Electrode sheet, jelly roll, cylindrical battery and battery pack

Abstract

An electrode sheet (10), a jelly roll, a cylindrical battery, and a battery pack. A plurality of tabs (20) are arranged at intervals on one side of the electrode sheet (10). In a first direction, the electrode sheet (10) comprises at least two segments (30). Each segment (30) has at least one tab (20). The width of each tab (20) is in the first direction, and the height of each tab (20) is in a second direction, with the second direction being perpendicular to the first direction. For the tabs (20) in the same segment (30), the tabs (20) have the same width and the same height. For tabs (20) in different segments (30), at least one of the width and height of the tabs (20) is different.

Description

Electrode sheets, winding cores, cylindrical cells and battery packs

[0001] This application claims priority to Chinese Patent Application No. 202410674912.0, filed with the Chinese Patent Office on May 28, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to an electrode sheet, a winding core, a cylindrical battery, and a battery pack. Background Technology

[0003] In related technologies, the tabs of the core of a cylindrical battery usually need to be flattened or kneaded to achieve the effects of flattening the ends, preventing scratches on the inner wall of the battery casing, current collection, and preventing short circuits. Invention Overview

[0004] However, during the process of flattening or patting the tabs of the cylindrical battery core, overlapping and misalignment can easily occur, leading to defects such as cavities or tab deformation.

[0005] This application provides an electrode sheet. A plurality of tabs are spaced apart on one side of the electrode sheet. Along a first direction, the electrode sheet includes at least two segments, each segment having at least one tab. The width of the tab is along the first direction, and the height of the tab is along a second direction perpendicular to the first direction. For tabs within the same segment, the width and height of the tabs are the same; for tabs in different segments, at least one of the width and height of the tab is different.

[0006] This application also provides a winding core. The winding core is formed by winding the aforementioned electrode sheets. The first direction is the direction in which the electrode sheets are wound.

[0007] This application also provides a cylindrical battery. The cylindrical battery includes the aforementioned wound core.

[0008] This application also provides a battery pack. The battery pack includes cylindrical batteries as described above. Beneficial effects

[0009] The electrode sheet provided in this application divides the electrode sheet into multiple segments, making the width and height of the tabs in the same segment the same, and making at least one of the width and height of the tabs in different segments different. Based on the different designs of the width and height of the tabs in different segments, the performance requirements of the equipment during the tab flattening process can be reduced, and the equipment can achieve efficient and precise flattening of the tabs, thereby improving the technical problems of overlapping and misalignment of the tabs during flattening. Attached Figure Description

[0010] Figure 1 is a schematic diagram of the structure of the electrode provided in an embodiment of this application.

[0011] Figure 2 is a schematic diagram of the structure of the electrode provided in an embodiment of this application.

[0012] Figure 3 is a schematic diagram of the structure of the electrode sheet provided in an embodiment of this application.

[0013] Figure 4 is a schematic diagram of the structure of the electrode provided in an embodiment of this application.

[0014] Figure 5 is a schematic diagram of the structure of the electrode provided in an embodiment of this application.

[0015] Figure 6 is a schematic diagram of the structure of the electrode provided in an embodiment of this application.

[0016] Figure 7 is a schematic diagram of the structure of the electrode provided in an embodiment of this application.

[0017] Figure 8 is a schematic diagram of the structure of the electrode provided in an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures:

[0019] 10. Electrode; 20. Electrode tab; 30. Segment; 40. Bevel. Embodiments of the present invention

[0020] This embodiment provides an electrode sheet 10. The electrode sheet 10 is used to wind and form a core. A plurality of tabs 20 are spaced apart on one side of the electrode sheet 10. Along a first direction, the electrode sheet 10 includes at least two segments 30. Each segment 30 has at least one tab 20. The width of the tab 20 is along the first direction, and the height of the tab 20 is along a second direction. Tabs 20 within the same segment 30 have the same width and the same height. Tabs 20 within different segments 30 have at least one different width and height.

[0021] In this embodiment, by dividing the electrode sheet 10 into multiple segments 30, the width and height of the tabs 20 within the same segment 30 are the same, while at least one of the width and height of the tabs 20 within different segments 30 is different. Based on the different designs of the width and height of the tabs 20 within different segments 30, the performance requirements of the equipment during the flattening process of the tabs 20 can be reduced, enabling the equipment to flatten the tabs 20 efficiently and accurately, thereby improving the technical problem of overlapping and misalignment of the tabs 20 during flattening.

[0022] As shown in Figure 1, the electrode sheet 10 can be divided into multiple segments 30, with each segment 30 containing a number of tabs 20. For example, each segment 30 may contain four, ten, fifty, or one hundred tabs 20. It is understandable that for a segment 30 of a certain length, the more tabs 20 there are, the closer the end-face structure formed after folding the tabs 20 will be to a circular shape. This also helps to improve the problem of overlapping and misalignment of the tabs 20 during flattening, thus improving the flatness of the end face. However, a larger number of tabs 20 means more cutting and folding during manufacturing, increasing the difficulty of forming the electrode. Furthermore, increased cutting frequency leads to reduced production efficiency, increased metal debris, and potentially higher battery defect rates. Therefore, the number of tabs 20 in each segment 30 can be rationally selected based on the current manufacturing process level and the preset manufacturing cost, thereby balancing the production process and defect rate to ensure the optimal production method.

[0023] Within the same segment 30, all tabs 20 have the same width and height. That is, within the same segment 30, any two tabs 20 have the same width and height. Within different segments 30, at least one of the width and height of each tab 20 is different. That is, within different segments 30, at least one of the width and height of any two tabs 20 is different.

[0024] As shown in Figure 2, the electrode 10 can be divided into multiple segments 30, so that each segment 30 has only one tab 20.

[0025] Since the electrode 10 is used to wind and form a core, it is mainly used in cylindrical batteries. The electrode 10 can be a positive or negative electrode. Correspondingly, the tab 20 can be a positive or negative tab.

[0026] The first direction can be the winding direction during the process of winding the electrode 10 to form a core. The winding direction is the direction in which the electrode 10 is gradually wound to form a core. During the winding process, the radius of the formed core will gradually increase. The direction perpendicular to the winding is the width direction of the electrode 10, or the height direction of the formed core.

[0027] It is understandable that, for the tabs 20 located within different segments 30, each tab 20 may differ only in width but have the same height. Alternatively, each tab 20 may differ only in height but have the same width. Furthermore, each tab 20 may differ in both width and height.

[0028] In some embodiments, along the winding direction, the width and height of the tabs 20 within different segments 30 increase progressively. This ensures that the inner sides of the tabs 20 are substantially flush after bending. It is understood that each tab 20 bends towards the center of the winding core, and as the electrode sheet 10 is gradually wound, the radius of the winding core increases. Tabs 20 with larger radii require a longer bending distance to align their inner sides with those with smaller radii. Therefore, the increasing height of the tabs 20 within different segments 30 compensates for the positional shift caused by the increased radius of the winding core, ensuring that the inner sides of the tabs 20 are substantially flush. This results in each tab 20 forming a roughly circular, cylindrical structure after bending.

[0029] In some embodiments, along the winding direction, the electrode 10 has only one tab 20 in each segment 30, and the width and height of each tab 20 increase progressively. This ensures that the inner sides of the tabs 20 are substantially flush after bending.

[0030] In some embodiments, the width and height of the tabs 20 located in different segments 30 can vary irregularly along the winding direction, for example, increasing first and then decreasing, or decreasing first and then increasing. Making the width and height of the tabs 20 vary irregularly can also reduce the overlap and interference between the tabs 20.

[0031] For all tabs 20, each tab 20 is spaced apart. As shown in Figure 1, the distance between any two adjacent tabs 20 is L.

[0032] In some embodiments, for tabs 20 located within the same segment 30, the spacing between any two adjacent tabs 20 is the same. For tabs 20 located in different segments 30, the spacing between any two adjacent tabs 20 is different.

[0033] In some embodiments, the spacing between any two adjacent tabs 20 on the electrode 10 is the same.

[0034] In some embodiments, the spacing between any two adjacent tabs 20 on the electrode 10 is different for all tabs 20 on the electrode 10.

[0035] Where 0 < L ≤ 2 mm. For example, L can be 0.05 mm, 0.1 mm, 0.2 mm, 0.5 mm, 1 mm, 1.8 mm, 2 mm, or any value between the two.

[0036] In some embodiments, the tab 20 is a component formed on the electrode 10 using a die-cutting or laser-cutting process. For tabs 20 with different heights or widths, the corresponding cutting parameters can be adjusted during die-cutting or laser cutting.

[0037] In some embodiments, the tab 20 is configured as a parallelogram, including two oppositely arranged hypotenuses 40, wherein the hypotenuses 40 are arranged at an angle to the electrode 10. For tabs 20 located in the same segment 30, the angle between the hypotenuses 40 and the electrode 10 is the same. For tabs 20 located in different segments 30, the angle between the hypotenuses 40 and the electrode 10 may be the same or different.

[0038] By designing the tab 20 as a parallelogram, die-cutting of the tab 20 is facilitated. This also reduces the deformation of the tab 20 during bending, improving the flatness and consistency of the end face. Furthermore, the width and height design of the tab 20 reduces the equipment requirements for the flattening process and improves the forming effect of the tab 20's end face.

[0039] During the die-cutting process to form the tab 20, the electrode 10 is in a state of continuous horizontal movement. Due to the relative movement between the electrode 10 and the cutting laser, the laser can directly cut out the bevel 40. This facilitates the processing and forming of the electrode 10, making the forming process of the electrode 10 simpler.

[0040] Specifically, for the parallelogram-shaped tab 20, its hypotenuse 40 is angled to the side of the electrode 10. For tabs 20 within the same segment 30, the angle between the hypotenuse 40 and the electrode 10 is the same. That is, the angle between the hypotenuse 40 and the electrode 10 is consistent for all tabs 20 within the same segment 30. Furthermore, all tabs 20 within the same segment 30 have the same height and width, indicating that all tabs 20 within the same segment 30 have the same shape.

[0041] In some embodiments, the angle between the hypotenuse 40 and the electrode 10 is different for the tabs 20 located in different segments 30. Specifically, the angle between the hypotenuse 40 and the electrode 10 gradually increases along the winding direction.

[0042] In some embodiments, for the tabs 20 located in different segments 30, the angle between the hypotenuse 40 and the electrode 10 is the same.

[0043] Based on the shape design of the tabs 20 in each segment 30 and the angle variation between the hypotenuse 40 and the electrode plate 10, the rear end face of the tabs 20 after bending can be made flatter. After bending, each tab 20 can form a roughly circular columnar structure. At the same time, it can reduce the overlap and interference of the tabs 20, reduce the degree of deformation caused by excessive internal stress during the bending process of the tabs 20, and improve the flatness and consistency of the end face.

[0044] It is understandable that, based on the parallelogram shape of the tab 20, and for tabs 20 within the same segment 30, the width and height of the tabs 20 are the same, and the angle between the hypotenuse 40 of the tab 20 and the electrode plate 10 is the same. For tabs 20 within different segments 30, at least one of the width and height of the tab 20 is different, and the angle between the hypotenuse 40 of the tab 20 and the electrode plate 10 may be the same or different. Therefore, the tabs 20 on the electrode plate 10 can have the following forms.

[0045] Form 1: As shown in Figure 3, for the tabs 20 within the same segment 30, the tabs 20 have the same width, the same height, and the same angle between the hypotenuse 40 of the tab 20 and the electrode plate 10. For the tabs 20 within different segments 30, the widths of the tabs 20 are different, namely D1, D2, D3...D n The height of the tabs 20 is the same, H. The angle between the hypotenuse 40 of the tab 20 and the electrode 10 is the same, α.

[0046] Form 2: As shown in Figure 4, for the tabs 20 within the same segment 30, the tabs 20 have the same width, the same height, and the same angle between the hypotenuse 40 of the tab 20 and the electrode plate 10. For the tabs 20 within different segments 30, the width of the tabs 20 is the same, all being D. The heights of the tabs 20 are different, namely H1, H2, H3...H n The angle between the hypotenuse 40 of the tab 20 and the electrode 10 is the same, α.

[0047] Form 3: As shown in Figure 5, for the tabs 20 within the same segment 30, the tabs 20 have the same width, the same height, and the same angle between the hypotenuse 40 of the tab 20 and the electrode plate 10. For the tabs 20 within different segments 30, the widths of the tabs 20 are different, namely D1, D2, D3...D n The heights of the tabs 20 are different, namely H1, H2, H3...H n The angle between the hypotenuse 40 of the tab 20 and the electrode 10 is the same, α.

[0048] Form 4: As shown in Figure 6, for the tabs 20 within the same segment 30, the tabs 20 have the same width, the same height, and the same angle between the hypotenuse 40 of the tab 20 and the electrode plate 10. For the tabs 20 within different segments 30, the widths of the tabs 20 are different, namely D1, D2, D3...D n The height of the tabs 20 is the same, H. The angle between the hypotenuse 40 of the tab 20 and the electrode plate 10 is different, α1, α2, α3...α n .

[0049] Form 5: As shown in Figure 7, for the tabs 20 within the same segment 30, the tabs 20 have the same width, the same height, and the same angle between the hypotenuse 40 of the tab 20 and the electrode plate 10. For the tabs 20 within different segments 30, the width of the tabs 20 is the same, all being D. The heights of the tabs 20 are different, namely H1, H2, H3...H n The angle between the hypotenuse 40 of the tab 20 and the electrode 10 is different, and is α1, α2, α3...α n .

[0050] Form Six: As shown in Figure 8, for the tabs 20 within the same segment 30, the tabs 20 have the same width, the same height, and the same angle between the hypotenuse 40 of the tab 20 and the electrode plate 10. For the tabs 20 within different segments 30, the widths of the tabs 20 are different, namely D1, D2, D3...D n The heights of the tabs 20 are different, namely H1, H2, H3...H n The angle between the hypotenuse 40 of the tab 20 and the electrode 10 is different, and is α1, α2, α3...α n .

[0051] The number of tabs 20 within each segment 30 can be rationally selected based on different battery models and production conditions. Understandably, for a given segment 30, a higher number of tabs 20 results in a more circular end-face structure after folding, which is more conducive to mitigating overlapping and misalignment issues that may occur during flattening, thus improving end-face flatness. However, a higher number of tabs 20 means more cutting and folding during manufacturing, increasing the difficulty of forming the battery. Furthermore, increased cutting frequency leads to reduced production efficiency, increased metal debris, and potentially higher battery defect rates. Therefore, the number of tabs 20 within each segment 30 can be rationally selected based on current manufacturing technology and pre-set manufacturing costs to balance production process and defect rate, ensuring optimal production methods.

[0052] As shown in Figure 2, in some embodiments, each segment 30 has a tab 20. Along the winding direction, the width of the tab 20 increases, the height of the tab 20 increases, and the angle between the hypotenuse 40 of the tab 20 and the electrode 10 increases.

[0053] Since each segment 30 has only one tab 20, the shape of the tab 20 gradually changes along the winding direction. Specifically, the width of the tab 20 increases, the height of the tab 20 increases, and the angle between the hypotenuse 40 of the tab 20 and the electrode 10 increases.

[0054] Understandably, each tab 20 bends towards the center of the core. As the electrode sheet 10 is gradually wound, the radius of the core increases. Tabs 20 with larger radii require a longer bending distance to align their inner sides with those with smaller radii. This increases the height of tabs 20 within different segments 30 to compensate for the positional shift caused by the increased core radius, ensuring the inner sides of the tabs 20 are essentially flush. Furthermore, it reduces the overlap and interference of tabs 20, minimizes deformation caused by excessive internal stress during bending, and improves the flatness and consistency of the end faces.

[0055] This embodiment provides a wound core. The wound core is formed by winding electrode sheets. The first square represents the direction in which the electrode sheets are wound.

[0056] In this embodiment, by dividing the electrode sheet 10 into multiple segments 30, the width and height of the tabs 20 within the same segment 30 are the same, while at least one of the width and height of the tabs 20 within different segments 30 is different. Based on the different designs of the width and height of the tabs 20 within different segments 30, the performance requirements of the equipment during the flattening process of the tabs 20 can be reduced, enabling the equipment to flatten the tabs 20 efficiently and accurately, thereby improving the technical problem of overlapping and misalignment of the tabs 20 during flattening.

[0057] In some embodiments, the width of the tab 20 is positively correlated with the radius corresponding to the position of the tab 20 on the winding core.

[0058] Understandably, as the electrode 10 is gradually wound to form a core, the radius of the core will gradually increase. If the width of the tab 20 at a larger radius position is the same as the width of the tab 20 at a smaller radius position, then there will be more tabs 20 on the circumference of the core at the larger radius position. More tabs 20 mean more cutting and folding during manufacturing, increasing the difficulty of forming the battery. Simultaneously, increased cutting reduces production efficiency, increases metal debris, and may raise the battery defect rate. Therefore, making the width of the tab 20 positively correlated with the radius corresponding to its position on the core allows for a smaller width for tabs 20 at smaller radii and a larger width for tabs 20 at larger radii. This allows for a more rational arrangement of the tab 20 widths at different radii on the core, reducing the difficulty of cutting and folding the tabs 20, decreasing the possibility of metal debris inside the battery, and lowering the battery defect rate.

[0059] In some embodiments, the width of the tab 20 is D, and the radius corresponding to the position of the tab 20 on the winding core is R.

[0060] satisfy: .

[0061] Where A is a constant.

[0062] For example, when the radius R corresponding to the position of the tab 20 on the core is 3 mm and A = 0.9, the width D of the tab 20 is 1.56 mm. For example, when the radius R corresponding to the position of the tab 20 on the core is 5 mm and A = 1.1, the width D of the tab 20 is 2.46 mm. For example, when the radius R corresponding to the position of the tab 20 on the core is 8 mm and A = 1.6, the width D of the tab 20 is 4.52 mm.

[0063] Where A is a constant, its value is affected by the material and thickness of electrode 10. For example, when electrode 10 is copper foil and the copper foil thickness is 8 micrometers, the range of A is: 0.5 ≤ A ≤ 2. For example, the value of A is 0.5, 1, 1.5, 2, or any value between any two. For example, when electrode 10 is aluminum foil and the aluminum foil thickness is 12 micrometers, the range of A is: 0.5 ≤ A ≤ 2. For example, the value of A is 0.5, 1, 1.5, 2, or any value between any two.

[0064] Along the winding direction of the electrode 10, there are electrodeless tabs 20 on both sides of the electrode 10, so that the tabs 20 are only present on the core at positions corresponding to certain radii. Generally, the radius R corresponding to the position of the tab 20 on the core is in the range of 3 mm ≤ R ≤ 8.5 mm.

[0065] In some embodiments, the height of the tab 20 is positively correlated with the radius corresponding to the position of the tab 20 on the winding core.

[0066] Understandably, as the electrode sheet 10 gradually winds to form a core, the radius of the core gradually increases. The tab 20 located at a larger radius requires a longer distance after bending to align its inner side with that of the tab 20 located at a smaller radius. Therefore, the height of the tab 20 is positively correlated with the radius corresponding to its position on the core; the tab 20 at a smaller radius is shorter, and the tab 20 at a larger radius is taller. This compensates for the positional shift caused by the increased core radius, ensuring that the inner sides of the tabs 20 are essentially flush. Consequently, each tab 20, after bending, roughly forms a cylindrical ring structure.

[0067] In some embodiments, the height of the tab 20 is H, and the radius corresponding to the position of the tab 20 on the winding core is R.

[0068] satisfy: .

[0069] Where B is a constant, d1 is the thickness of electrode 10, and d2 is the thickness of the diaphragm.

[0070] The thickness d1 of the electrode 10 has a range of 0.008 mm ≤ d1 ≤ 0.02 mm. The thickness d2 of the diaphragm has a range of 0.05 mm ≤ d2 ≤ 0.4 mm.

[0071] Taking electrode 10 with a thickness d1 = 0.01 mm and diaphragm thickness d2 = 0.1 mm as an example: When the radius R corresponding to the position of electrode 20 on the core is 3 mm and B = 2.5, the height H of electrode 20 is 2.03 mm. When the radius R corresponding to the position of electrode 20 on the core is 5 mm and B = 2.2, the height H of electrode 20 is 2.19 mm. When the radius R corresponding to the position of electrode 20 on the core is 8 mm and B = 2, the height H of electrode 20 is 2.43 mm.

[0072] Where B is a constant, its value is affected by the material and thickness of electrode 10. For example, when electrode 10 is copper foil and the copper foil thickness is 8 micrometers, the range of B is: 1 ≤ B ≤ 3. For example, B can be 1, 2, 3, or any value between any two. For example, when electrode 10 is aluminum foil and the aluminum foil thickness is 12 micrometers, the range of B is: 1 ≤ B ≤ 3. For example, B can be 1, 2, 3, or any value between any two.

[0073] In some embodiments, the angle between the hypotenuse 40 of the tab 20 and the electrode 10 is positively correlated with the radius corresponding to the position of the tab 20 on the winding core.

[0074] It is understandable that the angle between the hypotenuse 40 of the tab 20 and the electrode 10 is smaller when the radius is smaller, and larger when the radius is larger. That is, along the winding direction, the shape of the tab 20 will gradually approach that of a rectangle.

[0075] In some embodiments, the width of the tab is D, the angle between the hypotenuse 40 and the electrode 10 is α, and the radius corresponding to the position of the tab 20 on the winding core is R.

[0076] satisfy: .

[0077] Where C is a constant.

[0078] The calculation method for the width D of the electrode tab also adopts... .

[0079] For example, when the radius R corresponding to the position of the tab 20 on the core is 3 mm, and A=0.9, C=1, the angle α between the hypotenuse 40 and the electrode 10 is 60.2°. For example, when the radius R corresponding to the position of the tab 20 on the core is 5 mm, and A=1.1, C=0.8, the angle α between the hypotenuse 40 and the electrode 10 is 67.4°. For example, when the radius R corresponding to the position of the tab 20 on the core is 8 mm, and A=1.6, C=0.4, the angle α between the hypotenuse 40 and the electrode 10 is 77°.

[0080] Where C is a constant, its value is affected by the material and thickness of electrode 10. For example, when electrode 10 is copper foil and the copper foil thickness is 8 micrometers, the range of C is: 0.1 ≤ C ≤ 2. For example, C can take values ​​of 0.1, 0.5, 1, 2, or any value between any two. For example, when electrode 10 is aluminum foil and the aluminum foil thickness is 12 micrometers, the range of C is: 0.1 ≤ C ≤ 2. For example, C can take values ​​of 0.1, 0.5, 1, 2, or any value between any two.

[0081] In some embodiments, each segment 30 has at least two tabs 20. For tabs 20 located in the same segment 30, the width, height, and angle between the hypotenuse 40 and the electrode sheet 10 of all tabs 20 in the segment 30 are calculated using the radius corresponding to the position of the tab 20 located in the middle of the segment 30 on the core.

[0082] It is understandable that, given that each segment 30 has at least two tabs 20, after the segment 30 is wound, the tabs 20 on that segment 30 may be located at different radii of the core. If the width, height, and angle between the hypotenuse 40 and the electrode 10 of each tab 20 are calculated separately based on their respective radii, it will result in inconsistencies in the width, height, and angle between the hypotenuse 40 and the electrode 10 of the tabs 20 within that segment 30. Therefore, by selecting a tab 20 at an intermediate position as a reference, the width, height, and angle between the hypotenuse 40 and the electrode 10 of all tabs 20 within that segment 30 are calculated.

[0083] In some embodiments, each segment 30 contains an odd number of tabs 20. The radius corresponding to the position of the tab 20 located in the middle position on the core is used as a reference to calculate the width, height, and angle between the hypotenuse 40 and the electrode sheet 10 of all tabs 20 in the segment 30.

[0084] For example, if each segment 30 contains 11 tabs 20, then the radius corresponding to the position of the 6th tab 20 on the core is used as a reference to calculate the width, height, and the angle between the hypotenuse 40 and the electrode plate 10 of all tabs 20 within that segment 30. For example, if each segment 30 contains 101 tabs 20, then the radius corresponding to the position of the 51st tab 20 on the core is used as a reference to calculate the width, height, and the angle between the hypotenuse 40 and the electrode plate 10 of all tabs 20 within that segment 30.

[0085] In some embodiments, each segment 30 contains an even number of tabs 20. Therefore, the radius corresponding to the position of either of the two tabs 20 located in the middle on the core can be used as a reference to calculate the width, height, and the angle between the hypotenuse 40 and the electrode sheet 10 of all tabs 20 within that segment 30. It is understood that the radii corresponding to the two tabs 20 located in the middle on the core are not significantly different, or even the same. Therefore, choosing either one as a reference can essentially reflect the average value of the radii corresponding to the positions of all tabs 20 on the core within that segment 30.

[0086] For example, if each segment 30 contains 10 tabs 20, then the radius corresponding to the position of the 5th or 6th tab 20 on the core is used as a reference to calculate the width, height, and angle between the hypotenuse 40 and the electrode plate 10 of all tabs 20 within that segment 30. For example, if each segment 30 contains 100 tabs 20, then the radius corresponding to the position of the 50th or 51st tab 20 on the core is used as a reference to calculate the width, height, and angle between the hypotenuse 40 and the electrode plate 10 of all tabs 20 within that segment 30.

[0087] This embodiment provides a cylindrical battery. The cylindrical battery includes electrode plates 10.

[0088] In this embodiment, by dividing the electrode sheet 10 into multiple segments 30, the width and height of the tabs 20 within the same segment 30 are the same, while at least one of the width and height of the tabs 20 within different segments 30 is different. Based on the different designs of the width and height of the tabs 20 within different segments 30, the performance requirements of the equipment during the flattening process of the tabs 20 can be reduced, enabling the equipment to flatten the tabs 20 efficiently and accurately, thereby improving the technical problem of overlapping and misalignment of the tabs 20 during flattening.

[0089] This embodiment provides a battery pack. The battery pack includes cylindrical batteries.

[0090] In this embodiment, by dividing the electrode sheet 10 into multiple segments 30, the width and height of the tabs 20 within the same segment 30 are the same, while at least one of the width and height of the tabs 20 within different segments 30 is different. Based on the different designs of the width and height of the tabs 20 within different segments 30, the performance requirements of the equipment during the flattening process of the tabs 20 can be reduced, enabling the equipment to flatten the tabs 20 efficiently and accurately, thereby improving the technical problem of overlapping and misalignment of the tabs 20 during flattening.

Claims

1. A pole piece, one side of which is provided with a plurality of pole tabs at intervals, the pole piece comprising at least two segments each having at least one of the pole tabs, the width of the pole tab being in a first direction, the height of the pole tab being in a second direction perpendicular to the first direction, wherein, For the tabs located within the same segment, the tabs have the same width and the same height; for the tabs located in different segments, at least one of the width and height of the tabs is different.

2. The pole piece of claim 1, wherein, The electrode tab is shaped as a parallelogram, including two oppositely arranged hypotenuses, wherein the hypotenuses are set at an angle to the electrode plate, and for the electrode tabs located in the same segment, the angle between the hypotenuses and the electrode plate is the same.

3. The pole piece of claim 2, wherein, Each of the segments has a tab, and along the first direction, the width of the tab increases, the height of the tab increases, and the angle between the hypotenuse of the tab and the electrode plate increases.

4. A wound core, formed by winding an electrode sheet as described in any one of claims 1-3, wherein, The first direction is the direction in which the electrode is wound.

5. The winding core according to claim 4, wherein, The width of the tab is positively correlated with the radius corresponding to the position of the tab on the core.

6. The winding core according to claim 5, wherein, The width of the electrode tab is D, and the radius corresponding to the position of the electrode tab on the core is R; satisfy: ； Where A is a constant.

7. The core according to any one of claims 4-6, wherein, The height of the electrode tab is positively correlated with the radius corresponding to the position of the electrode tab on the winding core.

8. The winding core according to claim 7, wherein, The height of the electrode tab is H, and the radius corresponding to the position of the electrode tab on the core is R; satisfy: ； Where B is a constant, d1 is the thickness of the electrode, and d2 is the thickness of the diaphragm.

9. The core according to any one of claims 4-8, wherein, The angle between the hypotenuse of the electrode tab and the electrode sheet is positively correlated with the radius corresponding to the position of the electrode tab on the winding core.

10. The winding core according to claim 9, wherein, The width of the tab is D, the angle between the hypotenuse and the electrode sheet is α, and the radius corresponding to the position of the tab on the core is R; satisfy: ； Where C is a constant.

11. The core according to any one of claims 4-10, wherein, Each segment has at least two tabs. For tabs within the same segment, the width, height, and angle between the hypotenuse and the electrode sheet are calculated using the radius corresponding to the position of the tab located in the middle of the segment on the core.

12. A cylindrical battery comprising a winding core as described in any one of claims 5-11.

13. A battery pack comprising the cylindrical battery as claimed in claim 12.

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