Winding battery cell, cylindrical battery, and electric device

Abstract

A winding battery cell (100), a cylindrical battery (1000), and an electric device. The winding battery cell (100) comprises an electrode sheet (20); the electrode sheet (20) comprises an active material coating portion (21) and a tab portion (22); the tab portion (22) comprises a plurality of tabs (221) arranged in the length direction of the electrode sheet (20); the tab portion (22) of a winding starting section (23) is a first tab portion (223); the first tab portion (223) comprises a plurality of first tabs (231); the edge of the side of the first tabs (231) facing a reel hole (10) in a winding direction is a first side edge (2311); the first side edge (2311) obliquely extends towards a winding tail end in the direction from the active material coating portion (21) toward the tab portion (22); in the direction of the active material coating portion (21) toward the tab portion (22), the height of each first tab (231) extending out of the active material coating portion (21) is a first height; and in the winding direction, the heights of the plurality of first tabs (231) increase.

Description

Wound cells, cylindrical batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 2023226801513 and application date September 28, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a wound battery cell, a cylindrical battery, and an electrical device. Background Art

[0004] Pole sheet winding is one of the commonly used production methods for cylindrical battery cells. After the pole sheet is wound, the pole tab will be flattened and then welded to the current collecting plate. In related technologies, in order to avoid interference between the pole tab and the winding needle during the winding process, the pole tab is not set at the starting section of the pole sheet winding, so that the pole tab has less coverage on the pole sheet and the current capacity of the wound battery cell is lower.

[0005] Application Contents

[0006] The present application aims to solve at least one of the above-mentioned technical problems in the prior art to a certain extent.

[0007] In view of this, the present application needs to provide a wound battery cell having a stronger current carrying capacity.

[0008] The present application also provides a cylindrical battery having the above-mentioned wound battery cell.

[0009] The present application also provides an electrical device comprising the cylindrical battery.

[0010] According to the wound battery cell provided by the present application, the wound battery cell is wound and formed, and a winding axis hole is defined on the inner side. The wound battery cell includes a pole piece, the pole piece includes an active material coating portion and a pole ear portion, the pole ear portion is connected to one side of the active material coating portion in the width direction, the pole ear portion includes a plurality of pole ears arranged along the length direction of the pole piece, one end of the pole piece facing the winding axis hole in the winding direction is a winding starting section, and the other end of the pole piece opposite to the winding starting section in the winding direction is a winding ending section, the pole ear portion of the winding starting section is a first pole ear portion, the first pole ear portion includes a plurality of first pole ears, an edge of the first pole ear facing the winding axis hole in the winding direction is a first side edge, and in a direction from the active material coating portion toward the pole ear portion, the first side edge extends obliquely toward the winding ending section, and in a direction from the active material coating portion toward the pole ear portion, the height dimension of the first pole ear extending from the active material coating portion is a first height, and the first heights of the plurality of first pole ears increase in the winding direction.

[0011] According to the wound battery cell of the embodiment of the present application, by increasing the first height of the multiple first pole ears in the winding direction of the wound battery cell, the coverage of the pole ears on the pole piece can be increased, thereby increasing the current flow capacity of the wound battery cell, and the coverage of the flattened pole ears on the end of the wound battery cell can be increased, thereby increasing the current flow capacity of the wound battery cell. In addition, the number of overlapping layers of the first pole ears can be increased, thereby reducing the probability of the first pole ear being burned through when the current collecting device is welded to the first pole ear, thereby damaging the pole piece below the first pole ear, and improving the yield rate of the cylindrical battery. By extending the first side along the tilt, the number of overlapping areas between the first pole ears can be increased, thereby increasing the number of weldable areas on the first pole ear, facilitating the connection between the current collecting device and the first pole ear, and thereby improving the production efficiency of the cylindrical battery.

[0012] In addition, the wound battery cell according to the above embodiment of the present application may also have the following additional technical features:

[0013] According to an example of the present application, among the plurality of first pole tabs, a first height of the first pole tab closest to an end portion of the winding start section facing the winding shaft hole is less than or equal to 1 mm.

[0014] According to an example of the present application, the angle between the inclined extension direction of the first side edge and the length direction of the pole piece is a first angle, and along the winding direction, the first angle of the plurality of first pole tabs gradually increases.

[0015] According to an example of the present application, along the winding direction, the first angles of the plurality of first tabs increase linearly.

[0016] According to an example of the present application, the first angle of the first pole tab closest to the end of the winding start section facing the reel hole is 20°-30°.

[0017] According to an example of the present application, the first side edges of the plurality of first electrode tabs have the same length.

[0018] According to an example of the present application, the first electrode tab has a second side edge arranged opposite to the first side edge in the winding direction, the end edge of the first electrode tab away from the active material coating portion is the first end edge, the first end edge is connected between the first side edge and the second side edge, and the first end edge is connected to the first side edge and the second side edge in a circular arc.

[0019] According to an example of the present application, the first side edge and the second side edge are arranged in parallel, the first end edge is arranged perpendicular to the first side edge and the second side edge, or the first end edge extends parallel to the length direction of the pole piece.

[0020] According to an example of the present application, along the winding direction, the first heights of the plurality of first tabs increase linearly.

[0021] According to an example of the present application, the multiple first pole tabs of the first pole tab portion are divided into multiple pole tab groups, and the multiple pole tab groups are arranged in sequence along the winding direction, each pole tab group includes at least one first pole tab, and the first heights of the multiple first pole tabs in each pole tab group are the same, wherein, in two adjacent pole tab groups, the first height of the first pole tab of the pole tab group located on the upstream side of the winding direction is smaller than the first height of the first pole tab of the pole tab group located on the downstream side of the winding direction.

[0022] According to an example of the present application, in the winding direction, the distance between two adjacent tabs is 0.05 mm to 2 mm.

[0023] According to an example of the present application, the plurality of tabs are bent toward the side where the reel hole is located, and one end of the plurality of first tabs facing the reel hole is flush with the peripheral wall of the reel hole or located radially outside the reel hole.

[0024] According to an example of the present application, ends of the one ends of the plurality of first electrode tabs are aligned in the axial direction of the wound battery core.

[0025] According to an example of the present application, the pole piece also includes: a main body segment, the main body segment is connected to the end of the winding starting segment away from the reel hole, the pole ear portion of the main body segment is a second pole ear portion, the second pole ear portion includes a plurality of second pole ears, and in the direction from the active material coating portion toward the pole ear portion, the height dimension of the second pole ear extending out of the active material coating portion is a second height, and the second heights of the plurality of second pole ears are equal.

[0026] According to an example of the present application, a side edge of the second electrode tab in the winding direction toward the winding starting section is a third side edge, and in the direction from the active material coating portion toward the electrode tab portion, the third side edge extends obliquely toward the winding end.

[0027] According to an example of the present application, the electrode tab portion further includes a connection region, and the connection region is connected between the active material coating portion and the plurality of electrode tabs.

[0028] The cylindrical battery provided in the present application includes the wound battery cell according to the above embodiment.

[0029] The electrical device provided in this application includes the cylindrical battery of the above embodiment.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is a schematic diagram of a wound battery cell according to an embodiment of the present application;

[0032] FIG2 is a cross-sectional view of a wound battery cell according to an embodiment of the present application, wherein the tab is not flattened;

[0033] FIG3 is a schematic diagram of a pole piece according to an embodiment of the present application;

[0034] FIG4 is a schematic diagram of the winding start section shown in FIG3 ;

[0035] FIG5 is a schematic diagram of another pole piece according to an embodiment of the present application;

[0036] FIG6 is a schematic diagram of the winding start section shown in FIG5 ;

[0037] FIG. 7 is a schematic diagram of a cylindrical battery according to an embodiment of the present application.

[0038] Reference numerals:

[0039] 1000, cylindrical battery;

[0040] 100. Winding battery cells;

[0041] 10. Scroll hole;

[0042] 20. Pole piece; 21. Active material coating portion; 22. Pole ear portion; 221. Pole ear; 222. Connection area; 223. First pole ear portion; 224. Second pole ear portion; 23. Winding start section; 231. First pole ear; 2311. First side edge; 2312. Second side edge; 2313. First end edge; 24. Main section; 241. Second pole ear; 2411. Third side edge;

[0043] 200. Current collecting device. DETAILED DESCRIPTION

[0044] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0045] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the applicability of other processes and / or the use of other materials.

[0046] The following describes a wound battery cell 100 according to an embodiment of the first aspect of the present application with reference to FIG1 to FIG7 .

[0047] As shown in Figures 1 to 3, according to the wound battery cell 100 of the embodiment of the first aspect of the present application, the wound battery cell 100 is wound and formed, and a winding shaft hole 10 is defined on the inner side. The wound battery cell 100 includes a pole piece 20, and the pole piece 20 includes an active material coating portion 21 and a pole ear portion 22. The pole ear portion 22 is connected to one side of the active material coating portion 21 in the width direction (for example, the up and down direction shown in Figure 3), and the pole ear portion 22 includes a plurality of pole ears 221 arranged along the length direction of the pole piece 20 (for example, the left and right direction shown in Figure 3). One end of the pole piece 20 facing the winding shaft hole 10 in the winding direction (for example, the right to left direction shown in Figure 3) is the winding starting section 23, and the other end of the pole piece 20 opposite to the winding starting section 23 in the winding direction is the winding end (for example, the right end of the pole piece 20 shown in Figure 3). The pole ear portion 22 of the winding starting section 23 is The first pole ear portion 223 includes a plurality of first pole ears 231. The side edge of the first pole ear 231 facing the reel hole 10 in the winding direction is a first side edge 2311. In the direction from the active material coating portion 21 toward the pole ear portion 22, the first side edge 2311 extends obliquely toward the winding end. In the direction from the active material coating portion 21 toward the pole ear portion 22, the height dimension of the first pole ear 231 extending out of the active material coating portion 21 is a first height. That is, in the direction from the active material coating portion 21 toward the pole ear portion 22, the distance between the outermost side of the first pole ear 231 and the upper side edge of the active material coating portion 21 is formed as a first height. For example, in Figure 3, in the up and down direction, the distance b between the uppermost side of the first pole ear 231 and the upper side edge of the active material coating portion 21 is formed as the first height. In the winding direction, the first heights of the plurality of first pole ears 231 increase.

[0048] Among them, the active material coating part 21 is coated with active material. During the discharge process of the wound battery cell 100, the active material coating part 21 will be immersed in the electrolyte, and multiple pole tabs 221 are connected to the current collecting device 200. The electrolyte reacts with the active material of the active material coating part 21 on the pole piece 20 to generate current. The current is transmitted to the pole tab 221 through the pole piece 20, and the pole tab 221 outputs the current to the outside through the current collecting device 200, thereby realizing the discharge process of the wound battery cell 100.

[0049] It should be noted that during the discharge process of the wound battery cell 100, current will flow throughout the electrode sheet 20. Therefore, increasing the coverage of the electrode tab 221 on the electrode sheet 20 can improve the current capacity of the wound battery cell 100. During the winding process of the wound battery cell 100, as the electrode sheet 20 is wound, the winding diameter of the electrode sheet 20 becomes larger and larger, and the distance between the electrode sheet 20 and the edge of the winding shaft hole 10 also becomes larger and larger.

[0050] In this embodiment, the first height of the plurality of first pole tabs 231 is increased in the winding direction of the wound battery cell 100. In this way, at the end of the pole piece 20 facing the winding shaft hole 10, the first pole tab 231 can cover more areas of the pole piece 20. When the wound battery cell 100 is discharged, more pole tabs 221 can be used to conduct the current on the pole piece 20, thereby improving the current-carrying capacity of the wound battery cell 100.

[0051] In one embodiment of the present application, the first height of the first pole tab 231 and the angle between the inclined extension direction of the first side edge 2311 and the length direction of the pole piece can be set according to the distance between the first pole tab 231 and the edge of the scroll hole 10, so that the first height of the first pole tab 231 and the angle between the inclined extension direction of the first side edge 2311 and the length direction of the pole piece 20 are adapted to the distance between the pole piece 20 and the edge of the scroll hole 10. In this way, after flattening, the first pole tab 231 can be close to the edge of the scroll hole 10, thereby increasing the circumferential coverage of the first pole tab 231 in the scroll hole 10, and further increasing the end coverage of the first pole tab 231 in the wound battery cell 100. Therefore, when the current collecting device 200 is connected to the end of the wound battery cell 100, the contact area between the current collecting device 200 and the first pole tab 231 can be increased, thereby further improving the current flow capacity of the wound battery cell 100.

[0052] In addition, after being flattened, the first pole tabs 231 are close to the edge of the winding shaft hole 10, which can make the end of the winding starting section 23 with the first pole tab 231 more flat after winding, thereby facilitating the connection between the wound battery cell 100 and the current collecting device 200.

[0053] As shown in FIG7 , in actual applications, the current collecting device 200 is usually welded to the flattened tab 221. As is understood in the art, the tab 221 is relatively thin and easily burns through during the welding process. During the winding process of the electrode sheet 20, the tab overlaps with the tab of the previous circle to form an overlapped area. Welding the current collecting device 200 to the tab 221 in the overlapped area can reduce the probability of the tab 221 being burned through and damaging the electrode sheet 20 below the tab 221, thereby improving the yield rate of the cylindrical battery 1000.

[0054] In this embodiment, by increasing the first height of multiple first pole tabs 231 in the winding direction of the wound battery cell 100, the first pole tabs 231 wound downstream can overlap with more first pole tabs 231 wound upstream, thereby increasing the number of layers of the first pole tabs 231 in the overlapping area, thereby increasing the thickness of the first pole tabs 231 in the overlapping area. When the current collecting device 200 is welded to the first pole tabs 231 in the above-mentioned overlapping area, the probability of the first pole tab 231 being burned through and causing damage to the pole piece 20 below the first pole tab 231 can be further reduced, thereby further improving the yield rate of the cylindrical battery 1000.

[0055] By extending the first side edge 2311 obliquely toward the winding end in the direction from the active material coating portion 21 toward the pole ear portion 22, adjacent first pole ears 231 can be overlapped after flattening to form overlapping areas, thereby increasing the number of overlapping areas. As a result, the number of weldable areas on the first pole ear 231 can be increased, thereby facilitating the connection between the current collecting device 200 and the first pole ear 231.

[0056] According to the wound battery cell 100 of the first embodiment of the present application, by increasing the first height of the multiple first pole tabs 231 in the winding direction of the wound battery cell 100, the coverage of the pole tab 221 on the pole sheet 20 can be increased, thereby increasing the flow capacity of the wound battery cell 100. The coverage of the flattened pole tab 221 at the end of the wound battery cell 100 can also be increased, thereby increasing the flow capacity of the wound battery cell 100. In addition, the number of overlapping layers of the first pole tabs 231 can be increased, thereby reducing the probability of the first pole tab 231 being burned through when the current collecting device 200 is welded to the first pole tab 231, thereby damaging the pole sheet 20 below the first pole tab 231, thereby improving the yield rate of the cylindrical battery 1000. By extending the first side along an angle, the number of overlapping areas between the first pole tabs 231 can be increased, thereby increasing the number of weldable areas on the first pole tab 231, facilitating the connection between the current collecting device 200 and the first pole tab 231, and thereby improving the production efficiency of the cylindrical battery 1000.

[0057] In some embodiments of the present application, among the plurality of first pole tabs 231, the first pole tab 231 at the end closest to the winding start section 23 facing the reel hole 10 has a first height of less than or equal to 1 mm. For example, the first pole tab 231 at the end closest to the winding start section 23 facing the reel hole 10 may have a first height of 1 mm, 0.5 mm, or 0.4 mm. In this way, the first height of the first pole tab 231 located most upstream in the winding direction is not excessively large. The other first pole tabs 231 in the first pole tab portion 223 of the pole piece 20 are increased based on the first height of the first pole tab 231 located most upstream in the winding direction. This ensures that the first pole tab 231 that wraps around the reel hole 10 for the first time does not extend into the reel hole 10 after being flattened, thereby allowing the pole piece 20 to be wound normally. During the product design process, the first height of the first pole tab 231 located most upstream in the winding direction can be adjusted to meet more product design requirements and reduce product design difficulty.

[0058] In some embodiments of the present application, as shown in FIG4 and FIG6 , the angle between the inclined extension direction of the first side edge 2311 and the length direction of the pole piece 20 (e.g., the left-right direction shown in FIG4 ) is a first angle a. Along the winding direction, the first angle a of the plurality of first pole tabs 231 gradually increases. This facilitates gradually increasing the first height of the plurality of first pole tabs 231 along the winding direction, saves material for the first pole tabs 231, and reduces process difficulty, thereby improving production efficiency and reducing production costs.

[0059] In some embodiments of the present application, as shown in FIG4 , the first angles a of the plurality of first tabs 231 increase linearly along the winding direction. Therefore, during product design, the first heights of the plurality of first tabs 231 can be increased by adjusting the corresponding hypotenuse lengths of the first angles a according to the increase in the first angles, thereby reducing product design difficulty.

[0060] In some embodiments of the present application, the first angle a of the first pole ear 231 at the end portion facing the reel hole 10 closest to the winding starting section 23 is 20°-30°. For example, the first angle a of the first pole ear 231 at the end portion facing the reel hole 10 closest to the winding starting section 23 can be 20°, 25° or 30°. Thus, the first angle of the first pole ear 231 at the end portion facing the reel hole 10 closest to the winding starting section 23 can meet product design requirements. During the product design process, the size of the first angle a of the first pole ear 231 at the end portion facing the reel hole 10 closest to the winding starting section 23 can be adjusted to meet more product design requirements and reduce the difficulty of product design.

[0061] In some embodiments of the present application, as shown in FIG4 , the lengths H of the first side edges 2311 of the plurality of first tabs 231 are equal. Thus, the first height of the first tabs 231 can be gradually increased by increasing the first angle, thereby reducing the difficulty of product design.

[0062] In some embodiments of the present application, as shown in Figures 4 and 6, the first electrode tab 231 has a second side edge 2312 arranged opposite the first side edge 2311 in the winding direction. The end edge of the first electrode tab 231 away from the active material coating portion 21 is a first end edge 2313. The first end edge 2313 is connected between the first side edge 2311 and the second side edge 2312. The first end edge 2313 is connected to the first side edge 2311 and the second side edge 2312 in a circular arc. During the product design process, the dimensions, relative angles, and other parameters of the first side edge 2311, the second side edge 2312, and the first end edge 2313 can be adjusted to ensure that the first electrode tab 231 meets product design requirements and reduce product design difficulty.

[0063] By connecting the first end edge 2313 with the first side edge 2311 and the second side edge 2312 in an arc shape, the corners of the first tab 231 are smoother, which reduces burrs at the corners of the finished first tab 231 during production, thereby simplifying the production process and reducing production difficulty. Furthermore, fewer burrs reduce the probability of burrs falling off and causing a short circuit within the wound battery cell 100, thereby improving the reliability of the wound battery cell 100 during operation.

[0064] In some embodiments of the present application, as shown in Figures 4 and 6, the first side edge 2311 and the second side edge 2312 are arranged in parallel, and the first end edge 2313 is arranged perpendicular to the first side edge 2311 and the second side edge 2312, or the first end edge 2313 extends parallel to the length direction of the electrode piece 20. When the relative relationship between the first end edge 2313 and the first side edge 2311 and the second side edge 2312 is different, the overlapping relationship between the first electrode tabs 231 is also different. Therefore, during the product design process, the relative relationship between the first end edge 2313 and the first side edge 2311 and the second side edge 2312 can be selected according to product design requirements to meet more product design requirements.

[0065] In some embodiments of the present application, as shown in FIG6 , the first heights of the plurality of first electrode tabs 231 increase linearly along the winding direction. That is, the first height h1 of the second first electrode tab 231 increases by z compared to the first height h of the first first electrode tab 231 , and the first height h2 of the third first electrode tab 231 increases by z compared to the first height h1 of the second first electrode tab 231 . Thus, the first heights of the plurality of first electrode tabs 231 increase along the winding direction. Furthermore, during product design, product design requirements can be met by adjusting the first height h of the first electrode tab 231 located most upstream in the winding direction and the linearly increasing height z, thereby reducing product design difficulty.

[0066] In some embodiments of the present application, the electrode sheet 20 includes a positive electrode sheet 20 and a negative electrode sheet 20, and a diaphragm is provided between the positive electrode sheet 20 and the negative electrode sheet 20. In the direction perpendicular to the axis of the wound battery cell 100, the first height difference of the first electrode tab 231 on the two adjacent circles of the electrode sheet 20 is the sum of the thickness of the positive electrode sheet 20, the negative electrode sheet 20 and the two layers of diaphragm. In this way, during the winding process of the wound battery cell 100, the positive electrode sheet 20, the negative electrode sheet 20 and the diaphragm are wound together, and the first electrode tab 231 of the outer circle can be flattened to align the edge of the first electrode tab 231 of the inner circle, so that the first electrode tab 231 is more evenly covered around the scroll hole 10.

[0067] In some embodiments of the present application, the multiple first pole tabs 231 of the first pole tab portion 223 are divided into multiple pole tab groups. The multiple pole tab groups are arranged sequentially along the winding direction. Each pole tab group includes at least one first pole tab 231. The multiple first pole tabs 231 in each pole tab group have the same first height. Specifically, between two adjacent pole tab groups, the first pole tab 231 in the pole tab group located upstream in the winding direction has a smaller first height than the first pole tab 231 in the pole tab group located downstream in the winding direction. Thus, the first heights of the multiple first pole tabs 231 can be increased along the winding direction. During production, the first pole tabs 231 in a single pole tab group have the same first height, which can reduce production difficulty. During product design, the first heights of the multiple pole tab groups can be adjusted to meet design requirements, with fewer parameters to adjust, thus reducing product design difficulty.

[0068] In some embodiments of the present application, in the winding direction, the spacing between two adjacent pole tabs 221 is 0.05mm-2mm. That is, the spacing between the two closest edges of two adjacent pole tabs 221 in the winding direction is 0.05mm-2mm. For example, the spacing between two adjacent pole tabs 221 can be 0.05mm, 0.1mm or 2mm. In this way, the spacing between two adjacent pole tabs 221 does not affect the bending of the pole tabs 221 toward the reel hole 10, and the two adjacent pole tabs 221 can be overlapped. During the product design process, the spacing between two adjacent pole tabs 221 can be adjusted to meet more product design requirements and reduce the difficulty of product design.

[0069] In some embodiments of the present application, as shown in FIG1 , the plurality of tabs 221 are all bent toward the side where the reel hole 10 is located, and the ends of the plurality of first tabs 231 facing the reel hole 10 are flush with the peripheral wall of the reel hole 10 or located radially outside the reel hole 10. Thus, the first tabs 231 do not affect the winding of the electrode sheet 20, and can further increase the coverage of the first tabs 231 at the end of the wound battery cell 100 after flattening, further improving the current carrying capacity of the wound battery cell 100.

[0070] In some embodiments of the present application, the ends of the multiple first pole tabs 231 are aligned in the axial direction of the wound battery cell 100. That is, the edges of the multiple first pole tabs 231 near the reel hole 10 are aligned in the thickness direction of the first pole tab 231. In other words, the multiple first pole tabs 231 are flattened and overlapped together. In this way, the number of first pole tabs 231 in the overlapping area can be increased, thereby reducing the probability of the first pole tab 231 being burned through during welding of the current collecting device 200 to the first pole tab 231, thereby reducing the probability of damage to the pole piece 20 below the first pole tab 231, thereby improving the yield rate of the cylindrical battery 1000.

[0071] In some embodiments of the present application, as shown in Figures 3 and 5, the pole piece 20 also includes: a main body section 24, the main body section 24 is connected to the end of the winding starting section 23 away from the reel hole 10, the pole ear portion 22 of the main body section 24 is a second pole ear portion 224, and the second pole ear portion 224 includes a plurality of second pole ears 241. In the direction from the active material coating portion 21 to the pole ear portion 22, the height dimension of the second pole ear 241 extending out of the active material coating portion 21 is a second height, that is, in the direction from the active material coating portion 21 to the pole ear portion 22, the distance between the outermost side of the second pole ear 241 and the outer edge of the active material coating portion 21 is formed as a first height. For example, in Figure 3, in the up and down directions, the distance c between the uppermost side of the second pole ear 241 and the upper edge of the active material coating portion 21 is formed as a second height, and the second heights of the plurality of second pole ears 241 are equal. During the winding process of the pole tab, the main section 24 is wrapped around the outside of the winding starting section 23. When the main section 24 starts to wind, the second height of the first wound second pole tab 241 is less than or equal to the distance between the pole piece 20 corresponding to the first wound second pole tab 241 and the edge of the winding shaft hole 10. When the main section 24 continues to wind, the subsequent second pole tab 241 will not extend into the winding shaft hole 10 after being flattened, and at this time the pole tab 221 is covered all around the winding shaft hole 10. By having multiple second pole tabs 241 with equal second heights, the requirements for covering the pole tab 221 at the end of the wound battery cell 100 can be met, and the process difficulty can be reduced, reducing production costs.

[0072] In some embodiments of the present application, as shown in FIG3 and FIG5 , a side edge of the second pole tab 241 in the winding direction toward the winding starting section 23 is a third side edge 2411. In the direction from the active material coating portion 21 toward the pole tab portion 22, the third side edge 2411 extends obliquely toward the winding end. In this way, the second pole tab 241 is longer in a direction parallel to the pole piece 20. After the pole tab 221 is flattened, the overlap between the second pole tab 241 and the previous pole tab 221 can be increased. Furthermore, after two adjacent pole tabs 221 are flattened, the second pole tab 241 of the subsequent pole tab 221 can be pressed against the second pole tab 241 of the previous pole tab 221. This further increases the area of ​​the overlapping region between the pole tabs 221, thereby increasing the weldable area on the pole tab 221 and facilitating welding between the current collecting device 200 and the pole tab 221.

[0073] In some embodiments of the present application, as shown in FIG3 , the tab portion 22 further includes a connection region 222 , which connects between the active material coating portion 21 and the multiple tabs. The provision of the connection region 222 allows current to be transmitted from the active material coating portion 21 to the multiple tabs 221 . Furthermore, the distance between the ends of the wound battery cell 100 and the electrolyte can be increased, reducing the probability of contact between the current collecting device 200 connected to the multiple tabs 221 and the electrolyte, thereby improving the reliability of the wound battery cell 100 during operation.

[0074] In some embodiments of the present application, the pole piece 20 is produced by a die-cutting process, which has a high degree of automation and high production precision, thereby improving production efficiency and increasing the production precision of the pole piece 20.

[0075] The cylindrical battery 1000 according to the second embodiment of the present application includes the wound battery cell 100 according to the first embodiment of the present application.

[0076] According to the cylindrical battery 1000 of the second embodiment of the present application, by providing the wound battery cell 100 according to the first embodiment of the present application, the wound battery cell 100 has a stronger current carrying capacity, thereby improving the efficiency of the cylindrical battery 1000.

[0077] In some embodiments of the present application, as shown in FIG7 , the cylindrical battery 1000 further includes a current collecting device 200 , which is disposed at the end of the wound battery cell 100 and connected to the tab 221 . By providing the current collecting device 200 , the current collecting device 200 can transmit current between the multiple tabs 221 , thereby enabling the cylindrical battery 1000 to realize charging and discharging functions.

[0078] In some embodiments of the present application, the current collecting device 200 is a current collecting plate, which is welded to the tab 221. The welding connection is simple to operate and can achieve electrical connection, thereby improving production efficiency and ensuring that the functions of the cylindrical battery 1000 can be achieved.

[0079] The following describes a production process of a cylindrical battery 1000 according to an embodiment of the present application.

[0080] First, the electrode 20 is die-cut according to the set parameters, and the electrode tab 221 is die-cut above the connection area 222 according to the set parameters. Then, the electrode 20 is wound. After the winding is completed, the electrode tab 221 is pre-folded, and then the electrode tab 221 is flattened. Then, the current collecting plate is welded to the flattened multiple electrode tabs 221, thereby completing the production process of the cylindrical battery 1000.

[0081] According to the third embodiment of the present application, the electrical device includes the cylindrical battery 1000 according to the second embodiment of the present application.

[0082] According to the electric device of the third embodiment of the present application, by providing the cylindrical battery 1000 according to the second embodiment of the present application, the cylindrical battery 1000 is more efficient, thereby improving the performance of the electric device.

[0083] In the description of this application, it should be understood that the terms "center", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this application.

[0084] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0085] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0086] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0087] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0088] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A wound battery cell (100), characterized in that: The wound battery cell (100) is wound and formed, and defines a winding shaft hole (10) on the inner side thereof. The wound battery cell (100) comprises a pole piece (20), and the pole piece (20) comprises an active material coating portion (21) and a pole ear portion (22). The pole ear portion (22) is connected to one side of the active material coating portion (21) in the width direction. The pole ear portion (22) comprises a plurality of pole ears (221) arranged along the length direction of the pole piece (20). One end of the pole piece (20) facing the winding shaft hole (10) in the winding direction is a winding starting section (23), and the other end of the pole piece (20) opposite to the winding starting section (23) in the winding direction is a winding ending section. The pole ear portion (22) of the winding starting section (23) is a first pole ear portion (223), the first pole ear portion (223) includes a plurality of first pole ears (231), a side edge of the first pole ear (231) facing the winding shaft hole (10) in the winding direction is a first side edge (2311), and in the direction from the active material coating portion (21) toward the pole ear portion (22), the first side edge (2311) extends obliquely toward the winding end, In the direction from the active material coating portion (21) toward the pole ear portion (22), the height dimension of the first pole ear (231) extending out of the active material coating portion (21) is a first height, and in the winding direction, the first heights of the plurality of first pole ears (231) increase.

2. The wound battery cell (100) according to claim 1, characterized in that: Among the plurality of first pole tabs (231), a first height of the first pole tab (231) at the end closest to the winding start section (23) and facing the winding shaft hole (10) is less than or equal to 1 mm.

3. The wound battery cell (100) according to claim 1, characterized in that: The angle between the inclined extension direction of the first side edge (2311) and the length direction of the pole piece (20) is a first angle, and along the winding direction, the first angles of the plurality of first pole ears (231) gradually increase.

4. The wound battery cell (100) according to claim 3, characterized in that: Along the winding direction, the first angles of the plurality of first pole tabs (231) increase linearly.

5. The wound battery cell (100) according to claim 3, characterized in that: The first angle of the first pole lug (231) at the end closest to the winding start section (23) and facing the end of the winding shaft hole (10) is 20°-30°.

6. The wound battery cell (100) according to claim 3, characterized in that: The first side edges (2311) of the plurality of first electrode tabs (231) are of equal length.

7. The wound battery cell (100) according to claim 3, characterized in that: The first pole lug (231) has a second side edge (2312) arranged opposite to the first side edge (2311) in the winding direction, and the end edge of the first pole lug (231) away from the active material coating portion (21) is a first end edge (2313), and the first end edge (2313) is connected between the first side edge (2311) and the second side edge (2312), and the first end edge (2313) is connected to the first side edge (2311) and the second side edge (2312) in a circular arc.

8. The wound battery cell (100) according to claim 7, characterized in that: The first side edge (2311) and the second side edge (2312) are arranged in parallel, the first end edge (2313) is arranged perpendicular to the first side edge (2311) and the second side edge (2312), or the first end edge (2313) extends parallel to the length direction of the pole piece (20).

9. The wound battery cell (100) according to any one of claims 1 to 8, characterized in that: Along the winding direction, the first heights of the plurality of first pole tabs (231) increase linearly.

10. The wound battery cell (100) according to any one of claims 1 to 8, characterized in that: The plurality of first pole lugs (231) of the first pole lug portion (223) are divided into a plurality of pole lug groups, the plurality of pole lug groups are arranged in sequence along the winding direction, each pole lug group comprises at least one first pole lug (231), and the first heights of the plurality of first pole lugs (231) in each pole lug group are the same. Among them, in two adjacent pole lug groups, the first height of the first pole lug (231) of the pole lug group located on the upstream side of the winding direction is smaller than the first height of the first pole lug (231) of the pole lug group located on the downstream side of the winding direction.

11. The wound battery cell (100) according to claim 1, characterized in that: In the winding direction, the spacing between two adjacent pole tabs (221) is 0.05 mm to 2 mm.

12. The wound battery cell (100) according to any one of claims 1 to 11, characterized in that: The plurality of pole ears (221) are all bent toward the side where the reel hole (10) is located, and the ends of the plurality of first pole ears (231) facing the reel hole (10) are flush with the peripheral wall of the reel hole (10) or are located radially outside the reel hole (10).

13. The wound battery cell (100) according to claim 12, characterized in that: Ends of the one ends of the plurality of first pole tabs (231) are aligned in the axial direction of the wound battery core (100).

14. The wound battery cell (100) according to any one of claims 1 to 13, characterized in that: The pole piece (20) further comprises: a main body section (24), the main body section (24) being connected to an end of the winding starting section (23) away from the winding shaft hole (10), the pole ear portion (22) of the main body section (24) being a second pole ear portion (224), the second pole ear portion (224) comprising a plurality of second pole ears (241), and in a direction from the active material coating portion (21) toward the pole ear portion (22), the height dimension of the second pole ear (241) extending out of the active material coating portion (21) is a second height, and the second heights of the plurality of second pole ears (241) are equal.

15. The wound battery cell (100) according to claim 14, characterized in that: A side edge of the second pole lug (241) in the winding direction toward the winding starting section (23) is a third side edge (2411), and in the direction from the active material coating portion (21) toward the pole lug portion (22), the third side edge (2411) extends obliquely toward the winding end.

16. The wound battery cell (100) according to any one of claims 1 to 15, characterized in that: The electrode lug portion (22) further includes a connection region (222), wherein the connection region (222) is connected between the active material coating portion (21) and the plurality of electrode lugs (221).

17. A cylindrical battery (1000), characterized in that: It comprises a wound battery cell (100) according to any one of claims 1 to 16.

18. An electrical device, characterized in that: Comprising the cylindrical battery (1000) according to claim 17.

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