of curvature of the round section 63b gradually changes within 20% of the radius of the circle with the pitch (P) as its diameter.

[0112] Referring again to Fig. 5a The width (D) of segment 61 is preferably 1 mm or more. If D is less than 1 mm, when segment 61 is bent towards the core, an area or void (cavity) may occur where the segments 61 do not overlap sufficiently to ensure adequate weld strength.

[0113] Preferably, the width (D) of the segments 61 can be adaptively adjusted depending on the radius of the winding turn in which the segments 61 are located, so that the segments 61 overlap well in the radial direction when the segments 61 are bent towards the core of the electrode arrangement.

[0114] Fig. 6a is a diagram showing an arc (A1A2) that is defined by a lower end (line Dab in Fig. 5a) of segment 61 is formed, wherein the width D of segment 61 is defined in relation to the center O of the core of the electrode arrangement when the electrode 60 is wound according to an embodiment of the present disclosure.

[0115] Referring to Fig. 6a The arc (A1A2) has a length corresponding to the width (D) of segment 61 and has a circumferential angle (Φ) around the center of the core of the electrode arrangement. The circumferential angle (Φ) can be defined as the angle between two line segments connecting both ends of the arc (A1A2) and the center O of the core on a plane perpendicular to the winding axis passing through the arc (A1A2).

[0116] If the length of the arc (A1A2) of segment 61 is constant, the circumferential angle (Φ) decreases as the radius (r) of the winding turn in which segment 61 is located increases. Conversely, if the circumferential angle (Φ) of segment 61 is constant, the length of the arc (A1A2) increases proportionally as the radius (r) of the winding turn in which segment 61 is located increases.

[0117] The circumferential angle (Φ) influences the bending quality of segment 61. In the drawing, a solid arrow indicates the direction of the force applied to bend segment 61, and a dashed arrow indicates the direction in which segment 61 is bent. The bending direction is a direction towards the center O of the core.

[0118] The circumferential angle (Φ) of the segment 61 can be 45 degrees or less, preferably 30 degrees or less, depending on the radius (r) of the winding turn in which the segment 61 is located, in order to improve bending uniformity and prevent cracking.

[0119] In one aspect, the circumferential angle (Φ) of segment 61 along the radial direction of the electrode arrangement can gradually or stepwise increase or decrease within the above numerical range. In another aspect, the circumferential angle (Φ) of segment 61 along the radial direction of the electrode arrangement can gradually or stepwise increase or decrease, or vice versa, within the above numerical range. In yet another aspect, the circumferential angle (Φ) of segment 61 along the radial direction of the electrode arrangement can remain essentially constant within the above numerical range.

[0120] According to experiments, if the circumferential angle (Φ) of segment 61 exceeds 45 degrees, the bending shape of segment 61 is not uniform. The difference between the force exerted on the central part of segment 61 and the force exerted on the side part increases, so that the compression of segment 61 is not uniform in the circumferential direction. In addition, if the pressing force is increased to achieve uniformity of the bend, cracks may appear in the uncoated section 43 near the cut groove 63.

[0121] In one embodiment, the circumferential angles (Φ) of the segments 61 contained in the electrode 60 are essentially equal, and the widths of the segments 61 can increase proportionally as the radius (r) of the winding turn in which the segment 61 is located increases. The term "essentially equal" means completely identical or with a deviation of less than 5%.

[0122] For example, if the radius of the electrode arrangement is 22 mm and the radius of the core is 4 mm, and the segments 61 are arranged starting from the winding turn located at the point where the radius is 7 mm, and if the circumferential angles (Φ) of the segments 61 are uniform at 28.6 degrees, the widths (D) of the segments 61 can increase proportionally according to the radius (r) of the winding turn in which the segments 61 are located, as shown in Table 1 below. That is, the widths of the segments 61 can increase by 0.5 mm at essentially the same rate whenever the radius (r) of the winding turn increases by 1 mm. TABLE 1

[0123] Preferably, the width D(r) of the segment 61, which is located in a winding turn with a radius of r based on the core center O of the electrode arrangement, can be determined within a range that satisfies the formula 1 below. 1≤D(r)≤(2*π*r / 360°)*45°

[0124] Preferably, the widths D(r) of the multiple segments 61 in the winding direction can gradually or stepwise increase based on the core center of the electrode arrangement as the radius r of the winding turn in which the segment 61 is located increases, or vice versa.

[0125] In another aspect, the widths D(r) of the multiple segments 61 in the winding direction based on the core center of the electrode arrangement can gradually or stepwise increase in the range of 1 mm to 11 mm as the radius r of the winding turn in which the segment 61 is located increases, or vice versa.

[0126] In yet another aspect, the widths D(r) of the multiple segments 61 in the winding direction based on the core center of the electrode arrangement can gradually or stepwise increase and then gradually or stepwise decrease as the radius r of the winding turn in which the segment 61 is located increases, or vice versa.

[0127] In yet another aspect, the widths D(r) of the multiple segments 61 in the winding direction based on the core center of the electrode arrangement can gradually or stepwise increase and then gradually or stepwise decrease in the range of 1 mm to 11 mm as the radius r of the winding turn in which the segment 61 is located increases, or vice versa.

[0128] In yet another aspect, the rate at which the widths D(r) of segments 61 change as the radius r of the winding turn in which segment 61 is located increases can be the same or different.

[0129] In yet another aspect, the rate at which the widths D(r) of the segments 61 change in the range from 1 mm to 11 mm as the radius r of the winding turn in which the segment 61 is located increases can be the same or different.

[0130] Referring again to Fig. 5a The height (H) of segment 61 can be 2 mm or more. If the height H is less than 2 mm, when segment 61 is bent towards the core, an area or void (cavity) may occur where the segments 61 do not overlap sufficiently to ensure adequate weld strength.

[0131] The height (H) of segment 61 can be determined by applying the condition that segment 61 does not block the core when bent towards the core. Preferably, the height (H) of segment 61 can be adjusted such that 90% or more of the core's diameter can be opened outwards.

[0132] Preferably, the heights (H) of the segments 61 can increase from the core to the outer circumference depending on the radius of the winding turn and the radius of the core in which the segments 61 are located.

[0133] In one embodiment, if the heights (H) of the segments 61 increase stepwise over N steps from h1 to hN as the radius of the winding turn increases, assuming that the k-th height of the segment 61 (k is a natural number from 1 to N) is hk, the initial radius of the winding turn including the segment 61 with height hk is rk, and the radius of the core is rc, the heights h1 to hN of the segments 61 can be determined to satisfy Formula 2 below. 2mm≤hk≤rk−a*rc(preferably a is 0.90 to 1)

[0134] If the heights (hk) of the segments 61 satisfy formula 2, even if the segments 61 are bent towards the core, 90% or more of the diameter of the core can be open to the outside.

[0135] In one example, the radius of all winding turns of electrode 60 is 22 mm. The heights of segments 61 start at 3 mm and are successively increased to 3 mm, 4 mm, 5 mm, and 6 mm whenever the radius of the winding turn, including segment 61, increases by 1 mm. The heights can be kept essentially constant at 6 mm in the remaining winding turns. That is, among the radii of all winding turns, the radial width of the height-variable region of segment 61 is 3 mm, and the remaining radial region corresponds to the height-uniform region.

[0136] In this case, if α is 1 and the same sign condition is applied in the correct inequality, the initial radius r1, r2, r3, r4 of the winding turns including segments 61 with heights of 3 mm, 4 mm, 5 mm and 6 mm can be as a function of the radius (rc) of the core of the electrode arrangement as shown in Table 2 below. TABLE 2 Segmenthöhe ((mm) Element 3 (h1) 4 (h2) 5 (h3) 6 (h4) core radius (r c )(mm) 2 5 (r1) 6 (r2) 7 (r3) 8 (r4) 2,5 5,5 (r1) 6,5 (r2) 7,5 (r3) 8,5 (r4) 3 6 (r1) 7 (r2) 8 (r3) 9 (r4) 3,5 6,5 (r1) 7,5 (r2) 8,5 (r3) 9,5 (r4) 4 7 (r1) 8 (r2) 9 (r3) 10 (r4)

[0137] If the segments 61 are positioned at the radius positions shown in Table 2, the core is not blocked by the segments 61, even if the segments 61 are bent towards the core. In this case, r1, r2, r3, r4, shown in Table 1, can be shifted towards the core according to the value of α. For example, if α is 0.90, r1, r2, r3, r4 can be shifted towards the core by 10% of the core radius. In this case, if the segment 61 is bent towards the core, 10% of the core radius is blocked by the segment 61. r1, r2, r3, r4, shown in Table 1, are limiting positions of the starting point of the segment 61. Therefore, the position of segment 61 can be shifted by a predetermined distance towards the outer circumference and not by the radius shown in Table 2. Fig. Figure 6b is a diagram that schematically shows the relationship of the heights h1, h2, h3, h4 of the segments 61, the core radius (rc) and the radii r1, r2, r3, r4 of the winding turns, in which the segments 61 become recognizable.

[0138] Referring to Table 2 and Fig. For example, if the radius (rc) of the core C is 3 mm, the initial radii r1, r2, r3, and r4 of the winding turns, including segments 61 with heights of 3 mm (h1), 4 mm (h2), 5 mm (h3), and 6 mm (h4), can be 6 mm, 7 mm, 8 mm, and 9 mm, respectively. The height of segments 61 can be 6 mm from the radius of 9 mm to the last winding turn. Furthermore, segment 61 cannot be included in the winding turn with a radius smaller than 6 mm (r1). Since in this example the segment 61 with a height of 3 mm (h1), which is closest to the core C, is located from the winding turn with a radius of 6 mm, the segments 61, even when bent towards the core C, only cover the radial area of ​​3 mm to 6 mm and do not substantially block the core C.

[0139] In another embodiment, the height of segment 61 can increase at the same or a different rate as the initial radius r of the winding turn in which segment 61 is located increases based on the core center of the electrode arrangement.

[0140] Preferably the height (H) of segment 61 satisfies formula 2 and at the same time the maximum height of segment 61 can be limited.

[0141] Fig. 6c is a conceptual diagram for determining a maximum value (hmax) for the height (H) of segment 61 in a segment height variable area of ​​segment 61.

[0142] With reference to Fig. In the winding structure of the electrode arrangement, electrode (E1), which has segment 61, faces electrode (E2) with opposite polarity, with the separator S arranged radially between them. Both surfaces of electrode (E1) are coated with an active material layer (E1,active), and both surfaces of electrode (E2) are also coated with an active material layer (E2,active). For electrical insulation, the end (Send) of the separator S can extend further outward from the end (E2,end) of electrode (E2) to a length corresponding to the insulating gap (Wgap). Furthermore, the end of electrode (E1) does not extend further outward beyond the end of electrode (E2) for electrical insulation. Therefore, an area corresponding to the insulating gap (Wgap) should be secured at the lower end of the uncoated section 43.When the electrodes (E1, E2) and the separator S are wound, the end (Send) of the separator S also causes meandering (i.e., serpentine formation). Therefore, to ensure that segment 61 is exposed to the outside of the separator S, it is desirable that the area (Wmargin,min) corresponding to a minimum meander span of the separator S be allocated to the uncoated section 43. Furthermore, to allow for cutting segment 61, a minimum cutting waste span (Wscrap,min) should be allocated to the end of the current collector foil. Therefore, the maximum height (hmax) of segment 61 within the height-variable area of ​​segment 61 can be determined by Formula 3 below. In Formula 3, Wfoil corresponds to the width of the current collector foil before the current collector foil is cut. hmax=Wfoil−Wscrap,min−Wmargin,min−Wgap

[0143] Preferably, the insulating gap Wgap can be 0.2 mm to 6 mm if the first electrode is a positive electrode. Additionally, the insulating gap Wgap can be 0.1 mm to 2 mm if the first electrode is a negative electrode.

[0144] Preferably, the minimum scrap allowance Wscrap,min can be from 1.5 mm to 8 mm. The minimum scrap allowance (Wscrap,min) may not be assigned depending on the process of forming the segment 61. For example, the cutting groove 63 may be formed such that the upper edge of the segment 61 and the upper edge of the current collector foil coincide. In this case, Wscrap,min in Formula 3 may be 0.

[0145] Preferably, the minimum meander span Wmargin,min of the separator can be 0 mm to 1 mm.

[0146] In one example, the minimum scrap margin (Wscrap,min) can be 1.5 mm and the minimum meander margin (Wmargin,min) of the separator S can be 0.5 mm. Under these conditions, if the width (Wfoil) of the current collector foil before forming segment 61 is 8 mm to 12 mm and the insulating gap (Wgap) is 0.6 mm, 0.8 mm and 1.0 mm, the maximum height (hmax) of segment 61 can be calculated using formula 3 as shown in Table 3 below. TABLE 3 Element Separator gap ↔ Negative electrode (mm) 0,6 0,8 1 Breite des Stromkollektors Folie (mm) 8 5,4 5,2 5 9 6,4 6,2 6 10 7,4 7,2 7 11 8,4 8,2 8 12 9,4 9,2 9

[0147] Based on Table 3, the maximum height (hmax) of segment 61 in the height-variable range of segment 61 can be set to 10 mm. Therefore, the height of segment 61 in the height-variable range of segment 61 satisfies formula 2 and can increase stepwise or gradually along the radial direction of the electrode arrangement in the range from 2 mm to 10 mm. Referring again to Fig. 5a The pitch (P) of segment 61 can be adjusted in the range of 0.05 mm to 2 mm, preferably 0.5 mm to 1.0 mm. If the pitch (P) is less than 0.05 mm, cracks may occur in the uncoated section 43 near the lower end of the cut groove 63 due to stress when the electrode 60 moves during the winding process or the like. Furthermore, if the pitch (P) exceeds 2 mm, an area or void (cavity) may occur where the segments 61 do not overlap sufficiently to ensure adequate weld strength when the segment 61 is bent.

[0148] Furthermore, if the current collector 41 of the electrode 60 is made of aluminum, it is further preferred that the pitch (P) be 0.5 mm or more. If the pitch (P) is 0.5 mm or more, cracks can be prevented from occurring at the bottom of the cut groove 63, even if the electrode 60 moves at a speed of 100 mm / s or more under a voltage of 300 gf or more in the winding process or the like.

[0149] According to the experimental results, if the current collector 41 of the electrode 60 is an aluminum foil with a thickness of 15 µm and the pitch (P) is 0.5 mm or more, no cracks are produced on the bottom of the cut groove 63 when the electrode 60 moves under the above movement conditions.

[0150] The lower interior angles (θ) of the multiple segments 61 can increase from the core to the outer circumference. In one example, the lower interior angles (θ) of the multiple segments 61 can increase gradually or stepwise from the core to the outer circumference. The lower interior angle (θ) is an angle between a straight line extending from the bottom of the cut groove 63 and a straight line extending from the side section 63a of the segment 61. If the segment 61 is symmetrical in the left and right directions, the lower interior angles (θ) of the left and right sides are essentially equal.

[0151] As the radius of the electrode arrangement increases, the radius of curvature also increases. As the lower inner angle (θ) of segment 61 increases with the radius of the electrode arrangement, the stress generated in the radial and circumferential directions when segment 61 is bent can be reduced. Furthermore, as the lower inner angle (θ) increases when segment 61 is bent, the area overlapping segment 61 on the inside and the number of overlapping layers also increase, thus ensuring uniform weld strength in the radial and circumferential directions and allowing the bending surface area to be formed flat.

[0152] Preferably the lower internal angle (θ) can be determined by the radius of the winding turn in which the segment 61 is located and the width (D) of the segment 61.

[0153] Fig. Figure 6d is a schematic diagram to explain the formula that determines a lower interior angle (θ) of segment 61.

[0154] Referring to Fig. 6d the sides of segment 61 ideally coincide with line segment AE and line segment DE, which connect the core center (E) with both endpoints A and D of line segment AD according to the width (D) of segment 61.

[0155] If the side of segment 61 extends in the most ideal direction, assuming that line segment EF is approximately equal to line segment AE and line segment DE, the lower internal angle (θrefer) of segment 61 can be determined approximately from the width (D) of segment 61 and the radius (r) of the winding turn in which segment 61 is located, using formula 4 below. θrefer=cos−1(0.5∗Dr)

[0156] The angle in formula 4 is an ideal reference point for the lower internal angle (θrefer) of segment 61. Furthermore, a pitch (P) exists between adjacent segments 61 located in the same winding turn. The length of the pitch (P) is denoted by p. Since the pitch (P) exists between adjacent segments 61, a tolerance of 50% of the pitch (p) can be provided for the lower internal angle (θ). That is, the width of the top surface BC of segment 61 can be increased by a maximum of p / 2 relative to the top surface B'C'. The lower internal angle (θ') with the reflected tolerance can be expressed as in formula 5 below. The lower interior angle (θrefer) is the ideal reference point ∠BAG, and the lower interior angle (θ') is the angle ∠B'AG' that reflects the tolerance according to the pitch (p). In Formula 5, H is the height of segment 61 and p corresponds to the pitch. θ'=tan−1(2∗H∗tanθrefer2∗H−p∗tanθrefer)

[0157] Preferably, the lower inner angle (θ) of the segment 61 located at each winding of the electrode arrangement can satisfy the formula 6 below. Then, when the segments 61 are bent towards the core center of the electrode arrangement, the segments 61 adjacent in the circumferential direction do not interfere with each other and can be bent smoothly. cos−1(0.5∗Dr)≤θ≤tan−1(2∗H∗tanθrefer2∗H−p∗tanθrefer)

[0158] For example, if the electrode 60 forms a winding structure with a diameter of 22 mm and a core radius of 4 mm, the lower internal angle of the segment 61 in the height-variable area can gradually or stepwise increase in the range from 60 degrees to 85 degrees.

[0159] In another example, the lower interior angles (θ) of several segments 61 in one group unit or in two or more group units can increase gradually or stepwise from the core to the outer perimeter.

[0160] Furthermore, the lower left and lower right interior angles of segment 61 may be unequal. Nevertheless, the lower interior angle (θ) of any side can be designed such that it satisfies formula 6 described above.

[0161] Referring again to Fig. 4. The width (dB1) of the first section B1 is designed such that the core of the electrode assembly is opened outwards by 90% or more based on its diameter when the segment 61 of the third section B2 is bent towards the core. The width (dB1) of the first section B1 can increase proportionally to the bending length of the segment 61 of group 1. The bending length corresponds to a length from the bending point to the upper end face of the segment 61. Preferably, when the electrode 60 is used to manufacture an electrode assembly of a cylindrical battery with a form factor of 4680, the width (dB1) of the first section B1 can be adjusted from 180 mm to 350 mm, depending on the diameter of the core of the electrode assembly and the height of the segment 61 contained in group 1.

[0162] The bending point of segment 61 can be set at a line passing through the lower end of the cutting groove 63 or at a point spaced a predetermined distance above this line. When segment 61 is bent towards the core at a point spaced a certain distance from the lower end of the cutting groove 63, the segments overlap better in the radial direction. As the segments 61 are bent, an outer segment pushes a segment on an inner side based on the center of the core. At this point, if the bending point is spaced a predetermined distance from the lower end of the cutting groove 63, the inner segment is pushed by the outer segment in the winding axis direction, and the segments overlap better. The pitch of the bending point is preferably 1 mm or less.Since the minimum height of the segment is 2 mm, the ratio of the division (pitch) of the bending point to the minimum height can be 50% or less.

[0163] In one embodiment, the width of each segment group can be designed to form the same winding turn of the electrode arrangement. Here, the winding turn can be counted based on the end of the first section B1 when the electrode 60 is in a wound state.

[0164] In another modification, the width of each segment group can be designed such that it forms at least one winding of the electrode arrangement.

[0165] In yet another modification, the width and / or height and / or pitch of segments 61 belonging to the same segment group can gradually and / or incrementally and / or irregularly increase or decrease within the group or between adjacent groups.

[0166] Groups 1 to 8 are only examples of segment groups included in the third section B2. The number of groups, the number of segments 61 contained in each group, and the width of the group can preferably be adjusted so that the segments 61 overlap in several layers in order to distribute the stress during the bending process of the uncoated section 43 as much as possible and to ensure sufficient weld strength with the current collector.

[0167] If the number of segment groups is one, the heights of segments 61 in the third section B2 can be uniform.

[0168] The segment structure of the third section B2 can extend to the second section B3 (see dashed line). In this case, the second section B3 can also have multiple segments, like the third section B2. Preferably, the segment structure of the second section B3 can be substantially the same as that of the outermost segment group of the third section B2. In this case, the segments contained in the second section B3 and the third section B2 can have substantially the same width, height, and pitch. In a modified example, the segments of the second section B3 can have a width and / or height and / or pitch that is greater than that of the third section B2.

[0169] In the third section B2, the area (groups 1 to 7) in which the heights of the segments 61 increase stepwise based on the winding direction of the electrode 60 can be defined as a (segment) height-variable area, and the last segment group (group 8) can be defined as a height-uniform area in which the heights of the segments are kept uniform.

[0170] That is, in the third section B2, if the heights of the segments 61 increase stepwise from h1 to hN, the area in which the segments 61 with heights from h1 to hN-1 (N being a height index, a natural number greater than or equal to 2) correspond to the variable-height area, and the area in which the segments 61 with height hN are located corresponds to the uniform-height area. The ratio of the variable-height area and the uniform-height area to the length of the electrode 60 in the winding direction will be described later with reference to specific embodiments.

[0171] When electrode 60 is used to manufacture an electrode assembly for a cylindrical battery with a form factor of 4680, the width (dB1) of the first section B1 can be from 180 mm to 350 mm. The width of group 1 can be from 35% to 40% of the width of the first section B1. The width of group 2 can be from 130% to 150% of the width of group 1. The width of group 3 can be from 120% to 135% of the width of group 2. The width of group 4 can be from 85% to 90% of the width of group 3. The width of group 5 can be from 120% to 130% of the width of group 4. The width of group 6 can be from 100% to 120% of the width of group 5. The width of group 7 can be from 90% to 120% of the width of group 6. The width of group 8 can be 115% to 130% of the width of group 7. The width (dB3) of the second section B3 can be 180 mm to 350 mm, similar to the width of the first section B1.

[0172] The widths of groups 1 to 8 do not show a constant increase or decrease pattern, as the segment width gradually increases from group 1 to group 8, but the number of segments contained in each group is limited to an integer, and the electrode thickness exhibits a slight deviation in the winding direction. Thus, the number of segments in a specific segment group can be reduced. Therefore, the widths of the groups can show an irregular change pattern, as in the example above, from the core to the outer circumference.

[0173] That is, assuming that the width in the winding direction for each of the three segment groups that are successively adjacent to each other in the circumferential direction of the electrode arrangement is W1, W2 and W3 respectively, it is possible that the electrode arrangement contains a combination of segment groups in which W3 / W2 is smaller than W2 / W1.

[0174] In this specific example, groups 4 to 6 correspond to the case above. The width ratio of group 5 to group 4 is 120% to 130%, and the width ratio of group 6 to group 5 is 100% to 120%, which is less than 120% to 130%.

[0175] With reference to Fig. 5c The height (HB1) of the uncoated section of the first section B1 of the electrode 60 can be relatively smaller than the height (Hg) of the uncoated section at the bottom of the cut groove 63. The difference between the heights HB1 and Hg is a relative difference. The reference point for measuring heights can, in principle, be set arbitrarily. Preferably, the heights HB1 and Hg can be measured relative to the end of the insulating coating layer 44 or the end of the active material layer 42. If the height (Hg) of the uncoated section at the bottom of the cut groove 63 is not constant, the height (Hg) can be the average, median, maximum, or minimum value for the height of the uncoated section at the bottom of the cut groove 63.

[0176] If the height (HB1) of the uncoated section of the first section B1 is less than the height (Hg) of the uncoated section at the bottom of the cut groove 63, it can be prevented that a shape of the core collapses due to irregular bending of the uncoated section of the first section B1 near the core when the electrode 60 is wound to form an electrode assembly.

[0177] The level (HB1) may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, or 63% or less compared to the level (Hg).

[0178] The level (HB1) can be 0% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, or 37% or more compared to the level (Hg).

[0179] The upper and lower limits of the height (HB1) can be selectively combined from the above ranges. If the height (Hg) changes, the height (HB1) can also change.

[0180] In one embodiment, if the height (Hg) relative to the end of the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB1) can be 0 mm or more, 0.1 mm (12.5%) or more, 0.15 mm (18.8%) or more, 0.2 mm (25.0%) or more, 0.25 mm (31.3%) or more, 0.3 mm (37.5%) or more, 0.35 mm (43.8%) or more, or 0.4 mm (50.0%) or more.

[0181] In one embodiment, if the height (Hg) relative to the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB1) may be 0.75 mm (93.8%) or less, 0.70 mm (87.5%) or less, 0.65 mm (81.3%) or less, 0.60 mm (75.0%) or less, 0.55 mm (68.8%) or less, 0.50 mm (62.5%) or less, or 0.45 mm (56.3%) or less.

[0182] In one embodiment, the upper and lower limits of the height (HB1) can be selectively combined from the aforementioned ranges. If the height (Hg) changes, the height (HB1) can also change.

[0183] In a preferred embodiment, if the height (Hg) relative to the end of the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB1) can be 0.3 mm (37.5%) to 0.5 mm (62.5%).

[0184] With reference to Fig. 5d Optionally, the height (HB3) of the uncoated section of the second section B3 of the electrode 60 can be smaller than the height (Hg) of the uncoated section on the underside of the cut groove 63, as in the first section B1. The difference between the heights HB3 and Hg is a relative difference. The reference point for measuring heights can, in principle, be set arbitrarily. Preferably, the heights HB3 and Hg can be measured relative to the end of the insulating coating layer 44 or the end of the active material layer 42.

[0185] The level (HB3) may be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, or 63% or less compared to the level (Hg).

[0186] The height (HB3) can be 0% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, or 37% or more compared to the height (HB3).

[0187] The upper and lower limits of the height (HB3) can be selectively combined from the above ranges. If the height (Hg) changes, the height (HB3) can also change.

[0188] In one embodiment, if the height (Hg) relative to the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB3) can be 0 mm or more, 0.1 mm (12.5%) or more, 0.15 mm (18.8%) or more, 0.2 mm (25.0%) or more, 0.25 mm (31.3%) or more, 0.3 mm (37.5%) or more, 0.35 mm (43.8%) or more, or 0.4 mm (50.0%) or more.

[0189] In one embodiment, where the height (Hg) relative to the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB3) may be 0.75 mm (93.8%) or less, 0.70 mm (87.5%) or less, 0.65 mm (81.3%) or less, 0.60 mm (75.0%) or less, 0.55 mm (68.8%) or less, 0.50 mm (62.5%) or less, or 0.45 mm (56.3%) or less.

[0190] In one embodiment, the upper and lower limits of the height (HB3) can be selectively combined from the aforementioned ranges. If the height (Hg) changes, the height (HB3) can also change.

[0191] In a preferred embodiment, if the height (Hg) relative to the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB3) can be 0.3 mm (37.5%) to 0.5 mm (62.5%).

[0192] Fig. Figure 5e is a photograph showing the winding shape of the electrode arrangement and the structure of the uncoated section of the first section B1 when the negative electrode is unwound near the core. In the case where the electrode 60 is a negative electrode according to an embodiment of the present disclosure, the height (Hg) of the uncoated section at the bottom of the cut groove 63 is 0.8 mm relative to the end of the active material layer, and the height (HB1) of the uncoated section of the first section B1 is also 0.8 mm relative to the end of the active material layer.

[0193] As in Fig. As shown in Figure 5e, it can be seen that the uncoated section near the core is irregularly bent, so that the shape of the core collapses when the height (Hg) of the uncoated section at the bottom of the cut groove 63 and the height (HB1) of the uncoated section of the first section B1 are equal.

[0194] Fig. Figure 5f is a photograph showing the winding shape of the electrode arrangement and the structure of the uncoated section when the negative electrode is unwound near the core. In the case where the electrode 60 is a negative electrode according to an embodiment of the present disclosure, the height (Hg) of the uncoated section at the bottom of the cut groove 63 is 0.8 mm relative to the end of the active material layer, and the height (HB1) of the uncoated section of the first section B1 is 0.4 mm relative to the end of the active material layer.

[0195] As in Fig. As shown in Figure 5f, it can be determined that the uncoated section near the core is not irregularly bent, so that the shape of the core does not collapse when the height (HB1) of the uncoated section of the first section B1 is less than the height (Hg) of the uncoated section at the bottom of the cut groove 63.

[0196] Preferably, a structure in which the height (HB1) of the uncoated section of the first section B1 is less than the height (Hg) of the uncoated section at the bottom of the cut groove 63 can be applied to the negative electrode. If the current collector of the negative electrode and the current collector of the positive electrode are a copper foil and an aluminum foil, respectively, the thickness of the copper foil is designed to be thinner than the thickness of the aluminum foil. Furthermore, since the length of the negative electrode is longer than the length of the positive electrode, the winding starts from the negative electrode, so that the radius of curvature is smallest at the point where the winding of the negative electrode begins.Therefore, when bending the segments 61, the uncoated section of the first section B1 at the negative electrode is susceptible to stress applied in the radial direction and not at the positive electrode near the core of the electrode arrangement. Consequently, the uncoated section of the first section B1, which is susceptible to stress, can bend irregularly. However, such a phenomenon can be prevented if the height (HB1) of the first section B1 is less than the height (Hg) of the uncoated section at the bottom of the cut groove 63. Meanwhile, the present disclosure does not preclude the case in which the Fig. 5c and Fig. The structure shown in Figure 5d is applied to a positive electrode.

[0197] If the uncoated section 43 of the electrode 60 has a segmented structure, the electrode 60 can, according to yet another modification, have a segment-skipping region 64 in which some of the multiple segments are regularly or irregularly omitted, as in Fig. 7a shown.

[0198] Preferably, the segment-skipping region 64 can be multiple. In one example, the width of the segment-skipping region 64 from the core to the outer circumference can be constant. In another example, the width of the segment-skipping region 64 from the core to the outer circumference can increase or decrease regularly or irregularly. Preferably, the height of the uncoated section present in the segment-skipping region 64 can correspond to the height of the first section B1 and / or the second section B3.

[0199] The number of segments 61 that exist between the segment skip area 64 can be at least one. As in Fig. As shown in Figure 7a, the electrode 60 can have an uncoated section in which the number of segments 61 that are present between the segment-skipping regions 64 increases from the core to the outer circumference.

[0200] Preferably, the width of the segment-skipping area 64 can be adjusted such that, when the electrode 60 is wound as in Fig. As shown in Figure 7b, the segments located on each winding turn can be arranged within a preset independent area 66 based on the core center C of the electrode arrangement 65.

[0201] In other words, the multiple segments 61 can be arranged within multiple independent regions 66 based on the core center C when the electrode arrangement 65 is viewed in the winding axis direction. The number of independent regions 66 can be changed to 2, 3, 4, 5, etc.

[0202] Preferably, the independent region 66 can be fan-shaped. In this case, the angle between the independent regions 66 can be substantially equal. Furthermore, the circumferential angle (δ) of the independent region 66 can be 20 degrees or more, optionally 25 degrees or more, optionally 30 degrees or more, optionally 35 degrees or more, or optionally 40 degrees or more.

[0203] In one modification, the independent area 66 can have a geometric shape, such as a square, rectangle, parallelogram, trapezoid, etc.

[0204] In the present revelation, the form of segment 61 can be modified in various ways.

[0205] Fig. Figure 8a is a top view showing the structure of an electrode 70 according to another embodiment of the present disclosure.

[0206] Referring to Fig. 8a the electrode 70 is essentially the same as the previous embodiment, except that the shape of the segment 61' is different.

[0207] Segment 61' has a geometric shape with substantially equal upper and lower widths. Preferably, segment 61' can have a rectangular shape.

[0208] Fig. Figure 8b is a diagram showing definitions of width, height and division of the rectangular segment 61', and Fig. Figure 8c is a partially enlarged view showing the lower section of the cutting groove 63.

[0209] Referring to Fig. 8b and Fig. 8c The width (D), height (H), and pitch (P) of segment 61' can be adjusted to prevent the uncoated section 43 from tearing during bending and to prevent abnormal deformation of the uncoated section 43, while sufficiently increasing the number of overlapping layers of the uncoated section 43 to improve weld strength with the current collector. Abnormal deformation means that the uncoated section does not maintain a straight state below the bend point and deforms irregularly as it falls.

[0210] The width (D) of segment 61' is defined as the length between two points where two straight lines (L2) extending from the side sections 63a on both sides of segment 61' intersect a straight line (G) extending along the winding direction from the bottom of the round section 63b of the cut groove 63. The height (H) of segment 61' is defined as the shortest distance between the top side of segment 61' and the straight line (G) extending along the winding direction from the bottom of the round section 63b of the cut groove 63. The pitch (P) of segment 61' is defined as the length between two points where a straight line (L1) connecting both ends of the round section 63b intersects two straight lines (L2) extending from the side section 63a of segment 61'.

[0211] Preferably, the conditions for the width (D), height (H), and pitch (P) of segment 61' are essentially the same as those of the embodiment described above and are therefore not described again. However, since segment 61' has a rectangular shape, the lower interior angle of segment 61' can be constant at 90 degrees.

[0212] With reference to Fig. 8d and Fig. 8e The height (HB1) of the uncoated section of the first section B1 and / or the height (HB3) of the uncoated section of the second section B3 of the electrode 70 can be relatively smaller than the height (Hg) of the uncoated section at the bottom of the cut groove 63. The effect obtained by adjusting the height of the uncoated section is essentially the same as in the embodiment described above.

[0213] The height (HB1) of the uncoated section of the first section B1 and / or the height (HB3) of the uncoated section of the second section B3 can be set essentially the same as in the embodiment described above.

[0214] In other words, the level (HB1) and / or the level (HB3) relative to the level (Hg) can be 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, or 63% or less.

[0215] The level (HB1) and / or the level (HB3) can be 0% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, or 37% or more, relative to the level (Hg).

[0216] The upper and lower limits of height (HB1) and / or height (HB3) can be selectively combined from the above ranges. If the height (Hg) changes, the height (HB1) and / or the height (HB3) can also change.

[0217] In one embodiment, where the height (Hg) relative to the end of the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB1) and / or the height (HB3) may be 0 mm or more, 0.1 mm (12.5%) or more, 0.15 mm (18.8%) or more, 0.2 mm (25.0%) or more, 0.25 mm (31.3%) or more, 0.3 mm (37.5%) or more, 0.35 mm (43.8%) or more, or 0.4 mm (50.0%) or more.

[0218] In one embodiment, where the height (Hg) is 0.8 mm above the end of the active material layer 42 or the insulating coating layer 44, the height (HB1) and / or the height (HB3) may be 0.75 mm (93.8%) or less, 0.70 mm (87.5%) or less, 0.65 mm (81.3%) or less, 0.60 mm (75.0%) or less, 0.55 mm (68.8%) or less, 0.50 mm (62.5%) or less, or 0.45 mm (56.3%) or less.

[0219] In one embodiment, the upper and lower limits of the height (HB1) and / or the height (HB3) can be selectively combined from the aforementioned ranges. If the height (Hg) changes, the height (HB1) and / or the height (HB3) can also change.

[0220] In a preferred embodiment, where the height (Hg) relative to the end of the active material layer 42 or the insulating coating layer 44 is 0.8 mm, the height (HB1) and / or the height (HB3) can be 0.3 mm (37.5%) to 0.5 mm (62.5%).

[0221] Similar to electrode 60, electrode 70 can also have a segment-skipping region 64 in which some of the multiple segments are regularly or irregularly omitted, as in Fig. 8f shown.

[0222] If the electrode 70, which has the segment-skipping region 64, is wound into an electrode arrangement, the segments can also be located within the multiple independent regions 66, as shown in Fig. 7b shown.

[0223] As in the preceding embodiments, where the third section B2 and the second section B3 have several segments 61, 61', the shape of each segment 61, 61' can be modified in various ways.

[0224] Preferably, the segment can be deformed into different shapes while fulfilling at least one of the following conditions. Condition 1: The width of the lower section is greater than the width of the upper section. Condition 2: The width of the lower section is equal to the width of the upper section. Condition 3: The width is kept constant from the lower section to the upper section. Condition 4: The width decreases from the lower section to the upper section. Condition 5: The width decreases and then increases from the lower section to the upper section. Condition 6: The width increases and then decreases from the lower section to the upper section. Condition 7: The width increases from the lower section to the upper section and is then kept constant. Condition 8: The width decreases from the lower section to the upper section and is then kept constant. Condition 9: The interior angle of one side and the interior angle of the other side of the lower section are equal.

[0225] Here, the interior angle can be defined as an angle formed by the side segment of the segment based on the latitude of the lower segment. If the side segment is a curve, the interior angle is defined as the angle between the tangent drawn at the bottom of the curve and the latitude of the lower segment.

[0226] Condition 10: The interior angle of one side of the lower section and the interior angle of the other side are different.

[0227] Condition 11: The interior angle of one side of the lower section and the interior angle of the other side of the lower section are acute, right, or obtuse, respectively.

[0228] Condition 12: Symmetrical in the left and right directions, with respect to the winding axis direction

[0229] Condition 13: Asymmetrical in the left and right directions, with respect to the winding axis direction

[0230] Condition 14: The side section is even

[0231] Condition 15: The side section is curved.

[0232] Condition 16: The side segment is convex outwards.

[0233] Condition 17: The side segment is convex inwards.

[0234] Condition 18: The corner of the upper section and / or the lower section has a structure where straight lines meet.

[0235] Condition 19: The corner of the upper section and / or the lower section has a structure where a straight line and a curve meet.

[0236] Condition 20: The corner of the upper section and / or the lower section has a structure where curves meet.

[0237] Condition 21: The corner of the upper section and / or the lower section has a rounded structure.

[0238] Fig. Figure 9 is a diagram illustrating the shapes of segments according to various modifications of the present revelation.

[0239] As shown in the drawing, the segment can have various geometric shapes, with a dashed line connecting the lower sections of both cut grooves on either side serving as the basis. The geometric shape has a structure in which at least one straight line, at least one curved line, or a combination thereof are connected. In one example, the segment can have a polygonal shape, a round shape, or various combinations thereof.

[0240] In particular, the segment can have a left-right symmetrical trapezoidal shape (ⓐ); a left-right asymmetrical trapezoidal shape (ⓑ); a parallelogram shape (ⓒ); a triangular shape (ⓛ); a pentagonal shape (ⓚ); an arc shape (ⓔ); or an elliptical shape (ⓕ).

[0241] Since the shape of the segment does not correspond to the one in Fig. The form shown in 9 is limited; it can be transformed into other polygonal shapes, other round shapes, or combinations thereof to satisfy at least one of the conditions 1 to 21 described above.

[0242] In the polygonal shapes ⓐ, ⓑ, ⓒ, ⓚ and ⓛ of the segment, the corners of the upper section and / or the lower section can have a shape where straight lines meet or a rounded shape (see the enlarged view of the corners of the upper section and / or the lower section of shape ⓐ in Fig. 5b and Fig. 8b).

[0243] In the polygonal forms ⓐ, ⓑ, ⓒ, ⓚ, and ⓛ of the segment and the curved forms ⓔ and ⓕ of the segment, the interior angle (θ1) on one side and the interior angle (θ2) on the other side of the lower section can be equal or different, and the interior angle (θ1) on one side and the interior angle (θ2) on the other side of the lower section can be an acute angle, a right angle, or an obtuse angle, respectively. An interior angle is an angle at which the base and the side of a geometric figure meet. If the side is curved, the straight line can be replaced by a tangent extending from the point where the base meets the side.

[0244] The shape of the side section of the segment with a polygonal shape can be modified in various ways.

[0245] In one example, the side segment of the segment shape ⓐ can be transformed into an outwardly convex curvature, like the shape ⓓ, or can be transformed into an inwardly curved segment, like the shape ⓖ or ⓙ.

[0246] In another example, the side segment of the segment shape ⓐ can be transformed into a curved straight line indented into the segment, like the shape ⓗ or ⓘ. Although not shown, the side segment of the segment shape ⓐ can also be transformed into an outwardly convex curved straight line.

[0247] In the segment forms ⓓ, ⓖ, ⓙ, ⓗ and ⓘ, in which the side segment is modified in different ways, the interior angle (θ1) on one side and the interior angle (θ2) on the other side of the lower segment can be the same or different, and the interior angle (θ1) on one side and the interior angle (θ2) on the other side of the lower segment can be any acute angle, right angle or obtuse angle, respectively.

[0248] The width of the segment can exhibit various change patterns from bottom to top.

[0249] In one example, the segment width can be kept constant from bottom to top (shape ⓒ). In another example, the segment width can gradually decrease from bottom to top (shapes ⓐ, ⓑ, ⓓ, ⓔ, ⓕ, and ⓖ). In yet another example, the segment width can gradually decrease from bottom to top and then increase (shapes ⓘ and ⓙ). In yet another example, the segment width can gradually increase from bottom to top and then decrease (shape ⓚ). In yet another example, the segment width can gradually decrease from bottom to top and then remain constant (shape ⓗ). Although not shown, the segment width can gradually increase from bottom to top and then remain constant.

[0250] Among the in Fig. Of the nine illustrated segment shapes, the polygonal shape with a flat top can be rotated by 180 degrees. In one example, if segment shape ⓐ, ⓑ, ⓓ, or ⓖ is rotated by 180 degrees, the segment's width can gradually increase from bottom to top. In another example, if segment shape ⓗ is rotated by 180 degrees, the segment's width can remain constant from bottom to top and then gradually increase.

[0251] In the embodiments (modifications) described above, it is possible, according to a further aspect of the present disclosure, to modify the shape of segment 61, 61' differently according to the scope of the third section B2. For example, for an area where stress is concentrated, a round shape (e.g., semicircle, ellipse, etc.) that is advantageous for stress distribution can be used, and for an area where the stress is relatively low, a polygonal shape (e.g., square, trapezoid, parallelogram, etc.) with a wide area can be used as much as possible.

[0252] In another aspect, the multiple segments can have different shapes individually, in a group unit, or in two or more group units along a direction parallel to the winding direction of the electrode arrangement.

[0253] In the embodiments (modifications), the segment structure of the third section B2 can also be applied to the first section B1. However, if the segment structure is applied to the first section B1, a reversal forming phenomenon can occur, in which the end of the first section B1 is curved towards the outer circumference when segment 61, 61' of the third section B2 is bent according to the radius of curvature of the core. Therefore, even if no segment structure is present in the first section B1, or even if the segment structure is applied, it is desirable to adjust the width and / or height and / or pitch of segment 61, 61' to be as small as possible, to a level at which reversal forming does not occur, taking into account the radius of curvature of the core.

[0254] According to yet another aspect of the present disclosure, the segments exposed at the upper and lower sections of the electrode arrangement after the electrode 60, 70 has been wound into the electrode arrangement can be overlapped in several layers along the radial direction of the electrode arrangement to form a bending surface area.

[0255] Fig. Figure 10a is a schematic diagram showing a cross-section of the bending surface area F formed by bending the segments 61 towards the core C of the electrode arrangement 80. Fig. Figure 10a shows the cross-section of the bending surface area F only on the left side, relative to the winding axis of the electrode arrangement 80. The bending surface area F can be formed on both the upper and lower sections of the electrode arrangement 80. Fig. Figure 10b is a perspective top view schematically showing an electrode arrangement 80 in which the bending surface area F is formed.

[0256] With reference to Fig. 10a and Fig. In Figure 10b, the bending surface area F has a structure in which the segments 61 overlap in several layers in the winding axis direction. The overlap direction is the winding axis direction Y. Area ① is a segment-skipping area (first section B1) without a segment, and areas ② and ③ are areas containing winding turns that include the segments 61. Area ② is a height-variable area in which the heights of the segments 61 vary, and area ③ is a height-uniform area in which the heights of the segments are kept uniform up to the outer circumference of the electrode assembly. As will be described later, the lengths of area ② and area ③ can be variable in the radial direction. It is conceivable that the uncoated section (second section B3), which is contained in at least one winding turn that includes an outermost winding turn, does not have a segmented structure.In this case, the second section B3 in area ③ may be excluded.

[0257] In area ②, the heights of the segments 61 can be changed stepwise from the minimum height h1 (= hmin) to the maximum height hN (= hmax) within radius r1 to area rN of the electrode arrangement 80. The height-variable areas, in which the heights of the segments 61 vary, are r1 to rN. From radius rN to radius R of the electrode arrangement 80, the heights of the segments 61 are kept constant at hN. Constant heights mean that the deviation of the heights is within 5%.

[0258] At each radius position in region 2 and region 3, the number of segment stacks 61 varies depending on the radius position. Additionally, the number of segment stacks 61 can vary depending on the width of region 2, the minimum height (h1) and maximum height (hN) of the segments in the height-variable region of segments 61, and the amount of height change (Δh) of the segments 61. The number of segment stacks 61 is the number of segments that intersect an imaginary line drawn in the winding axis direction from any radius position of the electrode arrangement 80.

[0259] Preferably, the number of stacks of segments 61 at each position of the bending surface area F can be optimized according to the required weld strength of the current collector by adjusting the height, width and spacing of the segments 61 according to the radius of the winding turn containing the segment 61.

[0260] First, in the height-variable area (②) of the segments 61, when the minimum height (h1) of the segments is the same, specific embodiments describe how the number of stacks of segments 61 varies along the radial direction of the bending surface area F according to the change in the maximum height (hN) of the segments 61.

[0261] The electrode assemblies of embodiments 1-1 to 1-7 are prepared. The electrode assemblies of the embodiments have a radius of 22 mm and a core diameter of 4 mm. The positive electrode and the negative electrode contained in the electrode assembly have the features described in Fig. The electrode structure shown in Figure 4 is as follows. That is, the segment has a trapezoidal shape. The second section B3 of the positive and negative electrodes contains no segment. The length of the second section B3 is 3% to 4% of the total length of the electrode. The positive electrode, the negative electrode, and the separator are connected by the [missing information]. Fig. The windings described in the two methods are wound. The number of winding turns ranges from 48 to 56, but the winding turns in the embodiments are 51. The thickness of the positive electrode, the negative electrode, and the separator is 149 µm, 193 µm, and 13 µm, respectively. The thickness of the positive and negative electrodes includes the thickness of the active material layer. The thickness of the current collector of the positive electrode and the current collector of the negative electrode is 15 µm and 10 µm, respectively. The lengths of the positive and negative electrodes in the winding direction are 3948 mm and 4045 mm, respectively.

[0262] In each embodiment, the minimum height of the segments 61 is set to 3 mm, so that the height-variable area (②) of the segments 61 begins with a radius of 5 mm. Additionally, in each embodiment, the heights of the segments 61 are increased by 1 mm for every 1 mm increase in radius, and the maximum height of the segments 61 is changed from 4 mm to 10 mm.

[0263] In particular, in embodiment 1-1, the height-variable range (②) of the segments 61 is 5 mm to 6 mm, and the heights of the segments 61 are variable from a radius of 3 mm to 4 mm. In embodiment 1-2, the height-variable range (②) of the segments 61 is 5 mm to 7 mm, and the heights of the segments 61 are variable from 3 mm to 5 mm. In embodiment 1-3, the height-variable range (②) of the segments 61 is 5 mm to 8 mm, and the heights of the segments 61 are variable from 3 mm to 6 mm. In embodiment 1-4, the height-variable range (②) of the segments 61 is 5 mm to 9 mm, and the heights of the segments 61 are variable from 3 mm to 7 mm. In embodiment 1-5, the height-variable range (②) of the segments 61 is 5 mm to 10 mm, and the heights of the segments 61 are variable from 3 mm to 8 mm. In embodiment 1-6, the height-variable range (②) of the segments 61 is 5 mm to 11 mm, and the heights of the segments 61 are variable from 3 mm to 9 mm.In embodiment 1-7, the height-variable range (②) of the segments 61 is 5 mm to 12 mm, and the heights of the segments 61 are variable from 3 mm to 10 mm. In embodiments 1-1 to 1-7, the heights of the segments 61 are uniform from the radius corresponding to the upper limit of the height-variable range (②) to the outer circumference. In one example, in embodiment 1-7, the heights of the segments 61 are uniform at 10 mm from the radius of 12 mm to 22 mm. Furthermore, in the electrode arrangement of the comparative example, the heights of the segments 61 are maintained at a single height of 3 mm from the radius of 5 mm to the radius of 22 mm.

[0264] Fig. Figure 11a are graphs showing the results of counting the number of stacked segments along the radial direction in the flexural area F of the positive electrode formed at the upper section of the electrode arrangements according to embodiments 1-1 to 1-7 and the comparative example. The flexural area of ​​the negative electrode also shows essentially the same results. The horizontal axis of the graph is the radius based on the center of the core, and the vertical axis of the graph is the number of stacked segments counted at each point on the radius, which is also shown in the same way. Fig. 11b and Fig. 11c is applied, which will be explained later.

[0265] Referring to Fig. Figure 11a shows the stacking number uniformity region b1 of the segments generally shown in embodiments 1-1 to 1-7 and Comparative Example 1. The stacking number uniformity region b1 is a radial region of a flattened surface in each graph. The length of the stacking number uniformity region b1 increases as the maximum height of the segments decreases, and the stacking number uniformity region b1' of the Comparative Example is the longest. Furthermore, the stacking number of segments increases as the maximum height (hN) of the segments increases. That is, as the maximum height (hN) of the segments increases, so that the width of the height-variable region (②) of the segments increases, the stacking number of segments increases while the width of the stacking number uniformity region b1 decreases. On the outside of the stacking number uniformity region b1 appears the stacking number decrease region b2, in which the stacking number of segments decreases as the radius increases.The stack count decrease region b2 is a radial region where the number of stacked segments decreases as the radius of the electrode array increases. The stack count uniformity region b1 and the stack count decrease region b2 are radially adjacent and complementary. This means that if the length of one region increases, the length of the other region decreases. Additionally, in the stack count decrease region b2, the number of stacks decreases proportionally to the distance from the stack count uniformity region b1.

[0266] From the perspective of the number of segments stacked, in embodiments 1-1 to 1-7 the number of segments stacked is 10 or more within the stack uniformity range b1. A range in which the number of segments stacked is 10 or more can be defined as a desirable weld target range. The weld target range is a range to which at least a portion of the current collector can be welded.

[0267] In embodiments 1-1 to 1-7, the stack number uniformity region b1 begins at the radius point where the height-variable region (②) of the segments begins. That is, the height-variable region (②) begins at a radius of 5 mm and extends to the outer circumference.

[0268] In embodiments 1-1 to 1-7 and comparative example 1, the following Table 4 shows for the positive electrode the results of calculating a ratio of the length of the segment-skipping region (c, 1 in Fig. 10a) to the radius (ba) of the electrode arrangement excluding the core, a ratio (e / f) of the length of the stack count uniformity region b1 to the length (f) from the radius point (5 mm) where the stack count uniformity region begins to the outermost point (22 mm) of the electrode arrangement, a ratio (d / f) of the length of the height-variable region (d) of the segment to the length (f) from the radius point (5 mm) where the stack count uniformity region begins to the outermost point (22 mm) of the electrode arrangement, a ratio (h) of the length of the electrode region corresponding to the segment-skipping region (first section B1) to the total length of the electrode, a ratio (i) of the length of the electrode region corresponding to the height-variable region to the total length of the electrode, and a ratio (j) of the length of the electrode region corresponding to the height-uniform region.to the entire length of the electrode and the like.

[0269] With the exception that the negative electrode shows a difference of 0.1% to 1.2% for parameter h, the other parameters are essentially the same as those of the positive electrode. The sum of the components h, i, and j deviates slightly from 100%. This is because there is a segmentless area in the second section B3, corresponding to the outer circumferential uncoated section of the electrode. For example, in embodiment 1-1, there is no segment in the second section B3, which corresponds to approximately 4% of the total length of the electrode. In Table 4, a to f are parameters based on the length in the radial direction, and h, i, and j are parameters based on the length in the longitudinal direction of the electrode before it is wound into an electrode assembly. Furthermore, the parameters corresponding to the ratio (%) are values ​​rounded to one decimal place.These points are essentially the same as those in Tables 5 and 6, which will be explained later. TABLE 4

[0270] Considering embodiments 1-1 to 1-7 in Table 4, the number of segments stacked is 11 to 27, and the ratio (d / f) of the height-variable area (d) to the radial area f containing segments is 6% to 41%. Additionally, the ratio (e / f) of the stack-number uniformity area (e) to the radial area f containing segments is 47% to 82%. Furthermore, the ratio (c / (ba)) of the segment-skipping area (c, 1 in Fig. 10a) to the radius (ba) of the electrode arrangement, excluding the core, is 15%. Additionally, the ratio of the length of the electrode area corresponding to the segment-skipping region (first section B1) to the total length of the electrode is 6%, the ratio of the length of the electrode area corresponding to the height-variable region to the total length of the electrode is 3% to 32%, and the ratio of the length of the electrode area corresponding to the height uniformity region to the total length of the electrode is 59% to 87%. The stack count (g) of the stack count uniformity region is 1-1 to 1-7 or more in all embodiments. The stack count uniformity region (e) decreases as the height-variable region (d) of segments increases, but the stack count (g) of segments increases within the stack count uniformity region (e).Preferably, the stack number uniformity range (e) in which the stack number (g) of segments is 10 or more can be set as a welding target range.

[0271] In cylindrical batteries with form factors 1865 and 2170, the radius of the electrode arrangement is approximately 9 mm to 10 mm. Therefore, in a conventional cylindrical battery, such as in embodiments 1-1 to 1-7, the length of the segment area (f) in the radial direction cannot be guaranteed at the level of 17 mm, and the length of the stack number uniformity area (e) cannot be guaranteed at the level of 8 mm to 14 mm. This is because, in a conventional cylindrical battery, if the core radius is designed to be 2 mm, which is the same as in embodiments 1-1 to 1-7, the radial area in which segments can be arranged is essentially only 7 mm to 8 mm. Furthermore, in the conventional cylindrical battery, the electrode length in the winding direction is approximately 600 mm to 980 mm.This short electrode length is only about 15% to 24% of the length of the electrode (positive electrode 3948 mm, negative electrode 4045 mm) used in embodiments 1-1 to 1-7. Therefore, the numerical ranges for the parameters h, i, and j cannot simply be derived from the design specifications of the conventional cylindrical battery.

[0272] Next, if the maximum height (hN) of the segments in the height-variable area (② in Fig. 10a) of the segments is equal, explained by specific embodiments, how the stacking number of segments varies along the radial direction of the bending surface area F according to the change in the minimum height (h1) of the segments.

[0273] The electrode arrangements of embodiments 2-1 to 2-5 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable area (② in Fig. 10a) of segments 61, the minimum height (h1) is 4 mm and the maximum height (hN) varies from 6 mm to 10 mm in 1 mm increments. Therefore, in the electrode arrangements of embodiments 2-1 to 2-5, the height-variable range (② in Fig. 10a) the segments have a width of 2 mm, 3 mm, 4 mm, 5 mm or 6 mm and the segment skipping area (① in Fig. 10a) is a radial area with a radius of 2 mm to 6 mm.

[0274] The electrode arrangements of embodiments 3-1 to 3-4 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable area (② in Fig. 10a) of segments 61, the minimum height (h1) is 5 mm and the maximum height (hN) varies from 7 mm to 10 mm in 1 mm increments. Therefore, in the electrode arrangements of embodiments 3-1 to 3-4, the height-variable range (② in Fig. 10a) the segments have a width of 2 mm, 3 mm, 4 mm or 5 mm and the segment skipping area (① in Fig. 10a) is a radial area with a radius of 2 mm to 7 mm.

[0275] The electrode arrangements of embodiments 4-1 to 4-3 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable area (② in Fig. 10a) of segments 61, the minimum height (h1) is 6 mm and the maximum height (hN) varies from 8 mm to 10 mm in 1 mm increments. Therefore, in the electrode arrangements of embodiments 4-1 to 4-3, the width of the height-variable area (② in Fig. 10a) of the segments 2 mm, 3 mm and 4 mm and the segment skipping area (① in Fig. 10a) is a radial area with a radius of 2 mm to 8 mm.

[0276] The electrode arrangements of embodiments 5-1 to 5-2 have a radius of 22 mm and a core diameter C of 4 mm. In the height-variable area (② in Fig. 10a) of segments 61, the minimum height (h1) is 7 mm and the maximum height (hN) varies from 9 mm to 10 mm in 1 mm increments. Therefore, in the electrode arrangements of embodiments 5-1 to 5-2, the width of the height-variable area (② in Fig. 10a) of the segments 2 mm or 3 mm and the segment skipping area (① in Fig. 10a) is a radial area with a radius of 2 mm to 9 mm.

[0277] Fig. Figure 11b shows graphs that illustrate the results of counting the number of stacked segments along the radial direction in the bending surface region F of the positive electrode formed on the upper section of the electrode arrangements according to embodiments 2-1 to 2-5, embodiments 3-1 to 3-4, embodiments 4-1 to 4-3, and embodiments 5-1 to 5-2. The bending surface region of the negative electrode also shows essentially the same results.

[0278] In Fig. Figure 11b shows graph (a) as the result of counting the number of stacked segments along the radial direction in the bending surface area F for embodiments 2-1 to 2-5, graph (b) as for embodiments 3-1 to 3-4, graph (c) as for embodiments 4-1 to 4-3 and graph (d) as for embodiments 5-1 to 5-2.

[0279] Referring to Fig. In 11b, the stack count uniformity region b1 of the segments appears common in all embodiments. The stack count uniformity region b1 is a radial region of the flat surface in the graph. The length of the stack count uniformity region b1 increases when the maximum height (hN) of the segments decreases, provided the minimum height (h1) of the segments remains constant. The length of the stack count uniformity region b1 also increases when the minimum height (h1) of the segments decreases, provided the maximum height (hN) of the segments remains constant. Furthermore, within the stack count uniformity region b1, the number of stacked segments increases when the maximum height (hN) of the segments increases. Even in these embodiments, the stack count decrease region b2 appears close to the stack count uniformity region b1.

[0280] In all embodiments, the number of segments stacked within the stack number uniformity range b1 is 10 or more. Preferably, a range in which the number of segments stacked is 10 or more can be set as a desirable welding target range.

[0281] In the embodiments, the stack number uniformity region b1 begins at the radius point where the height-variable region (② in Fig. 10a) of the segments begins. In embodiments 2-1 to 2-5, the height-variable area (② in Fig. 10a) of the segments of 6 mm and extends to the outer circumference. In embodiments 3-1 to 3-4, the height-variable area (② in Fig. 10a) of the segments of 7 mm and extends to the outer circumference. In embodiments 4-3 to 4-3, the height-variable area (② in Fig. 10a) of the segments of 8 mm and extends to the outer circumference. In embodiments 5-1 to 5-2, the height-variable area (② in Fig. 10a) the segments of 9 mm and extends to the outer circumference.

[0282] Table 5 below shows the results of calculating various parameters for embodiments 2-1 to 2-5, embodiments 3-1 to 3-4, embodiments 4-1 to 4-3 and embodiments 5-1 to 5-2, including a ratio (e / f) of the length of the stack count uniformity region to the length from the radius point (6 mm, 7 mm, 8 mm, 9 mm) where the stack count uniformity region begins to the outermost point (22 mm) of the electrode arrangement, a ratio (d / f) of the length of the height variable region (②) of the segments to the length from the radius point (6 mm, 7 mm, 8 mm, 9 mm) where the stack count uniformity region begins to the outermost point (22 mm) of the electrode arrangement, and the like. TABLE 5 Ref. a.Kernradius(mm) b.RadiusderWicklungsstruktur(mm) c.Segmentüberspringbereich(mm) d.HöhevariablerBereich(mm) e.Stapelanzahlgleichmäßigkeitsbereich(mm) f.Segmentbereich(mm) g.Stapelanzahl c / (b-a)(%) d / f(%) e / f(%) h.Verhältnis desSegmentüberspringbereichs i.Verhältn is deshöhenvariablenBereichs j.Verhältnis deshöhengleichmäßigenBereichs Ausführungsform 2-1 2 22 4 2 7 16 16 20% 13% 44% 10% 6% 81% Ausführungsform 2-2 2 22 4 3 8 16 18 20% 19% 50% 10% 11% 77% Ausführungsform 2-3 2 22 4 2 9 16 21 20% 25% 56% 10% 16% 72% embodiment 2-4 2 22 4 5 10 16 24 20% 31% 63% 10% 20% 68% Design 2-5 2 22 4 6 11 16 26 20% 38% 69% 10% 25% 65% embodiment 3-1 2 22 5 2 6 15 18 25% 13% 40% 13% 7% 77% embodiment 3-2 2 22 5 3 7 15 21 25% 20% 47% 13% 12% 72% embodiment 3-3 2 22 5 4 8 15 24 25% 27% 53% 13% 16% 68% embodiment 3-4 2 22 5 5 9 15 26 25% 33% 60% 13% 22% 62% embodiment 4-1 2 22 6 2 5 14 21 30% 14% 36% 16% 9% 72% embodiment 4-2 2 22 6 3 6 14 24 30% 21% 43% 16% 13% 68% embodiment 4-3 2 22 6 4 7 14 26 30% 29% 50% 16% 19% 62% Design 5-1 2 22 7 2 4 13 24 35% 15% 31% 20% 9% 68% Design 5-2 2 22 7 3 5 13 26 35% 23% 38% 20% 15% 62%

[0283] Referring to embodiments 2-5, 3-4, 4-3 and 5-2 of Table 5 together with Fig. 10a and Fig.In 11b, the maximum height (hN) of the segments in the height-variable area (②) of the segments is 10 mm, but the minimum height (h1) of the segments increases to 4 mm, 5 mm, 6 mm, and 7 mm x 1 mm, and the length of the height-variable area (②) decreases to 6 mm, 5 mm, 4 mm, and 3 mm x 1 mm. In the four embodiments, the ratio (e / f) of the stack count uniformity area is greatest in embodiments 2-5 at 69% and smallest in embodiment 5-2 at 38%, and the stack counts of the stack count uniformity areas are all the same. From the results shown in Table 5, if the maximum height (hN) of the segments is equal, it can be understood that if the width of the height-variable region (2) of the segment increases as the minimum height (h1) of the segments decreases, the width of the stack count uniformity region also increases proportionally.The reason is that if the minimum length (h1) of the segments is smaller, the radius point where the segment starts is closer to the kernel, and thus the area where the segments are stacked extends towards the kernel.

[0284] Referring to Table 5, we can see that the number of segments stacked is 16 to 26, the ratio (d / f) of the height-variable region (2) of the segments is 13% to 38%, and the ratio (e / f) of the stack-number uniformity region is 31% to 69%. Additionally, the ratio (c / (ba)) of the segment-skipping region (1) to the radius (ba) of the electrode array, excluding the core, is 20% to 35%. Furthermore, the ratio of the length of the electrode area corresponding to the segment-skipping region (①) to the total electrode length is 10% to 20%, the ratio of the length of the electrode area corresponding to the height-variable region (②) to the total electrode length is 6% to 25%, and the ratio of the length of the electrode area corresponding to the height-uniformity region (③) to the total electrode length is 62% to 81%.

[0285] In the cylindrical batteries with form factors 1865 and 2170, the electrode arrangement has a radius of approximately 9 mm to 10 mm. Therefore, unlike in the embodiments, it is not possible to ensure the length of the segment region (f) in the radial direction at the level of 13 mm to 16 mm, nor is it possible to ensure the length of the stack-number uniformity region (e), in which the stack number of segments is 10 or more, at the level of 5 mm to 11 mm, while ensuring the length of the segment-skipping region (c, ①) at the level of approximately 4 mm to 7 mm. This is because, in the conventional cylindrical battery, when the core radius is designed to be 2 mm, which is the same as in the embodiments, the radial area in which segments can be arranged is essentially only 7 mm to 8 mm.Furthermore, in a conventional cylindrical battery, the electrode length in the winding direction is approximately 600 mm to 980 mm. In these embodiments, this short electrode length is only about 15% to 24% of the total electrode length (positive electrode 3948 mm, negative electrode 4045 mm). Therefore, the numerical ranges for the parameters h, i, and j cannot simply be derived from the design specifications of conventional cylindrical batteries.

[0286] Next, if the minimum height (h1) and the maximum height (hN) of the segments in the height-variable area (②) of the segments are equal, specific embodiments will explain how the number of segments stacked changes according to the diameter of the core C of the electrode arrangement along the radial direction of the bending surface area F.

[0287] The electrode arrangements of embodiments 6-1 to 6-6 have a radius of 22 mm, and the radius of the core C is 4 mm. In the height-variable region (②) of the segments 61, the minimum height (h1) of the segments is 3 mm, and the maximum height (hN) of the segments varies from 5 mm to 10 mm in 1 mm increments. Therefore, in the electrode arrangements of embodiments 6-1 to 6-6, the width of the height-variable region (②) of the segments is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 7 mm, respectively, and the segment-skipping region (①) is a radial region with a radius of 4 mm to 7 mm.

[0288] The electrode arrangements of embodiments 7-1 to 7-6 have a radius of 22 mm, and the radius of the core C is 2 mm. In the height-variable region (②) of the segments 61, the minimum height (h1) of the segments is 3 mm, and the maximum height (hN) of the segments varies from 5 mm to 10 mm in 1 mm increments. Therefore, in the electrode arrangements of embodiments 7-1 to 7-6, the height-variable region (②) of the segments has a width of 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, and 7 mm, respectively, and the segment-skipping region (①) is all a radial region with a radius of 2 mm to 5 mm.

[0289] Fig.Figure 11c shows graphs that illustrate the results of counting the number of stacked segments along the radial direction in the bending surface region F of the positive electrode formed at the upper section of the electrode arrangement according to embodiments 6-1 to 6-6 and embodiments 7-1 to 7-6. Essentially the same results appear in the bending surface region of the negative electrode.

[0290] In Fig. Figure 11c shows graph (a) as the result of counting the number of stacked segments along the radial direction in the bending surface area F for embodiments 6-1 to 6-6, and graph (b) as the result for embodiments 7-1 to 7-6.

[0291] Referring to Fig.In Figure 11c, the stack count uniformity region b1 of the segments appears common in all embodiments. The stack count uniformity region b1 is a radial region of the flat surface in the graph. The length of the stack count uniformity region b1 in the radial direction increases when the maximum height (hN) of the segments decreases, provided the minimum height (h1) of the segments is constant. Furthermore, in the stack count uniformity region b1, the stack count of segments increases when the maximum height (hN) of the segments increases. In the embodiments, the stack count decrease region b2 is identified close to the stack count uniformity region b1.

[0292] In all embodiments, the number of segments stacked within the stack number uniformity range b1 is 10 or more. Preferably, a range in which the number of segments stacked is 10 or more can be set as a desirable welding target range.

[0293] In the embodiments, the stack number uniformity region b1 begins at the radius point where the height-variable region (2) of the segments begins. In embodiments 6-1 to 6-6, the radius at which the height-variable region (②) of the segments begins is 7 mm, and in embodiments 7-1 to 7-6, the radius at which the height-variable region (②) of the segments begins is 5 mm.

[0294] Table 6 below shows the results of calculating various parameters for embodiments 6-1 to 6-6 and embodiments 7-1 to 7-6, including a ratio (e / f) of the length of the stack number uniformity region to the length from the radius point (7 mm, 5 mm) where the stack number uniformity region begins to the outermost point (22 mm) of the electrode arrangement, a ratio (d / f) of the length of the height variable region (②) of the segments to the length from the radius point (7 mm, 5 mm) where the stack number uniformity region begins to the outermost point (22 mm) of the electrode arrangement, and the like. TABLE 6

[0295] If you Fig.As can be seen in Figure 10a and embodiments 6-6 and 7-6 of Table 6, the minimum height (h1) and the maximum height (hN) of the segments in the height-variable region (②) of the segments are 3 mm and 10 mm, respectively. However, in embodiment 6-6, the radius of the core is 2 mm larger than in embodiment 7-6. Therefore, in embodiment 6-6, the stacking number uniformity region (e) and the segment region (f) are 2 mm smaller than in embodiment 7-6, and the stacking number of segments is the same in the stacking number uniformity region. This result is due to the difference in the radius of the core. From the results shown in Table 6, if the width of the height-variable region (②) of the segments is the same, it can be understood that if the radius (a) of the kernel is smaller, the ratio (d / f) of the height-variable region (②) decreases, but the ratio (e / f) of the stack count uniformity region increases.Table 6 shows that the number of segments stacked ranges from 13 to 26, the ratio (d / f) of the height-variable area (②) of the segments ranges from 12% to 47%, and the ratio (e / f) of the length of the stack-number uniformity area ranges from 40% to 76%. Additionally, the ratio (c / (ba)) of the segment-skipping area (①) to the radius (ba) of the electrode array, excluding the core, ranges from 15% to 17%. Furthermore, the ratio of the length of the electrode area corresponding to the segment-skipping area (①) to the total electrode length is 6%, the ratio of the length of the electrode area corresponding to the height-variable area (②) to the total electrode length is 7% to 32%, and the ratio of the length of the electrode area corresponding to the height-uniformity area (③) to the total electrode length is 59% to 83%.

[0296] In cylindrical batteries with form factors 1865 and 2170, the radius of the electrode arrangement is approximately 9 mm to 10 mm. Therefore, unlike in the embodiments, the length of the segment region (f) in the radial direction is not guaranteed at the level of 15 mm to 17 mm, and simultaneously, the length of the stack-number uniformity region (e), in which the stack number of segments is 10 or more, cannot be guaranteed at the level of 6 mm to 13 mm, while the length of the segment-skipping region (①) is guaranteed at the level of approximately 3 mm. This is because, in the conventional cylindrical battery, when the core radius is designed to be 2 mm to 4 mm, which is the same as in the embodiments, the radial area in which segments can be arranged is essentially only 5 mm to 8 mm. Furthermore, in the conventional cylindrical battery, the electrode length in the winding direction is approximately 600 mm to 980 mm.In these embodiments, this short electrode length is only about 15% to 24% of the total electrode length (positive electrode 3948 mm, negative electrode 4045 mm). Therefore, the numerical ranges for the parameters h, i, and j cannot simply be derived from the design specifications of conventional cylindrical batteries.

[0297] Taking into full consideration the data in Tables 4 to 6, the number of segments stacked within the segment stacking uniformity range can be 11 to 26. Additionally, the ratio (d / f) of the height-variable area (2) of the segments can be 6% to 47%. Furthermore, the ratio (e / f) of the stacking uniformity range can be 31% to 82%. Additionally, the ratio (c / (ba)) of the length of the segment-skipping area (①) to the radius of the electrode arrangement, excluding the core, can be 15% to 35%. Additionally, the ratio of the length of the electrode area corresponding to the segment-skipping area (①) to the total length (length in the winding direction) of the electrode can be 6% to 20%. Additionally, the ratio of the length of the electrode area corresponding to the height-variable area (②) of the segments to the total length of the electrode can be 3% to 32%.Additionally, the ratio of the length of the electrode area corresponding to the height uniformity area (③) of the segments to the total length of the electrode can be 59% to 87%.

[0298] In the meantime, the parameters described in Tables 4 to 6 are varied according to design factors, including the radius (a) of the core; the radius (b) of the electrode arrangement; the minimum height (h1) and the maximum height (hN) in the height-variable area (②) of the segments; the amount of height change (Δh) of the segments per 1 mm step of the radius; the thickness of the positive electrode, the negative electrode and the separator, and the like.

[0299] Therefore, within the segment stack uniformity range, the number of segment stacks can be increased to 10 to 35. The ratio (d / f) of the height-variable area (②) of the segments can be increased to 1% to 50%. Furthermore, the ratio (e / f) of the stack uniformity range can be increased to 30% to 85%. Additionally, the ratio (c / (ba)) of the length of the segment skip area (①) to the radius of the electrode arrangement, excluding the core, can be increased to 10% to 40%. Additionally, the ratio of the length of the electrode area corresponding to the segment skip area (①) to the total length (length in the winding direction) of the electrode can be increased to 1% to 30%. Additionally, the ratio of the length of the electrode area corresponding to the height-variable area (②) of the segments to the total length of the electrode can be increased to 1% to 40%.Additionally, the ratio of the length of the electrode area corresponding to the uniform height region (③) of the segments to the total length of the electrode can be increased to 50% to 90%. In the embodiments, the height index N of the maximum height (hN) of the segments contained in the variable height region (②) and the uniform height region (③) is 2 to 8. For example, Table 4 shows that the height index N for embodiments 1-1 and 1-7 is 2 and 8, respectively. However, the height index N can vary depending on the amount of height change (δh) of the segment in the radial direction of the electrode arrangement. If the radial length of the variable height region (②) is fixed, the height index N increases accordingly, or conversely, if the amount of height change (δh) of the segment decreases. Preferably, the altitude index N can be further extended to 2 to 20, or optionally to 2 to 30.

[0300] In the bending surface area F, which is formed on the upper section and the lower section of the electrode arrangement, the stack number uniformity area can be used as the welding target area of ​​the current collector.

[0301] Preferably, the welding area of ​​the current collector overlaps the stack number uniformity area by at least 50% in the radial direction of the electrode arrangement, and a higher overlap ratio is advantageous.

[0302] Preferably, the resting area of ​​the welding area of ​​the current collector, which does not overlap with the stack number uniformity area, can overlap with the stack number decrease area adjacent to the stack number uniformity area in the radial direction.

[0303] Advantageously, the rest area of ​​the welding area of ​​the current collector, which does not overlap with the stack count uniformity area, can overlap with the area of ​​the stack count decrease area where the segment stack count is 10 or more.

[0304] When the current collector is welded to the area where the number of segment stacks is 10 or more, it is desirable to weld it in order to improve weld strength and prevent damage to the separator or the active material layer during welding. This is particularly beneficial when the current collector is welded using a high-power laser with high transmission properties.

[0305] When the stack number uniformity area, in which 10 or more of the segments are stacked, and the current collector are welded with a laser, even if the power of the laser is increased to improve the weld quality, the stack number uniformity area absorbs most of the laser energy to form a weld bead, thus making it possible to prevent the separator and the active material layer under the bending surface area F from being damaged by the laser.

[0306] Since the number of segment stacks is 10 or more in the laser irradiation area, weld beads with sufficient volume and thickness are formed. Therefore, adequate weld strength can be ensured, and the resistance of the weld interface can be reduced to a level suitable for fast charging.

[0307] When welding the current collector, the laser power can be determined by the desired weld strength between the bending surface area F and the current collector. The weld strength increases proportionally to the number of segments stacked. This is because the volume of the weld beads formed by the laser increases with the number of segments. The weld beads are formed when the material of the current collector and the material of the segment are fused together. Therefore, a larger weld bead volume results in a stronger bond between the current collector and the bending surface area, and the contact resistance of the weld interface is reduced.

[0308] Preferably, the weld strength can be 2 kgf / cm² or more, more preferably 4 kgf / cm² or more. The maximum weld strength can vary depending on the power of the laser welding equipment. Furthermore, the weld strength can preferably be set to 8 kgf / cm² or less, more preferably 6 kgf / cm² or less. However, the present disclosure is not limited to these possibilities.

[0309] If the weld strength meets the above numerical range, the properties of the weld interface will not deteriorate even if strong vibration is applied to the electrode arrangement along the winding axis direction and / or the radial direction, and the resistance of the weld interface can be reduced because the volume of the weld beads is sufficient.

[0310] The laser power required to meet the weld strength requirement varies depending on the laser equipment and can be appropriately adjusted in the range of 250 W to 320 W or in the range of 40% to 100% of the maximum laser power provided by the equipment.

[0311] Weld strength can be defined as the tensile force (kgf / cm²) per unit area of ​​the current collector when the current collector begins to separate from the bending surface area F. Specifically, after the current collector is fully welded, a tensile force can be applied to it, with the magnitude of the force gradually increasing. When the tensile force exceeds a threshold, the segment begins to separate from the weld interface. At this point, the value obtained by dividing the tensile force applied to the current collector by the area of ​​the current collector is the weld strength.

[0312] In the bending surface area F, the segments are stacked in a multitude of layers, and according to the above embodiments, the number of stacked segments can increase to a minimum of 10 and a maximum of 35.

[0313] The thickness of the current collector of the positive electrode (foil), which forms the uncoated section 43, can be 10 µm to 25 µm, and the thickness of the current collector of the negative electrode (foil), which forms the uncoated section 43, can be 5 µm to 20 µm. Therefore, the bending surface area F of the positive electrode can include an area where the total stack thickness of the segments is 100 µm to 875 µm. Additionally, the bending surface area F of the negative electrode can include an area where the total layer thickness of the segments is 50 µm to 700 µm.

[0314] Fig. Figure 12 is a top view of the electrode arrangement showing the stack number uniformity region b1 and the stack number decrease region b2 in the bending surface region F of the segments 61, 61' according to an embodiment of the present disclosure.

[0315] Referring to Fig.12 corresponds to the area between two circles, indicated by the thick solid line, the bending area area F of the segments, and the area between two circles, indicated by the dashed line, corresponds to the stack count uniformity area b1, in which the stack count of segments is 10 or more, and the outer area of ​​the stack count uniformity area b1 corresponds to the stack count decrease area b2.

[0316] In one example, when the current collector (Pc) is welded to the bending area F, a weld pattern (Wp) is created on the surface of the current collector (Pc). The weld pattern (Wp) can be an arrangement of line patterns or dot patterns. The weld pattern (Wp) corresponds to the weld area and can overlap by 50% or more with the stack count uniformity area b1 of the segments along the radial direction. Therefore, part of the weld pattern (Wp) can be contained within the stack count uniformity area b1, and the remainder of the weld pattern (Wp) can be contained within the stack count decrease area b2 outside the stack count uniformity area b1. Of course, the entire weld pattern (Wp) can overlap with the stack count uniformity area b1 to maximize weld strength and reduce the resistance of the weld area.

[0317] The area of ​​the bending surface region F can be defined as the sum of the area of ​​the stack count uniformity region b1 and the area of ​​the stack count decrease region b2 of the segment. Since the ratio (e / f) of the stack count uniformity region b1 is 30% to 85%, preferably 31% to 82%, the ratio of the area of ​​the stack count uniformity region b1 to the area of ​​the bending surface region F can be 9% (302 / 1002) to 72% (852 / 1002), preferably 10% (312 / 1002) to 67% (822 / 1002).

[0318] Preferably, the edge of the section where the current collector (Pc) contacts the bending surface area F can cover the end of the segment 61, 61' that is bent towards the core C in the last winding turn of the height uniformity area (③). In this case, since the weld pattern (Wp) is formed in a state where the segments 61, 61' are pressed through the current collector (Pc), the current collector (Pc) and the bending surface area F are strongly coupled. As a result, because the segments 61, 61', which are stacked in the winding axis direction, come into close contact with each other, the resistance at the weld interface can be reduced and lifting of the segments 61, 61' can be prevented.

[0319] Meanwhile, the bending direction of the segments can be opposite to that described above. That is, the segments can be bent from the core towards the outer circumference. In this case, the pattern in which the heights of the segments change along the winding direction (X-axis direction) can be opposite to that of the embodiments (modifications) described above. For example, the heights of the segments can gradually decrease from the core to the outer circumference. Furthermore, the structure applied to the first section B1 and the structure applied to the second section B3 can be interchanged.Preferably, the height change pattern can be designed such that the heights of the segments gradually decrease from the core to the outer circumference, but when the segment closest to the outer circumference of the electrode arrangement is bent towards the outer circumference, the end of the segment does not protrude from the outer circumference of the electrode arrangement.

[0320] The electrode structure of the above embodiments (modifications) can be applied to at least one of the first and second electrodes with different polarities, which are contained in the jellyroll-type electrode arrangement or another electrode arrangement known in the art. Additionally, if the electrode structure of the above embodiments (modifications) is applied to any one of the first and second electrodes, the conventional electrode structure can be applied to the other. Furthermore, the electrode structures applied to the first and second electrodes can be different from each other.

[0321] For example, if the first electrode and the second electrode are a positive electrode and a negative electrode respectively, any of the above embodiments (modifications) can be applied to the first electrode, and the conventional electrode structure (see Fig. 1) can be applied to the second electrode.

[0322] As another example, if the first electrode and the second electrode are a positive electrode and a negative electrode respectively, any one of the above embodiments (modifications) can be selectively applied to the first electrode, and any one of the above embodiments (modifications) can be selectively applied to the second electrode.

[0323] In the present disclosure, an active material of the positive electrode coated on the positive electrode and an active material of the negative electrode coated on the negative electrode can employ any active material known in the art without restriction.

[0324] In one example, the active material of the positive electrode can be an alkali metal compound expressed by a general formula A[AxMy]O2+z (A has at least one element from Li, Na and K; M has at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru and Cr; x ≥ 0, 1 ≤ x+y ≤ 2, -0,1 ≤ z ≤ 2; and the stoichiometric coefficients x, y, z and M are chosen such that the compound retains electrical neutrality).

[0325] In another example, the active material of the positive electrode can be an alkali metal compound xLiM1O2-(1-x)Li2M2O3 disclosed in US6,677,082, US6,680,143 et al., wherein M1 has at least one element with an average oxidation state of 3; M2 has at least one element with an average oxidation state of 4; and 0 ≤ x ≤ 1).

[0326] In yet another example, the active material of the positive electrode can be lithium metal phosphate, expressed by a general formula LiaM1xFe1-xM2yP1-yM3zO4-z (M1 comprises at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M2 comprises at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M3 comprises a halogen element, optionally F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; the stoichiometric coefficients a, x, y, and z are chosen such that the compound maintains electrical neutrality), or Li3M2(PO4)3 [M has at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al].

[0327] Preferably, the active material of the positive electrode can comprise primary particles and / or secondary particles in which the primary particles are aggregated.

[0328] In one example, the active material of the negative electrode can be carbon, lithium metal or a lithium metal compound, silicon or a silicon compound, tin or a tin compound, or the like. Metal oxides such as TiO₂ and SnO₂ with a potential of less than 2 V can also be used as the active material of the negative electrode. The carbon material can be low-crystalline carbon, high-crystalline carbon, or the like.

[0329] The separator can utilize a porous polymer film, for example, a porous polymer film made from a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methacrylate copolymer, or the like, or laminates thereof. Alternatively, the separator can utilize a common porous nonwoven fabric, for example, a nonwoven fabric made from high-melting-point glass fiber, polyethylene terephthalate fiber, or the like.

[0330] At least one surface of the separator may have a coating layer of inorganic particles. It is also possible that the separator itself is made of a coating layer of inorganic particles. The particles forming the coating layer may have a structure coupled with a binder, such that gaps exist between adjacent particles.

[0331] The inorganic particles can be made from an inorganic material with a dielectric constant of 5 or more. The inorganic particles can include at least one material selected from the group consisting of Pb(Zr,Ti)O3 (PZT), Pb 1-x LaxZr 1-y Ti y O3 (PLZT), PB(Mg3Nb 2 / 3 )O3-PbTiO3 (PMN-PT), BaTiO3, Hafnium oxide (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0332] The structure of the electrode arrangement according to one embodiment of the present disclosure is described in detail below.

[0333] Fig. Figure 13 is a cross-sectional view of an electrode arrangement of jellyroll type 100, in which the electrode 60 of the embodiment is applied along the Y-axis direction (winding axis direction) to the first electrode (positive electrode) and the second electrode (negative electrode).

[0334] With reference to Fig. 13 The uncoated section 43a of the first electrode has a first section B1 adjacent to the core of the electrode arrangement 100, a second section B3 adjacent to the surface of the outer circumference of the electrode arrangement 100, and a third section B2 located between the first section B1 and the second section B3.

[0335] The height of the uncoated section of the first section B1 is relatively smaller than the height of the segments 61. Additionally, the height of the first section B1 is smaller than the height of the uncoated section at the bottom of the cut groove between the segments. Furthermore, in the third section B2, the bend length of the segment 61 located on the innermost side is equal to or less than the radial length (R) of the first section B1. The bend length (H) corresponds to the distance from the point where the innermost segment 61 is bent to an upper end of the segment 61. In one modification, the bend length H can be less than the sum of the radial length (R) of the winding turn formed by the first section B1 and 10% of the radius of the core 102.

[0336] Therefore, even when the segments 61 are bent, 90% or more of the diameter of the core 102 of the electrode assembly 100 remains open to the outside. The core 102 is a cavity in the center of the electrode assembly 100. If the core 102 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Additionally, by inserting a welding device through the core 102, a welding process between the current collector at the negative electrode (or the positive electrode) and the battery casing (or the rivet terminal) can be improved.

[0337] The height of the second section B3 is relatively smaller than the height of segment 61. Therefore, while the beaded section of the battery casing is pressed close to the winding of the second section B3, it is possible to prevent a phenomenon in which an internal short circuit occurs when the beaded section and the top edge of the electrode assembly 100 touch each other. Optionally, the height of the second section B3 can be smaller than the height of the uncoated section at the bottom of the cut groove between the segments.

[0338] In one modification, the second section B3 can contain segments 61, and the height of segments 61 of the second section B3 can be different from that in Fig. 13 shown gradually or stepwise decrease. In addition, in Fig.13. The heights of the segments 61 are the same in a part near the outer circumference. However, the heights of the segments 61 can increase gradually or stepwise from the boundary between the first section B1 and the third section B2 to the boundary between the third section B2 and the second section B3. A region in which the heights of the segments 61 change corresponds to the segment-height variable region (② in Fig. 10a).

[0339] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure of other embodiments (modifications).

[0340] The ends 101 of the segments 61 can be bent in the radial direction of the electrode arrangement 100, for example, from the outer circumference towards the core. At this point, the uncoated sections of the first section B1 and the second section B3 are essentially not bent. Furthermore, the height of the first section B1 is less than the height of the uncoated section at the bottom of the cut groove between the segments. Thus, deformation of the uncoated section of the first section B1 when the segments 61 are bent is prevented.

[0341] Since the third section B2 contains several segments 61 arranged radially, the bending stress can be reduced to prevent the uncoated sections 43a, 43b from tearing or deforming abnormally near the bending point. Furthermore, if the width and / or height and / or spacing of the segments 61 are adjusted according to the numerical range of the embodiment described above, the segments 61 are bent towards the core and overlapped sufficiently in multiple layers to ensure adequate weld strength, and no empty hole (cavity) is formed in the bending area F.

[0342] Fig. Figure 14 is a cross-sectional view of an electrode arrangement 110 according to yet another embodiment of the present disclosure along the Y-axis direction (winding axis direction).

[0343] With reference to Fig.14 The electrode arrangement 110 has essentially the same configuration as the electrode arrangement 100 of Fig. 13, except that the second section B3 also includes segments 61 and the height of segment 61 of the second section B3 is essentially equal to the height of segment 61 at the outermost side of the third section B2.

[0344] In the electrode arrangement 110, the height of the uncoated section of the first section B1 is relatively smaller than the heights of the segments 61 contained in the third section B2. Furthermore, in the third section B2, the bending length (H) of the segment 61 located on the innermost side of the uncoated section is equal to or less than the radial length (R) of the winding turns formed by the first section B1. Preferably, the winding turns formed by the first section B1 can include a segment-skipping region (① in Fig.10a) without a segment. In one modification, the bending length H can be less than the sum of the radial lengths (R) of the winding turns formed by the first section B1 and 10% of the radius of the core 112.

[0345] Therefore, even when the segments 61 contained in the third section B2 are bent, 90% or more of the diameter of the core 112 of the electrode assembly 110 is open to the outside. If the core 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Additionally, the welding process between the current collector at the negative electrode (or the positive electrode) and the battery casing (or the rivet terminal) can be improved by inserting a welding device through the core 112.

[0346] In one modification, the structure in which the heights of the segments 61 contained in the third section B2 gradually or stepwise increase from the core to the outer circumference can be extended to the winding turns formed by the second section B3. In this case, the heights of the segments 61 can gradually or stepwise increase from the boundary between the first section B1 and the third section B2 to the surface of the outermost side of the electrode arrangement 110.

[0347] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure of other embodiments (modifications).

[0348] The ends 111 of the segments 61 contained in the third section B2 can be bent in the radial direction of the electrode arrangement 110, for example, from the outer circumference towards the core. At this point, the uncoated section of the first section B1 is essentially not bent.

[0349] Since the third section B2 contains several segments 61 arranged radially, the bending stress is reduced, thus preventing cracking or abnormal deformation of the uncoated sections 43a, 43b near the bending point. Furthermore, if the width and / or height and / or spacing of the segment 61 are adjusted according to the numerical ranges of the embodiment described above, the segments 61 are bent towards the core and overlapped sufficiently in multiple layers to ensure adequate weld strength, and no void (cavity) is formed in the bending area.

[0350] Fig. Figure 15 is a cross-sectional view showing the electrode arrangement 120 according to yet another embodiment of the present disclosure along the Y-axis direction (winding axis direction).

[0351] With reference to Fig.15 is the electrode arrangement 120 essentially with the electrode arrangement 100 of Fig. 13 identical, except that the heights of the segments 61 contained in the third section B2 exhibit a pattern that gradually or stepwise increases and then decreases. The radial area in which the heights of the segments 61 change can be referred to as the height-variable area (② in Fig. 10a) of the segments are considered. Even in this case, the height-variable area of ​​the segments 61 can be designed such that the uniform stacking number range, in which the stacking number of the segments 61 is 10 or more, appears in the desirable numerical range described above in the bending surface area F formed by bending the segments 61.

[0352] In the electrode arrangement 120, the height of the uncoated section of the first section B1 is relatively smaller than the heights of the segments 61. Additionally, the bending length H of the segment 61 located on the innermost side of the uncoated section is equal to or less than the radial length R of the winding turns formed by the first section B1. The area corresponding to the winding turns formed by the first section B1 corresponds to the segment skip area (1 in Fig. 10a) without segment. In one modification, the bending length H can be less than the sum of the radial lengths R of the winding turns formed by the first section B1 and 10% of the radius of the core 122.

[0353] Therefore, even when the segments 61 contained in the third section B2 are bent towards the core, 90% or more of the diameter of the core 122 of the electrode assembly 120 is open to the outside. If the core 122 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Additionally, by inserting a welding device through the core 122, the welding process between the current collector of the negative electrode (or the positive electrode) and the battery casing (or the rivet terminal) can be improved.

[0354] Furthermore, the height of the uncoated section of the second section B3 is relatively smaller than the heights of the segments 61, and preferably the segments 61 cannot be formed within the second section B3. Therefore, it is possible to prevent the phenomenon of the beaded section and the end edge of the electrode arrangement 120 coming into contact with each other and causing an internal short circuit while the beaded section of the battery casing is pressed near the winding turns formed by the second section B3. In one modification, the second section B3 can contain segments, and the heights of the segments of the second section B3 can decrease gradually or stepwise towards the outer circumference.

[0355] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or an electrode structure of other embodiments (modifications).

[0356] The ends 121 of the segments 61 contained in the third section B2 can be bent from the outer circumference of the electrode arrangement 120 towards the core. At this point, the uncoated sections of the first section B1 and the second section B3 are essentially not bent.

[0357] Since the third section B2 contains several segments 61 arranged radially, the bending stress is reduced to prevent the uncoated sections 43a, 43b from cracking or deforming abnormally. Furthermore, when the width and / or height and / or spacing of the segments 61 are adjusted according to the numerical range of the embodiment described above, the segments 61 are bent towards the core and overlapped sufficiently in multiple layers to ensure adequate weld strength, and no void (cavity) is formed in the bending surface area F.

[0358] Fig. Figure 16 is a cross-sectional view showing the electrode arrangement 130 according to yet another embodiment of the present disclosure along the Y-axis direction (winding axis direction).

[0359] With reference to Fig.16 The electrode arrangement 130 is essentially the same as the electrode arrangement 120 of Fig. 15 identical, except that the second section B3 comprises segments 61 and the heights of the segments 61 have a pattern that gradually or stepwise decreases from the boundary point of the second section B3 and the third section B2 to the outermost surface of the electrode arrangement 130.

[0360] In the electrode arrangement 130, the height of the uncoated section of the first section B1 is relatively smaller than the heights of the segments 61. Additionally, the bending length H of the segment 61 closest to the core 132 is equal to or less than the radial length R of the winding turns formed by the first section B1. The winding turns formed by the first section B1 correspond to the segment skip area (1 in Fig.10a) without segment. In one modification, the bending length H can be less than the sum of the radial lengths R of the winding turns formed by the first section B1 and 10% of the radius of the core 132.

[0361] Therefore, even when the segments 61 contained in the third section B2 are bent towards the core, 90% or more of the diameter of the core 132 of the electrode assembly 130 is open to the outside. If the core 132 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Additionally, by inserting a welding device through the core 132, the welding process between the current collector of the negative electrode (or the positive electrode) and the battery casing (or the rivet terminal) can be improved.

[0362] The second uncoated section 43b has the same structure as the first uncoated section 43a. In one modification, the second uncoated section 43b can have a conventional electrode structure or the electrode structure of other embodiments (modifications).

[0363] The ends 131 of the segments 61 contained in the third section B2 can be bent from the outer circumference of the electrode arrangement 130 towards the core. At this point, the uncoated section of the first section B1 is essentially not bent.

[0364] Since the third section B2 contains several segments 61 arranged radially, the bending stress is reduced to prevent the uncoated sections 43a, 43b from tearing or deforming abnormally near the bending point. Furthermore, when the width and / or height and / or spacing of the segments 61 are adjusted according to the numerical range of the embodiment described above, the segments 61 are bent towards the core and overlapped sufficiently in multiple layers to ensure adequate weld strength, and no void (cavity) is formed in the bending area F.

[0365] Furthermore, in the above embodiments (modifications), the ends of the segments 61 contained in the third section B2 can be bent from the core towards the outer circumference. In this case, the winding turns formed by the second section B3 are preferably referred to as the segment-skipping region (① in Fig.10a) designed without a segment and not bent towards the outer circumference. Additionally, the radial width of the winding turns formed by the second section B3 can be equal to or greater than the bending length of the outermost segment. In this case, if the outermost segment is bent towards the outer circumference, the end of the bent section does not project beyond the outer circumference of the electrode assembly to the inner surface of the battery casing. Furthermore, the structural change pattern of the segments contained in the third section B2 can be the opposite of the embodiments (modifications) described above. For example, the heights of the segments can increase stepwise or gradually from the outer circumference to the core. That is, by successively arranging the segment skip region (① in Fig. 10a), of the height-variable area (② in Fig. 10a) and the area of ​​uniform height (③ in Fig.10a) From the outer circumference of the electrode arrangement towards the core, in the bending area F the uniform stacking number range in which the stacking number of segments is 10 or more can appear in a desirable numerical range.

[0366] Various electrode arrangement structures according to an embodiment of the present disclosure can be applied to a cylindrical battery of the jellyroll type.

[0367] Preferably, the cylindrical battery can, for example, be a cylindrical battery whose form factor ratio (defined as a value obtained by dividing the diameter of the cylindrical battery by its height, namely a ratio of diameter (Φ) to height (H)) is greater than approximately 0.4. Here, the form factor means a value that specifies the diameter and height of a cylindrical battery.

[0368] The cylindrical battery can have a diameter of 35 mm or more, preferably 40 mm to 50 mm. The cylindrical battery can have a height of 70 mm or more, preferably 75 mm to 90 mm. The cylindrical battery according to one embodiment of the present disclosure can be, for example, a 46110 battery, a 4875 battery, a 48110 battery, a 4880 battery, or a 4680 battery. In the numerical value representing the form factor, the first two numbers indicate the diameter of the battery, and the remaining numbers indicate the height of the battery.

[0369] When an electrode assembly with a tabless structure is applied to a cylindrical battery with a form factor ratio greater than 0.4, the stress exerted in the radial direction when the uncoated section is bent is high, making it prone to cracking. Furthermore, when welding the current collector to the bending area of ​​the uncoated section, it is necessary to sufficiently increase the number of stacked layers of the uncoated section in the bending area to ensure adequate weld strength and reduce resistance. This requirement can be met by the electrode and electrode assembly according to the embodiments (modifications) of this disclosure.

[0370] A battery according to an embodiment of the present disclosure can be an approximately cylindrical battery, the diameter of which is approximately 46 mm, the height of which is approximately 110 mm and the form factor ratio of which is 0.418.

[0371] A battery according to another embodiment can be an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 75 mm and a form factor ratio of 0.640.

[0372] A battery according to yet another embodiment can be an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 110 mm and a form factor ratio of 0.436.

[0373] A battery according to yet another embodiment can be an approximately cylindrical battery with a diameter of approximately 48 mm, a height of approximately 80 mm and a form factor ratio of 0.600.

[0374] A battery according to yet another embodiment can be an approximately cylindrical battery with a diameter of approximately 46 mm, a height of approximately 80 mm and a form factor ratio of 0.575.

[0375] Traditionally, batteries with a form factor ratio of approximately 0.4 or less were used. That is, traditionally, for example, an 1865 battery, a 2170 battery, and so on, were used. The 1865 battery has a diameter of approximately 18 mm, a height of approximately 65 mm, and a form factor ratio of 0.277. The 2170 battery has a diameter of approximately 21 mm, a height of approximately 70 mm, and a form factor ratio of 0.300.

[0376] The cylindrical battery according to one embodiment of the present disclosure is described in detail below.

[0377] Fig.Figure 17 is a cross-sectional view showing a cylindrical battery 190 according to an embodiment of the present disclosure along the Y-axis direction.

[0378] With reference to Fig. 17 The cylindrical battery 190 according to an embodiment of the present disclosure comprises an electrode arrangement 110 with a first electrode, a separator and a second electrode, a battery housing 142 for receiving the electrode arrangement 110 and a sealing body 143 for sealing an open end of the battery housing 142.

[0379] The battery housing 142 is a cylindrical container with an opening at the top. The battery housing 142 is made of a conductive metal material, such as aluminum, steel, or stainless steel. A nickel plating layer may be formed on the surface of the battery housing 142. The battery housing 142 accommodates the electrode assembly 110 inside through the top opening and also holds the electrolyte.

[0380] The electrolyte can be a salt with a structure like A+B-. B- has at least one anion selected from the group consisting of F-, Cl-, Br-, I-, NO3-, N(CN)2-, BF4-, ClO4-, AlO4-, AlCl4-, PF6-, SbF6-, AsF6-, BF2C2O4-, BC4O8-, (CF3)2PF4-, (CF3)3PF3-, (CF3)4PF2-, (CF3)5PF-, (CF3)6P-, CF3SO3-, C4F9SO3-, CF3CF2SO3-, (CF3SO2)2N-, (FSO2)2N-, CF3CF2(CF3)2CO-, (CF3SO2)2CH-, (SF5)3C-, (CF3SO2)3C-, CF3(CF2)7SO3-, CF3CO2-, CH3CO2-, SCN- and (CF3CF2SO2)2N- consists.

[0381] The electrolyte can also be dissolved in an organic solvent. The organic solvent can be propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, or a mixture thereof.

[0382] The electrode arrangement 110 can have a jellyroll shape. The electrode arrangement 110 can be produced by winding a laminate formed by successively laminating a lower separator, a first electrode, an upper separator, and a second electrode at least once, with respect to the winding center C, as shown in Fig. 2 shown.

[0383] The first and second electrodes have opposite polarities. That is, if one has a positive polarity, the other has a negative polarity. At least one of the first and second electrodes can have an electrode structure according to the embodiments (modifications) described above. Furthermore, the other of the first and second electrodes can have a conventional electrode structure or an electrode structure according to embodiments (modifications). The electrode pair included in the electrode arrangement 110 is not limited to one pair; it can include two or more pairs.

[0384] The segments contained in the third section B2 are bent in the radial direction of the electrode arrangement 110, for example from the outer circumference towards the core, to form a bending surface area F.

[0385] The first section B1 has a lower height than the other section and corresponds to the segment-skipping area a1 without a segment, so it is not bent towards the core. The height of the uncoated section of the first section B1 can be smaller than the uncoated section at the bottom of the cut groove between the segments.

[0386] Preferably, the bending surface area F can include the segment-skipping area a1, the segment-height-variable area a2 and the segment-height-uniform area a3 from the core to the outer circumference.

[0387] As in Fig. 11a, Fig. 11b and Fig. As shown in 11c, the bending surface area F includes a stack count uniformity area b1 with a stack count of 10 or more adjacent to the segment skip area a1.

[0388] The bending surface area F can also include a stack count reduction area b2 adjacent to the outer circumference of the electrode arrangement 110, where the stack count of segments decreases towards the outer circumference. Preferably, the stack count uniformity area b1 can be set as a welding target area.

[0389] In the bending surface area F, the preferred numerical ranges of the ratio (a2 / c) of the height-variable area a2 of the segments to the radial area c containing segments, the ratio (b1 / c) of the uniform stacking number area b1 of the segments and the ratio of the area of ​​the uniform stacking number area b1 to the area of ​​the bending surface area F have already been described above and are therefore not described again.

[0390] The first current collector 144 can be laser-welded to the bending surface area F of the first uncoated section 146a, and the second current collector 145 can be laser-welded to the bending surface area F of the second uncoated section 146b. The welding process can be replaced by ultrasonic welding, resistance welding, spot welding, and the like.

[0391] Preferably, 50% or more of the weld areas W of the first current collector 144 and the second current collector 145 can overlap with the stack count uniformity area b1 of the bending surface area F. Optionally, the remaining area of ​​the weld area W can overlap with the stack count reduction area b2 of the bending surface area F. For high weld strength, low weld interface resistance, and to prevent damage to the separator or the active material layer, it is advantageous for the entire weld area W to overlap the stack count uniformity area b1.

[0392] Preferably, in the stack number uniformity area b1 and optionally in the stack number decrease area b2, which overlaps with the welding area W, the stack number of segments can be 10 to 35.

[0393] If the number of segments in the stack reduction area b2, which overlaps with the welding area W, is less than 10, the laser power for the stack reduction area b2 can optionally be reduced compared to the laser power for the stack uniformity area b1. That is, if the welding area W overlaps with both the stack uniformity area b1 and the stack reduction area b2 simultaneously, the laser power can be varied according to the number of segments in the stack. In this case, the weld strength of the stack uniformity area b1 can be greater than the weld strength of the stack reduction area b2.

[0394] In the bending surface area F formed on the upper section and the lower section of the electrode arrangement 110, the radial length of the segment skipping area a1 and / or the segment height variable area a2 and / or the segment height uniform area a3 can be the same or different.

[0395] The bending surface area F formed on the upper and lower sections of the electrode arrangement 110 can also form a planar symmetrical structure. Therefore, when the bending surface area F on the upper section is projected towards the bending surface area F on the lower section, they can essentially overlap.

[0396] In the electrode arrangement 110, the uncoated section of the first section B1 has a relatively smaller height than other sections. Additionally, as shown in Fig.14 shows the bending length H of the segment closest to the core, less than the sum of the radial length R of the winding turns formed by the first section B1 and 10% of the radius of the core 112.

[0397] Therefore, even if the segments contained in the third section B2 are bent towards the core, 90% or more of the diameter of the core 112 of the electrode assembly 110 can be open to the outside. If the core 112 is not blocked, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. Additionally, by inserting a welding device through the core 112, the welding process between the second current collector 145 and the battery housing 142 can be improved.

[0398] When the width and / or height and / or pitch of the segments are adjusted to meet the numerical range of the above embodiment, when the segments are bent, the segments will overlap sufficiently in multiple layers to ensure adequate weld strength, and no empty hole (cavity) will be formed in the bending area F.

[0399] Preferably, the first current collector 144 and the second current collector 145 can have outer diameters that define the end of the segment 61 ( Fig.12) cover, which is bent at the last winding turn of the first electrode and the second electrode. In this case, welding is possible in a state while the segments forming the bending area F are pressed uniformly through the current collector, and the tightly stacked state of the segments can be well maintained even after welding. The tightly stacked state means a state in which there is essentially no gap between the segments, as in Fig. Figure 10a shows that the densely stacked state helps to reduce the resistance of the cylindrical battery 190 to a level suitable for fast charging (for example, 4 milliohms) or less.

[0400] The sealing body 143 can include a cap plate 143a, a first seal 143b to provide an airtight seal between the cap plate 143a and the battery housing 142, which has insulation, and a connecting plate 143c that is electrically and mechanically coupled to the cap plate 143a.

[0401] 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 bending surface area F of the first electrode and is electrically insulated from the battery housing 142 by means of the first seal 143b. Thus, the cap plate 143a can function as the first electrode terminal (for example, the positive electrode) of the cylindrical battery 190.

[0402] The cap plate 143a is placed on the corrugated section 147 formed on the battery housing 142 and is secured by a crimp section 148. The first seal 143b can be arranged between the cap plate 143a and the crimp section 148 to ensure the airtightness of the battery housing 142 and the electrical insulation between the battery housing 142 and the cap plate 143a. The cap plate 143a can have a projection 143d extending upwards from its center.

[0403] The battery housing 142 is electrically connected to the bending 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.

[0404] The battery housing 142 has the beaded section 147 and the crimped section 148 on its upper surface. The beaded section 147 is formed by press-fitting the circumference of the outer circumferential surface of the battery housing 142. The beaded section 147 prevents the electrode assembly 110 contained in the battery housing 142 from escaping through the upper opening of the battery housing 142 and can act as a support section on which the sealing body 143 is placed.

[0405] The second section B3 of the first electrode may not have a segment and may be notched in the same structure as the first section B1. Preferably, the inner circumference of the beaded section 147 may be spaced apart from the winding turns formed by the second section B3 of the first electrode by a predetermined distance. This is because the second section B3 is notched like the first section B1. In particular, the lower end of the inner circumference of the beaded section 147 is separated from the winding turns formed by the second section B3 of the first electrode by a predetermined distance. Furthermore, since the uncoated section of the second section B3 has a low height, the winding turns of the second section B3 are not significantly affected, even when the battery casing 142 is press-fitted on the outside to form the beaded section 147.Therefore, the winding turns of the second section B3 are not pressed by other components such as the beaded section 147, thus preventing partial deformation of the electrode arrangement 110 and preventing a short circuit within the cylindrical battery 190.

[0406] If the press fit depth of the bead section 147 is defined as D1 and the radial length from the inner circumference of the battery housing 142 to the boundary point between the second section B3 and the third section B2 is defined as D2, the relation expression D1 ≤ D2 can preferably be satisfied. In this case, when press-fitting the battery housing 142 to form the bead section 147, it is possible to essentially prevent damage to the winding turns formed by the second section B3.

[0407] The crimp section 148 is formed on the bead section 147. The crimp section 148 has an elongated and curved shape to cover the outer circumference of the cap plate 143a, which is arranged on the bead section 147, and part of the upper surface of the cap plate 143a.

[0408] The cylindrical battery 190 can further include a first current collector 144 and / or a second current collector 145 and / or an insulator 146.

[0409] The first current collector 144 is coupled to the upper section of the electrode assembly 110. The first current collector 144 is made of a conductive metal material, such as aluminum, copper, steel, nickel, and so on, and is electrically connected to the flexural area F of the first electrode. The electrical connection can be made by welding. A guide 149 can be connected to the first current collector 144. The guide 149 can extend upwards over the electrode assembly 110 and be coupled to the connecting plate 143c or directly to the lower surface of the cap plate 143a. The guide 149 can be connected to other components by welding.

[0410] Preferably, the first current collector 144 can be formed integrally with the guide 149. In this case, the guide 149 can have an elongated plate shape extending outwards from near the center of the first current collector 144.

[0411] The first current collector 144 and the bending surface area F of the first electrode can be coupled, for example, by laser welding. Laser welding can be carried out by partially melting a base material of the current collector. In a modification, the first current collector 144 and the bending surface area F can be welded with a solder placed between them. In this case, the solder can have a lower melting point compared to the first current collector 144 and the first uncoated section 146a. Laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, or the like.

[0412] The second current collector 145 can be coupled to the lower surface of the electrode arrangement 110. One side of the second current collector 145 can be coupled to the flexural area F of the second electrode by welding, and the other side can be coupled to the inner lower surface of the battery housing 142 by welding. The coupling structure between the second current collector 145 and the flexural area F of the second electrode can be essentially the same as the coupling structure between the first current collector 144 and the flexural area F of the first electrode.

[0413] The insulator 146 can cover the first current collector 144. The insulator 146 can cover the first current collector 144 on its upper surface, thus preventing direct contact between the first current collector 144 and the inner circumference of the battery housing 142.

[0414] The insulator 146 has a guide hole 151, allowing the guide 149, which extends upwards from the first current collector 144, to be pulled out through it. The guide 149 is pulled upwards through the guide hole 151 and coupled to the lower surface of the connecting plate 143c or the lower surface of the cap plate 143a.

[0415] A circumferential region of the edge of the insulator 146 can be arranged between the first current collector 144 and the bead section 147 to fix the coupled body of the electrode assembly 110 and the first current collector 144. This restricts the movement of the coupled body of the electrode assembly 110 and the first current collector 144 in the vertical direction of the battery 140, thereby improving the mounting stability of the battery 140.

[0416] The insulator 146 can be made from an insulating polymer resin. For example, the insulator 146 can be made from polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0417] The battery casing 142 may further comprise a vent section 152 formed on its lower surface. The vent section 152 corresponds to a region of smaller thickness compared to the perimeter of the lower surface of the battery casing 142. The vent section 152 is structurally weaker compared to the surrounding area. Thus, if an anomaly occurs in the cylindrical battery 190 and the internal pressure rises to a predetermined level or higher, the vent section 152 may rupture, allowing the gas generated inside the battery casing 142 to escape. The internal pressure at which the vent section 152 ruptures may be approximately 15 kgf / cm² to 35 kgf / cm².

[0418] The vent section 152 can be continuous or discontinuous, tracing a circle on the lower surface of the battery casing 142. In one modification, the vent section 152 can be configured in a straight pattern or other patterns.

[0419] Fig. Figure 18 is a cross-sectional view showing a cylindrical battery 200 according to another embodiment of the present disclosure along the Y-axis direction.

[0420] With reference to Fig. 18 The structure of the electrode arrangement of the cylindrical battery 200 is essentially the same as that of the cylindrical battery 190. Fig. 17, and the other structure, with the exception of the electrode arrangement, is changed.

[0421] In particular, the cylindrical battery 200 has a battery housing 171 through which a riveted connection 172 is installed. The riveted connection 172 is installed through a perforation hole formed in the closed surface (the upper surface in the drawing) of the battery housing 171. The riveted connection 172 is riveted to the perforation hole of the battery housing 171 in a state in which a second seal 173, made of an insulating material, is positioned between them. The riveted connection 172 is exposed to the outside in a direction opposite to the direction of gravity.

[0422] The rivet terminal 172 has a terminal exposure section 172a and a terminal insert section 172b. The terminal exposure section 172a is exposed outside the closed surface of the battery housing 171. The terminal exposure section 172a may be located approximately in the central section of the closed surface of the battery housing 171. The maximum diameter of the terminal exposure section 172a may be larger than the maximum diameter of the perforation hole formed in the battery housing 171. The terminal insert section 172b may be electrically connected to the uncoated section 146a of the first electrode through approximately the central section of the closed surface of the battery housing 171. The lower edge of the terminal insert section 172b may be riveted to the inner surface of the battery housing 171.This means that the lower edge of the terminal insert section 172b can have a shape that is curved towards the inner surface of the battery housing 171. A flat section 172c is included on the inside of the lower edge of the terminal insert section 172b. The maximum diameter of the lower section of the riveted terminal insert section 172b can be larger than the maximum diameter of the perforation hole in the battery housing 171.

[0423] The flat section 172c of the connection insert section 172b can be welded to the central section of the first current collector 144, which is connected to the bending surface area F of the first electrode. The welding is preferably laser welding, but can be replaced by other welding processes such as ultrasonic welding.

[0424] An insulator 174, made of an insulating material, can be arranged between the first current collector 144 and the inner surface of the battery housing 171. The insulator 174 covers the upper section of the first current collector 144 and the upper edge of the electrode arrangement 110. This prevents the second section B3 of the electrode arrangement 110 from contacting the inner surface of the battery housing 171 with a different polarity and causing a short circuit.

[0425] The thickness of the insulator 174 corresponds to the distance between the upper surface of the first current collector 144 and the inner surface of the closed section of the battery housing 171, or is slightly greater than this distance. Thus, the insulator 174 can contact both the upper surface of the first current collector 144 and the inner surface of the closed section of the battery housing 171.

[0426] The connecting insert section 172b of the riveted connection 172 can be welded to the first current collector 144 through the perforation hole of the insulator 174. The diameter of the perforation hole formed in the insulator 174 can be larger than the diameter of the riveted section on the underside of the connecting insert section 172b. Preferably, the perforation hole exposes the lower section of the connecting insert section 172b and the second seal 173.

[0427] The second seal 173 is arranged between the battery housing 171 and the rivet terminal 172 to prevent the battery housing 171 and the rivet terminal 172 from making electrical contact with each other if they have opposite polarities. Thus, the upper surface of the battery housing 171, which has an approximately flat shape, can function as the second electrode terminal (for example, the negative electrode) of the cylindrical battery 200.

[0428] The second seal 173 has a seal exposure section 173a and a seal insert section 173b. The seal exposure section 173a is located between the terminal exposure section 172a of the rivet terminal 172 and the battery housing 171. The seal insert section 173b is located between the terminal insert section 172b of the rivet terminal 172 and the battery housing 171. The seal insert section 173b can be deformed together with the terminal insert section 172b when it is riveted to ensure close contact with the inner surface of the battery housing 171. The second seal 173 can, for example, be made of a polymer resin that has insulating properties.

[0429] The seal exposure section 173a of the second seal 173 can have an extended shape to cover the outer circumference of the terminal exposure section 172a of the rivet terminal 172. When the second seal 173 covers the outer circumference of the rivet terminal 172, it is possible to prevent a short circuit from occurring while an electrical connecting part, such as a busbar, is coupled to the upper surface of the battery housing 171 and / or the rivet terminal 172. Although not shown in the drawings, the seal exposure section 173a can have an extended shape to cover not only the outer circumference of the terminal exposure section 172a, but also a portion of its upper surface.

[0430] If the second seal 173 is made of a polymer resin, it can be thermally fused to the battery housing 171 and the rivet terminal 172. In this case, the airtightness at the coupling interface between the second seal 173 and the rivet terminal 172, and at the coupling interface between the second seal 173 and the battery housing 171, can be improved. Furthermore, if the seal exposure section 173a of the second seal 173 has a shape that extends to the upper surface of the terminal exposure section 172a, the rivet terminal 172 can be integrally coupled to the second seal 173 by overmolding.

[0431] In the upper surface of the battery housing 171, a remaining area 175, which is distinct from the area occupied by the rivet terminal 172 and the second seal 173, corresponds to the second electrode terminal with a polarity opposite to that of the rivet terminal 172.

[0432] The second current collector 176 is coupled to the lower section of the electrode arrangement 110. The second current collector 176 is made of a conductive metal material, such as aluminum, steel, copper, or nickel, and is electrically connected to the bending surface area F of the second electrode.

[0433] Preferably, the second current collector 176 is electrically connected to the battery housing 171. For this purpose, at least one section of the edge of the second current collector 176 can be arranged and fixed between the inner surface of the battery housing 171 and a first seal 178b. In one example, at least one section of the edge of the second current collector 176 can be fixed to the corrugated section 180 by welding in such a way that it is supported on the lower surface of the corrugated section 180 formed on the underside of the battery housing 171. In another modification, at least one section of the edge of the second current collector 176 can be welded directly to the inner wall surface of the battery housing 171.

[0434] Preferably, the second current collector 176 and the bending surface area F of the second electrode can be coupled by welding, for example, laser welding. Furthermore, the welded area of ​​the second current collector 176 and the bending surface area F can be spaced apart from the core C by a predetermined distance based on the inner circumference of the beaded section 180.

[0435] A sealing body 178 for sealing the lower open end of the battery housing 171 comprises a cap plate 178a and a first seal 178b. The first seal 178b electrically isolates the cap plate 178a and the battery housing 171. A crimp section 181 secures the edge of the cap plate 178a and the first seal 178b to one another. The cap plate 178a has a vent section 179. The configuration of the vent section 179 is essentially the same as in the embodiment described above (modification). The lower surface of the cap plate 178a can be positioned above the lower end of the crimp section 181. In this case, a space is formed under the cap plate 178a to allow for gentle venting. This is particularly advantageous when the cylindrical battery 200 is installed such that the crimp section 181 faces the direction of gravity.

[0436] Preferably, the cap plate 178a is made of a conductive metal material. However, since the first seal 178b is arranged between the cap plate 178a and the battery housing 171, the cap plate 178a has no electrical polarity. The sealing body 178 seals the open end of the lower section of the battery housing 171 and serves primarily to release gas when the internal pressure of the battery 200 rises above a threshold value. The internal pressure threshold is 15 kgf / cm² to 35 kgf / cm².

[0437] Preferably, the rivet terminal 172, which is electrically connected to the flexural area F of the first electrode, is used as the first electrode terminal. Additionally, a portion 175 on the upper surface of the battery housing 171, which is electrically connected to the flexural area F of the second electrode via the second current collector 176, is used as the second electrode terminal, having a different polarity than the first electrode terminal. With two electrode terminals located on the upper section of the cylindrical battery 200 as described above, it is possible to arrange electrical connection components, such as busbars, on only one side of the cylindrical battery 200. This can simplify the battery pack structure and improve energy density.Since part 175, which serves as the second electrode connection, has an approximately flat shape, a sufficient contact surface for connecting electrical connection components, such as busbars, can be ensured. Thus, the cylindrical battery 200 can reduce the resistance at the connection point of the electrical connection components to a desirable level.

[0438] Fig. Figure 19 is a cross-sectional view showing a cylindrical battery 210 according to yet another embodiment of the present disclosure along the Y-axis direction.

[0439] With reference to Fig. 19 comprises the cylindrical battery 210 which is in Fig. Electrode arrangement 100 shown in Figure 13, and other configurations except for electrode arrangement 100, are essentially the same as those shown in Figure 13. Fig.17 cylindrical battery 190 shown. Thus, with reference to Fig. 13 and Fig. The configuration described in 17 can be applied essentially the same way to this embodiment.

[0440] Preferably, the first and second uncoated sections 146a, 146b of the electrode arrangement 100 comprise several segments 61. The segments 61 are bent in the radial direction of the electrode arrangement 100, for example, from the outer circumference towards the core. Since, at this point, the uncoated sections of the first section B1 and the second section B3 of the first uncoated section 146a have a lower height than other sections and do not comprise any segments, they are essentially not bent. This is the same for the second uncoated section 146b.

[0441] Even in this embodiment, the bending surface area F formed by the segments 61 can include the segment-skipping area a1, the segment-height-variable area a2, and the segment-height-uniform area a3 from the core to the outer circumference. However, since the uncoated section of the second section B3 is not bent, the radial length of the bending surface area F can be shorter than in the embodiment above.

[0442] As in Fig. 11a, Fig. 11b and Fig. As shown in 11c, the bending surface area F includes a stack count uniformity area b1 with a stack count of 10 or more adjacent to the segment skip area a1.

[0443] The bending surface area F can also include a stack count reduction area b2 adjacent to the winding turns of the second section B3 of the electrode arrangement 100, where the stack count of segments decreases towards the outer circumference. Preferably, the stack count uniformity area b1 can be set as a welding target area.

[0444] In the bending surface area F, the preferred numerical ranges of the ratio (a2 / c) of the height-variable area a2 of the segments to the radial area c containing segments, the ratio (b1 / c) of the uniform stacking number area b1 of the segments and the ratio of the area of ​​the uniform stacking number area b1 to the area of ​​the bending surface area F have already been described above and are therefore not described again.

[0445] The first current collector 144 can be welded to the bending surface area F of the first uncoated section 146a and the second current collector 145 can be welded to the bending surface area F of the second uncoated section 146b.

[0446] The overlapping relationship between the stack count uniformity region b1 and the stack count decrease region b2 and the welding region W, the outer diameters of the first current collector 144 and the second current collector 145 and the configuration in which the first section B1 does not block the core are essentially the same as described above.

[0447] Furthermore, the second section B3 comprises no segments, and the height of the uncoated section is less than that of the segments of the third section B2. Therefore, when the segments of the third section B2 are bent, the second section B3 is essentially not bent. Moreover, since the winding turns of the second section B3 are sufficiently spaced from the bead section 147, the problem of damage to the winding turns of the second section B3 while the bead section 147 is press-fitted can be solved.

[0448] Fig. Figure 20 is a cross-sectional view showing a cylindrical battery 220 according to yet another embodiment of the present disclosure along the Y-axis direction.

[0449] With reference to Fig. The cylindrical battery 220 comprises 20 units, which are in Fig.Electrode arrangement 100 shown in Figure 13, and other configurations except for electrode arrangement 100, are essentially the same as those shown in Figure 13. Fig. 18 cylindrical battery 200 shown. Thus, with reference to Fig. 13 and Fig. The configuration described in 18 can be applied essentially the same way to this embodiment.

[0450] Preferably, the first and second uncoated sections 146a, 146b of the electrode arrangement 100 comprise several segments 61. Since the uncoated sections of the first section B1 and the second section B3 of the first uncoated section 146a have a lower height than the other sections and do not include any segments, they are essentially not bent at this point. This is also identical in the case of the second uncoated section 146b.

[0451] Therefore, in this embodiment, similar to the embodiment of Fig. 19, the bending surface area F includes a segment-skipping area a1, a segment-height-variable area a2, and a segment-height-uniform area a3 from the core to the outer circumference. However, since the uncoated section of the second section B3 is not bent, the radial length of the bending surface area F can be shorter than in the case of the embodiment above.

[0452] As in Fig. 11a, Fig. 11b and Fig. As shown in 11c, the bending surface area F includes a stack count uniformity area b1 with a stack count of 10 or more adjacent to the segment skip area a1.

[0453] The bending surface area F can also include a stack count reduction area b2 adjacent to the winding turns of the second section B3 of the electrode arrangement 100, in which the stack count of segments decreases towards the outer circumference. Preferably, the stack count uniformity area b1 can be set as a welding target area.

[0454] In the bending surface area F, the preferred numerical ranges of the ratio (a2 / c) of the height-variable area a2 of the segments to the radial area c containing segments, the ratio (b1 / c) of the uniform stacking number area b1 of the segments and the ratio of the area of ​​the uniform stacking number area b1 to the area of ​​the bending surface area F have already been described above and are therefore not described again.

[0455] The first current collector 144 can be welded to the bending surface area F of the first uncoated section 146a and the second current collector 176 can be welded to the bending surface area F of the second uncoated section 146b.

[0456] The overlapping relationship between the stack count uniformity region b1 and the stack count decrease region b2 and the welding region W, the outer diameters of the first current collector 144 and the second current collector 176 and the configuration in which the first section B1 does not block the core are essentially the same as described above.

[0457] In the embodiments (modifications), the first current collector 144 and the second current collector 176, which are contained in the cylindrical batteries 200, 220 including the rivet terminal 172, can have an improved structure, as shown in Fig. 21 and Fig. 22 shown.

[0458] The improved structure of the first current collector 144 and the second current collector 176 can help to reduce the resistance of the cylindrical battery, improve its vibration resistance, and increase its energy density. In particular, the first current collector 144 and the second current collector 176 are more effective when used in a large cylindrical battery with a diameter-to-height ratio greater than 0.4.

[0459] Fig. Figure 21 is a top view showing the structure of the first current collector 144 according to an embodiment of the present disclosure.

[0460] With reference to Fig. 20 and Fig.21 Together, the first current collector 144 can comprise an edge section 144a, a first uncoated section coupling section 144b, and a terminal coupling section 144c. The edge section 144a, the first uncoated section coupling section 144b, and the terminal coupling section 144c can be welded to the inner surface of the battery housing 171. The edge section 144a is arranged on the electrode assembly 100. The edge section 144a can have a substantially circular edge shape in which an open space is formed. The drawings of this disclosure illustrate only one case in which the edge section 144a has a substantially circular edge shape, but this disclosure is not limited to such cases. The edge section 61 can have a substantially rectangular edge shape, a hexagonal edge shape, an octagonal edge shape, or other edge shapes, other than those shown in the figure.The number of boundary sections 144a can be increased to two or more. In this case, another boundary section in the form of a border within boundary section 144a may be included.

[0461] The connecting coupling section 144c can have a diameter equal to or greater than the diameter of the flat section 172c formed on the underside of the rivet connection 172 to provide a welding area for coupling with the flat section 172c formed on the underside of the rivet connection 172.

[0462] The first coupling section 144b of the uncoated section extends inwards from the edge section 144a and is coupled to the bending surface area F of the uncoated section 146a by welding. The connecting coupling section 144c is spaced apart from the first coupling section 144b of the uncoated section and is positioned within the edge section 144a. The connecting coupling section 144c can be coupled to the rivet connection 172 by welding. The connecting coupling section 144c can, for example, be located approximately in the center of the interior space (open) surrounded by the edge section 144a. The connecting coupling section 144c can be positioned at a location corresponding to the hole formed in the core C of the electrode assembly 100.The connection coupling section 144c can be configured to cover the hole formed in the core C of the electrode assembly 100, so that the hole formed in the core C of the electrode assembly 100 is not exposed outside the connection coupling section 144c. For this purpose, the connection coupling section 144c can have a larger diameter or width than the hole formed in the core C of the electrode assembly 100.

[0463] The first coupling section 144b of the uncoated section and the connecting coupling section 144c can be arranged not directly, but rather spaced apart and indirectly connected by the edge section 144a. Since the first current collector 144 has a structure in which the first coupling section 144b of the uncoated section and the connecting coupling section 144c are not directly connected, but rather connected by the edge section 144c as described above, it is possible, when a shock and / or vibration occurs on the cylindrical battery 220, to distribute the shock applied to the coupling section between the first coupling section 144b of the uncoated section and the first uncoated section 146a, and to the coupling section between the connecting coupling section 144c and the rivet terminal 172.The drawings of the present disclosure illustrate only one case in which four first coupling sections 144b of the uncoated section are provided, but the present disclosure is not limited to this. The number of first coupling sections 144b of the uncoated section can be determined differently, taking into account the manufacturing difficulties according to the complexity of the shape, the electrical resistance, the open space within the edge section 144a, the electrolyte impregnation, and the like.

[0464] The first current collector 144 can further comprise a bridge section 144d extending inwards from the edge section 144a and connected to the terminal coupling section 144c. At least a portion of the bridge section 144d can have a smaller cross-sectional area compared to the first coupling section 144b of the uncoated section and the edge section 144a. For example, at least a portion of the bridge section 144d can be configured to have a smaller width and / or thickness compared to the first coupling section 144b of the uncoated section. In this case, the electrical resistance in the bridge section 144d increases. Therefore, when a current flows through the bridge section 144d, the relatively high resistance causes a portion of the bridge section 144d to melt due to overcurrent heating. Thus, the overcurrent is irreversibly blocked.The cross-sectional area of ​​bridge section 144d can be adjusted to a suitable level, taking into account the overcurrent blocking function.

[0465] The bridge section 144d can include a tapered section 144e, the width of which gradually decreases from the inner surface of the edge section 144a to the connecting coupling section 144c. The inclusion of the tapered section 144e improves the stiffness of the component at the connection between the bridge section 144d and the edge section 144a. Furthermore, the inclusion of the tapered section 144e allows, for example, a transfer device and / or a worker to easily and safely transport the first current collector 144 and / or a coupled body of the first current collector 144 and the electrode assembly 100 by grasping the tapered section 144e during the manufacturing process of the cylindrical battery 220.This means that if the tapered section 144e is provided, it is possible to prevent product defects that may occur from gripping a section where welding is carried out with other components such as the first uncoated section coupling section 144b and the connection coupling section 144c.

[0466] The first coupling section 144b of the uncoated section can be provided in multiples. The multiple first coupling sections 144b of the uncoated section can be arranged at substantially regular intervals from one another in the extension direction of the edge section 144a. The extension length of each of the multiple first coupling sections 144b of the uncoated section can be substantially the same. The first coupling section 144b of the uncoated section can be coupled to the bending surface area F of the uncoated section 146a by laser welding. The welding can be replaced by ultrasonic welding, spot welding, or the like.

[0467] A weld pattern 144f, formed by welding between the first coupling section 144b of the uncoated section and the bending surface area F, can have a structure extending along the radial direction of the electrode arrangement 100. The weld pattern 144f can be an arrangement of line patterns or dot patterns.

[0468] The weld pattern 144f corresponds to the weld area. Therefore, it is desirable that the weld pattern 144f overlaps the stack count uniformity area b1 of the bending surface area F by 50% or more. The weld pattern 144f that does not overlap with the stack count uniformity area b1 may overlap with the stack count decrease area b2. Advantageously, the entire weld pattern 144f may overlap with the stack count uniformity area b1 of the bending surface area F. In the bending surface area F below the point where the weld pattern 144f is formed, the stack count uniformity area b1 and, optionally, the stack count decrease area b2 preferably have a stack count of 10 or more.

[0469] The connecting coupling section 144c can be arranged to be surrounded by the multiple first coupling sections 144b of the uncoated section. The connecting coupling section 144c can be coupled to the flat section 172c of the riveted connection 172 by welding. The bridge section 144d can be positioned between a pair of adjacent first coupling sections 144b of the uncoated section. In this case, the distance from the bridge section 144d to any one of the pair of first coupling sections 144b of the uncoated section along the extension direction of the edge section 144a can be substantially the same as the distance from the bridge section 144d to the other of the pair of first coupling sections 144b of the uncoated section along the extension direction of the edge section 144a.The multiple first coupling sections 144b of the uncoated section can be formed to have substantially the same cross-sectional area. The multiple first coupling sections 144b of the uncoated section can be formed to have substantially the same width and thickness.

[0470] Although not shown in the drawings, the bridge section 144d can be provided in multiples. Each of the multiple bridge sections 144d can be arranged between a pair of first coupling sections 144b of the uncoated section that are adjacent to each other. The multiple bridge sections 144d can be arranged at substantially regular intervals from one another in the extension direction of the edge section 144a. The distance from each of the multiple bridge sections 144d to one of the pair of first coupling sections 144b of the uncoated section that are adjacent to each other along the extension direction of the edge section 144a can be substantially the same as the distance from each of the multiple bridge sections 144d to the other first coupling section 144b of the uncoated section.

[0471] In the case where the first coupling section 144b of the uncoated section and / or the bridge section 144d are provided in multiples as described above, if the distance between the first coupling sections 144b of the uncoated section and / or the distance between the bridge sections 144d and / or the distance between the first coupling section 144b of the uncoated section and the bridge section 144d is uniform, a current flowing from the first coupling section 144b of the uncoated section to the bridge section 144d, or a current flowing from the bridge section 144d to the first coupling section 144b of the uncoated section, can be formed smoothly.

[0472] Bridge section 144d may have a notch section N formed to partially reduce the cross-sectional area of ​​bridge section 144d. The cross-sectional area of ​​the notch section N can be adjusted, for example, by partially reducing the width and / or thickness of bridge section 144d. When the notch section N is provided, the electrical resistance in the area where the notch section N is formed is increased, thus enabling rapid current interruption in the event of an overcurrent.

[0473] The notch section N is preferably provided in an area corresponding to the stack number uniformity region of the electrode arrangement 100 in order to prevent foreign substances generated during the breaking process from flowing into the electrode arrangement 100. This is because the number of overlapping layers of the segments of the uncoated section 146a is kept to a maximum in this area, and thus the overlapping segments can act as a mask.

[0474] The notch section N can be wrapped with an insulating tape. Since the heat generated in the notch section N is then not dissipated to the outside, the notch section N can break open more quickly if an overcurrent flows through the bridge section 144d.

[0475] Fig. Figure 22 is a top view showing the structure of the second current collector 176 according to an embodiment of the present disclosure.

[0476] With reference to Fig. 20 and Fig.The second current collector 176 is arranged below the electrode assembly 100. Additionally, the second current collector 176 can be configured to electrically connect the uncoated section 146b of the electrode assembly 100 and the battery housing 171. The second current collector 176 is made of a conductive metal material and is electrically connected to the flexural area F of the uncoated section 146b. The edge section of the second current collector 176 can be arranged and fixed between the inner surface of the battery housing 171 and the first seal 178b. Specifically, the edge section of the second current collector 176 can be arranged between the lower surface of the corrugated section 180 of the battery housing 171 and the first seal 178b.However, the present disclosure is not limited thereto and the edge section of the second current collector 176 may be welded to the inner wall surface of the battery housing 171 in an area where the corrugated section 180 is not formed.

[0477] The second current collector 176 can include a support section 176a located beneath the electrode assembly 100, a second coupling section 176b of the uncoated section extending from the support section 176a approximately along the radial direction of the electrode assembly 100 and coupled to the flexural area F of the uncoated section 176b, and a housing coupling section 176c extending from the support section 176a to the inner surface of the battery housing 171 approximately along an inclined direction based on the radial direction of the electrode assembly 100 and coupled to the inner surface of the battery housing 171. The second coupling section 176b of the uncoated section and the housing coupling section 176c are indirectly connected through the support section 176a and are not directly connected to each other.Therefore, when an external shock is applied to the cylindrical battery 220 of the present disclosure, it is possible to minimize the possibility of damage to the coupling section of the second current collector 176 and the electrode arrangement 100, and to the coupling section of the second current collector 176 and the battery housing 171. However, the second current collector 176 of the present disclosure is not limited to the structure in which the second coupling section 176b of the uncoated section and the housing coupling section 176c are only indirectly connected. For example, the second current collector 176 may have a structure that does not include the support section 176a for indirectly connecting the second coupling section 176b of the uncoated section and the housing coupling section 176c, and / or a structure in which the uncoated section 176b and the housing coupling section 176c are directly connected.

[0478] The support section 176a and the second coupling section 176b of the uncoated section are arranged below the electrode assembly 100. The second coupling section 176b of the uncoated section is coupled to the bending surface area F of the uncoated section 146b. In addition to the second coupling section 176b of the uncoated section, the support section 176a can also be coupled to the uncoated section 146b. The second coupling section 176b of the uncoated section and the bending surface area F of the uncoated section 146b can be coupled by welding. Welding can be replaced by ultrasonic welding or spot welding. The support section 176a and the second coupling section 176b of the uncoated section are arranged higher than the beaded section 180 when the beaded section 180 is formed on the battery housing 171.

[0479] The support section 176a has a current collector hole 176d formed in a position corresponding to the hole formed in the core C of the electrode assembly 100. The core C of the electrode assembly 100 and the current collector hole 176d, which are interconnected, can serve as a passage for inserting a welding rod for welding between the rivet terminal 172 and the connection coupling section 144c of the first current collector 144, or for irradiating a laser beam.

[0480] The current collector hole 176d can have a radius of 0.5 rc or greater than the radius (rc) of the hole formed in the core C of the electrode assembly 100. If the radius of the current collector hole 176d is between 0.5 rc and 1.0 rc, then, in the event of venting in the cylindrical battery 220, the phenomenon of the separator winding structure or the electrodes near the core C of the electrode assembly 100 being forced out of the core C due to the venting pressure is prevented. If the radius of the current collector hole 176d is greater than 1.0 rc, the opening of the core C is maximized, thus improving electrolyte injection during the electrolyte injection process.

[0481] If the second coupling section 176b of the uncoated section is provided in multiples, the multiple second coupling sections 176b of the uncoated section can have a shape that extends approximately radially from the support section 176a of the second current collector 176 to the side wall of the battery housing 171. The multiple second coupling sections 176b of the uncoated section can be positioned to be spaced apart from one another along the circumference of the support section 176a.

[0482] The housing coupling section 176c can be provided in multiples. In this case, the multiple housing coupling sections 176c can have a shape extending approximately radially from the center of the second current collector 176 to the side wall of the battery housing 171. Thus, the electrical connection between the second current collector 176 and the battery housing 171 can be established at multiple points. Since the coupling for the electrical connection is established at multiple points, the coupling area can be maximized, thereby minimizing the electrical resistance. The multiple housing coupling sections 176c can be positioned to be spaced apart from one another along the circumference of the support section 176a. At least one housing coupling section 176c can be positioned between the second coupling sections 176b of the uncoated section that are adjacent to each other.The multiple housing coupling sections 176c can, for example, be coupled to the beaded section 180 in the inner surface of the battery housing 171. The housing coupling sections 176c can be coupled to the lower surface of the beaded section 180, in particular by laser welding. Welding can be replaced, for example, by ultrasonic welding, spot welding, or the like. By coupling the multiple housing coupling sections 176c to the beaded section 180 by welding in this manner, the current path can be radially distributed, so that the resistance level of the cylindrical battery 220 is limited to approximately 4 milliohms or less.Since the lower surface of the corrugated section 180 has a shape extending in a direction approximately parallel to the upper surface of the battery housing 171, namely in a direction approximately perpendicular to the side wall of the battery housing 171, and the housing coupling section 176c also has a shape extending in the same direction, namely in the radial and circumferential directions, the housing coupling section 176c can also be in stable contact with the corrugated section 180. Furthermore, since the housing coupling section 176c is in stable contact with the flat section of the corrugated section 180, the two components can be gently welded, thereby improving the coupling force between the two components and minimizing the increase in resistance at the coupling section.

[0483] The housing coupling section 176c can include a contact section 176e coupled to the inner surface of the battery housing 171 and a connecting section 176f for connecting the support section 176a and the contact section 176e.

[0484] The contact section 176e is coupled to the inner surface of the battery housing 171. In the case where the corrugated section 180 is formed on the battery housing 171, the contact section 176e can be coupled to the corrugated section 180 as described above. In particular, the contact section 176e can be electrically coupled to the flat section formed on the lower surface of the corrugated section 180 formed on the battery housing 171 and can be located between the lower surface of the corrugated section 180 and the first seal 178b. In this case, for stable contact and coupling, the contact section 176e can have a shape that extends along the corrugated section 180 by a predetermined length along the circumferential direction of the battery housing 171.

[0485] The connecting section 176f can be bent at an obtuse angle. The bend point can be higher than the center point of the connecting section 176f. When the connecting section 176f is bent, the contact section 176e can be stably supported against the flat surface of the corrugated section 180. The connecting section 176f is divided into a lower section and an upper section based on the bend point, and the lower section can be longer than the upper section. Additionally, the lower section of the bend point can have a greater angle of inclination based on the surface of the supporting section 176a than the upper section. When the connecting section 176f is bent, a pressure (force) exerted in the vertical direction of the battery housing 171 can be absorbed.For example, in the process of dimensioning the battery housing 171, when pressure is applied to the contact section 176e, causing the contact section 176e to move vertically to the support section 176b, the bending point of the connecting section 176f moves upwards, so that the shape of the connecting section 176 is deformed to buffer the stress.

[0486] Furthermore, the maximum distance from the center of the second current collector 176 to the end of the second coupling section 176b of the uncoated section along the radial direction of the electrode arrangement 100 is preferably equal to or less than the inner diameter of the battery housing 171 in a region where the corrugated section 180 is formed, namely the minimum inner diameter of the battery housing 171. This is intended to prevent the end of the second coupling section 176b of the uncoated section from pressing the edge of the electrode arrangement 100 during the dimensioning process of compressing the battery housing 171 along the vertical direction.

[0487] The second coupling section 176b of the uncoated section has a hole 176g. The hole 176g can be used as a passage through which the electrolyte can move. The weld pattern 176h, formed by welding between the second coupling section 176b of the uncoated section and the bending surface area F, can have a structure extending along the radial direction of the electrode arrangement 100. The weld pattern 176h can be a line pattern or a dot pattern.

[0488] The weld pattern 176h corresponds to the weld area. Therefore, it is preferred that the weld pattern 176h overlaps by 50% or more with the stack count uniformity area b1 of the bending surface area F, which is located in the lower section of the electrode arrangement 100. The weld pattern 176h that does not overlap with the stack count uniformity area b1 may overlap with the stack count decrease area b2. Advantageously, the entire weld pattern 176h may overlap with the stack count uniformity area b1 of the bending surface area F. In the bending surface area F at the upper section of the point where the weld pattern 176h is formed, the stack count uniformity area b1 and, optionally, the stack count decrease area b2 preferably have a stack count of 10 or more.

[0489] The outer diameters of the first current collector 144 and the second current collector 176, described above, differ from each other. The outer diameter is the outer diameter of the contact area between the bending surface region F and the current collector. The outer diameter is defined as the maximum value of the distance between two points where a straight line passing through the center of the core C of the electrode arrangement intersects the edge of the contact area. Since the second current collector 176 is located within the beaded section, its outer diameter is smaller than that of the first current collector 144. Furthermore, the length of the weld pattern 144f of the first current collector 144 is longer than the length of the weld pattern 176h of the second current collector 176. Preferably, the weld pattern 144f and the weld pattern 176h extend from substantially the same point based on the center of the core C toward the outer circumference.

[0490] The cylindrical battery 200, 220 according to an embodiment of the present disclosure has the advantage that an electrical connection can be made on its upper section.

[0491] Fig. Figure 23 is a top view illustrating a state in which several cylindrical batteries 200 are electrically connected, and Fig. 24 is a partially enlarged view of Fig. 23. The cylindrical battery 200 can be replaced by a cylindrical battery 220 with a different structure.

[0492] With reference to Fig. 23 and Fig. 24. Several cylindrical batteries 200 can be connected in series and parallel to an upper section of the cylindrical batteries 200 using a busbar 210. The number of cylindrical batteries 200 can be increased or decreased depending on the capacity of the battery pack.

[0493] In each cylindrical battery 200, the rivet terminal 172 can have a positive polarity, and the flat surface 171a around the rivet terminal 172 of the battery casing 171 can have a negative polarity, or vice versa.

[0494] Preferably, the multiple cylindrical batteries 200 can be arranged in multiple columns and rows. Columns are oriented vertically, with respect to the drawing, and rows are oriented to the left and right, with respect to the drawing. Additionally, to maximize space efficiency, the cylindrical batteries 200 can be arranged in a nearest-pack structure. The nearest-pack structure is formed by creating an equilateral triangle by connecting the centers of the rivet terminals 172, which are exposed from the battery housing 171. Preferably, the busbar 210 connects the cylindrical batteries 200 that are arranged in the same column in parallel and connects the cylindrical batteries 200 that are arranged in two adjacent columns in series.

[0495] Preferably the busbar 210 can have a body section 211, several first busbar connections 212 and several second busbar connections 213 for serial and parallel connection.

[0496] The body section 211 can extend along the gap of the cylindrical batteries 200 between adjacent rivet terminals 172. Alternatively, the body section 211 can extend along the gap of the cylindrical batteries 200 and can be bent regularly in a zigzag shape.

[0497] The multiple first busbar connections 212 can extend in a lateral direction of the body section 211 and can be electrically coupled to the riveted connection 172 of the cylindrical battery 200, which is located in a lateral direction. The electrical connection between the first busbar connection 212 and the riveted connection 172 can be achieved by laser welding, ultrasonic welding, or the like.

[0498] The multiple secondary busbar connections 213 can extend in the opposite lateral direction of the body section 211 and can be electrically coupled to the flat surface 171a around the riveted connection 172, which is located in the opposite lateral direction. The electrical coupling between the secondary busbar connection 213 and the flat surface 171a can be carried out by laser welding, ultrasonic welding, or the like.

[0499] Preferably, the body section 211, the multiple first busbar connections 212, and the multiple second busbar connections 213 can be made from a conductive metal plate. The metal plate can be, for example, an aluminum plate or a copper plate, but the present disclosure is not limited to this. In a modified example, the body section 211, the multiple first busbar connections 212, and the second busbar connections 213 can be manufactured as separate pieces and then coupled together by welding or the like.

[0500] The cylindrical battery 200 of the present disclosure, as described above, has a structure in which the resistance is minimized by enlarging the weld area by means of the bending surface area F, multiplexing current paths by means of the second current collector 176, minimizing a current path length, or the like. The AC resistance of the cylindrical battery 200, measured by a resistance meter between the positive electrode and the negative electrode, namely between the rivet terminal 172 and the flat surface 171a around the rivet terminal 172, can be approximately 4 milliohms or less and is suitable for fast charging.

[0501] Since in the cylindrical battery 200 according to the present disclosure the rivet terminal 172, which has a positive polarity, and the flat surface 171a, which has a negative polarity, are located in the same direction, it is easy to electrically connect the cylindrical batteries 200 using the busbar 210.

[0502] Since the rivet terminal 172 of the cylindrical battery 200 and the flat surface 171a around the rivet terminal 172 have a large area, the coupling surface of the busbar 210 can also be sufficiently ensured to adequately reduce the resistance of the battery pack which has the cylindrical battery 200.

[0503] Since electrical wiring can be carried out on the upper section of the cylindrical battery 200, there is also an advantage in maximizing the energy density per unit volume of the battery module / pack.

[0504] The cylindrical battery according to the above embodiments (modifications) can be used to manufacture a battery pack.

[0505] Fig. Figure 25 is a diagram schematically showing a battery pack according to an embodiment of the present disclosure.

[0506] With reference to Fig. Figure 25 shows a battery pack 300 according to one embodiment of the present disclosure, comprising a unit in which cylindrical batteries 301 are electrically connected, and a pack housing 302 for receiving the unit. The cylindrical battery 301 can be any of the batteries according to the above embodiments (modifications). For the sake of simplicity, components such as a busbar for electrically connecting the cylindrical batteries 301, a cooling unit, and an external connection are not shown in the drawing.

[0507] The Batterypack 300 can be mounted on a vehicle. The vehicle can be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid vehicle. The vehicle can be a four-wheeled vehicle or a two-wheeled vehicle.

[0508] Fig. 26 is a diagram that schematically shows a vehicle equipped with the 300 battery pack from Fig. 25 is included.

[0509] With reference to Fig. 26. A vehicle V according to one embodiment of the present disclosure includes a battery pack 300 according to one embodiment of the present disclosure. The vehicle V is powered according to one embodiment of the present disclosure by receiving power from the battery pack 300.

[0510] According to one aspect of the present disclosure, the internal resistance of the battery can be reduced and the energy density increased by using the uncoated section itself, which protrudes from the upper and lower sections of the electrode arrangement, as an electrode tab.

[0511] According to another aspect of the present disclosure, it is possible to prevent a short circuit within the cylindrical battery due to partial deformation of the electrode arrangement by improving the structure of the uncoated section of the electrode arrangement so that the electrode arrangement and the inner circumference of the battery casing do not interfere with the process of forming the corrugated section of the battery casing.

[0512] According to yet another aspect of the present disclosure, it is possible to prevent the uncoated section from tearing when bent by improving the structure of the uncoated section of the electrode arrangement, and it is possible to improve the weld strength of the current collector by sufficiently increasing the number of overlapping layers of the uncoated section.

[0513] According to yet another aspect of the present disclosure, it is possible to improve the impregnation (speed and uniformity) of the electrolyte by forming several segments in the uncoated section of the electrode, aligning the several segments so that they are arranged in a predetermined direction when the electrode is wound, and leaving the end of the active material layer formed on the electrode in the area where the segments are not arranged exposed between the winding turns of the separator.

[0514] According to yet another aspect of the present disclosure, it is possible to improve the properties where the current collector is welded by providing a segment structure in the uncoated section of the electrode and optimizing the dimensions (width, height, pitch) of the segments to sufficiently increase the number of segment stacks in the area used as the welding target area.

[0515] According to yet another aspect of the present disclosure, it is possible to provide an electrode arrangement in which the notch quality of the cut groove is improved by optimizing the lower structure of the cut groove by forming multiple segments by repeatedly forming a cut groove along the winding direction in the uncoated section of the electrode.

[0516] According to yet another aspect of the present disclosure, it is possible to provide an electrode arrangement in which the core shape does not collapse while the segments are bent by adjusting the height of the uncoated section at the bottom of the cut groove and the height of the uncoated section of an area adjacent to the core of the electrode arrangement relatively by forming several segments by repeatedly forming a cut groove along the winding direction in the uncoated section of the electrode.

[0517] According to yet another aspect of the present disclosure, an electrode arrangement with improved energy density and reduced resistance can be provided by using a structure in which a current collector is welded to a wide area of ​​the bending surface area formed by bending the segments.

[0518] According to yet another aspect of the present disclosure, a cylindrical battery can be provided with a design in which the electrical contacting on its upper section is improved.

[0519] According to yet another aspect of the present disclosure, by improving the structure of the uncoated section adjacent to the core of the electrode assembly, the cavity in the core of the electrode assembly is prevented from being blocked when the uncoated section is bent, thus improving the electrolyte injection process and the process of welding the battery casing (or rivet connection) and the current collector.

[0520] According to yet another aspect of the present disclosure, it is possible to provide a cylindrical battery with a structure in which the internal resistance is low, an internal short circuit is prevented and the weld strength between the current collector and the uncoated section is improved, and a battery pack and a vehicle containing the cylindrical battery.

[0521] In particular, the present disclosure may provide a cylindrical battery having a diameter-to-height ratio of 0.4 or more and a resistance of 4 milliohms or less, and a battery pack and a vehicle containing the cylindrical battery.

[0522] The present disclosure has been described in detail. However, it is understood that the detailed description and the specific examples, although they indicate preferred embodiments of the disclosure, serve only for illustration, since various changes and modifications within the scope of the disclosure will be apparent to the person skilled in the art from this detailed description. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] KR 10-2022-0089945

[0002] US 6,677,082

[0325] US 6,680,143

[0325]

Claims

An electrode arrangement comprising: a first electrode; a second electrode; and a separator arranged between the first electrode and the second electrode, wherein the first electrode, the second electrode, and the separator are wound around a winding axis in a winding direction, thus defining a core and an outer circumference of the electrode arrangement, wherein the first electrode has a first active material section coated with an active material layer along the winding direction and a first uncoated section not coated with an active material layer and exposed beyond the separator, wherein the first uncoated section has a first section adjacent to the core of the electrode arrangement, a second section adjacent to the outer circumference of the electrode arrangement, and a third section between the first section and the second section.wherein the third section has several segments spaced apart along the winding direction by forming a cut groove in several places along the winding axis direction, and the height of the first section is relatively smaller than the height of the uncoated section at a bottom of the cut groove. Electrode arrangement according to claim 1, wherein, with reference to the end of the active material layer, the height of the first section is 0% to 95% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 2, wherein the height of the first section is 37.5% to 62.5% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 1, further comprising: an insulating coating layer configured to cover the boundary between the first uncoated section and the active material layer, wherein, with respect to the end of the insulating coating layer, the height of the first section is 0% to 95% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 4, wherein the height of the first section is 37.5% to 62.5% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 1, wherein the height of the second section is relatively smaller than the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 6, wherein, with reference to the end of the active material layer, the height of the second section is 0% to 95% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 7, wherein the height of the second section is 37.5% to 62.5% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 6, further comprising: an insulating coating layer configured to cover the boundary between the first uncoated section and the active material layer, wherein, with respect to the end of the insulating coating layer, the height of the second section is 0% to 95% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 9, wherein the height of the second section is 37.5% to 62.5% of the height of the uncoated section at the bottom of the cut groove. Electrode arrangement according to claim 1, wherein a current collector of the first electrode is thinner than a current collector of the second electrode. Electrode arrangement according to claim 11, wherein the current collector of the first electrode is a copper foil, and wherein the current collector of the second electrode is an aluminum foil. Electrode arrangement according to claim 1, wherein the first electrode is a negative electrode. Battery comprising: an electrode arrangement according to any one of claims 1 to 13; a battery housing with an open end and a base opposite the open end, wherein the battery housing is configured to accommodate the electrode arrangement in a space between the open end and the base, wherein the battery housing is electrically connected to one of the first electrode and the second electrode, thus having a first polarity; a sealing element configured to tightly close the open end of the battery housing; and a terminal having a surface exposed to the outside of the battery housing, wherein the terminal is electrically connected to another of the first electrode and the second electrode, thus having a second polarity. Battery according to claim 14, wherein the sealing body comprises: a cap plate configured to tightly close the open end of the battery housing; and a seal configured to surround an edge of the cap plate, the seal being crimped to the open end of the battery housing; and wherein the terminal with the second polarity is the cap plate. Battery according to claim 14, further comprising: a current collector electrically connected to the uncoated section of the first electrode with the first polarity, wherein the current collector has an edge that is at least partially coupled to a side wall of the battery housing, wherein the sealing body comprises: a cap plate, and a seal configured to surround an edge of the cap plate, the seal being crimped to the open end of the battery housing, and wherein the battery housing has a rivet terminal insulated in a perforation hole formed in a center of the bottom of the battery housing, the rivet terminal being electrically connected to the second electrode and thus having the second polarity. Battery according to claim 16, wherein the cap plate has no polarity. Battery pack comprising a plurality of batteries according to any one of claims 14 to 17. Vehicle comprising the battery pack according to claim 18.

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