Battery cell and battery
By setting clearance grooves on the cell electrodes, the problem of short circuits caused by electrode folding during drop tests in square cells is solved, thus improving the safety of the cells and batteries.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-03-06
AI Technical Summary
In drop tests, the head side of the square battery cell near the tab is prone to folding, causing a short circuit and posing a safety hazard.
An avoidance groove is set on the electrode of the battery cell. The avoidance groove runs through the electrode along the thickness direction of the battery cell and extends to the edge in the length direction. This reduces the overlap between the edge of the electrode and the tab, increases the distance between the edge of the electrode and the winding center, and reduces the risk of folding.
By setting up clearance grooves, the risk of the electrode sheets breaking during drop tests is reduced, thus improving the safety of the cells and batteries.
Smart Images
Figure CN223978052U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, specifically to battery cells and batteries. Background Technology
[0002] In related technologies, the battery cell is a crucial component for storing energy in a battery. Current battery manufacturing processes require winding electrode sheets with tabs to form the cell. After being packaged into a battery, these cells typically undergo drop testing. During drop testing, the electrode sheets of a prismatic cell are prone to folding over on the side closest to the tabs, potentially leading to a short circuit and safety issues. Utility Model Content
[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a battery cell with enhanced safety.
[0004] This utility model also proposes a battery having the above-mentioned electrodes.
[0005] According to a first aspect embodiment of the present invention, the battery cell has a wound structure and has a predetermined length, width, and thickness, including: a straight region and a bent region arranged along the width direction of the battery cell; and...
[0006] An electrode includes flat portions stacked in the flat region along the thickness direction of the battery cell, wherein one layer of the flat portions is defined as a first flat portion. Along the thickness direction of the battery cell, the first flat portion is located at the outermost edge of the flat region. The first flat portion has a first edge and a second edge on different sides of the length direction of the battery cell. The first flat portion also has a first clearance groove that penetrates the first flat portion along the thickness direction of the battery cell and extends to the first edge along the length direction of the battery cell.
[0007] The first electrode tab extends partially into the interior of the straight region along the direction from the first edge to the second edge;
[0008] The battery cell has a projection plane perpendicular to the thickness direction of the straight section. The projection of the first electrode tab onto the projection plane is a first projection, and the projection of the first clearance groove onto the projection plane is a second projection. In the width direction of the battery cell, the first projection is located within the range of the second projection.
[0009] The battery cell according to the embodiments of this utility model has at least the following beneficial effects: Since the first tab extends into the interior of the flat region along the direction from the first edge to the second edge, a portion of the first edge will have a larger distance from the center of the coiled electrode sheet due to the stacked first tab. During drop tests, the inner side of the electrode sheet near the first edge and overlapping with the first tab is easily impacted by the test surface and may fold. This utility model, by providing a clearance groove to remove the portion of the first flat portion near the first edge and overlapping with the first tab, makes the edge of the entire first flat portion less prone to folding after impact with the test surface, reducing the risk of short circuits and improving the safety of the battery cell.
[0010] According to some embodiments of the present invention, the battery cell further includes a second tab, a portion of which extends into the interior of the flat region, and the projection of the second tab onto the projection plane is a third projection, which is offset from the first projection.
[0011] According to some embodiments of the present invention, the second tab extends partially into the interior of the flat region along the direction from the first edge to the second edge; in the width direction of the battery cell, the third projection is located within the range of the second projection.
[0012] According to some embodiments of the present invention, the second tab extends partially into the interior of the flat region along the direction from the first edge to the second edge; the first flat portion also has a second clearance groove, the second clearance groove penetrates the first flat portion along the thickness direction of the battery cell and extends to the first edge along the length direction of the battery cell; the projection of the second clearance groove on the projection plane is a fourth projection, and in the width direction of the battery cell, the third projection is located within the range of the fourth projection.
[0013] According to some embodiments of the present invention, the battery cell further includes a second tab, which extends partially into the interior of the flat region along the direction from the second edge to the first edge; the first flat region also has a second clearance groove, which penetrates the first flat region along the thickness direction of the battery cell and extends to the second edge along the length direction of the battery cell; the projection of the second tab on the projection plane is a third projection, and the projection of the second clearance groove on the projection plane is a fourth projection, and in the width direction of the battery cell, the third projection is located within the range of the fourth projection.
[0014] According to some embodiments of this utility model, one of the flat portions is defined as the second flat portion. Along the thickness direction of the battery cell, the first flat portion and the second flat portion are respectively located on both sides of the flat area. The second flat portion has a third edge in the length direction of the battery cell. The first edge and the third edge are located on the same side in the length direction of the battery cell. The second flat portion also has a third clearance groove. The third clearance groove penetrates the second flat portion along the thickness direction of the battery cell and extends to the third edge along the length direction of the battery cell. The projection of the third clearance groove on the projection plane is a fifth projection. In the width direction of the battery cell, the first projection is located within the range of the fifth projection.
[0015] According to some embodiments of the present invention, the battery cell further includes a head adhesive tape, one of the flat portions is defined as the second flat portion, and along the thickness direction of the battery cell, the first flat portion and the second flat portion are respectively located on both sides of the flat area; the head adhesive tape is attached to the side of the first flat portion away from the second flat portion, and wraps around the first edge to and attaches to the side of the second flat portion away from the first flat portion.
[0016] According to some embodiments of the present invention, in the length direction of the battery cell, the distance between the edge of the first clearance groove and the first edge is 1mm to 3mm.
[0017] The battery according to a second aspect of the present invention includes a cell as described in any of the above embodiments.
[0018] The battery according to the present invention has at least the following beneficial effects: Since the portion of the first straight part of the cell that is close to the first edge and located in the area overlapping with the second tab is removed by the first clearance groove, the edge of the first straight part as a whole will be less likely to be folded after being impacted by the test ground because the part of the first edge that is thickened by the second tab is cut off, the risk of short circuit is further reduced, and the overall safety performance of the battery can also be improved.
[0019] According to some embodiments of the present invention, the battery includes an aluminum-plastic film, which wraps the battery cell and forms a shallow pit surface and a deep pit surface, and the first clearance groove is disposed on the side close to the shallow pit surface.
[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:
[0022] Figure 1 This is a front view schematic diagram of a battery cell according to some embodiments of the first aspect of this utility model;
[0023] Figure 2 for Figure 1 A top-view diagram of the battery cell;
[0024] Figure 3 for Figure 1 A schematic diagram of the battery cell viewed from another direction;
[0025] Figure 4 This is a front view schematic diagram of a battery cell according to some embodiments of the second aspect of this utility model;
[0026] Figure 5 This is a front view schematic diagram of a battery cell according to some embodiments of the third aspect of this utility model;
[0027] Figure 6 This is a front view schematic diagram of a battery cell according to some embodiments of the fourth aspect of this utility model;
[0028] Figure 7 for Figure 6 Schematic diagram of the cross section at point AA;
[0029] Figure 8 This is a front view schematic diagram of a battery cell according to some embodiments of the fifth aspect of this utility model;
[0030] Figure 9 This is a front view schematic diagram of a battery according to some embodiments of the sixth aspect of the present utility model;
[0031] Figure 10 for Figure 9 Schematic diagram of cross-section at point AA.
[0032] Figure label:
[0033] Cell 10, straight area 11, bending area 12;
[0034] Electrode 100, straight portion 110, first straight portion 111, first edge 1111, second edge 1112, first clearance groove 1113, second clearance groove 1114, second straight portion 112, third edge 1121, third clearance groove 1122;
[0035] First pole ear 200;
[0036] Second pole ear 300;
[0037] Head tape 400;
[0038] 20. Aluminum-plastic film, 21. Deep pit surface, 22. Shallow pit surface, 23. Top seal. Detailed Implementation
[0039] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.
[0040] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0041] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0042] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.
[0043] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0044] Please refer to Figures 1-10 As shown, this utility model proposes a battery cell 10, which has a wound structure and a predetermined length, width, and thickness. It should be noted that the length, width, and thickness of the battery cell 10 mentioned in this utility model are only used as a directional reference and do not represent a specific size relationship between the length, width, and thickness.
[0045] Please refer to Figure 2As shown, the battery cell 10 of this utility model includes components in its own width direction (i.e., Figure 1 , Figure 2 The straight area 11 and the bent area 12 are arranged in the left-right direction shown in the figure. The straight area 11 and the bent area 12 further make the battery cell 10 form an approximately cuboid structure. Compared with the circular winding structure, the battery cell 10 of this utility model has a larger overall heat dissipation area and higher energy density.
[0046] Please refer to Figure 1 , Figure 2 As shown, the battery cell 10 of this invention also includes an electrode 100, which includes a flat portion 110 located in the flat region 11 and stacked along the thickness direction of the battery cell 10. The electrode 100 of this invention is formed as part of a wound structure by winding, thus the continuous electrode 100 is divided into multiple layers of flat portions 110 within the flat region 11, and the multiple layers of flat portions 110 are stacked along the thickness direction of the battery cell 10.
[0047] For ease of understanding by those skilled in the art, this utility model defines one of the straight sections 110 as the first straight section 111. Please refer to... Figure 1 , Figure 2 As shown, along the thickness direction of the cell 10, the first straight portion 111 is located at the outermost edge of the straight region 11 (e.g., Figure 2 (as shown on the front or rear side). The first straight portion 111 is along the length direction of the cell 10 (i.e., the front or rear side). Figure 1 The first straight portion 111 has a first edge 1111 and a second edge 1112 on different sides (shown in the upper or lower direction). The first straight portion 111 also has a first clearance groove 1113, which is along the thickness direction of the cell 10 (i.e., Figure 2 (As shown in the front-back direction) it penetrates the first straight portion 111 and extends along the length of the cell 10 to the first edge 1111.
[0048] Please refer to Figure 1 , Figure 2 As shown, the battery cell 10 of this invention also includes a first tab 200. The first tab 200 extends partially into the interior of the flat region 11 along the direction from the first edge 1111 to the second edge 1112. It should be noted that the above description does not mean that the first tab 200 of this invention must be inserted into the interior of the flat region 11 after the electrode sheet 100 is wound to form the battery cell 10. Exemplarily, in the processing of some embodiments, a portion of the first tab 200 is connected to the flat electrode sheet 100 and is located inside the flat region 11 after winding, while another portion extends out of the flat region 11 along the direction from the second edge 1112 to the first edge 1111.
[0049] In existing technology, battery cells need to be packaged in aluminum-plastic film and then subjected to drop tests so that those skilled in the art can assess the safety performance of the same batch of cells under extreme conditions. However, some cells short-circuit after the drop test, leading to spontaneous combustion. Analysis of the short-circuited cells revealed that the electrode sheet folded over on the side near the tab, causing the active material facing inwards towards the flat area to come into contact with the aluminum-plastic film, resulting in a short circuit in the cell.
[0050] Please refer to Figure 2 As shown, Figure 2 The diagram shows one of the more ideal winding shapes of the battery cell 10, and the thickness of the flat region 11 of the battery cell 10 (i.e., Figure 2 The dimensions (in the front and back directions) are the same everywhere. The inventors discovered in practice that after being processed into a battery, the flat area 11 of the cell 10 is often squeezed in its own thickness direction, making the area with the stacked tabs thicker. The distance between the edge of the corresponding electrode 100 and the center of the electrode 100 winding is larger. During the drop test, the inner side of the electrode 100 near the aforementioned edge is more likely to be impacted by the test ground and fold, ultimately causing the cell 10 to short circuit.
[0051] Please refer to Figure 1 , Figure 2 As shown, the first electrode tab 200 of this utility model extends into the interior of the flat region 11 along the direction from the first edge 1111 to the second edge 1112. Therefore, a portion of the first edge 1111 will have a larger distance from the center of the electrode sheet 100 due to the stacked first electrode tab 200. The inner side of the first flat portion 111, which is close to the first edge 1111 and overlapped with the first electrode tab 200 (see reference). Figure 1 , Figure 2 The first straight section (the upper front side of section 111) is more prone to flipping when impacted by the test ground.
[0052] Please refer to Figure 1 As shown, where Figure 1 The outline of the first tab 200 extending into the flat region 11 is shown by dashed lines. The battery cell 10 of this invention has a projected plane perpendicular to the thickness direction of the flat region 11 (i.e., parallel to...). Figure 1(The first tab 200 is projected onto the projection plane as a first projection, and the first clearance groove 1113 is projected onto the projection plane as a second projection. In the width direction of the cell 10, the first projection is located within the range of the second projection.) Through the above solution, the portion of the first straight portion 111 near the first edge 1111 and located in the area overlapping with the first tab 200 is removed by the first clearance groove 1113. After being impacted by the test ground, the entire edge of the first straight portion 111 is less likely to bend due to the thicker part of the first edge 1111 being cut off, thus reducing the risk of short circuit and improving the safety of the cell 10.
[0053] On the other hand, the first straight portion 111 can limit the adjacent straight portions 110 and the separator of the battery cell 10 in the winding state. Therefore, the edges of the straight portions 110 adjacent to the first straight portion 111 and the edges of the separator are less likely to bend after being impacted by the test ground, and the risk of short circuit will also be reduced, thus improving the safety of the battery cell 10.
[0054] Without departing from the inventive concept of this utility model, those skilled in the art may also provide additional clearance slots to increase the safety performance of the battery cell 10.
[0055] Please refer to Figures 1-3 As shown, where Figure 3 The outline of the first tab 200 extending into the flat region 11 is shown by dashed lines. As a preferred embodiment, in some embodiments, one of the flat portions 110 is defined as the second flat portion 112. Along the thickness direction of the cell 10, the first flat portion 111 and the second flat portion 112 are located on both sides of the flat region 11. The second flat portion 112 has a third edge 1121 in the length direction of the cell 10. The first edge 1111 and the third edge 1121 are located on the same side in the length direction of the cell 10. The second flat portion 112 also has a third clearance groove 1122. The third clearance groove 1122 penetrates the second flat portion 112 along the thickness direction of the cell 10 and extends to the third edge 1121 along the length direction of the cell 10. The projection of the third clearance groove 1122 on the projection plane is the fifth projection. In the width direction of the cell 10, the first projection is located within the range of the fifth projection.
[0056] With the above solution, the portion of the second straight section 112 that is close to the third edge 1121 and located in the area overlapping with the first tab 200 is removed by the third clearance groove 1122. The third clearance groove 1122 can further reduce the risk of the edge of the second straight section 112 being flipped after being impacted by the test ground, thereby further improving the safety of the cell 10.
[0057] Please refer to Figure 6 , Figure 7 As shown, where Figure 7 The cross-sectional view is for illustrative purposes only and does not represent a limitation on the structure of the battery cell 10 in the embodiments of this utility model. As a preferred embodiment, in some embodiments, the battery cell 10 further includes a head adhesive tape 400, wherein one of the flat portions 110 is defined as the second flat portion 112. Along the thickness direction of the battery cell 10, the first flat portion 111 and the second flat portion 112 are respectively located on both sides of the flat area 11; the head adhesive tape 400 is attached to the side of the first flat portion 111 away from the second flat portion 112, and wraps around the first edge 1111 to the side of the second flat portion 112 away from the first flat portion 111.
[0058] Through the above solution, the distance between the two ends of the head adhesive tape 400 in the thickness direction of the battery cell 10 will be affected by the size of the middle part of the head adhesive tape 400, thereby limiting the movement of the first straight part 111 connected to the head adhesive tape 400 in the thickness direction of the battery cell 10, and limiting the movement of the second straight part 112 connected to the head adhesive tape 400 in the thickness direction of the battery cell 10, thereby reducing the risk of the straight part 110 folding in the drop test.
[0059] Specifically, please refer to Figure 7 As shown, taking the movement of the first straight portion 111 as an example, when the part of the first straight portion 111 with the head adhesive tape 400 is attached to the outside, it will be restricted by the second straight portion 112 attached to the other end of the head adhesive tape 400. Therefore, when the part of the first straight portion 111 near the first edge 1111 is moved to the outside, it will also be restricted by the second straight portion 112, making it less likely to fold relative to itself.
[0060] Without departing from the inventive concept of this utility model, the present utility model does not impose specific limitations on the shape and specifications of the clearance groove. In some embodiments, the outline of the first clearance groove 1113 is semi-circular. As a preferred embodiment, please refer to... Figure 1 As shown, the first clearance groove 1113 has a rectangular outline. The rectangular outline is beneficial for the processing of the electrode 100, and the specifications of the clearance groove are easier to adjust, thereby facilitating the evaluation of various parameters of the electrode 100 by those skilled in the art.
[0061] Without departing from the inventive concept of this utility model, the present utility model does not impose specific limitations on the specifications of the clearance groove. As a preferred embodiment, please refer to... Figure 1 As shown, Figure 1The distance D between the edge of the first clearance groove 1113 and the first edge 1111 along the length of the cell 10 is shown. The distance D between the edge of the first clearance groove 1113 and the first edge 1111 is 1 mm to 3 mm. When D is less than 3 mm, the active material content of the electrode 100 is higher, which enables the cell 10 to have a higher energy density. When D is greater than 1 mm, the possibility of the first straight portion 111 folding can be effectively reduced, thus effectively improving the safety performance of the cell 10.
[0062] Please refer to Figure 1 , Figure 2 As shown, in some embodiments, the battery cell 10 further includes a second tab 300, a portion of which extends into the interior of the flat region 11. The projection of the second tab 300 onto the projection plane is a third projection, which is offset from the first projection. Through this scheme, the first tab 200 and the second tab 300 are offset from each other in the width direction, preventing the first flat portion 111 from simultaneously stacking on the first tab 200 and the second tab 300 in the thickness direction of the battery cell 10. This reduces the distance between the portion of the first flat portion 111 and the tab stacked on top of the winding center, and lowers the risk of the portion near the first edge 1111 folding over during a drop test.
[0063] Based on the above solutions, please refer to Figure 1 , Figure 4 As shown, where Figure 1 , Figure 4 The outlines of the first tab 200 and the second tab 300 extending into the flat region 11 are shown. In some embodiments, the second tab 300 extends partially into the interior of the flat region 11 along the direction from the first edge 1111 to the second edge 1112; in the width direction of the cell 10, the third projection is located within the range of the second projection. With the above solution, the portion of the first flat portion 111 near the first edge 1111 and located in the area overlapping with the second tab 300 is removed by the first clearance groove 1113. After being impacted by the test ground, the edge of the first flat portion 111 is less likely to bend because the thickened part of the first edge 1111 is cut off by the second tab 300, further reducing the risk of short circuit and improving the safety of the cell 10.
[0064] On the other hand, during the processing of cell 10, the equipment only needs to process a clearance groove to remove the part that overlaps with the first tab 200 and the second tab 300, which is beneficial to improving the manufacturing efficiency of cell 10.
[0065] As previously mentioned, the solution for further reducing the folding of the flat portion 110 in cell 10 using the head adhesive tape 400 is described above. Please refer to the following for details. Figure 4 , Figure 5As shown, in some embodiments, the portion of the head adhesive tape 400 used to attach the first flat portion 111 faces the length direction of the cell 10 (i.e., Figure 4 , Figure 5 (In the downward direction) it crosses the first clearance slot 1113.
[0066] Please refer to Figure 1 , Figure 6 As shown, where Figure 6 The outlines of the first tab 200 and the second tab 300 extending into the flat region 11 are shown. In some embodiments, the second tab 300 extends partially into the interior of the flat region 11 along the direction from the first edge 1111 to the second edge 1112; the first flat region 111 also has a second clearance groove 1114, which penetrates the first flat region 111 along the thickness direction of the cell 10 and extends to the first edge 1111 along the length direction of the cell 10; the projection of the second clearance groove 1114 on the projection plane is a fourth projection, and in the width direction of the cell 10, the third projection is located within the range of the fourth projection. Through the above scheme, the portion of the first flat region 111 near the first edge 1111 and located in the area overlapping with the second tab 300 is removed by the second clearance groove 1114, making the edge of the first flat region 111 less prone to folding after being impacted by the test ground, further reducing the risk of short circuit, and further improving the safety of the cell 10.
[0067] Compared to directly setting a clearance groove to cut off the part that overlaps with the first tab 200 and the second tab 300, the above solution can further retain the relatively thin part of the first straight portion 111 near the first edge 1111, which increases the content of active material in the cell 10 and is beneficial to increasing the energy density of the cell 10.
[0068] As previously described, a third clearance groove 1122 is provided on the second straight portion 112 to further reduce the risk of tipping over. In conjunction with the above solution, those skilled in the art can also provide a fourth clearance groove on the part where the second straight portion 112 overlaps with the second tab 300, thereby further reducing the risk of tipping over.
[0069] Please refer to Figure 8 As shown, in some embodiments, the battery cell 10 further includes a second tab 300, which extends partially into the interior of the straight portion 11 along the direction from the second edge 1112 to the first edge 1111. The first straight portion 111 also has a second clearance groove 1114, which penetrates the first straight portion 111 along the thickness direction of the battery cell 10 and extends to the second edge 1112 along the length direction of the battery cell 10. The projection of the second tab 300 onto the projection plane is a third projection, and the projection of the second clearance groove 1114 onto the projection plane is a fourth projection. In the width direction of the battery cell 10, the third projection is located within the range of the fourth projection.
[0070] The second tab 300 extends into the interior of the straight section 11 along the direction from the second edge 1112 to the first edge 1111. This causes the portion of the first straight section 111 close to the second edge 1112 and overlapping with the second tab 300 to be further away from the winding center, making it more prone to folding during drop tests. Through this design, the portion of the first straight section 111 close to the second edge 1112 is less likely to fold after impact from the test surface, further reducing the risk of short circuits and enhancing the safety of the battery cell 10.
[0071] This utility model also proposes a battery, including the cell 10 as described in any of the above embodiments. Since the portion of the first straight portion 111 of the cell 10 near the first edge 1111 and located in the area overlapping with the second tab 300 is removed by the first clearance groove 1113, the edge of the entire first straight portion 111 will be less prone to folding after being impacted by the test ground because the part of the first edge 1111 that is thickened by the second tab 300 is cut off, thus further reducing the risk of short circuit and improving the overall safety performance of the battery.
[0072] Please refer to Figure 9 , Figure 10 As shown, where Figure 10 This illustration is merely intended to show the battery structure and does not limit the battery structure in the embodiments of this utility model. Further, in some embodiments, the battery includes an aluminum-plastic film 20, which wraps the battery cell 10 and forms a shallow pit surface 22 and a deep pit surface 21. A first clearance groove 1113 is disposed on the side near the shallow pit surface 22. After the aluminum-plastic film 20 wraps the battery cell 10, it forms a top seal 23, which is typically located on one side of the battery cell 10 in the thickness direction. In the thickness direction, the surface of the battery near the top seal 23 is the shallow pit surface 22, and the surface away from the top seal 23 is the deep pit surface 21. The shallow pit surface 22 and the deep pit surface 21 facilitate battery assembly to external devices, allowing the external devices to utilize the space on the side of the top seal 23 near the deep pit surface 21. However, during drop testing, if the side of the deep pit surface 21 is impacted by the test ground, the electrode 100 on the side of the shallow pit surface 22 is prone to folding. Therefore, by placing the first clearance groove 1113 on the side closer to the shallow pit surface 22, it is less likely to flip when the battery top seal 23 is impacted on the side closer to the deep pit surface 21, thereby improving the overall safety performance of the battery.
[0073] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.
Claims
1. An electric cell, characterized by, The electric core has a winding structure and a set length, width and thickness, comprising: a flat area and a bending area arranged along the width direction of the electric core; and The tab comprises flat parts arranged along the thickness direction of the electric core in the flat area, and one of the flat parts is defined as a first flat part, which is located at the outermost side of the flat area along the thickness direction of the electric core; the first flat part has a first edge and a second edge on different sides of the first flat part along the length direction of the electric core, and the first flat part further has a first avoiding slot which penetrates the first flat part along the thickness direction of the electric core and extends to the first edge along the length direction of the electric core; The first tab partially extends into the interior of the flat area along the direction from the first edge to the second edge; The electric core has a projection plane perpendicular to the thickness direction of the flat area, the projection of the first tab on the projection plane is a first projection, and the projection of the first avoiding slot on the projection plane is a second projection, and the first projection is located within the range of the second projection along the width direction of the electric core.
2. The electric cell of claim 1, wherein, The electric core further comprises a second tab partially extending into the interior of the flat area, and the projection of the second tab on the projection plane is a third projection, which is staggered with the first projection.
3. The electric cell of claim 2, wherein, The second tab partially extends into the interior of the flat area along the direction from the first edge to the second edge; and the third projection is located within the range of the second projection along the width direction of the electric core.
4. The electric cell of claim 2, wherein, The second tab partially extends into the interior of the flat area along the direction from the first edge to the second edge; the first flat part further has a second avoiding slot which penetrates the first flat part along the thickness direction of the electric core and extends to the first edge along the length direction of the electric core; the projection of the second avoiding slot on the projection plane is a fourth projection, and the third projection is located within the range of the fourth projection along the width direction of the electric core.
5. The electric cell of claim 1, wherein, The electric core further comprises a second tab partially extending into the interior of the flat area along the direction from the first edge to the second edge; the first flat part further has a second avoiding slot which penetrates the first flat part along the thickness direction of the electric core and extends to the first edge along the length direction of the electric core; the projection of the second avoiding slot on the projection plane is a fourth projection, and the third projection is located within the range of the fourth projection along the width direction of the electric core.
6. The electric cell of claim 1, wherein, The definition of one of the flat parts is a second flat part, and the first flat part and the second flat part are located on both sides of the flat area along the thickness direction of the battery cell; the second flat part has a third edge in the length direction of the battery cell, and the first edge and the third edge are located on the same side in the length direction of the battery cell; the second flat part also has a third avoiding slot, which penetrates through the second flat part along the thickness direction of the battery cell and extends to the third edge along the length direction of the battery cell; the third avoiding slot is projected as a fifth projection on the projection plane, and the first projection is located within the range of the fifth projection in the width direction of the battery cell.
7. The electric cell of claim 1, wherein, The battery cell also includes a head adhesive tape, and the definition of one of the flat parts is a second flat part, and the first flat part and the second flat part are located on both sides of the flat area along the thickness direction of the battery cell; the head adhesive tape is attached to the side of the first flat part away from the second flat part and is wound around the first edge to the side of the second flat part away from the first flat part.
8. The electric cell of claim 1, wherein, In the length direction of the battery cell, the distance between the edge of the first avoiding slot and the first edge is 1mm to 3mm.
9. A battery characterized by The battery cell includes any one of claims 1 to 8.
10. The battery of claim 9, wherein, The battery includes an aluminum plastic film, the aluminum plastic film wraps the battery cell and forms a shallow pit surface and a deep pit surface, and the first avoiding slot is arranged on one side close to the shallow pit surface.