Electrode sheet, wound battery cell, cylindrical battery, and electric device

Abstract

An electrode sheet, a wound battery cell, a cylindrical battery, and an electric device. The electrode sheet comprises a body (10), and in the width direction of the body (10), the body (10) comprises a coated portion (1) and a tab portion (2), wherein the tab portion (2) comprises a plurality of tabs (23) arranged in the length direction of the body (10), and each tab (23) is connected to the coated portion (1); the two ends of the body (10) in the length direction are respectively a first end (3) and a second end (4); in a direction from the first end (3) to the second end (4), the tab portion (2) comprises a first area (21) located at the first end (3), and a plurality of tabs (23) located in the first area (21) are all first tabs (211); and in the direction from the first end (3) to the second end (4), the width of the plurality of first tabs (211) in the length direction of the body (10) gradually decreases.

Description

Electrode sheets, wound cells, cylindrical batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on and claims the priority of Chinese patent application No. 2023226805957 and application date 2023-09-28. The entire contents of the Chinese patent application are hereby incorporated into this application as a reference. Technical Field

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

[0004] Cylindrical batteries are a widely used type of battery. Pole sheet winding is one of the common 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 set at the starting section of the pole sheet winding is not easy to bend due to its size, thereby reducing production efficiency, and reducing the size is likely to affect the current capacity of the wound battery cell.

[0005] Summary of the Invention

[0006] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a pole piece that not only ensures the current carrying capacity of the wound battery cell, but also improves the overall bendability of the first tab in the first region, thereby improving production efficiency.

[0007] The present application also proposes a wound battery cell having the above-mentioned electrode sheet.

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

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

[0010] According to the pole piece of the embodiment of the present application, it includes: a main body, along the width direction of the main body, the main body includes a coating portion and a pole ear portion, the pole ear portion includes a plurality of pole ears arranged along the length direction of the main body, each of the pole ears is connected to the coating portion, the two ends of the main body in the length direction are respectively a first end and a second end, in the direction from the first end to the second end, the pole ear portion includes a first area located at the first end, and the plurality of pole ears located in the first area are all first pole ears, and in the direction from the first end to the second end, the width of the plurality of first pole ears along the length direction of the main body gradually decreases.

[0011] According to the pole piece of the embodiment of the present application, a plurality of first pole ears are arranged in the first area, and the two ends in the length direction of the main body are respectively the first end and the second end. The first area is located at the first end, and in the direction from the first end to the second end, the width of the plurality of first pole ears along the length direction of the main body gradually decreases, thereby ensuring the overcurrent capacity of the wound battery cell and improving the overall bending degree of the first pole ears in the first area, thereby improving production efficiency.

[0012] In some embodiments of the present application, in a direction from the first end to the second end, the widths of the plurality of first tabs along the length direction of the body decrease linearly.

[0013] In some embodiments of the present application, a width of the first tab closest to the first end along the length direction of the body is 10-100 mm.

[0014] In some embodiments of the present application, a distance between the first electrode tab closest to the first end and the first end is 0-1 mm.

[0015] In some embodiments of the present application, in a direction from the first end to the second end, heights of the plurality of first tabs in a width direction of the body gradually increase.

[0016] In some embodiments of the present application, the first electrode tab is inclined toward the second end in a direction from the coating portion to the electrode tab portion.

[0017] In some embodiments of the present application, in the direction from the coating portion to the tab portion, two opposite edges of the first tab in the length direction of the body are inclined toward the second end and have the same inclination angle.

[0018] In some embodiments of the present application, in a direction from the first end to the second end, an edge of the end of the first electrode tab away from the coating portion is inclined toward a direction away from the coating portion.

[0019] In some embodiments of the present application, the angle between the edges of the first electrode tab on two opposite sides in the length direction of the body close to the first end and the length direction of the body is a first angle, and in the direction from the first end to the second end, the first angle of multiple first electrode tabs gradually increases.

[0020] In some embodiments of the present application, the first angle of the first electrode tab closest to the first end is 20°-30°.

[0021] In some embodiments of the present application, in a direction from the first end to the second end, the first angles of the plurality of first tabs increase linearly.

[0022] In some embodiments of the present application, a difference between the first angles of two adjacent first tabs is 0.1°-5°.

[0023] In some embodiments of the present application, an edge of the first electrode tab facing away from the coating portion is parallel to the length direction of the body.

[0024] In some embodiments of the present application, the angle between the edges of the first electrode tab on two opposite sides in the length direction of the body close to the first end and the length direction of the body is a first angle, and in the direction from the first end to the second end, the first angles of multiple first electrode tabs are equal.

[0025] In some embodiments of the present application, in a direction from the first end to the second end, heights of the plurality of first tabs in a width direction of the body increase linearly.

[0026] In some embodiments of the present application, a height of the first electrode tab closest to the first end in the width direction of the body is 0.5-1.5 mm.

[0027] In some embodiments of the present application, a height difference between two adjacent first tabs in the width direction of the body is 0.05-0.5 mm.

[0028] In some embodiments of the present application, the pole ear portion further includes a second region, which is located on a side of the first region close to the second end, and the plurality of pole ears located in the second region are all second pole ears, and the plurality of second pole ears have the same shape and size.

[0029] In some embodiments of the present application, the width of the second tab along the length direction of the body is 2-6 mm; and / or the height of the second tab along the width direction of the body is 4-8 mm.

[0030] In some embodiments of the present application, the second electrode tab is inclined toward the second end in a direction from the coating portion to the electrode tab portion.

[0031] In some embodiments of the present application, the angle between the edges of the second tab close to the first end on two opposite sides in the length direction of the body and the length direction of the body is 2°-20°.

[0032] In some embodiments of the present application, along the length direction of the body, the maximum width of the first tab is less than or equal to 20 times the width of the second tab.

[0033] In some embodiments of the present application, along the length direction of the body, a distance between edges of two adjacent tabs close to each other in the length direction of the body is 0.05-2 mm.

[0034] In some embodiments of the present application, along the width direction of the body, the body further includes a hollow foil buffer portion, and the hollow foil buffer portion is located between the coating portion and the electrode ear portion.

[0035] According to the embodiment of the present application, the wound battery cell includes: a positive electrode sheet, a negative electrode sheet and a separator, the positive electrode sheet and the negative electrode sheet are stacked and wound along the length direction of the positive electrode sheet and the negative electrode sheet, the separator is arranged between the positive electrode sheet and the negative electrode sheet, at least one of the positive electrode sheet and the negative electrode sheet is the above-mentioned electrode sheet, and a winding shaft hole is provided on the inner side of the wound battery cell, the first end is arranged close to the winding shaft hole relative to the second end, and the pole ears are all bent toward the winding shaft hole.

[0036] According to the wound battery cell of the embodiment of the present application, by setting the above-mentioned electrode sheet, multiple first electrode ears are set in the first area, and the two ends of the length direction of the main body are respectively the first end and the second end. The first area is located at the first end. In the direction from the first end to the second end, the width of the multiple first electrode ears along the length direction of the main body gradually decreases, thereby ensuring the current capacity of the wound battery cell and improving the overall bending degree of the first electrode ears in the first area, thereby improving production efficiency.

[0037] In some embodiments of the present application, edges of the first electrode tabs at one end facing the reel hole are flush.

[0038] The cylindrical battery according to an embodiment of the present application includes the above-mentioned wound battery cell.

[0039] According to the cylindrical battery of the embodiment of the present application, by setting the above-mentioned wound battery cell and the above-mentioned electrode sheet, a plurality of first electrode tabs are set in the first area, and the two ends in the length direction of the body are respectively the first end and the second end. The first area is located at the first end, and in the direction from the first end to the second end, the width of the plurality of first electrode tabs along the length direction of the body gradually decreases, thereby ensuring the current capacity of the wound battery cell and improving the overall bending degree of the first electrode tabs in the first area, thereby improving production efficiency.

[0040] An electrical device according to an embodiment of the present application includes the above-mentioned cylindrical battery.

[0041] According to the electrical device of the embodiment of the present application, by setting the above-mentioned cylindrical battery, setting the above-mentioned wound battery cell, setting the above-mentioned electrode sheet, setting multiple first electrode ears in the first area, the two ends of the length direction of the main body are respectively the first end and the second end, the first area is located at the first end, and in the direction from the first end to the second end, the width of the multiple first electrode ears along the length direction of the main body gradually decreases, thereby ensuring the current capacity of the wound battery cell and improving the overall bending degree of the first electrode ears in the first area, thereby improving production efficiency.

[0042] 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

[0043] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0044] FIG1 is a top view of an unfolded pole piece according to an embodiment of the present application, wherein the first angle of the first pole tab is gradually increased;

[0045] FIG2 is a top view of a pole piece according to an embodiment of the present application when unfolded, wherein the first angle of the first pole tab remains unchanged;

[0046] FIG3 is a schematic diagram of a pole piece when unfolded according to an embodiment of the present application;

[0047] FIG4 is a cross-sectional view of the connection between the electrode tab of a pole piece and a current collecting device according to an embodiment of the present application.

[0048] Reference numerals:

[0049] 100, pole piece;

[0050] 10. Ontology;

[0051] 1. Coating department;

[0052] 2. Tab portion; 21. First region; 211. First tab; 22. Second region; 221. Second tab; 23. Tab;

[0053] 3. First end;

[0054] 4. Second end;

[0055] 5. Empty foil buffer part;

[0056] 20. Scroll hole;

[0057] 30. Current collecting device. DETAILED DESCRIPTION

[0058] The following describes in detail embodiments of the present application. Examples of the embodiments 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 only used to explain the present application and are not to be construed as limiting the present application.

[0059] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0060] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0061] The pole piece 100 according to an embodiment of the present application is described below with reference to FIG. 1 to FIG. 4 .

[0062] As shown in FIG. 1 and FIG. 2 , a pole piece 100 according to an embodiment of the present application includes a body 10 .

[0063] Specifically, referring to Figures 1 and 2, along the width direction of the main body 10, the main body 10 includes a coating portion 1 and a pole ear portion 2, the pole ear portion 2 includes a plurality of pole ears 23 arranged along the length direction of the main body 10, each pole ear 23 is connected to the coating portion 1, and the two ends of the length direction of the main body 10 are respectively a first end 3 and a second end 4. In the direction from the first end 3 to the second end 4, the pole ear portion 2 includes a first area 21 located at the first end 3, and the plurality of pole ears 23 located in the first area 21 are all first pole ears 211.

[0064] It can be understood that the coating part 1 will coat the active material. During the discharge process of the electrode 100, the active material coating part 1 will be immersed in the electrolyte, and the multiple pole ears 23 are connected to the current collecting device 30 in the width direction of the main body 10 to form a wound battery cell. The electrolyte reacts with the active material of the coating part 1 to generate current, thereby realizing the discharge process of the wound battery cell.

[0065] The electrode sheet 100 is wound around the winding center from the first end 3 to the second end 4, and then the multiple tabs 23 are pre-bent (the tabs 23 are bent toward the winding center). The multiple tabs 23 are then flattened to form a wound battery cell. Finally, the current collecting device 30 and the tabs 23 are connected, such as by welding. During this process, the tabs 23 will overlap with the tabs 23 of the previous circle to form an overlapping area. Since the overlapping area of ​​the tabs 23 must maintain a certain thickness (thickness along the width direction of the body 10) when the current collecting device 30 and the tabs 23 are connected, this is to avoid structural damage to the electrode sheet 100 during the connection, such as welding, and to increase connection reliability. Therefore, the thinner the overlapping area of ​​the tabs 23, the more difficult it is to connect.

[0066] By arranging multiple first pole tabs 211 in the first region 21, the number of overlapping areas of the first pole tabs 211 is increased, and the thickness of the overlapping areas of the first pole tabs 211 can be increased, thereby ensuring that the current collecting device 30 and the first pole tab 211 can be connected. By connecting the current collecting device 30 and multiple first pole tabs 211, the connection area between the current collecting device 30 and the pole tab portion 2 can be increased, thereby improving the current flow capacity of the wound battery cell. At the same time, since the overlapping areas of the first pole tabs 211 are thick, the difficulty of connecting the current collecting device 30 and the pole tab 23 is also reduced.

[0067] Furthermore, as shown in Figures 1 and 2, the width of the plurality of first electrode tabs 211 along the length of the body 10 gradually decreases from the first end 3 to the second end 4. It is understood that because the winding center is located closer to the first end 3 relative to the second end 4, to avoid interference between the winding center and the first electrode tabs 211 after bending, the height of the first electrode tabs 211 along the width of the body 10 needs to be reduced as they are closer to the first end 3. At the same time, to ensure the connection area between the first electrode tabs 211 near the first end 3 and the current collecting device 30, it is necessary to increase the width of the first electrode tabs 211 along the length of the body 10. Therefore, the first electrode tabs 211 closest to the first end 3 have the largest width along the length of the body 10. In the direction from the first end 3 to the second end 4, the width of the plurality of first electrode tabs 211 along the length of the body 10 gradually decreases, and the bendability of the plurality of first electrode tabs 211 also gradually increases, thereby improving the overall bendability of the first electrode tabs 211 in the first region 21, thereby improving production efficiency.

[0068] Therefore, in the direction from the first end 3 to the second end 4, the width of the multiple first pole tabs 211 along the length direction of the main body 10 gradually decreases, which not only ensures the current capacity of the wound battery cell, but also improves the overall bending ease of the first pole tabs 211 in the first area 21, thereby improving production efficiency.

[0069] According to the pole piece 100 of the embodiment of the present application, a plurality of first pole tabs 211 are arranged in the first region 21, and the two ends of the length direction of the main body 10 are respectively the first end 3 and the second end 4, and the first region 21 is located at the first end 3. In the direction from the first end 3 to the second end 4, the width of the plurality of first pole tabs 211 along the length direction of the main body 10 gradually decreases, thereby ensuring the current capacity of the wound battery cell and improving the overall bending degree of the first pole tabs 211 in the first region 21, thereby improving production efficiency.

[0070] In some embodiments of the present application, as shown in Figures 1 and 2, the distance L1 between the first pole tab 211 closest to the first end 3 and the first end 3 is 0-1mm, such as 0mm, 0.2mm, 0.5mm or 1mm, thereby increasing the coverage of the pole tab 23 on the pole piece 100 along the length direction of the main body 10, thereby increasing the area of ​​the area covered by the wound battery cell after the pole tab 23 is flattened, so that the current collecting device 30 can be connected to more pole tabs 23, thereby improving the current carrying capacity of the wound battery cell.

[0071] The distance between the first tab 211 closest to the first end 3 and the first end 3 refers to the distance between the edges of the first tab 211 closest to the first end 3 on two opposite sides in the length direction of the body 10 close to the first end 3 and the first end 3 .

[0072] In some embodiments of the present application, as shown in Figures 1 and 2 , the heights of the plurality of first electrode tabs 211 in the width direction of the body 10 gradually increase from the first end 3 to the second end 4. By gradually increasing the heights of the plurality of first electrode tabs 211 in the width direction of the body 10 from the first end 3 to the second end 4, the flattened first electrode tabs 211 increase their coverage area on the wound battery cell, thereby allowing the current collecting device 30 to connect to more electrode tabs 23, thereby improving the current carrying capacity of the wound battery cell.

[0073] In addition, since the heights of the plurality of first electrode tabs 211 in the width direction of the body 10 gradually increase from the first end 3 to the second end 4, the first electrode tab 211 closest to the first end 3 has the smallest height. Therefore, when the first electrode tab 211 is bent, structural interference between the first electrode tab 211 and the winding center can be avoided.

[0074] In some embodiments of the present application, as shown in Figures 1 and 2, the first pole tab 211 is inclined toward the second end 4 in the direction from the coating portion 1 to the pole tab portion 2. It can be understood that, given the same area of ​​the first pole tab 211, when the first pole tab 211 is inclined toward the second end 4 in the direction from the coating portion 1 to the pole tab portion 2, compared to when the first pole tab extends along the direction from the coating portion to the pole tab portion, the first pole tab 211 covers a larger area along the length direction of the body 10 on the pole piece 100, thereby increasing the area of ​​the area covered by the wound battery cell after the pole tab 23 is flattened, thereby improving the current capacity of the wound battery cell.

[0075] In some embodiments of the present application, as shown in Figures 1 and 2 , in the direction from the coating portion 1 to the tab portion 2, both opposing edges of the first tab 211 in the longitudinal direction of the body 10 are inclined toward the second end 4 at the same angle. It is understood that, given the same area of ​​the first tab 211, when both opposing edges of the first tab 211 in the longitudinal direction of the body 10 are inclined toward the second end 4 in the direction from the coating portion 1 to the tab portion 2, compared to when both opposing edges of the first tab in the longitudinal direction of the body 10 extend in the direction from the coating portion to the tab portion, the first tab 211 covers a greater area of ​​the pole piece 100 along the longitudinal direction of the body 10. This increases the area of ​​the tab 23 covering the wound cell after flattening, thereby improving the current capacity of the wound cell. Furthermore, when both opposing edges of the first tab 211 in the longitudinal direction of the body 10 are inclined toward the second end 4 in the direction from the coating portion 1 to the tab portion 2, the same angle simplifies the structure and improves production efficiency.

[0076] In some embodiments of the present application, as shown in FIG1 , in the direction from the first end 3 to the second end 4, the edge of the first pole tab 211 at the end facing away from the coating portion 1 is inclined toward the direction facing away from the coating portion 1. It is understandable that, compared to the edge of the first pole tab at the end facing away from the coating portion being parallel to the opposite edges of the coating portion at both ends along the width direction of the body, in the direction from the first end 3 to the second end 4, the edge of the first pole tab 211 at the end facing away from the coating portion 1 is inclined toward the direction facing away from the coating portion 1, which can make the height of the first pole tab 211 along the width direction of the body 10 higher, thereby further increasing the area of ​​the region covered by the wound battery cell after the pole tab 23 is flattened, thereby improving the current capacity of the wound battery cell.

[0077] In some embodiments of the present application, as shown in FIG1 , the angle between the edges of the first tab 211 on two opposing sides of the first tab 211 in the longitudinal direction of the body 10, which are located near the first end 3, and the longitudinal direction of the body 10 is a first angle. The first angles of the plurality of first tabs 211 gradually increase in the direction from the first end 3 to the second end 4. This facilitates gradually increasing the heights of the plurality of first tabs 211 along the width of the body 10, thereby increasing the coverage of the flattened tab 23 in the wound cell and thereby increasing the current carrying capacity of the wound cell.

[0078] In some embodiments of the present application, as shown in Figure 1, the first angle a of the first pole tab 211 closest to the first end 3 is 20°-30°, such as 20°, 25° or 30°, so that the first angle of the first pole tab 211 closest to the first end 3 can meet the product design requirements, and at the same time, the angle between the first pole tab 211 closest to the first end 3 and the length direction of the main body 10 is appropriate, avoiding the first pole tab 211 closest to the first end 3 being too high in the width direction of the main body 10 due to the first angle being too large, thereby causing structural interference between the first pole tab 211 closest to the first end 3 and the winding center, and also avoiding the first pole tab 211 closest to the first end 3 being too small in the width direction of the main body 10 due to the first angle being too small, which is not conducive to the bending and flattening of the first pole tab 211.

[0079] In some embodiments of the present application, as shown in FIG1 , the first angles of the plurality of first tabs 211 increase linearly from the first end 3 to the second end 4. Thus, during product design, by adjusting the length of the corresponding hypotenuse of the first angle a according to the increasing first angle, the height of the plurality of first tabs 211 along the width direction of the body 10 can be increased, thereby reducing the difficulty of product design. Furthermore, after being bent and flattened, the edges of the plurality of first tabs 211 toward the winding center are smoother, thereby making the thickness of the overlapping regions of the tabs 23 more uniform, facilitating the connection of the tabs 23 to the current collecting device 30.

[0080] In some embodiments of the present application, as shown in FIG1 , the difference in the first angles of two adjacent first tabs 211 is 0.1°-5°, such as 0.1°, 1°, 2°, or 5°. This prevents the difference in the first angles of two adjacent first tabs 211 from being too small or too large, thereby preventing the height difference of the two adjacent first tabs 211 along the width direction of the body 10 from being too small or too large. This allows for a certain variation in the height of the two adjacent first tabs 211 along the width direction of the body 10, thereby increasing the coverage of the flattened tab 23 in the wound battery cell and thus increasing the current capacity of the wound battery cell. This also prevents the height of the two adjacent first tabs 211 along the width direction of the body 10 from varying too much, thereby making the thickness of the overlapping region of the tabs 23 more uniform and facilitating welding.

[0081] In some embodiments of the present application, as shown in FIG2 , the edge of the first electrode tab 211 facing away from the coating portion 1 is parallel to the length direction of the body 10. This simplifies the structure of the first electrode tab 211 and improves production efficiency.

[0082] In some embodiments of the present application, as shown in FIG2 , the angle between the edges of the first tab 211 on two opposing sides of the first tab 211 in the longitudinal direction of the body 10, which are closer to the first end 3, and the longitudinal direction of the body 10 is a first angle a. In the direction from the first end 3 to the second end 4, the first angles of the plurality of first tabs 211 are equal. This simplifies the structure of the first tab 211 and improves production efficiency.

[0083] In some embodiments of the present application, as shown in FIG2 , the height of the plurality of first tabs 211 in the width direction of the body 10 increases linearly from the first end 3 to the second end 4. This facilitates the gradual increase in the height of the plurality of first tabs 211 in the width direction of the body 10 from the first end 3 to the second end 4, thereby increasing the coverage of the flattened tabs 23 in the wound battery cell and thus increasing the current capacity of the wound battery cell. At the same time, the linear increase in height can reduce the difficulty of product design. Furthermore, after being bent and flattened, the edges of the plurality of first tabs 211 toward the winding center are smoother, thereby making the thickness of the overlapping area of ​​the tabs 23 more uniform and facilitating welding.

[0084] In some embodiments of the present application, as shown in Figure 2, the height of the first pole tab 211 closest to the first end 3 in the width direction of the body 10 is 0.5-1.5 mm, such as 0.5 mm, 0.8 mm, 1 mm, 1.2 mm or 1.5 mm. It can be understood that if the height of the first pole tab 211 closest to the first end 3 in the width direction of the body 10 is too small, the first pole tab 211 closest to the first end 3 is not easy to bend and flatten, thereby reducing production efficiency. If the height of the first pole tab 211 closest to the first end 3 in the width direction of the body 10 is too large, the first pole tab 211 closest to the first end 3 is likely to interfere with the winding center after bending.

[0085] Therefore, the height of the first electrode tab 211 closest to the first end 3 in the width direction of the body 10 is 0.5-1.5 mm, so that the height of the first electrode tab 211 closest to the first end 3 in the width direction of the body 10 is appropriate, which makes the first electrode tab 211 closest to the first end 3 easy to bend and avoids interference with the winding center after bending.

[0086] In some embodiments of the present application, as shown in FIG2 , the height difference between two adjacent first tabs 211 in the width direction of the body 10 is 0.05-0.5 mm, such as 0.05 mm, 0.1 mm, 0.2 mm, or 0.5 mm. This prevents the height difference between two adjacent first tabs 211 in the width direction of the body 10 from being too small or too large, thereby ensuring that the height of the two adjacent first tabs 211 in the width direction of the body 10 varies to a certain extent, thereby increasing the coverage of the flattened tab 23 in the wound battery cell and thus increasing the current capacity of the wound battery cell. It also prevents the height of the two adjacent first tabs 211 in the width direction of the body 10 from varying too much, thereby making the thickness of the overlapping area of ​​the tabs 23 more uniform and facilitating welding.

[0087] In some embodiments of the present application, as shown in Figures 1 and 2, the widths of the plurality of first tabs 211 along the length of the body 10 decrease linearly from the first end 3 to the second end 4. This makes the structure of the plurality of first tabs 211 more regular, which is beneficial to improving production efficiency.

[0088] For example, in the example shown in Figure 1, in the direction from the first end 3 to the second end 4, the width of the multiple first tabs 211 along the length direction of the main body 10 linearly decreases in a range of 0.05-0.5mm, such as 0.05mm, 0.1mm, 0.2mm or 0.5mm, etc. In the example shown in Figure 2, in the direction from the first end 3 to the second end 4, the width of the multiple first tabs 211 along the length direction of the main body 10 linearly decreases in a range of 0.2-20mm, such as 0.2mm, 1mm, 5mm or 20mm, etc.

[0089] In some embodiments of the present application, as shown in Figures 1 and 2, the width of the first electrode tab 211 closest to the first end 3 along the length of the body 10 is 10-100 mm, such as 10 mm, 20 mm, 50 mm, or 100 mm. It is understood that if the width of the first electrode tab 211 closest to the first end 3 along the length of the body 10 is too small, since the widths of the plurality of first electrode tabs 211 along the length of the body 10 linearly decrease from the first end 3 to the second end 4, the width of the first electrode tab 211 along the length of the body 10 is too small, which is not conducive to the connection between the first electrode tab 211 and the current collecting device 30. If the width of the first electrode tab 211 closest to the first end 3 along the length of the body 10 is too large, it is easy to make the first electrode tab 211 closest to the first end 3 difficult to bend, thereby reducing production efficiency.

[0090] Therefore, the width of the first electrode tab 211 closest to the first end 3 along the length direction of the main body 10 is 10-100 mm, which not only ensures the width of the first electrode tab 211 along the length direction of the main body 10, which is conducive to the connection with the current collecting device 30, but also makes the first electrode tab 211 closest to the first end 3 easy to bend, thereby improving production efficiency.

[0091] In some embodiments of the present application, as shown in Figures 1-3, the tab portion 2 further includes a second region 22, which is located on a side of the first region 21 near the second end 4. The multiple tabs 23 located in the second region 22 are all second tabs 221, and the multiple second tabs 221 have the same shape and size. It is understood that if the multiple second tabs 221 have the same shape and size, then the multiple second tabs 221 have the same height along the width of the body 10. The height of the first second tab 221 wound is less than or equal to the distance between it and the edge of the winding center. When the pole piece 100 continues to be wound, the subsequent second tabs 221 will not extend into the winding center after being flattened, and the circumference of the winding center will now cover the tabs 23. Therefore, the equal height of the second tabs 221 can meet the requirement that the ends of the wound cell along the width of the body 10 are covered by the tabs 23, and can also ensure that the second tabs 221 will not interfere with the winding center after being flattened. At the same time, the same shape and size of the plurality of second electrode tabs 221 can reduce process difficulty and lower production costs.

[0092] In some embodiments of the present application, as shown in Figures 1 and 2, the width of the second electrode tab 221 along the length direction of the body 10 is 2-6 mm, such as 2 mm, 3 mm, 4 mm, or 6 mm. In this way, the width of the second electrode tab 221 along the length direction of the body 10 is ensured, which is conducive to connection with the current collecting device 30, and the second electrode tab 221 is easy to bend, thereby improving production efficiency.

[0093] Furthermore, as shown in Figures 1 and 2, the height of the second tab 221 along the width direction of the body 10 is 4-8 mm, such as 4 mm, 5 mm, 6 mm, or 8 mm. Thus, the height of the second tab 221 along the width direction of the body 10 is appropriate, which not only makes the second tab 221 easy to bend, but also avoids interference with the winding center after the second tab 221 is bent.

[0094] In some embodiments of the present application, as shown in Figures 1 and 2, the second pole tab 221 is inclined toward the second end 4 in the direction from the coating portion 1 to the pole tab portion 2. It can be understood that, given the same area of ​​the second pole tab 221, the second pole tab 221 is inclined toward the second end 4 in the direction from the coating portion 1 to the pole tab portion 2, compared to the first pole tab extending along the direction from the coating portion to the pole tab portion. The second pole tab 221 covers a larger area along the length direction of the body 10 on the pole piece 100, thereby increasing the area of ​​the area covered by the wound battery cell after the pole tab 23 is flattened, thereby improving the current capacity of the wound battery cell.

[0095] In some embodiments of the present application, as shown in Figures 1 and 2, the angle b between the edges of the second pole tab 221 and the first pole tab 211 on two opposite sides in the length direction of the body 10, close to the first end 3, and the length direction of the body 10 is 2°-20°, such as 2°, 5°, 10° or 20°. As a result, the angle between the edges of the second pole tab 221 and the first pole tab 211 on two opposite sides in the length direction of the body 10, close to the first end 3, and the length direction of the body 10 is appropriate, thereby avoiding the height of the second pole tab 221 along the width direction of the body 10 being too high due to an excessively large angle, thereby causing structural interference between the second pole tab 221 and the winding center. At the same time, it can also avoid the height of the second pole tab 221 along the width direction of the body 10 being too small due to an excessively small angle, thereby being unfavorable for the bending and flattening of the second pole tab 221.

[0096] In some embodiments of the present application, as shown in Figures 1 and 2, the maximum width of the first electrode tab 211 along the length direction of the body 10 is less than or equal to 20 times the width of the second electrode tab 221. It is understood that if the maximum width of the first electrode tab 211 along the length direction of the body 10 is greater than 20 times the width of the second electrode tab 221, the width of the first electrode tab 211 along the length direction of the body 10 will be too large or the width of the second electrode tab 221 will be too small. If the maximum width of the first electrode tab 211 along the length direction of the body 10 is too large, it will be detrimental to the bending and flattening of the first electrode tab 211 near the first end 3, resulting in low production efficiency. If the width of the second electrode tab 221 along the length direction of the body 10 is too small, it will be detrimental to the connection between the second electrode tab 221 and the current collecting device 30.

[0097] Therefore, along the length direction of the body 10 , the width of the first electrode tab 211 is less than or equal to 20 times the width of the second electrode tab 221 , which is beneficial for bending and flattening the first electrode tab 211 , improving production efficiency, and facilitating the connection between the second electrode tab 221 and the current collecting device 30 .

[0098] In some embodiments of the present application, as shown in Figures 1 and 2, along the length direction of the main body 10, the spacing between the edges of two adjacent pole tabs 23 close to each other in the length direction of the main body 10 is 0.05-2mm, such as 0.05mm, 0.15mm, 0.10mm or 2mm, etc. It can be understood that along the length direction of the main body 10, the spacing between the edges of two adjacent pole tabs 23 close to each other in the length direction of the main body 10 is too small, the pole tabs 23 are not easy to bend, and the production efficiency is reduced. Along the length direction of the main body 10, the spacing between the edges of two adjacent pole tabs 23 close to each other in the length direction of the main body 10 is too large, so that the coverage range of the pole tabs 23 along the length direction of the main body 10 is too small, resulting in a decrease in the overcurrent capacity of the wound battery cell.

[0099] Therefore, along the length direction of the main body 10, the spacing between the edges of two adjacent pole tabs 23 close to each other in the length direction of the main body 10 is 0.05-2 mm, so that the spacing between the two adjacent pole tabs 23 is appropriate, which is conducive to the bending of the pole tabs 23 and ensures production efficiency, and also ensures the coverage range of the pole tabs 23 along the length direction of the main body 10 and ensures the current capacity of the wound battery cell.

[0100] In some embodiments of the present application, as shown in Figures 1 and 2, the body 10 further includes a hollow foil buffer portion 5 along the width direction of the body 10, and the hollow foil buffer portion 5 is located between the coating portion 1 and the electrode tab portion 2. It is understood that the hollow foil buffer portion 5 can undergo a certain degree of deformation. When the electrode tab portion 2 and the current collecting device 30 are connected in the width direction of the body 10, in order to reduce the connection gap between the electrode tab portion 2 and the current collecting device 30, the hollow foil buffer portion 5 can deform to keep the connection end surfaces of the electrode tab portion 2 and the current collecting device 30 parallel, thereby reducing the connection gap between the electrode tab portion 2 and the current collecting device 30, improving the connection reliability between the electrode tab portion 2 and the current collecting device 30, and thus improving the current carrying capacity of the wound battery cell.

[0101] The following describes a wound battery cell according to an embodiment of the present application with reference to the following.

[0102] According to an embodiment of the present application, the wound battery cell includes a positive electrode sheet, a negative electrode sheet and a separator. The positive electrode sheet and the negative electrode sheet are stacked and wound along the length direction of the positive electrode sheet and the negative electrode sheet. The separator is arranged between the positive electrode sheet and the negative electrode sheet. At least one of the positive electrode sheet and the negative electrode sheet is the above-mentioned electrode sheet 100.

[0103] It is understood that the positive and negative electrodes are insulated by a separator, thereby preventing short circuits between the positive and negative electrodes. At least one of the positive and negative electrodes is the aforementioned electrode 100. For example, both the positive and negative electrodes are the aforementioned electrode 100, or the positive electrode is the aforementioned electrode 100 and the negative electrode is not the aforementioned electrode 100, or the negative electrode is the aforementioned electrode 100, with the aforementioned electrode 100 located on the positive electrode portion. This increases the current capacity of the wound battery cell. Furthermore, the tabs 23 on the positive and negative electrodes are located at opposite ends along the width of the body 10, respectively, thereby preventing short circuits between the tabs 23 on the positive electrode and the tabs 23 on the negative electrode.

[0104] Furthermore, as shown in Figure 3, a winding hole 20 is defined on the inner side of the wound cell. The first end 3 is positioned relative to the second end 4, near the winding hole 20. The tabs 23 are all bent toward the winding hole 20, and the ends of the multiple first tabs 211 facing the winding hole 20 are flush with the peripheral wall of the winding hole 20 or located radially outward of the winding hole 20. The winding hole 20 is used to position a winding needle, thereby facilitating the winding of the positive and negative electrode sheets and the separator. The ends of the multiple first tabs 211 facing the winding hole 20 are flush with the peripheral wall of the winding hole 20 or located radially outward of the winding hole 20, thereby making the thickness of the overlapping areas of the tabs 23 more uniform and facilitating the connection of the tabs 23 to the current collecting device 30. The winding center is the winding hole 20.

[0105] The production process of the wound battery cell is as follows: stack the positive electrode sheet, negative electrode sheet and separator, then wind the positive electrode sheet, negative electrode sheet and separator from the first end 3 to the second end 4 around the reel hole 20, then bend the tab 23 toward the reel hole 20, and flatten the tab 23 to complete the production of the wound battery cell.

[0106] According to the wound battery cell of the embodiment of the present application, by setting the above-mentioned electrode piece 100, a plurality of first electrode tabs 211 are set in the first region 21, and the two ends of the length direction of the main body 10 are respectively the first end 3 and the second end 4. The first region 21 is located at the first end 3. In the direction from the first end 3 to the second end 4, the width of the plurality of first electrode tabs 211 along the length direction of the main body 10 gradually decreases, thereby ensuring the current capacity of the wound battery cell and improving the overall bending degree of the first electrode tabs 211 in the first region 21, thereby improving production efficiency.

[0107] In some embodiments of the present application, as shown in Figures 3 and 4 , the edges of the multiple first electrode tabs 211 facing the reel hole 20 are aligned. It is understood that after the multiple first electrode tabs 211 are bent, the edges of the multiple first electrode tabs 211 facing the reel hole 20 are aligned, so that the area covered by each first electrode tab 211 is equal. As a result, the thickness of the overlapping area of ​​the electrode tabs 23 can be made more uniform, which facilitates the connection of the electrode tabs 23 to the current collecting device 30.

[0108] The following describes a cylindrical battery according to an embodiment of the present application.

[0109] The cylindrical battery according to an embodiment of the present application includes the above-mentioned wound battery cell.

[0110] According to the cylindrical battery of the embodiment of the present application, by setting the above-mentioned wound battery cell and the above-mentioned electrode sheet 100, a plurality of first electrode tabs 211 are set in the first region 21, and the two ends of the length direction of the main body 10 are respectively the first end 3 and the second end 4. The first region 21 is located at the first end 3. In the direction from the first end 3 to the second end 4, the width of the plurality of first electrode tabs 211 along the length direction of the main body 10 gradually decreases, thereby ensuring the current capacity of the wound battery cell and improving the overall bending degree of the first electrode tabs 211 in the first region 21, thereby improving production efficiency.

[0111] The following describes an electrical device according to an embodiment of the present application.

[0112] An electrical device according to an embodiment of the present application includes the above-mentioned cylindrical battery.

[0113] The following describes the production process of a cylindrical battery according to an embodiment of the present application.

[0114] First, the electrode sheet 100 is die-cut according to the set parameters, and the electrode tabs 23 and the hollow foil buffer portion 5 are die-cut on one side of the width direction of the body 10 according to the set parameters. Then, the electrode sheet 100 is wound, and after the winding is completed, the electrode tabs 23 are pre-folded, and then the electrode tabs 23 are flattened. Then, the current collecting device 30 is welded to the multiple flattened electrode tabs 23, thereby completing the production process of the cylindrical battery.

[0115] According to the electrical device of the embodiment of the present application, by setting the above-mentioned cylindrical battery, setting the above-mentioned wound battery cell, setting the above-mentioned electrode sheet 100, setting multiple first electrode tabs 211 in the first area 21, and the two ends of the length direction of the main body 10 are respectively the first end 3 and the second end 4, the first area 21 is located at the first end 3, and in the direction from the first end 3 to the second end 4, the width of the multiple first electrode tabs 211 along the length direction of the main body 10 gradually decreases, thereby ensuring the current flow capacity of the wound battery cell and improving the overall bending degree of the first electrode tabs 211 in the first area 21, thereby improving production efficiency.

[0116] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," 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 illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0117] 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 pole piece, wherein: include: A body (10), wherein along the width direction of the body (10), the body (10) comprises a coating portion (1) and a pole ear portion (2), the pole ear portion (2) comprises a plurality of pole ears (23) arranged along the length direction of the body (10), each of the pole ears (23) being connected to the coating portion (1), The two ends of the body (10) in the length direction are respectively a first end (3) and a second end (4); in the direction from the first end (3) to the second end (4), the pole ear portion (2) includes a first region (21) located at the first end (3); the plurality of pole ears (23) located in the first region (21) are all first pole ears (211); and in the direction from the first end (3) to the second end (4), the widths of the plurality of first pole ears (211) along the length direction of the body (10) gradually decrease.

2. The pole piece according to claim 1, wherein: In the direction from the first end (3) to the second end (4), the widths of the plurality of first pole tabs (211) along the length direction of the body (10) decrease linearly.

3. The pole piece according to claim 2, wherein: The width of the first pole lug (211) closest to the first end (3) along the length direction of the body (10) is 10-100 mm.

4. The pole piece according to any one of claims 1 to 3, wherein: The distance between the first pole lug (211) closest to the first end (3) and the first end (3) is 0-1 mm.

5. The pole piece according to any one of claims 1 to 4, wherein: In the direction from the first end (3) to the second end (4), the heights of the plurality of first pole tabs (211) in the width direction of the body (10) gradually increase.

6. The pole piece according to claim 5, wherein: The first electrode tab (211) is inclined toward the second end (4) in a direction from the coating portion (1) to the electrode tab portion (2).

7. The pole piece according to claim 6, wherein: In the direction from the coating portion (1) to the pole lug portion (2), two opposite edges of the first pole lug (211) in the length direction of the body (10) are both inclined toward the second end (4) with the same inclination angle.

8. The pole piece according to claim 6, wherein: In the direction from the first end (3) to the second end (4), an edge of the end of the first electrode tab (211) that is away from the coating portion (1) is inclined in a direction away from the coating portion (1).

9. The pole piece according to claim 6, wherein: An angle between the edges of the first pole lug (211) on two opposite sides in the length direction of the main body (10) close to the first end (3) and the length direction of the main body (10) is a first angle, and in the direction from the first end (3) to the second end (4), the first angles of the plurality of first pole lugs (211) gradually increase.

10. The pole piece according to claim 9, wherein: The first angle of the first pole lug (211) closest to the first end (3) is 20°-30°.

11. The pole piece according to claim 9, wherein: In the direction from the first end (3) to the second end (4), the first angles of the plurality of first pole tabs (211) increase linearly.

12. The pole piece according to claim 9, wherein: The difference between the first angles of two adjacent first pole tabs (211) is 0.1°-5°.

13. The pole piece according to claim 6, wherein: The edge of one end of the first electrode tab (211) facing away from the coating portion (1) is parallel to the length direction of the body (10).

14. The pole piece according to claim 13, wherein: The angle between the edges of the first pole lug (211) on two opposite sides in the length direction of the main body (10) close to the first end (3) and the length direction of the main body (10) is a first angle, and in the direction from the first end (3) to the second end (4), the first angles of multiple first pole lugs (211) are equal.

15. The pole piece according to claim 13, wherein: In the direction from the first end (3) to the second end (4), the heights of the plurality of first pole tabs (211) in the width direction of the body (10) increase linearly.

16. The pole piece according to claim 15, wherein: The height of the first pole tab (211) closest to the first end (3) in the width direction of the body (10) is 0.5-1.5 mm.

17. The pole piece according to claim 13, wherein: The height difference between two adjacent first electrode tabs (211) in the width direction of the body (10) is 0.05-0.5 mm.

18. The pole piece according to any one of claims 1 to 17, wherein: The pole lug portion (2) further comprises a second region (22), wherein the second region (22) is located on a side of the first region (21) close to the second end (4), and the plurality of pole lugs (23) located in the second region (22) are all second pole lugs (221), and the plurality of second pole lugs (221) have the same shape and size.

19. The pole piece according to claim 18, wherein: The width of the second pole tab (221) along the length direction of the body (10) is 2-6 mm; And / or, the height of the second pole tab (221) along the width direction of the body (10) is 4-8 mm.

20. The pole piece according to claim 18, wherein: The second electrode tab (221) is inclined toward the second end (4) in a direction from the coating portion (1) to the electrode tab portion (2).

21. The pole piece according to claim 20, wherein: The angle between the edge of the second pole lug (221) close to the first end (3) on two opposite sides in the length direction of the body (10) and the length direction of the body (10) is 2°-20°.

22. The pole piece according to claim 18, wherein: Along the length direction of the body (10), the maximum width of the first pole lug (211) is less than or equal to 20 times the width of the second pole lug (221).

23. A pole piece according to any one of claims 1 to 22, wherein: Along the length direction of the body (10), the spacing between the edges of two adjacent pole tabs (23) close to each other in the length direction of the body (10) is 0.05-2 mm.

24. A pole piece according to any one of claims 1 to 23, wherein: Along the width direction of the body (10), the body (10) further comprises a hollow foil buffer portion (5), wherein the hollow foil buffer portion (5) is located between the coating portion (1) and the pole ear portion (2).

25. A wound battery cell, wherein: include: A positive electrode sheet, a negative electrode sheet and a separator, wherein the positive electrode sheet and the negative electrode sheet are stacked and wound along the length direction of the positive electrode sheet and the negative electrode sheet, the separator is arranged between the positive electrode sheet and the negative electrode sheet, and at least one of the positive electrode sheet and the negative electrode sheet is a electrode sheet according to any one of claims 1 to 24, The inner side of the wound battery core is provided with a reel hole (20), the first end (3) is arranged close to the reel hole (20) relative to the second end (4), and the pole ears (23) are all bent towards the reel hole (20).

26. The wound battery cell according to claim 25, wherein: The edges of the first pole tabs (211) at one end facing the reel hole (20) are flush.

27. A cylindrical battery, wherein: Comprising the wound battery cell according to claim 25 or 26.

28. An electrical device, wherein: Comprising a cylindrical battery according to claim 27.

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