A battery cell, a battery, and an electrical device.

Abstract

This application provides a battery cell, a battery, and an electrical device. The battery cell includes a cell and a coating film. The coating film includes a first coating film, which covers the circumference of the cell along a first direction or a second direction. The first coating film has a first end and a second end, which are non-overlapping. The first direction is perpendicular to the second direction. According to this application, the battery cell with the first coating film covering the circumference of the cell along the first direction or the second direction reduces the displacement of the electrode plates and increases the overall binding force, thus suppressing the expansion of the cell in the first or second direction and in the thickness direction. The non-overlapping first and second ends of the first coating film also prevent shear stress at the interface of the first coating film, achieving a uniform stress distribution.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Technology

[0002] During charging and discharging, the battery electrodes expand anisotropically. Traditional encapsulation structures cannot conduct expansion stress, leading to localized stress concentration, causing separator wrinkles, electrode interface peeling, and electrode displacement, resulting in poor interface contact and rapid increase in internal resistance after cycling. Utility Model Content

[0003] This application provides a battery cell, a battery, and an electrical device, which are designed to provide a constraint force for the battery cell and prevent electrode displacement and short circuit.

[0004] According to a first aspect of this application, a battery cell includes: a battery cell; a coating film, the coating film including a first coating film, the first coating film covering the circumferential direction of the battery cell along a first direction or a second direction of the battery cell, the first coating film having a first end and a second end, the first end and the second end being non-overlapping, and the first direction being perpendicular to the second direction.

[0005] According to the battery cell of the first aspect of this application, the first coating film covers the circumferential direction of the battery cell along the first direction or the second direction of the battery cell. The distance between the first end and the second end of the first coating film is ΔG and satisfies: ΔG≥0mm. Under the coating of the first coating film, the displacement of the electrode is reduced and the overall binding force is increased. This can suppress the expansion of the battery cell in the first direction or the second direction and the thickness direction of the battery cell. It can also avoid the generation of shear stress at the interface of the first coating film and achieve uniform stress distribution.

[0006] According to some embodiments of this application, the first coating film covers the circumferential direction of the battery cell along a first direction, and the battery cell is provided with two tabs on one side along the first direction, with the first coating film located between two adjacent tabs.

[0007] By setting the first coating film 21 to wrap around the cell 1 in the first direction, a basic constraint frame is formed, which fixes the root area of ​​the tab 11 and restricts the initial displacement of the electrode during the stacking and liquid injection process.

[0008] According to some embodiments of this application, the battery cell includes two side areas and two large surface areas. The two side areas are arranged opposite each other along a first direction or a second direction of the battery cell, and the two large surface areas are arranged opposite each other along a third direction of the battery cell. The area of ​​the large surface area is larger than the area of ​​the side areas, and the thickness of the first coating film covering the large surface area is greater than the thickness of the first coating film covering the side areas. The first direction, the second direction, and the third direction are perpendicular to each other.

[0009] By setting the thickness of the first coating film covering the large area to be greater than the thickness of the first coating film covering the side area, the expansion force and gas generation in different areas are matched, the constraint force is balanced, and different expansion margins are given to release the stress in different areas.

[0010] According to some embodiments of this application, the thickness of the first coating film covering the large area is A1, and the thickness of the first coating film covering the side area is A2, and satisfies: A1≥2A2.

[0011] By setting the thickness of the first coating film covering the large surface area to be twice or more than the thickness of the first coating film covering the side surface area, the expansion force of different areas of the battery cell can be better addressed.

[0012] According to some embodiments of this application, the first coating film covers the circumferential direction of the battery cell along a first direction. The coating film further includes a second coating film, which covers the circumferential direction of the battery cell along a second direction. The first coating film has a third end and a fourth end in the second direction, and the second coating film has a fifth end and a sixth end in the second direction. The third end and the fifth end are not overlapped, and the fourth end and the sixth end are not overlapped.

[0013] The battery cell can be fully encapsulated by the second and first coating films. The expansion force of the battery cell can be suppressed in the width, length and thickness directions. Shear stress can also be avoided at the interface between the first and second coating films, thus achieving uniform stress distribution.

[0014] According to some embodiments of this application, the battery cell includes two side areas and two large surface areas. The two side areas are arranged opposite to each other along a second direction of the battery cell, and the two large surface areas are arranged opposite to each other along a third direction of the battery cell. The area of ​​the large surface areas is larger than the area of ​​the side areas, and the thickness of the second coating film covering the large surface areas is greater than the thickness of the second coating film covering the side areas.

[0015] By setting the thickness of the second coating film covering the large area to be greater than the thickness of the second coating film covering the side area, the expansion force and gas generation in different areas are matched, the constraint force is balanced, and different expansion margins are given to release the stress in different areas.

[0016] According to some embodiments of this application, the thickness of the second coating film covering the large area is B1, and the thickness of the second coating film covering the side area is B2, and satisfies: B1≥2B2.

[0017] By setting the thickness of the second coating film covering the large surface area to be twice or more than the thickness of the second coating film covering the side surface area, the expansion force of different areas of the battery cell can be better coped with.

[0018] According to some embodiments of this application, the coating film is provided with a plurality of wetting pores.

[0019] By providing multiple wetting pores in the coating film, the efficiency of electrolyte wetting into the cell is accelerated, thereby shortening the wetting time of the battery cell.

[0020] According to some embodiments of this application, the plurality of the impregnation holes are arranged in a row and column pattern.

[0021] By setting multiple wetting holes arranged in rows and columns, the uniformity of electrolyte wetting is improved.

[0022] According to some embodiments of this application, the diameter of the impregnation hole is D and satisfies: 0.1mm≤D≤10mm; and / or, the distance between two adjacent impregnation holes is L and satisfies: 1mm≤L≤100mm.

[0023] By rationally designing the size of the wetting holes, the wetting efficiency of the electrolyte can be accelerated, and the structural strength of the first and second coating films can be avoided. Similarly, by rationally arranging the position of the wetting holes, the wetting efficiency of the electrolyte can be accelerated, and the structural strength of the first and second coating films can be avoided.

[0024] According to some embodiments of this application, the thickness of the coating film is C and satisfies: 50μm≤C≤100μm.

[0025] By rationally designing the thickness of the coating film, it is possible to ensure the structural strength of the coating film in the circumferential direction of the cell without taking up too much internal space of the battery cell.

[0026] According to some embodiments of this application, in the second direction of the battery cell, the distance between the first coating film and the tab is E and satisfies: E≤0.1mm.

[0027] By arranging the first coating film and the tab at intervals in the second direction, the first coating film will not come into contact with the tab, and the risk of tab breakage caused by electrode displacement can also be suppressed.

[0028] The battery according to the second aspect of this application includes: the battery cell according to the first aspect of this application.

[0029] According to the battery of the second aspect of this application, by setting the battery cell according to the above embodiment of this application, the displacement of the electrode is reduced under the coating film, the overall binding force is increased, the expansion of the cell in the first direction, the second direction and the third direction can be suppressed, and shear stress can be avoided at the coating film interface, thus achieving uniform stress distribution and improving the safety of the battery.

[0030] According to the third aspect of this application, by setting the battery according to the embodiment of this application, the displacement of the electrode is reduced under the coating film, the overall binding force is increased, the expansion of the cell in the first, second and third directions can be suppressed, and shear stress can be avoided at the coating film interface, thus achieving uniform stress distribution and improving the safety of the electrical device. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of a battery cell provided in an embodiment of this application;

[0032] Figure 2 This is a schematic diagram of a battery cell provided in another embodiment of this application;

[0033] Figure 3 This is a schematic diagram of a battery cell provided in another embodiment of this application;

[0034] Figure 4 yes Figure 3 The schematic diagram of the battery cell shown shows that wetting holes are provided on the side of the cell.

[0035] Figure 5 yes Figure 3 The schematic diagram of the battery cell shown shows that wetting holes are provided in both the side area and the large surface area of ​​the cell.

[0036] Explanation of reference numerals in the attached figures:

[0037] 10. Battery cells;

[0038] 1. Battery cell; 11. Electrode; 12. Side area; 13. Large surface area;

[0039] 2. Coating film; 21. First coating film; 211. First end; 212. Second end; 213. Third end; 214. Fourth end; 22. Second coating film; 221. Fifth end; 222. Sixth end; 23. Immersion hole. Detailed Implementation

[0040] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0041] The following is for reference. Figures 1-5 The battery cell 10 of the present application is described.

[0042] The battery cell 10 provided in this application embodiment, such as Figures 1-3 As shown, the battery cell 10 includes a cell 1 and a coating film 2. The coating film 2 includes a first coating film 21. The first coating film 21 covers the circumference of the cell 1 along a first direction (refer to the Y direction shown in the figure) or a second direction (refer to the X direction shown in the figure). The first coating film 21 has a first end 211 and a second end 212. The first end 211 and the second end 212 are not overlapped. The first direction is perpendicular to the second direction.

[0043] The first covering film 21 can be an adhesive tape. The side of the first covering film 21 facing the battery cell 1 is coated with adhesive to fix the first covering film 21 to the outer periphery of the battery cell 1. The adhesion is improved after hot pressing.

[0044] The battery cell 1 includes a positive electrode, a separator, and a negative electrode. The positive electrode, separator, and negative electrode are stacked sequentially to form a battery cell assembly. The battery cell 1 is composed of multiple battery cell assemblies. A first coating film 21 is used to cover the circumference of the battery cell 1 to fix the positive electrode, separator, and negative electrode, and to prevent the positive electrode, separator, and negative electrode of the battery cell 1 from shifting when the battery cell 1 is moved or when liquid is injected.

[0045] The first coating film 21 covers the circumference of the battery cell 1 along a first direction, thus limiting the battery cell 1 in the first direction and the thickness direction. Alternatively, the first coating film 21 covers the circumference of the battery cell 1 along a second direction, thus limiting the battery cell 1 in the second direction and the thickness direction. Even in an environment where the battery cell 10 generates gas, the first coating film 21 can still maintain a tight fit with the battery cell 1, suppressing the expansion of the battery cell 1 in the first or second direction and the thickness direction, avoiding uneven stress on the first coating film 21, and thus preventing wrinkles from forming on the first coating film 21.

[0046] For example, cell 1 is an elongated body with a length direction, a width direction, and a thickness direction. The dimension of cell 1 along the length direction is larger than the dimension along the width direction, and both the dimension along the length direction and the dimension along the width direction are larger than the dimension along the thickness direction. The first direction is the length direction of cell 1, and the second direction is the width direction of cell 1.

[0047] The first coating film 21 surrounds the battery cell 1 in the first or second direction and terminates on the same side as the starting end. The starting and ending positions do not overlap, forming a non-overlapping closed loop. That is, there is a certain gap between the first end 211 and the second end 212 of the first coating film 21, or the first end 211 and the second end 212 of the first coating film 21 abut against each other, so as to avoid shear stress at the interface of the first coating film 21 and ensure that there is no delamination between the layers after long-term cycling.

[0048] For example, the distance between the first end 211 and the second end 212 of the first covering film 21 can be 0 mm, 1 mm, 2 mm or 3 mm, etc.

[0049] For example, the cell 1 has a dimension of W2 in the second direction, and the first coating film 21 is wrapped around the outer periphery of the cell 1 along the second direction. The width of the first coating film 21 is between 0.8W2 and W2.

[0050] According to the battery cell 10 of this application embodiment, the first coating film 21 covers the circumferential direction of the battery cell 1 along the first direction or the second direction of the battery cell. Under the coating of the first coating film 21, the displacement of the electrode is reduced and the overall binding force is increased. This can suppress the expansion of the battery cell 1 in the first direction, the second direction and the thickness direction of the battery cell. The first end 211 and the second end 212 of the first coating film 21 are not overlapped, which can also avoid the generation of shear stress at the interface of the first coating film 21 and achieve uniform stress distribution.

[0051] In some embodiments of this application, such as Figures 1-2 As shown, the first coating film 21 covers the circumference of the battery cell 1 along the first direction. The battery cell 1 has two tabs 11 on one side along the first direction. The first coating film 21 is located between two adjacent tabs 11. The first coating film 21 wraps around the battery cell 1 along the first direction to form a basic constraint frame, which fixes the root area of ​​the tabs 11 and restricts the initial displacement of the electrode during the stacking and liquid injection process.

[0052] The two tabs 11 are the positive tab and the negative tab, respectively. The positive tab is drawn from the positive plate, and the negative tab is drawn from the negative plate.

[0053] For example, the distance between the two tabs 11 is W, and the first coating film 21 is wrapped around the outer periphery of the cell 1 along the first direction of the cell 1. The width of the first coating film 21 is between 0.8W and W.

[0054] In some embodiments of this application, such as Figure 1 As shown, the battery cell 1 includes two side areas 12 and two large surface areas 13. A first coating film 21 covers the circumference of the battery cell 1 along a first direction. The two side areas 12 are arranged opposite each other along the first direction of the battery cell 1, and the two large surface areas 13 are arranged opposite each other along a third direction of the battery cell 1 (refer to the Z direction shown in the attached figure). The first direction is the length direction of the battery cell 1, and the third direction is the thickness direction of the battery cell 1. That is, the two side areas 12 are arranged opposite each other along the length direction of the battery cell 1, and the two side areas 12 are respectively the top surface and the bottom surface of the battery cell 1. The two large surface areas 13 are arranged opposite each other along the thickness direction of the battery cell 1, and the two large surface areas 13 are respectively the two large side surfaces of the battery cell 1. The area of ​​the large surface area 13 is larger than the area of ​​the side areas 12. The first direction, the second direction, and the third direction are mutually perpendicular.

[0055] The thickness of the first coating film 21 covering the large surface area 13 is greater than the thickness of the first coating film 21 covering the side surface area 12. When the cell 1 expands, the expansion force of the large surface area 13 is greater than that of the side surface area 12. Therefore, the thickness of the first coating film 21 is designed to be greater in the large surface area 13 than in the side surface area 12 to match the expansion force and gas generation in different areas, balance the constraint force, provide different expansion margins, and release stress in different areas. Figure 2 As shown, in some other embodiments of this application, the battery cell 1 includes two side areas 12 and two large surface areas 13. A first covering film 21 covers the circumference of the battery cell 1 along a second direction. The two side areas 12 are arranged opposite to each other along the second direction of the battery cell 1, and the two large surface areas 13 are arranged opposite to each other along a third direction of the battery cell 1 (refer to the Z direction shown in the figure). The second direction is the width direction of the battery cell 1, and the third direction is the thickness direction of the battery cell 1. That is, the two side areas 12 are arranged opposite to each other along the width direction of the battery cell 1, and the two side areas 12 are respectively two small side surfaces of the battery cell 1. The two large surface areas 13 are arranged opposite to each other along the thickness direction of the battery cell 1, and the two large surface areas 13 are respectively two large side surfaces of the battery cell 1. The area of ​​the large surface area 13 is larger than the area of ​​the side areas 12.

[0056] The thickness of the first coating film 21 covering the large surface area 13 is greater than the thickness of the first coating film 21 covering the side surface area 12. When the cell 1 expands, the expansion force of the large surface area 13 is greater than the expansion force of the side surface area 12. The thickness of the first coating film 21 is designed to be greater than that of the first coating film 21 covering the large surface area 13 to match the expansion force and gas generation in different areas, balance the constraint force, provide different expansion margins, and release the stress in different areas.

[0057] In some embodiments of this application, such as Figures 1-2 As shown, the thickness of the first coating film 21 covering the large surface area 13 is A1, and the thickness of the first coating film 21 covering the side surface area 12 is A2, and satisfies: A1≥2A2. The thickness of the first coating film 21 covering the large surface area 13 is twice or more the thickness of the first coating film 21 covering the side surface area 12, which can better cope with the expansion force of different areas of the cell 1.

[0058] For example, the thickness of the coating film 2 is between 50 μm and 100 μm, the thickness of the first coating film 21 covering the large surface area 13 can be 100 μm, and the thickness of the first coating film 21 covering the side surface area 12 can be 50 μm.

[0059] In some embodiments of this application, such as Figure 3 As shown, the first coating film 21 covers the circumferential direction of the battery cell 1 along the first direction of the battery cell 1. The coating film 2 also includes a second coating film 22, which covers the circumferential direction of the battery cell 1 along the second direction (refer to the X direction shown in the figure). The first coating film 21 has a third end 213 and a fourth end 214 in the second direction, and the second coating film 22 has a fifth end 221 and a sixth end 222 in the second direction. The third end 213 and the fifth end 221 are not overlapped, and the fourth end 214 and the sixth end 222 are not overlapped.

[0060] For example, the distance between the third end 213 of the first coating film 21 and the fifth end 221 of the second coating film 22 can be 0 mm, 1 mm, 2 mm or 3 mm, etc.

[0061] For example, the distance between the fourth end 214 of the first covering film 21 and the sixth end 222 of the second covering film 22 can be 0mm, 1mm, 2mm or 3mm, etc.

[0062] The first direction is the length direction of the battery cell 1, and the second direction is the width direction of the battery cell 1. The first coating film 21 covers the circumference of the battery cell 1 along the length direction of the battery cell 1, and the starting position and the ending position do not overlap. The second coating film 22 covers the circumference of the battery cell 1 along the width direction of the battery cell 1, and the starting position of the second coating film 22 does not overlap with the outer edge of the first coating film 21 along the width direction of the battery cell 1 on one side, and the ending position of the second coating film 22 does not overlap with the outer edge of the first coating film 21 along the width direction of the battery cell 1 on the other side.

[0063] The second coating film 22 and the first coating film 21 can fully cover the battery cell 1, suppressing the expansion force of the battery cell 1 in the width direction, length direction and thickness direction, and solving the problem of uncontrolled electrode displacement caused by uniaxial constraint.

[0064] There is a certain gap between the first end 211 and the second end 212 of the first covering film 21, or the first end 211 and the second end 212 of the first covering film 21 abut against each other. There is a certain gap between the fifth end 221 of the second covering film 22 and the third end 213 of the first covering film 21, or the fifth end 221 of the second covering film 22 and the third end 213 of the first covering film 21 abut against each other. There is a certain gap between the sixth end 222 of the second covering film 22 and the fourth end 214 of the first covering film 21, or the sixth end 222 of the second covering film 22 and the fourth end 214 of the first covering film 21 abut against each other. This is to avoid uneven stress on the first covering film 21 and the second covering film 22, and to avoid wrinkles on the first covering film 21 and the second covering film 22.

[0065] The outer periphery of the battery cell 1 is fully wrapped by the first coating film 21 and the second coating film 22. An aluminum-plastic film is also wrapped around the outer periphery of the first coating film 21 and the second coating film 22. After the aluminum-plastic film is broken open, a continuous sealing interface is formed, which isolates water vapor and inhibits water vapor from entering the battery cell 1 through the first coating film 21 and the second coating film 22. The first coating film 21 and the second coating film 22 can also block the intrusion of water and oxygen, reduce the hydrolysis rate of LiPF, and reduce the generation of side reactions.

[0066] In some embodiments of this application, such as Figure 3 As shown, the battery cell 1 includes two side areas 12 and two large surface areas 13. The two side areas 12 are arranged opposite each other along the second direction of the battery cell 1, and the two large surface areas 13 are arranged opposite each other along the third direction of the battery cell 1. The two side areas 12 are arranged opposite each other along the width direction of the battery cell 1, and the two side areas 12 are the two sides of the battery cell 1. The two large surface areas 13 are arranged opposite each other along the thickness direction of the battery cell 1, and the two large surface areas 13 are the two large sides of the battery cell 1. The area of ​​the large surface area 13 is larger than the area of ​​the side areas 12.

[0067] The thickness of the second coating film 22 covering the large surface area 13 is greater than the thickness of the second coating film 22 covering the side surface area 12. When the cell 1 expands, the expansion force of the large surface area 13 is greater than the expansion force of the side surface area 12. The thickness of the second coating film 22 is designed to be greater than that of the second coating film 22 covering the large surface area 13 to match the expansion force and gas generation in different areas, balance the constraint force, provide different expansion margins, and release the stress in different areas.

[0068] In some embodiments of this application, such as Figure 3 As shown, the thickness of the second coating film 22 covering the large surface area 13 is B1, and the thickness of the second coating film 22 covering the side surface area 12 is B2, and satisfies: B1≥2B2. The thickness of the second coating film 22 covering the large surface area 13 is twice or more the thickness of the second coating film 22 covering the side surface area 12, which can better cope with the expansion force of different areas of the cell 1.

[0069] For example, the thickness of the coating film 2 is between 50 μm and 100 μm, the thickness of the second coating film 22 covering the large surface area 13 can be 100 μm, and the thickness of the second coating film 22 covering the side surface area 12 can be 50 μm.

[0070] In some embodiments of this application, such as Figures 4-5 As shown, the coating film 2 has multiple wetting holes 23, which are used to connect the battery cell 1 with the external environment. The coating film 2 includes a first coating film 21 and a second coating film 22. The first coating film 21 is used to cover the circumference of the battery cell 1 along a first direction. Multiple wetting holes 23 can be provided on the first coating film 21. The wetting holes 23 are used to accelerate the efficiency of electrolyte wetting into the battery cell 1, thereby shortening the wetting time of the battery cell 10. The second coating film 22 is used to cover the circumference of the battery cell 1 along a second direction. Multiple wetting holes 23 can be provided on the second coating film 22. The electrolyte is preferentially injected into the central region of the battery cell 1 through the wetting holes 23 on the first coating film 21 covering the root of the tab 11, and then diffuses to the edge of the battery cell 1 along the wetting holes 23 on the second coating film 22 covering the side region 12, thereby shortening the wetting time.

[0071] For example, during the injection phase, the wetting pores 23 are opened to promote penetration, and during the circulation phase, the first coating membrane 21 and the second coating membrane 22 are thermally contracted, partially closing the wetting pores 23 and inhibiting electrolyte evaporation loss.

[0072] In some embodiments of this application, such as Figures 4-5 As shown, the multiple wetting holes 23 are arranged in rows and columns, which improves the uniformity of electrolyte wetting.

[0073] In some embodiments of this application, such as Figures 4-5 As shown, the diameter of the wetting hole 23 is D and satisfies: 0.1mm≤D≤10mm. A reasonable design of the size of the wetting hole 23 can accelerate the wetting efficiency of the electrolyte and avoid reducing the structural strength of the first coating membrane 21 and the second coating membrane 22. For example, the diameter of the wetting hole 23 can be 0.1mm, 3mm, 5mm, 7mm, or 10mm, etc.

[0074] The distance between two adjacent wetting holes 23 is L and satisfies: 1mm≤L≤100mm. A reasonable arrangement of the wetting holes 23 can accelerate the wetting efficiency of the electrolyte and avoid reducing the structural strength of the first coating membrane 21 and the second coating membrane 22. For example, the distance between two adjacent wetting holes 23 can be 1mm, 20mm, 50mm, 70mm, or 100mm, etc.

[0075] In some embodiments of this application, such as Figures 4-5 As shown, the thickness of the coating film 2 is C and satisfies: 50μm≤C≤100μm. This ensures the structural strength of the coating film 2 around the cell 1 while minimizing its internal space occupation by the cell. For example, the thickness of the coating film 2 can be 50μm, 70μm, 80μm, or 100μm.

[0076] In some embodiments of this application, such as Figure 1 , Figure 3 As shown, in the second direction of the cell 1, the distance between the first coating film 21 and the tab 11 is E and satisfies: E≤0.1mm. The first coating film 21 will not come into contact with the tab 11, and can also suppress the risk of tab 11 breakage caused by electrode displacement. For example, in the second direction, the distance between the first coating film 21 and the tab 11 can be 0.05mm, 0.07mm, 0.08mm or 0.1mm, etc.

[0077] The battery provided in this application embodiment includes: the battery cell 10 according to the first aspect of this application.

[0078] According to the battery of the second aspect of this application, by setting the battery cell 10 according to the above embodiment of this application, the displacement of the electrode is reduced under the coating film 2, the overall binding force is increased, the expansion of the cell 1 in the first direction, the second direction and the third direction can be suppressed, and the shear stress generated at the interface of the coating film 2 can be avoided, thereby achieving uniform stress distribution and improving the safety of the battery.

[0079] The electrical device provided in this application includes the battery described above according to the second aspect of this application.

[0080] According to the third aspect of this application, by setting the battery according to the embodiment of this application, the displacement of the electrode is reduced under the coating film 2, the overall binding force is increased, the expansion of the cell 1 in the first direction, the second direction and the third direction can be suppressed, and the shear stress generated at the interface of the coating film 2 can be avoided, thus achieving uniform stress distribution and improving the safety of the electrical device.

[0081] In this application, "multiple" refers to two or more.

[0082] In this application, unless otherwise expressly defined, the terms "installation," "connection," and "linking" 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 between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0083] The terms “first,” “second,” “third,” “fourth,” etc., in this application (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0084] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0085] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, if the method includes steps A and B, it means that the method may include steps A and B performed sequentially, or it may include steps B and A performed sequentially. For example, if the method may also include step C, it means that step C may be added to the method in any order. For example, the method may include steps A, B, and C, or it may include steps A, C, and B, or it may include steps C, A, and B, etc.

[0086] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell (10) characterized by, include: Battery cell (1); The coating film (2) includes a first coating film (21), which covers the circumferential direction of the battery cell (1) along a first direction or a second direction of the battery cell (1). The first coating film (21) has a first end (211) and a second end (212), which are not overlapping. The first direction is perpendicular to the second direction.

2. The battery cell (10) according to claim 1, characterized in that The first coating film (21) covers the circumferential direction of the battery cell (1) along the first direction. The battery cell (1) has two tabs (11) on one side along the first direction. The first coating film (21) is located between two adjacent tabs (11).

3. The battery cell (10) according to claim 1, characterized in that The battery cell (1) includes two side areas (12) and two large areas (13). The two side areas (12) are arranged opposite each other along a first direction or a second direction of the battery cell (1). The two large areas (13) are arranged opposite each other along a third direction of the battery cell (1). The area of ​​the large areas (13) is larger than the area of ​​the side areas (12). The thickness of the first coating film (21) covering the large areas (13) is greater than the thickness of the first coating film (21) covering the side areas (12). The first direction, the second direction and the third direction are perpendicular to each other.

4. The battery cell (10) according to claim 3, characterized in that The thickness of the first coating film (21) covering the large surface area (13) is A1, and the thickness of the first coating film (21) covering the side surface area (12) is A2, and satisfies: A1≥2A2.

5. The battery cell (10) according to claim 1, characterized in that The first coating film (21) covers the circumferential direction of the battery cell (1) along a first direction. The coating film (2) further includes a second coating film (22). The second coating film (22) covers the circumferential direction of the battery cell (1) along a second direction. The first coating film (21) has a third end (213) and a fourth end (214) in the second direction. The second coating film (22) has a fifth end (221) and a sixth end (222) in the second direction. The third end (213) and the fifth end (221) are not overlapping. The fourth end (214) and the sixth end (222) are not overlapping.

6. The battery cell (10) according to claim 5, characterized in that, The battery cell (1) includes two side areas (12) and two large areas (13). The two side areas (12) are arranged opposite to each other along a second direction of the battery cell (1), and the two large areas (13) are arranged opposite to each other along a third direction of the battery cell (1). The area of ​​the large areas (13) is larger than the area of ​​the side areas (12), and the thickness of the second coating film (22) covering the large areas (13) is greater than the thickness of the second coating film (22) covering the side areas (12).

7. The battery cell (10) according to claim 6, characterized in that The thickness of the second coating film (22) covering the large surface area (13) is B1, and the thickness of the second coating film (22) covering the side surface area (12) is B2, and satisfies: B1≥2B2.

8. The battery cell (10) according to claim 1, characterized in that The coating membrane (2) is provided with multiple wetting pores (23).

9. The battery cell (10) according to claim 8, characterized in that The multiple wetting holes (23) are arranged in a row and column.

10. The battery cell (10) according to claim 8, characterized in that The diameter of the immersion hole (23) is D and satisfies: 0.1mm≤D≤10mm; and / or the distance between two adjacent immersion holes (23) is L and satisfies: 1mm≤L≤100mm.

11. The battery cell (10) according to claim 1, characterized in that The thickness of the coating film (2) is C and satisfies: 50μm≤C≤100μm.

12. The battery cell (10) according to claim 2, characterized in that In the second direction of the battery cell (1), the distance between the first coating film (21) and the tab (11) is E and satisfies: E≤0.1mm.

13. A battery, characterized by include: The battery cell (10) according to any one of claims 1-12.

14. An electrical device, comprising: include: The battery according to claim 13.

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