Wound cell, cylindrical battery and electrical apparatus

Abstract

A wound cell 100, a cylindrical battery 1000, and an electrical apparatus. The wound cell 100 is formed by winding and defines a roll hole 10 on the inner side. The wound cell 100 comprises an electrode sheet 20, the electrode sheet 20 comprising an active substance coating part 21 and a tab part 22, and the tab part 22 being connected to one side of the active substance coating part 21. The tab part 22 comprises a plurality of tabs 221, the end of the electrode sheet 20 facing the roll hole 10 in a winding direction being a winding start section 23, the tab part 22 at the winding start section 23 being a first tab part 224, and the first tab part 224 comprising a plurality of first tabs 2211. In a direction that the active substance coating part 21 faces the tab part 22, the height size of the first tabs 2211 extending out of the active substance coating part 21 is a first height; in the winding direction of the wound cell 100, the first height of the plurality of first tabs 2211 is gradually increased.

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 202322673214.2 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 higher current 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 in the present application, the wound battery cell is wound into shape and a winding axis hole is defined on the inner side. The wound battery cell includes a pole piece, and 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. The end of the pole piece facing the winding axis hole in the winding direction is a winding starting section. The portion of the winding starting section is a first pole ear portion. The first pole ear portion includes a plurality of first pole ears. In the direction from the active material coating portion toward the pole ear portion, the height dimension of the first pole ear extending out of the active material coating portion is a first height. In the winding direction of the wound battery cell, the first heights of the plurality of first pole ears gradually increase.

[0011] According to the wound battery cell of the embodiment of the present application, by gradually 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 sheet can be increased, thereby increasing the flow capacity of the wound battery cell, and the coverage of the flattened pole ears at the end of the wound battery cell can be increased, thereby further increasing the 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 sheet below the first pole ear, thereby improving the yield rate of cylindrical electric batteries.

[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, in the winding direction, the first heights of the plurality of first tabs increase linearly.

[0015] According to an example of the present application, in the width direction of the pole piece, the edge of the first pole ear on one side away from the active material coating portion is a first edge, and in the winding direction, at least a portion of the first edge extends along a straight line and / or curve gradually away from the active material coating portion.

[0016] According to an example of the present application, in the winding direction, the first edge extends along an oblique line gradually away from the active material coating portion.

[0017] According to an example of the present application, the first edges of the plurality of first electrode tabs are collinear.

[0018] According to an example of the present application, in the winding direction, the first edge extends along an arc line away from the active material coating portion, and the first edges of the plurality of first electrode tabs have a common tangent line.

[0019] 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.

[0020] 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.

[0021] 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 of 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.

[0022] 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.

[0023] According to an example of the present application, a plurality of liquid holes are formed on the electrode tab portion. The liquid holes are formed at the connection position between the electrode tab and the connection area, and are formed between two adjacent electrode tabs.

[0024] According to an example of the present application, the liquid hole is formed by the edge of one side of the electrode tab in the winding direction being recessed toward the edge of the other side.

[0025] According to an example of the present application, in the length direction of the electrode piece, the width of the liquid hole is 0.2 mm-2 mm, and the width of the liquid hole is greater than the distance between two adjacent electrode ears.

[0026] According to an example of the present application, the plurality of liquid holes include a plurality of first through holes and a plurality of second through holes, the plurality of second through holes are arranged at intervals between the plurality of first through holes, and the flow cross-sectional area of ​​the first through holes is smaller than the flow cross-sectional area of ​​the second through holes.

[0027] According to an example of the present application, the end of the pole tab away from the active material coating portion is the inner end of the pole tab, and in the direction from the active material coating portion toward the pole tab portion, the inner end of the pole tab extends obliquely toward the downstream side of the pole piece in the winding direction.

[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 schematic diagram of the pole piece shown in FIG1 in an unfolded state;

[0033] FIG3 is a cross-sectional view of a wound battery cell according to an embodiment of the present application, wherein the tab is not flattened;

[0034] FIG4 is a schematic diagram of a tab and a liquid passage according to an embodiment of the present application;

[0035] FIG5 is a schematic diagram of another electrode tab and liquid passage hole according to an embodiment of the present application;

[0036] FIG6 is a schematic diagram of a tab and a liquid hole according to another embodiment of the present application;

[0037] FIG7 is a schematic diagram of a pole piece according to an embodiment of the present application;

[0038] FIG8 is a schematic diagram of another pole piece according to an embodiment of the present application;

[0039] FIG9 is a schematic diagram of a cylindrical battery according to an embodiment of the present application.

[0040] Reference numerals:

[0041] 1000, cylindrical battery;

[0042] 100. Winding battery cells;

[0043] 10. Scroll hole;

[0044] 20. Pole piece; 21. Active material coating portion; 22. Pole tab portion; 221. Pole tab; 2211. First pole tab; 22111. First edge; 222. Connection area; 223. Liquid passage hole; 224. First pole tab portion; 225. Second pole tab portion; 223a. First through hole; 223b. Second through hole; 23. Winding start section; 24. Main body section; 241. Second pole tab; 25. Inner end of pole tab;

[0045] 200. Current collecting device. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] 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 FIG9 .

[0049] As shown in Figures 1, 2, 3 and 9, 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 reel 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 2), 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 2). The end of the pole piece 20 facing the reel hole 10 in the winding direction (for example, from right to left as shown in Figure 2) is a winding starting section 23, and the portion of the winding starting section 23 is The first pole ear portion 224 includes a plurality of first pole ears 2211. In the direction from the active material coating portion 21 to the pole ear portion 22, the height dimension of the first pole ear 2211 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 to the pole ear portion 22, the distance between the outermost side of the first pole ear 2211 and the upper edge of the active material coating portion 21 is formed as the first height. For example, in Figure 2, in the up and down directions, the distance a between the uppermost side of the first pole ear 2211 and the upper edge of the active material coating portion 21 is formed as the first height. In the winding direction of the wound battery cell 100, the first heights of the plurality of first pole ears 2211 gradually increase.

[0050] 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.

[0051] It should be noted that during the discharge of the wound battery cell 100 , current will flow in the entire 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 .

[0052] During the winding process of the wound battery cell 100, as the pole piece 20 is wound, the winding diameter of the pole piece 20 becomes larger and larger, and the distance between the pole piece 20 and the edge of the reel hole 10 also becomes larger and larger. In this embodiment, the first heights of the multiple first pole ears 2211 are gradually increased in the winding direction of the wound battery cell 100. In this way, at the end of the pole piece 20 facing the reel hole 10, the first pole ear 2211 can cover more areas of the pole piece 20. During the discharge of the wound battery cell, more pole ears 221 can be used to divert the current in the pole piece 20, thereby increasing the overcurrent capacity of the wound battery cell 100.

[0053] During the winding process, the first height of the first pole ear 2211 can be adapted to the distance between the pole piece 20 and the edge of the winding shaft hole 10. When the winding is completed, the pole ear 221 will be concentrated at the end of the wound battery cell 100, and the flattened first pole ear 2211 can be close to the edge of the winding shaft hole 10. Thus, the coverage range of the first pole ear 2211 at the end of the wound battery cell 100 can be improved. 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 ear 2211 can be increased, thereby further improving the current carrying capacity of the wound battery cell 100.

[0054] In addition, after being flattened, the first pole tabs 2211 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 2211 more flat after winding, thereby facilitating the connection between the winding battery cell 100 and the current collecting device 200.

[0055] In practical applications, the current collecting device 200 is typically welded to the flattened tab 221. As is well understood in the art, the tab 221 is relatively thin and easily burns through during welding. During the winding process of the pole piece 20, the tab 221 overlaps with the tab 221 of the previous winding, forming an overlapped region. Welding the current collecting device 200 to the tab 221 in the overlapped region can reduce the probability of the tab 221 being burned through, thereby damaging the pole piece 20 below the tab 221, thereby improving the yield rate of the cylindrical battery 1000.

[0056] In this embodiment, by increasing the first height of multiple first pole tabs 2211 in the winding direction of the wound battery cell 100, the first pole tabs 2211 wound downstream can overlap with more first pole tabs 2211 wound upstream, thereby increasing the number of layers of the first pole tabs 2211 in the overlapping area, thereby increasing the thickness of the first pole tabs 2211 in the overlapping area. When the current collecting device 200 is welded to the first pole tabs 2211 in the above-mentioned overlapping area, the probability of the first pole tab 2211 being burned through and causing damage to the pole piece 20 below the first pole tab 2211 can be further reduced, thereby further improving the yield rate of the cylindrical battery 1000.

[0057] According to the wound battery cell 100 of the first aspect embodiment of the present application, by gradually increasing the first heights of the multiple first pole tabs 2211 in the winding direction of the wound battery cell 100, the coverage of the pole tab 221 on the pole piece 20 can be increased, thereby increasing the current flow capacity of the wound battery cell, and the coverage of the flattened pole tab 221 on the end of the wound battery cell 100 can be increased, thereby further increasing the current flow capacity of the wound battery cell 100. In addition, the number of overlapping layers of the first pole tab 2211 can be increased, thereby reducing the probability of the first pole tab 2211 being burned through when the current collecting device 200 is welded to the first pole tab 2211, thereby damaging the pole piece 20 below the first pole tab 2211, thereby improving the yield rate of the cylindrical battery 1000.

[0058] In some embodiments of the present application, among the multiple first pole tabs 2211, the first pole tab 2211 at the end closest to the winding start section 23 and facing the winding shaft hole 10 has a first height of less than or equal to 1 mm. For example, the first height of the first pole tab 2211 located most upstream in the winding direction can be 1 mm, 0.5 mm, or 0.4 mm. In this way, the first height of the first pole tab 2211 located most upstream in the winding direction is not too large. The other first pole tabs 2211 in the first pole tab portion 224 of the pole piece 20 are increased based on the first height of the first pole tab 2211 located most upstream in the winding direction. This ensures that the first pole tab 2211 that wraps around the winding shaft hole 10 for the first time does not extend into the winding shaft 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 2211 located most upstream in the winding direction can be adjusted to meet more product design requirements and reduce product design difficulty.

[0059] In some embodiments of the present application, as shown in Figures 2 and 3 , the first heights of the plurality of first tabs 2211 increase linearly in the winding direction. This allows the first heights of the plurality of first tabs 2211 to increase in the winding direction. Furthermore, during product design, product design requirements can be met by adjusting the first height of the first tab 2211 located most upstream in the winding direction and the linearly increasing height, thereby reducing product design difficulty.

[0060] In some embodiments of the present application, the electrode sheet 20 includes a positive electrode sheet and a negative electrode sheet, and a diaphragm is provided between the positive electrode sheet and the negative electrode sheet. In the direction perpendicular to the axis of the wound battery cell 100, the first height difference of the first electrode tab 2211 on the two adjacent circles of the electrode sheet 20 is the sum of the thickness of the positive electrode sheet, the negative electrode sheet 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 2211 of the outer circle can be flattened to align the edge of the first electrode tab 2211 of the inner circle, so that the first electrode tab 2211 is more evenly covered around the scroll hole 10.

[0061] In some embodiments of the present application, as shown in FIG4-8 , in the width direction of the electrode sheet 20, the edge of the first electrode tab 2211 away from the active material coating portion 21 is a first edge 22111. In the winding direction, at least a portion of the first edge 22111 extends along a straight line and / or a curve that gradually moves away from the active material coating portion 21. In other words, at least a portion of the first edge 22111 may extend along a straight line that gradually moves away from the active material coating portion 21, or at least a portion of the first edge 22111 may extend along a curve that gradually moves away from the active material coating portion 21, or at least a portion of the first edge 22111 may extend along both a straight line and a curve that gradually moves away from the active material coating portion 21.

[0062] As a result, the first edge 22111 is longer in the width direction of the electrode sheet 20. When the first electrode tab 2211 is flattened, the first edge 22111 can overlap with the first electrode tab 2211 of the previous circle. That is, the first electrode tab 2211 of the outer circle has an overlapping area with the first electrode tab 2211 of the previous circle. In this way, the first electrode tab 2211 has a larger weldable area, thereby facilitating the welding of the current collecting device 200 to the first electrode tab 2211. At the same time, the first electrode tab 2211 of the outer circle will press the first electrode tab 2211 of the inner circle, which can improve the stability of the wound battery cell 100 structure. In addition, at least a portion of the first edge 22111 extends along a straight line and / or curve that gradually moves away from the active material coating portion 21, which can save material for the first electrode tab 2211 and reduce production costs.

[0063] During the product design process, parameters such as the shape and extension size of the first edge 22111 can be adjusted to meet more product design requirements and reduce the difficulty of product design.

[0064] In some embodiments of the present application, in the winding direction, the first edge 22111 extends along an oblique line that gradually moves away from the active material coating portion 21. As a result, the first edge 22111 is longer in the width direction of the electrode sheet 20. When the first electrode tab 2211 is flattened, the first edge 22111 can overlap with the first electrode tab 2211 of the previous circle. That is, the first electrode tab 2211 of the outer circle overlaps with the first electrode tab 2211 of the previous circle. This provides a larger weldable area for the first electrode tab 2211, thereby facilitating welding of the current collecting device 200 to the first electrode tab 2211. Furthermore, the first electrode tab 2211 of the outer circle presses against the first electrode tab 2211 of the inner circle, thereby improving the structural stability of the wound battery cell 100. Furthermore, the first edge 22111 extends along an oblique line that gradually moves away from the active material coating portion 21, which can save material for the first electrode tab 2211 and reduce production costs.

[0065] During the product design process, parameters such as the size of the extended oblique line of the first edge 22111 and the angle with the horizontal plane can be adjusted to meet more product design requirements and reduce the difficulty of product design.

[0066] In some embodiments of the present application, as shown in FIG2 , the first edges 22111 of the plurality of first pole tabs 2211 are collinear, that is, the first edges 22111 of the plurality of first pole tabs 2211 are extended so that their extension lines coincide. In this way, in the winding direction, the collinear line of the plurality of first edges 22111 is extended away from the pole piece 20 , and the heights of the plurality of first edges 22111 on the collinear line gradually increase, thereby gradually increasing the first height 2211 of the first pole tab. During product design, the first heights of the plurality of first pole tabs 2211 can be adjusted by adjusting the angle C between the collinear line of the first edges 22111 and the length direction of the pole piece 20 , thereby reducing the difficulty of product design.

[0067] In some embodiments of the present application, in a direction from one end of the electrode sheet 20 toward the other end, the first edge 22111 extends along an arc away from the active material coating portion 21, and the first edges 22111 of the plurality of first electrode tabs 2211 have a common tangent line. That is, in the direction in which the common tangent line extends, the plurality of first edges 22111 are tangent to the common tangent line. In this way, in the winding direction, the common tangent line of the plurality of first edges 22111 extends away from the electrode sheet 20, and the heights of the plurality of first edges 22111 tangent to the common tangent line gradually increase, thereby gradually increasing the first height 2211 of the first electrode tab. During the product design process, the first heights of the plurality of first electrode tabs 2211 can be adjusted by adjusting the angle between the common tangent line of the first edges 22111 and the length direction of the electrode sheet 20, thereby reducing the difficulty of product design.

[0068] 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 2211 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 2211 do not affect the winding of the electrode sheet 20, and the coverage of the flattened first tabs 2211 at the end of the wound battery cell 100 can be further increased, thereby further improving the current carrying capacity of the wound battery cell 100.

[0069] In some embodiments of the present application, ends of one end of the plurality of first pole tabs 2211 are aligned in the axial direction of the wound battery cell 100. That is, the edges of the plurality of first pole tabs 2211 close to the reel hole 10 are aligned in the thickness direction of the first pole tab 2211. In other words, the plurality of first pole tabs 2211 are flattened and overlapped together. In this way, the number of first pole tabs 2211 in the overlapping area can be increased, thereby reducing the probability of the first pole tab 2211 being burned through during welding of the current collecting device 200 to the first pole tab 2211, thereby reducing the probability of damage to the electrode sheet 20 below the first pole tab 2211, thereby improving the yield rate of the cylindrical battery 1000.

[0070] In some embodiments of the present application, as shown in Figure 2, 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 225, and the second pole ear portion 225 includes a plurality of second pole ears 241. In the 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, 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 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 2, in the up and down directions, the distance b between the uppermost side of the second pole ear 241 and the upper edge of the active material coating portion 21 is formed as the second height. 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 reel hole 10. When the main section 24 continues to wind, the subsequent second pole tab 241 will not extend into the reel hole 10 after being flattened, and at this time the pole tab 221 is covered all around the reel 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.

[0071] In some embodiments of the present application, as shown in FIG2 , the tab portion 22 further includes a connection region 222 , which is connected between the active material coating portion 21 and the plurality of tabs 221 . The provision of the connection region 222 allows current to be transmitted from the active material coating portion 21 to the plurality of tabs 221 , and increases the distance between the ends of the wound battery cell 100 and the electrolyte, thereby reducing the probability of contact between the current collecting device 200 connected to the plurality of tabs 221 and the electrolyte, thereby improving the reliability of the wound battery cell 100 during operation.

[0072] In some embodiments of the present application, as shown in FIG2 , the tab portion 22 is formed with a plurality of liquid-passing holes 223. The liquid-passing holes 223 are formed at the connection between the tab 221 and the connection region 222, and are formed between two adjacent tabs 221. By providing the liquid-passing holes 223, when the wound battery cell 100 is placed in an electrolyte, the electrolyte can contact the electrode sheet 20 through the liquid-passing holes 223, thereby improving the degree of electrolyte infiltration into the electrode sheet 20 and improving the power generation efficiency of the wound battery cell 100.

[0073] In some embodiments of the present application, as shown in FIG2 , the liquid-passing hole 223 is formed by a depression of one side edge of the electrode tab 221 toward the other side edge in the length direction of the electrode piece 20. Thus, the liquid-passing hole 223 can be provided on the electrode tab 221, and the process is relatively simple, which can improve production efficiency and reduce production costs. In addition, the length of the connection between the electrode tab 221 and the electrode piece 20 can be reduced, thereby reducing the difficulty of flattening the electrode tab 221 and further improving production efficiency.

[0074] In some embodiments of the present application, as shown in Figures 7 and 8, the two side edges of the liquid hole 223 in the length direction of the electrode piece 20 are perpendicular to the side edge of the connection area 222 away from the active material coating portion 21. Therefore, in the process of flattening the electrode tab 221, the two side edges of the liquid hole 223 in the length direction of the electrode piece 20 are subjected to more uniform force, thereby further reducing the difficulty of flattening the electrode tab 221 and improving the position accuracy after flattening the electrode tab 221.

[0075] In some embodiments of the present application, as shown in Figures 4-6, the liquid passage hole 223 is a circular hole, an elliptical hole, an oblong hole, or a polygonal hole. In this way, during the product design process, the shape of the liquid passage hole 223 can be adjusted according to product design requirements to meet product design requirements.

[0076] In some embodiments of the present application, as shown in FIG4-6 , the width W of the liquid passage hole 223 in the length direction of the electrode 20 is 0.2 mm to 2 mm. For example, the width W of the liquid passage hole 223 can be 0.2 mm, 0.5 mm, or 2 mm, and the width W of the liquid passage hole 223 is greater than the spacing between two adjacent electrode tabs 221. The spacing between two adjacent electrode tabs 221 refers to the spacing between the two closest edges of the two adjacent electrode tabs 221. Thus, the liquid passage capacity of the liquid passage hole 223 can be guaranteed, thereby ensuring the degree of electrolyte infiltration into the electrode 20. During the product design process, the width W of the liquid passage hole 223 can be adjusted to meet more product design requirements.

[0077] In some embodiments of the present application, the plurality of liquid-passing holes 223 include a plurality of first through-holes 223a and a plurality of second through-holes 223b. The plurality of second through-holes 223b are spaced apart between the plurality of first through-holes 223a, and the flow cross-sectional area of ​​the first through-holes 223a is smaller than the flow cross-sectional area of ​​the second through-holes 223b. Thus, the liquid-passing holes 223 can meet the different liquid-passing requirements at different positions of the wound battery cell 100, thereby ensuring the electrolyte's infiltration effect on the electrode sheet 20. During the product design process, parameters such as the number of the first and second through-holes 223a, 223b, and their positions can be adjusted to meet more product design requirements.

[0078] In some embodiments of the present application, in the width direction of the electrode 20, the height L1 of the first through hole 223a is 0.2mm-2mm, for example, the height L1 of the first through hole 223a can be 0.2mm, 0.5mm or 2mm, and the difference between the height L2 of the second through hole 223b and the height of the first through hole 223a is 0.2mm-1mm, for example, the difference between the height L2 of the second through hole 223b and the height L1 of the first through hole 223a can be 0.2mm, 0.5mm or 1mm. Thus, it can be ensured that the flow cross-sectional area of ​​the first through hole 223a and the second through hole 223b can meet the liquid flow requirements of the electrolyte. During the product design process, the difference between the height L1 of the first through hole 223a, the height L2 of the second through hole 223b and the height L1 of the first through hole 223a can be adjusted to meet more product design requirements and reduce the difficulty of product design.

[0079] In some embodiments of the present application, in the circumferential direction of the wound battery cell 100, the number of tabs 221 between two adjacent second through holes 223b is 3 to 20. For example, the number of tabs 221 between two adjacent second through holes 223b can be 3, 10, or 20. Thus, the distribution of the second through holes 223b can meet the electrolyte flow requirements. During the product design process, the number of tabs 221 between two adjacent second through holes 223b can be adjusted to meet more product design requirements and reduce product design difficulty.

[0080] In some embodiments of the present application, as shown in Figures 4-8 , the end of the tab 221 that is distal to the active material coating portion 21 is the tab inner end 25. In the direction from the active material coating portion 21 toward the tab portion 22, the tab inner end 25 extends obliquely toward the downstream side of the pole piece 20 in the winding direction. Thus, the tab inner end 25 is longer in a direction parallel to the pole piece 20. After the tab 221 is flattened, the tab inner end 25 is located inside the wound battery cell 100, thereby increasing the overlap area between the tab inner end 25 and the previous tab 221. Furthermore, after two adjacent tabs 221 are flattened, the tab inner end 25 of the subsequent tab 221 can be pressed against the tab inner end 25 of the previous tab 221. This further increases the overlap area between the tabs 221, thereby increasing the weldable area of ​​the first tab 2211 and facilitating welding of the current collecting device 200 to the first tab 2211.

[0081] In some embodiments of the present application, as shown in Figures 8 and 9, the spacing N between two adjacent inner ends 25 of the pole tabs is 0.02mm-2.0mm. For example, the spacing N between two adjacent inner ends 25 of the pole tabs can be 0.02mm, 0.1mm, 1.0mm or 2.0mm. Thus, the spacing N between two adjacent inner ends 25 of the pole tabs does not affect the bending of the pole tab 221 toward the reel hole 10, and the adjacent inner ends 25 of the pole tabs can be overlapped. During the product design process, the spacing N between two adjacent inner ends 25 of the pole tabs can be adjusted to meet more product design requirements and reduce the difficulty of product design.

[0082] In some embodiments of the present application, the active material coating portion 21 includes a current collector and an active material layer disposed on the current collector, and the tab portion 22 is electrically connected to the current collector. The current collector provides an attachment point for the active material layer, which reacts with the electrolyte, enabling the wound battery cell 100 to achieve charge and discharge functions. During the charge and discharge process of the wound battery cell 100, current can be transmitted between the active material layer and the tab portion 22 through the current collector.

[0083] In some embodiments of the present application, as shown in Figures 4, 5, 8, and 9, the edges of the tabs 221 are chamfered to create smoother chamfers. This reduces burrs at the corners of the finished tabs 221 during production, thereby simplifying the production process and reducing production difficulty. Furthermore, fewer burrs can reduce the probability of burr shedding causing a short circuit within the wound cell 100, thereby improving the reliability of the wound cell 100 during operation. Preferably, the chamfer size is less than or equal to 1.0 mm, for example, the chamfer size can be 1.0 mm, 0.8 mm, or 0.1 mm. This ensures that the chamfer does not affect the overall structure of the tabs 221.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] In some embodiments of the present application, as shown in FIG9 , 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.

[0088] 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.

[0089] The following describes a production process of a cylindrical battery 1000 according to an embodiment of the present application.

[0090] 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.

[0091] The electrical device according to the third embodiment of the present application includes the cylindrical battery 1000 according to the second embodiment of the present application.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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) in the winding direction facing the winding shaft hole (10) is a winding starting section (23), the pole ear portion (22) of the winding starting section (23) is a first pole ear portion (224), and the first pole ear portion (224) includes a plurality of first pole ears (2211). In the direction from the active material coating portion (21) toward the pole ear portion (22), the height dimension of the first pole ear (2211) 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 (2211) gradually increase.

2. The wound battery cell (100) according to claim 1, characterized in that: Among the plurality of first pole tabs (2211), a first height of the first pole tab (2211) 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: In the winding direction, the first heights of the plurality of first pole tabs (2211) increase linearly.

4. The wound battery cell (100) according to claim 1, characterized in that: In the width direction of the pole piece (20), an edge of the first pole tab (2211) that is away from the active material coating portion (21) is a first edge (22111), In the winding direction, at least a portion of the first edge (22111) extends along a straight line and / or a curve that gradually moves away from the active material coating portion (21).

5. The wound battery cell (100) according to claim 4, characterized in that: In the winding direction, the first edge (22111) extends along an oblique line gradually away from the active material coating portion (21).

6. The wound battery cell (100) according to claim 5, characterized in that: The first edges (22111) of the plurality of first pole tabs (2211) are collinear.

7. The wound battery cell (100) according to claim 4, characterized in that: In the winding direction, the first edge (22111) extends along an arc line away from the active material coating portion (21), and the first edges (22111) of the plurality of first electrode tabs (2211) have a common tangent line.

8. The wound battery cell (100) according to any one of claims 1 to 7, characterized in that: The plurality of pole ears (221) are all bent toward the side where the reel hole (10) is located, and one end of the plurality of first pole ears (2211) facing the reel hole (10) is flush with the peripheral wall of the reel hole (10) or is located radially outside the reel hole (10).

9. The wound battery cell (100) according to claim 8, characterized in that: The ends of the one ends of the plurality of first pole tabs (2211) are aligned in the axial direction of the wound battery core (100).

10. The wound battery cell (100) according to any one of claims 1 to 9, 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 start 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 (225), the second pole ear portion (225) comprising a plurality of second pole ears (241), In the direction from the active material coating portion (21) toward the pole lug portion (22), the height dimension of the second pole lug (241) extending out of the active material coating portion (21) is a second height, and the second heights of a plurality of second pole lugs (241) are equal.

11. The wound battery cell (100) according to claim 1, 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).

12. The wound battery cell (100) according to any one of claims 1 to 11, characterized in that: The pole lug portion (22) is formed with a plurality of liquid-passing holes (223), and the liquid-passing holes (223) are formed at the connection position between the pole lug (221) and the connection area (222), and are formed between two adjacent pole lugs (221).

13. The wound battery cell (100) according to claim 12, characterized in that: The liquid passage hole (223) is formed by the edge of one side of the pole ear (221) in the winding direction being recessed toward the edge of the other side.

14. The wound battery cell (100) according to claim 12, characterized in that: In the length direction of the pole piece (20), the width of the liquid passage hole (223) is 0.2 mm-2 mm, and the width of the liquid passage hole (223) is greater than the distance between two adjacent pole ears (221).

15. The wound battery cell (100) according to claim 12, characterized in that: The plurality of liquid passage holes (223) include a plurality of first through holes (223a) and a plurality of second through holes (223b), the plurality of second through holes (223b) are arranged at intervals between the plurality of first through holes (223a), and the flow cross-sectional area of ​​the first through holes (223a) is smaller than the flow cross-sectional area of ​​the second through holes (223b).

16. The wound battery cell (100) according to claim 1, characterized in that: The end of the pole lug (221) away from the active material coating portion (21) is the inner end (25) of the pole lug, and in the direction from the active material coating portion (21) toward the pole lug portion (22), the inner end (25) of the pole lug extends obliquely toward the downstream side of the pole piece (20) in the winding direction.

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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