Battery cell and battery

Abstract

The utility model discloses a kind of electric core and battery, electric core includes: electrode assembly, electrode assembly includes electrode main body and the tab connected with electrode main body;Aluminum plastic film, aluminum plastic film is wrapped in electrode main body, tab is from electrode main body through the top seal portion of aluminum plastic film and extends to aluminum plastic film outside;Wherein, top seal portion is provided with structure weakening zone at the position corresponding to tab.When the heat production of electrode main body increases, heat can break through structure weakening zone faster, and the top seal portion of aluminum plastic film is broken, so as to release heat in advance, so, the temperature difference of environment in electric core and outside environment can be effectively reduced, reduce the internal reaction of electric core, improve the thermal stability of electric core.

Description

Technical Field

[0001] This utility model relates to the field of energy storage device technology, and in particular to a battery cell and battery. Background Technology

[0002] Lithium-ion batteries boast advantages such as high energy density, high output power, and long cycle life, and are commonly used in mobile electronic devices like Bluetooth headsets, mobile phones, laptops, tablets, and cameras, as well as portable power banks. With the rapid advancement of electronic product technology, higher demands are being placed on the energy density, battery life, and fast charging capabilities of lithium-ion batteries. However, as the demand for energy density in lithium batteries increases, safety issues are becoming increasingly prominent. Lithium batteries can experience varying degrees of abnormal temperature rise under extreme environments. When the battery temperature reaches a certain level, its internal materials undergo thermal decomposition, releasing large amounts of gas and heat, causing the battery temperature to rise rapidly and triggering thermal runaway, potentially leading to fires or even explosions and posing safety hazards.

[0003] When a lithium-ion battery is heated, the negative electrode SEI film begins to decompose, followed by the decomposition and melting of the separator. This causes a reaction between the negative electrode and the electrolyte, which in turn causes the positive electrode and the electrolyte to decompose. The reactions within the battery promote each other, causing the battery to release a large amount of heat and harmful gases in a short period of time. When the battery cannot dissipate heat sufficiently, thermal runaway will occur, which will trigger an internal short circuit and eventually lead to battery combustion or explosion. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a battery cell with high thermal stability.

[0005] This utility model also proposes a battery having the above-mentioned battery cell.

[0006] A battery cell according to a first aspect of the present invention includes: an electrode assembly, the electrode assembly including an electrode body and a tab connected to the electrode body; and an aluminum-plastic film, the aluminum-plastic film wrapping the electrode body, the tab extending from the electrode body through the top sealing portion of the aluminum-plastic film and extending to the outside of the aluminum-plastic film.

[0007] The top seal portion is provided with a structural weakening zone at the position where it connects to the electrode tab.

[0008] The battery cell according to the embodiments of this utility model has at least the following beneficial effects:

[0009] In the battery cell of this invention, when the heat generated by the electrode body increases, the heat can break through the structural weakening zone more quickly and puncture the top seal of the aluminum-plastic film, thereby releasing heat in advance. In this way, the temperature difference between the internal and external environments of the battery cell can be effectively reduced, internal reactions of the battery cell can be reduced, and the thermal stability of the battery cell can be improved.

[0010] According to some embodiments of the present invention, the electrode tab includes a positive electrode tab, and the structural weakening region is provided at the position where the top seal is connected to the positive electrode tab.

[0011] According to some embodiments of the present invention, the top seal has an electrode cover portion covering a portion of the electrode tab structure. The electrode cover portion includes a first cover area and a second cover area, wherein the second cover area is located at one end of the electrode cover portion near the electrode body.

[0012] Wherein, the connection strength between the second covering area and the electrode is less than the connection strength between the first covering area and the electrode to form the structural weakening area.

[0013] According to some embodiments of the present invention, the second covering area is a triangular structure, the second covering area has a first vertex and a first side opposite to the first vertex, the first vertex is disposed away from the electrode body, and the first side is closer to the electrode body than the first vertex.

[0014] According to some embodiments of the present invention, the second covering area is an isosceles triangle structure or an equilateral triangle structure.

[0015] According to some embodiments of this utility model, the angle of the first vertex is α, which satisfies: 30° < α < 90°.

[0016] According to some embodiments of the present invention, the distance between the first vertex and the outer edge of the top sealing portion is D, which satisfies: D ≥ 0.6mm.

[0017] According to some embodiments of the present invention, the distance from the first side to the first vertex is L, and the distance from the inner edge to the outer edge of the top sealing portion is W;

[0018] It must satisfy: 0.6mm ≤ L ≤ 1mm; and / or, W / L ≥ 2.

[0019] According to some embodiments of this utility model, the distance from the first side to the first vertex is L, and the length of the first side is R; the distance from the inner edge to the outer edge of the top seal is W, and the width of the electrode cover is K along the width direction of the electrode ear; satisfying: 2≤ KW / RL ≤ 6.

[0020] According to some embodiments of the present invention, the second covering area is a trapezoidal structure, wherein the long side of the trapezoidal structure is closer to the electrode body than its short side.

[0021] According to some embodiments of the present invention, the angle between any hypotenuse of the trapezoidal structure and the long side of the trapezoidal structure is between 60° and 80°.

[0022] The battery according to a second aspect of the present invention includes the battery cell described in the above embodiment.

[0023] The battery according to the embodiments of the present invention has at least the following beneficial effects:

[0024] The battery of this invention has the aforementioned cell. When the heat generated by the electrode body increases, the heat can break through the structural weakening zone more quickly and puncture the top seal of the aluminum-plastic film, thereby releasing heat in advance. In this way, the temperature difference between the internal and external environments of the cell can be effectively reduced, internal reactions of the cell can be reduced, and the thermal stability of the cell can be improved.

[0025] 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

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0027] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present invention before it is sealed with an aluminum-plastic film;

[0028] Figure 2 This is a schematic diagram of the structure of a battery cell after being sealed in an aluminum-plastic film according to an embodiment of the present invention;

[0029] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0030] Figure 4 This is an enlarged view of the tab cover portion according to an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the structure of the top seal upper cutter or the top seal lower cutter;

[0032] Figure 6 This is an enlarged view of the tab cover portion of another embodiment of the present invention.

[0033] Icon labels:

[0034] 100. Electrode assembly; 110. Electrode body; 120. Electrode tab; 121. Positive electrode tab; 122. Negative electrode tab;

[0035] 200, Aluminum-plastic film; 210, Pit location; 220, Top sealing part; 220a, Inner edge of the top sealing part; 220b, Outer edge of the top sealing part; 221, Electrode cover part; 2211, First covering area; 2212, Second covering area; 2212a, First vertex; 2212b, First side; 222, Structural weakening area;

[0036] 300. Top sealing knife; 310. Groove;

[0037] 400. Lower top sealing knife. Detailed Implementation

[0038] 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.

[0039] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They 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, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0040] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0041] like Figure 1 , Figure 2 As shown, a battery cell provided in one embodiment of the present invention includes an electrode assembly 100 and an aluminum-plastic film 200.

[0042] The electrode assembly 100 includes an electrode body 110 and a tab 120 connected to the electrode body 110.

[0043] Specifically, the electrode body 110 includes a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate. The electrode body 110 can be formed by stacking and winding the positive electrode plate, the separator, and the negative electrode plate.

[0044] The positive electrode material in the positive electrode sheet can be LiCoO2, LiNiO2, LiMnO2, LiMn2O4, LiMnPO4, LiFePO4, LiNi1 / 3Co1 / 3Mn1 / 3O2, or LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.85 Co 0.15 Al 0.05 One or more of O2. The negative electrode active material layer in the negative electrode sheet may include, but is not limited to, one or more of graphite, soft carbon, hard carbon, carbon fiber, mesophase carbon microspheres, silicon-based materials, tin-based materials, lithium titanate, or other metals that can form alloys with lithium. The separator includes one or more of polyethylene, polypropylene, polyvinylidene fluoride, and their multilayer composite films.

[0045] Furthermore, the tab 120 includes a positive tab 121 and a negative tab 122, wherein the positive tab 121 is connected to the positive electrode plate and the negative tab 122 is connected to the negative electrode plate.

[0046] like Figure 2 As shown, the aluminum-plastic film 200 is wrapped around the electrode body 110, and the tab 120 extends from the electrode body 110 through the top sealing portion 220 of the aluminum-plastic film 200 and out of the aluminum-plastic film 200.

[0047] Combination Figure 1 and Figure 2 Specifically, before the aluminum-plastic film 200 wraps the electrode body 110, it is necessary to punch out a pit 210 in the aluminum-plastic film 200. After the electrode body 110 is placed in the pit 210, the tab 120 extends outward from the pit 210 to protrude from the aluminum-plastic film 200. Then, the aluminum-plastic film 200 is folded according to the fold line to cover the electrode body 110. After that, the aluminum-plastic film 200 can be top-sealed and side-sealed by hot pressing to wrap the electrode body 110. At this time, the tab 120 passes through the top sealing part 220 of the aluminum-plastic film 200 from the electrode body 110 and extends to the outside of the aluminum-plastic film 200.

[0048] Combination Figure 2 and Figure 3 A structural weakening zone 222 is provided at the position where the top seal 220 connects to the tab 120.

[0049] Specifically, during the top sealing of the aluminum-plastic film 200, the aluminum-plastic film 200 is also heat-pressed to the tab 120. The structural weakening zone 222 at the connection point between the top sealing portion 220 and the tab 120 refers to an area where the connection strength between the aluminum-plastic film 200 and the tab 120 is relatively low in the portion of the aluminum-plastic film 200 covering the tab 120; this area is the structural weakening zone 222. When the heat generated by the electrode body 110 increases, the heat can more quickly penetrate the structural weakening zone 222 and break open the top sealing portion 220 of the aluminum-plastic film 200, thereby releasing heat earlier. This effectively reduces the temperature difference between the internal and external environments of the battery cell, reduces internal reactions within the battery cell, and improves the thermal stability of the battery cell. It should be noted that when the battery cell is placed in a high-temperature environment, the temperature at the tab 120 is higher than the temperature at other locations on the battery cell. The temperature at the tab 120 can reach the melting point of the top seal 220 of the aluminum-plastic film 200 more quickly. Compared to other locations on the top seal 220, the thermal shock generated by the electrode body 110 is more likely to break the aluminum-plastic film 200 earlier. In particular, when the battery cell is placed in a high-temperature environment, the temperature at the positive tab 121 is higher than the temperature at the negative tab 122. Specifically, the current density near the positive tab 121 is higher than the current density near the negative tab 122. Therefore, the temperature at the positive tab 121 is higher than the temperature at the negative tab 122 at high temperatures. The positive tab 121 is more prone to heat-induced opening. In one embodiment, the structural weakening region 222 is provided at the location where the top seal 220 connects to the positive tab 121.

[0050] Combination Figure 3 and Figure 4 Furthermore, the top seal 220 has a tab cover 221 that covers a portion of the structure of the tab 120. Specifically, one end of the tab 120 is connected to the electrode body 110, and the other end extends out of the aluminum-plastic film 200. The aluminum-plastic film 200 does not cover the entire tab 120, but only a portion of its structure. The portion of the aluminum-plastic film 200 covering the tab 120 is defined as the tab cover 221, which includes a first covering area 2211 and a second covering area 2212. The second covering area 2212 is located at the end of the tab cover 221 closer to the electrode body 110. The connection strength between the second covering area 2212 and the tab 120 is less than the connection strength between the first covering area 2211 and the tab 120, thus forming a structural weakening area 222.

[0051] Combination Figure 4 and Figure 5It is understood that the top sealing portion 220 of the aluminum-plastic film 200 is sealed by a top sealing tool. The top sealing tool includes a lower top sealing tool 400 and an upper top sealing tool 300 disposed above the lower top sealing tool 400. After the top sealing portion 220 of the aluminum-plastic film 200 is placed between the lower top sealing tool 400 and the upper top sealing tool 300, the aluminum-plastic film 200 is top sealed by causing the upper top sealing tool 300 to move downward and squeeze the aluminum-plastic film 200 (during this process, both the lower top sealing tool 400 and the upper top sealing tool 300 will heat the aluminum-plastic film 200 and heat press it). The upper sealing blade 300 and / or the lower sealing blade 400 have grooves 310 on their lower sidewalls, which correspond to the positions of the tabs 120 of the electrode assembly 100. When the upper sealing blade 300 and the lower sealing blade 400 seal the aluminum-plastic film 200, the aluminum-plastic film 200 at the positions corresponding to the grooves 310 will not be completely fused, forming a structurally weakened area 222. Furthermore, corresponding to the tab cover 221, the first cover area 2211 is normally hot-pressed and bonded to the tab 120, while the second cover area 2212 is subjected to less pressure from the sealing blades, forming a structurally weakened area 222. The connection strength between the second cover area 2212 and the tab 120 is less than the connection strength between the first cover area 2211 and the tab 120.

[0052] Furthermore, the inner edge of the lower sidewall of the upper sealing blade 300 (corresponding to the inner edge 220a of the top sealing portion 220) and / or the inner edge of the upper sidewall of the lower sealing blade 400 (corresponding to the inner edge 220a of the top sealing portion 220) are provided with the aforementioned groove 310. Thus, when the aluminum-plastic film 200 is hot-pressed using the upper sealing blade 300 and the lower sealing blade 400, the structurally weakened area 222 (second covering area 2212) formed on the aluminum-plastic film 200 is located at the inner edge 220a of the top sealing portion, specifically at the end of the tab covering portion 221 near the electrode body 110. Thus, when the battery cell is working, heat can first enter the space between the second covering area 2212 and the tab 120. When the heat generated by the electrode body 110 increases, the thermal shock can also quickly break open the first covering area 2211, thereby releasing heat in advance.

[0053] It should be noted that by changing the depth of the groove 310 on the upper sealing knife 300 or the lower sealing knife 400, the connection strength between the second covering area 2212 and the electrode 120 can be changed. The deeper the groove 310, the lower the connection strength between the second covering area 2212 and the electrode 120. When the groove 310 is too deep, the second covering area 2212 and the electrode 120 may not bond together, which can also form a structural weakening area 222. The depth of the groove 310 can be set between 0.08mm and 0.12mm, so that the second covering area 2212 and the electrode 120 are not completely fused together, effectively forming the structural weakening area 222.

[0054] like Figure 4 As shown, in some embodiments, the second covering area 2212 has a triangular structure, having a first vertex 2212a and a first side 2212b opposite to the first vertex 2212a. The first vertex 2212a is positioned away from the electrode body 110, and the first side 2212b is closer to the electrode body 110 than the first vertex 2212a. Specifically, the first side 2212b is flush with the inner edge 220a of the top seal portion 220, and the first vertex 2212a is located on the side of the first side 2212b away from the electrode body 110.

[0055] Understandably, according to the principle of stress concentration, the stress of a triangle can be concentrated at the vertex. The thermal shock in the space between the second covering area 2212 and the tab 120 can more easily break open the outer edge 220b of the top seal 220 through the first vertex 2212a, release the gas in advance, reduce the temperature difference between the inside and outside of the cell, and improve thermal stability.

[0056] In this embodiment, the second covering area 2212 has an equilateral triangle structure. The symmetry of the equilateral triangle causes the three vertices to bear high stress simultaneously, resulting in a higher overall stress concentration coefficient. In other embodiments, the second covering area 2212 has an isosceles triangle structure, with the first vertex 2212a being the apex of the second covering area 2212. The stress concentration at the apex is higher, and the hot air in the space between the second covering area 2212 and the tab 120 can more easily push open the outer edge 220b of the top seal 220 through the first vertex 2212a. Preferably, by setting the shape of the second covering area 2212 such that the stress concentration coefficient Kt of the triangular region between the second covering area 2212 and the tab 120 satisfies 2.0 ≤ Kt ≤ 4.0, the thermal shock in the space between the second covering area 2212 and the tab 120 can more easily push open the outer edge 220b of the top seal 220.

[0057] like Figure 4 As shown, in some embodiments, the angle of the first vertex 2212a is α, satisfying: 30° < α < 90°. It is understood that if the first vertex 2212a is an obtuse angle, due to the large radius of curvature, almost no stress concentration occurs. Furthermore, the smaller the angle, the smaller the radius of curvature, leading to a sharp increase in local stress. If the vertex angle is less than 30°, there is a risk that the top seal 220 of the battery cell may be broken during the formation process. Therefore, setting the angle α of the first vertex 2212a between 30° and 90° ensures that thermal shock within the space between the second covering area 2212 and the tab 120 can more easily break open the outer edge 220b of the top seal 220, and also mitigates the problem of the top seal 220 being broken during the formation process.

[0058] In some embodiments, the distance between the first vertex 2212a and the outer edge 220b of the top seal 220 is D, satisfying: D ≥ 0.6 mm. This can mitigate the problem of electrolyte penetration caused by the first vertex 2212a being too close to the outer edge 220b of the top seal 220. The value of D can be, but is not limited to, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, etc.

[0059] Furthermore, the distance from the first side 2212b to the first vertex 2212a is L, and the width of the top sealing portion 220 is W, satisfying: W / L ≥ 2, 0.6mm ≤ L ≤ 1mm. Here, the width of the top sealing portion 220 refers to the distance between the inner edge 220a and the outer edge 220b of the top sealing portion 220. It can be understood that W / L ≥ 2 allows for a larger distance D between the first vertex 2212a and the outer edge 220b of the top sealing portion 220, mitigating the problem of electrolyte penetration caused by the first vertex 2212a being too close to the outer edge 220b of the top sealing portion 220.

[0060] Furthermore, the length of the first side 2212b is R, and the width of the tab cover 221 along the width direction of the tab 120 is K, satisfying: 2 ≤ KW / RL ≤ 6. It is understandable that if the proportion of the second cover area 2212 is too large, there is a risk of leakage; if the proportion is too small, the improvement in thermal performance will be less effective. Therefore, by ensuring that 2 ≤ KW / RL ≤ 6, the risk of leakage can be reduced, and the cell can also have better thermal performance.

[0061] The following provides test data for several different embodiments:

[0062]

[0063] Thermal performance test: The lithium-ion battery made from the above cells was charged at 0.5C CC to 4.53V, CV to 0.02C. The charged battery was placed in a thermal shock test chamber (suspension test). It was heated by convection or circulating hot air at an initial temperature of 25±3℃. The oven temperature was increased at a rate of 5±2℃ / min until the cell could not catch fire or explode. The temperature was maintained for 60 minutes and then stopped. The test was considered passed.

[0064] The test results are shown in the table below:

[0065]

[0066] It should be noted that the higher the maximum temperature that can be passed, the better the thermal stability of the lithium battery.

[0067] like Figure 6 As shown, in some other embodiments, the second covering area 2212 has a trapezoidal structure, with the longer side of the trapezoid closer to the electrode body 110 than its shorter side. Similarly, when the battery cell is working, heat can first enter the space between the second covering area 2212 and the tab 120. When the heat generated by the electrode body 110 increases, the thermal shock can also quickly break open the first covering area 2211, thereby releasing heat earlier. In addition, the cross-sectional area of ​​the space between the second covering area 2212 and the tab 120 gradually decreases along the direction from the longer side to the shorter side of the trapezoidal structure. Thus, when heat enters the space between the second covering area 2212 and the tab 120, the closer to the shorter side, the greater the pressure of the thermal shock, which helps to break open the first covering area 2211 more quickly, thereby releasing heat earlier.

[0068] Furthermore, the second covering area 2212 can be an isosceles trapezoidal structure, where the angle between any hypotenuse and the long side of the trapezoid is the same. Of course, in other embodiments, the second covering area 2212 may not be an isosceles trapezoidal structure. In this case, the angle between any hypotenuse and the long side of the trapezoid is between 60° and 80°.

[0069] Furthermore, the distance between the long and short sides of the trapezoidal structure can be set between 0.1mm and 0.5mm, and the length of the long side of the trapezoidal structure can be set between 2mm and 5mm. This ensures that the area of ​​the trapezoidal structure is within a reasonable range, preventing the area of ​​the second covering area 2212 from being too large or too small. If the area of ​​the second covering area 2212 is too large, there is a risk of leakage; if the area is too small, the improvement in thermal performance will be less effective.

[0070] This utility model also provides a battery, which includes the battery cell of the above embodiment, wherein the battery is a lithium-ion battery.

[0071] The battery of this utility model has the above-mentioned cell. When the heat generated by the electrode body 110 increases, the heat can break through the structural weakening zone 222 more quickly and break open the top seal 220 of the aluminum-plastic film 200, thereby releasing the heat in advance. In this way, the temperature difference between the internal environment and the external environment of the cell can be effectively reduced, the internal reaction of the cell can be reduced, and the thermal stability of the cell can be improved.

[0072] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. 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.

[0073] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, include: An electrode assembly, the electrode assembly including an electrode body and a tab connected to the electrode body; An aluminum-plastic film is wrapped around the electrode body, and the tab extends from the electrode body through the top sealing portion of the aluminum-plastic film and out of the aluminum-plastic film. The connection between the top seal and the electrode ear is provided with a structural weakening zone.

2. The battery cell according to claim 1, characterized in that, The electrode includes a positive electrode, and the structural weakening region is provided at the position where the top seal connects to the positive electrode.

3. The battery cell according to claim 1, characterized in that, The top seal has an electrode cover portion that covers a portion of the electrode tab structure. The electrode cover portion includes a first cover area and a second cover area, with the second cover area located at one end of the electrode cover portion near the electrode body. Wherein, the connection strength between the second covering area and the electrode is less than the connection strength between the first covering area and the electrode to form the structural weakening area.

4. The battery cell according to claim 3, characterized in that, The second coverage area has a triangular structure, with a first vertex and a first side opposite to the first vertex. The first vertex is positioned away from the electrode body, and the first side is closer to the electrode body than the first vertex.

5. The battery cell according to claim 4, characterized in that, The second coverage area is an isosceles triangle structure or an equilateral triangle structure.

6. The battery cell according to claim 4, characterized in that, The angle of the first vertex is α, which satisfies: 30° < α < 90°; And / or, the distance between the first vertex and the outer edge of the top seal is D, satisfying: D ≥ 0.6mm; And / or, the distance from the first side to the first vertex is L, the length of the first side is R, the distance from the inner edge to the outer edge of the top seal is W, and the width of the electrode cover is K along the width direction of the electrode tab, satisfying: 2≤KW / RL≤ 6.

7. The battery cell according to claim 4, characterized in that, The distance from the first side to the first vertex is L, and the distance from the inner edge to the outer edge of the top seal is W; It must satisfy: 0.6mm ≤ L ≤ 1mm; and / or, W / L ≥ 2.

8. The battery cell according to claim 3, characterized in that, The second coverage area has a trapezoidal structure, and the longer side of the trapezoidal structure is closer to the electrode body than its shorter side.

9. The battery cell according to claim 8, characterized in that, The trapezoidal structure is an isosceles trapezoidal structure.

10. A battery, characterized in that, Includes the battery cell as described in any one of claims 1 to 9.

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