Battery monomer, battery module and battery pack

Abstract

The utility model discloses a battery monomer, battery module and battery pack, battery monomer includes battery cell and insulating film, battery cell has two opposite end face along the first direction and is located the side face between two end face, the side face includes two first side face and two second side face, two first side face is opposite along the second direction, two second side face is opposite along the first direction, and the two second side face is opposite along the second direction. The two second side faces are oppositely arranged in the third direction, and the first side face is used for being connected with a module shell through a structural adhesive layer; the insulating film covers the side surfaces and comprises a first insulating film and a second insulating film, the first insulating film covers the first side surface, the second insulating film covers at least one of the two second side surfaces, and the bonding strength between the first insulating film and the first side surface is greater than that between the second insulating film and the second side surface. According to the battery monomer disclosed by the utility model, the condition that the insulating film is stripped from the battery core in the process of detaching the battery monomer from the module shell can be reduced or avoided, and meanwhile, the cost can be relatively low.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery monomer, a battery module and a battery pack. Background Art

[0002] In the related art, the side of the battery cell is usually coated with an insulating film to ensure the insulation and safety between the battery cells after multiple battery cells are assembled into a battery module. However, when the battery cell in the related art is removed from the module shell, there is a risk that the insulating film will peel off from the battery cell. The above problem can be solved by using an insulating film with higher bonding strength, but it will lead to higher production costs. Therefore, there is room for improvement. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to propose a battery cell, the insulating film of which includes a first insulating film and a second insulating film, the first insulating film covers the first side of the battery cell connected to the module shell, the second insulating film covers the second side of the battery cell, and the bonding strength between the first insulating film and the first side is greater than the bonding strength between the second insulating film and the second side, so that the bonding strength between the insulating film and the first side of the battery cell is greater, which can reduce or avoid the situation where the insulating film is peeled off from the battery cell during the disassembly process of the battery cell from the module shell; in addition, since the bonding strength between the second insulating film and the second side is less than the bonding strength between the first insulating film and the first side, the production cost can be lower.

[0004] The utility model provides a battery module with the battery monomer.

[0005] The utility model also provides a battery pack having the battery module.

[0006] A battery cell according to an embodiment of the first aspect of the utility model includes: a battery cell, wherein the battery cell has two end faces arranged opposite to each other along a first direction and a side face located between the two end faces, wherein the side face includes two first side faces and two second side faces, wherein the two first side faces are arranged opposite to each other along a second direction, and the two second side faces are arranged opposite to each other along a third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other, and the first side face is used to be connected to a module shell through a structural adhesive layer; an insulating film, wherein the insulating film is coated on the side face and includes a first insulating film and a second insulating film, wherein the first insulating film covers the first side face, and the second insulating film covers at least one of the two second side faces, and the bonding strength between the first insulating film and the first side face is greater than the bonding strength between the second insulating film and the second side face.

[0007] According to the battery cell of the embodiment of the utility model, the insulating film of the battery cell includes a first insulating film and a second insulating film, the first insulating film covers the first side surface of the battery cell connected to the module shell, the second insulating film covers the second side surface of the battery cell, and the bonding strength between the first insulating film and the first side surface is greater than the bonding strength between the second insulating film and the second side surface, so that the bonding strength between the insulating film and the first side surface of the battery cell can be greater, which can reduce or avoid the occurrence of the insulating film peeling off from the battery cell during the disassembly process of the battery cell from the module shell; in addition, since the bonding strength between the second insulating film and the second side surface is less than the bonding strength between the first insulating film and the first side surface, the production cost can be lowered.

[0008] According to some embodiments of the present invention, the first insulating film and the second insulating film are formed independently.

[0009] According to some embodiments of the present invention, the first insulating film and the second insulating film are made of different materials; and / or the thickness of the first insulating film is greater than the thickness of the second insulating film.

[0010] According to some embodiments of the utility model, the first side surface is adjacent to the second side surface, one end of the first insulating film adjacent to the second insulating film is a first edge portion, one end of the second insulating film adjacent to the first insulating film is a second edge portion, and the first edge portion and the second edge portion are overlapped to form an overlapping area.

[0011] According to some embodiments of the present invention, part of the overlapping area covers the first side surface and another part of the overlapping area covers the second side surface, and the second edge portion covers a side of the first edge portion away from the first side surface.

[0012] According to some embodiments of the utility model, the first insulating film is the same as the second insulating film, the first insulating film is fixed to the first side through a first adhesive layer, the second insulating film is fixed to the second side through a second adhesive layer, the thickness of the first adhesive layer is greater than or equal to the thickness of the second adhesive layer and / or the viscosity of the first adhesive layer is greater than or equal to the viscosity of the second adhesive layer.

[0013] According to some embodiments of the present invention, the first insulating film and the second insulating film are integrally formed.

[0014] According to some embodiments of the present invention, the area of ​​the first side surface is smaller than the area of ​​the second side surface.

[0015] According to the second aspect of the present invention, the battery module comprises: a module shell; and a battery cell according to the first aspect of the present invention, wherein the battery cell is disposed in the module shell.

[0016] According to the battery module of the embodiment of the utility model, by setting the above-mentioned battery cell, the insulating film of the battery cell includes a first insulating film and a second insulating film, the first insulating film covers the first side surface of the battery cell connected to the module shell, and the second insulating film covers the second side surface of the battery cell, and the bonding strength between the first insulating film and the first side surface is greater than the bonding strength between the second insulating film and the second side surface, so that the bonding strength between the insulating film and the first side surface of the battery cell can be greater, which can reduce or avoid the occurrence of the insulating film peeling off from the battery cell during the disassembly process of the battery cell from the module shell; in addition, since the bonding strength between the second insulating film and the second side surface is less than the bonding strength between the first insulating film and the first side surface, the production cost can be lower.

[0017] According to the embodiment of the third aspect of the utility model, the battery pack includes: a battery case; and a battery module according to the embodiment of the second aspect of the utility model, wherein the battery module is disposed in the battery case.

[0018] According to the battery pack of the embodiment of the utility model, by setting the above-mentioned battery module, the insulating film of the battery cell includes a first insulating film and a second insulating film, the first insulating film covers the first side of the battery cell connected to the module shell, and the second insulating film covers the second side of the battery cell, and the bonding strength between the first insulating film and the first side is greater than the bonding strength between the second insulating film and the second side, so that the bonding strength between the insulating film and the first side of the battery cell can be greater, which can reduce or avoid the occurrence of the insulating film peeling off from the battery cell during the disassembly process of the battery cell from the module shell; in addition, since the bonding strength between the second insulating film and the second side is less than the bonding strength between the first insulating film and the first side, the production cost can be lower.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 is a schematic diagram of a battery cell according to some embodiments of the present utility model;

[0022] Figure 2 yes Figure 1 A schematic diagram of the connection between the battery cell of the battery cell and the first insulating film;

[0023] Figure 3is a schematic diagram of the arrangement of multiple battery cells of a battery module according to some embodiments of the utility model;

[0024] Figure 4 It is a schematic diagram of multiple battery cells and a module housing of a battery module according to some embodiments of the present invention.

[0025] Reference numerals:

[0026] 200. Battery module;

[0027] 100. Battery cell;

[0028] 10. Battery core; 11. End face; 12. Side face; 13. First side face; 14. Second side face; 15. Positive and negative electrodes; 16. Explosion-proof valve;

[0029] 20. Insulating film; 21. First insulating film; 22. First edge portion; 23. Second insulating film; 24. Second edge portion; 25. Overlapping region;

[0030] 30. Module shell; 40. Structural adhesive layer. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] A battery cell 100 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0033] Reference Figure 1-Figure 2 According to the battery cell 100 of the first embodiment of the utility model, the battery cell 10 and the insulating film 20 are included. The battery cell 10 has two end faces 11 arranged opposite to each other along a first direction (for example, refer to the e1 direction in the accompanying drawings) and a side face 12 located between the two end faces 11. The side face 12 includes two first side faces 13 and two second side faces 14. The two first side faces 13 are arranged opposite to each other along a second direction (for example, refer to the e2 direction in the accompanying drawings), and the two second side faces are arranged opposite to each other along a third direction (for example, refer to the e3 direction in the accompanying drawings). The first direction, the second direction and the third direction are perpendicular to each other. The first side face 13 is used to connect with the module shell 30 through the structural adhesive layer 40.

[0034] Among them, the two end surfaces 11 of the battery cell 10 can be provided with a variety of components, such as the positive and negative electrodes 15 of the battery cell 10, the explosion-proof valve 16 and other components, the side 12 of the battery cell 10 includes a first side 13 and a second side 14, the first side 13 is used to connect with the module shell 30 through the structural adhesive layer 40, and the first sides 13 of multiple battery cells 10 are respectively connected to the module shell 30 through the structural adhesive layer 40, and can then be assembled into a battery module.

[0035] It should be noted that the “plurality” in the present invention refers to two or more than two.

[0036] The insulating film 20 is coated on the side surface 12 and includes a first insulating film 21 and a second insulating film 23. The first insulating film 21 covers the first side surface 13, and the second insulating film 23 covers at least one of the two second side surfaces 14. For example, the second insulating film 23 covers one of the second side surfaces 14, and for another example, the second insulating film 23 covers both second side surfaces 14. The bonding strength between the first insulating film 21 and the first side surface 13 is greater than the bonding strength between the second insulating film 23 and the second side surface 14. By providing the insulating film 20 on the side surface 12 of the battery cell 10, the insulating film 20 can insulate and protect the battery cell 10, and can ensure the insulation and safety between the battery cells 10 after the multiple battery cells 100 are assembled into a battery module.

[0037] The first insulating film 21 covers the first side surface 13 of the battery cell 10 connected to the module shell 30, and the second insulating film 23 covers the second side surface 14 of the battery cell 10. The bonding strength between the first insulating film 21 and the first side surface 13 is greater than the bonding strength between the second insulating film 23 and the second side surface 14, so that the bonding strength between the insulating film 20 and the first side surface 13 of the battery cell 10 is relatively large, which can reduce or avoid the situation where the insulating film 20 is peeled off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30. In addition, if the first insulating film 21 with a relatively large bonding strength is used, the production cost of the battery cell 100 will be relatively high. By providing the second insulating film 23, and the bonding strength between the second insulating film 23 and the second side surface 14 is less than the bonding strength between the first insulating film 21 and the first side surface 13, the production cost can be relatively low.

[0038] According to the battery cell 100 of the embodiment of the utility model, the insulating film 20 of the battery cell 100 includes a first insulating film 21 and a second insulating film 23, the first insulating film 21 covers the first side surface 13 of the battery cell 10 connected to the module shell 30, and the second insulating film 23 covers the second side surface 14 of the battery cell 10, and the bonding strength between the first insulating film 21 and the first side surface 13 is greater than the bonding strength between the second insulating film 23 and the second side surface 14, so that the bonding strength between the insulating film 20 and the first side surface 13 of the battery cell 10 can be greater, which can reduce or avoid the insulating film 20 from peeling off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30; in addition, since the bonding strength between the second insulating film 23 and the second side surface 14 is less than the bonding strength between the first insulating film 21 and the first side surface 13, the production cost can be lower.

[0039] Reference Figure 1-Figure 2 According to some embodiments of the present invention, the first insulating film 21 and the second insulating film 23 are independently formed. The first insulating film 21 and the second insulating film 23 are independently formed, the first insulating film 21 covers the first side surface 13 and is connected to the first side surface 13, and the second insulating film 23 covers the second side surface 14 and is connected to the second side surface 14, so that the connection method between the insulating film 20 and the side surface 12 of the battery cell 10 is relatively simple and the operation is relatively convenient.

[0040] Reference Figure 1-Figure 2 According to some embodiments of the present invention, the first insulating film 21 and the second insulating film 23 are made of different materials. The first insulating film 21 is used to cover the first side surface 13 of the battery cell 10, and the second insulating film 23 is used to cover the second side surface 14 of the battery cell 10. The first insulating film 21 and the second insulating film 23 are made of different materials, so that the bonding strength of the first insulating film 21 is relatively large, thereby reducing or avoiding the first insulating film 21 from peeling off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30, and at the same time, reducing or avoiding the high cost of the insulating film 20.

[0041] For example, the second insulating film 23 can be a single-layer thin film structure such as polypropylene and polyethylene, which has a lower cost; the second insulating film 23 can be a composite film structure formed by a composite of polymer materials and ceramic materials, which has a higher cost and higher insulation and safety. The first insulating film 21 and the second insulating film 23 are made of different materials. While ensuring the insulating effect of the insulating film 20, the high cost of the insulating film 20 can be avoided.

[0042] Reference Figure 1According to some embodiments of the present invention, the thickness of the first insulating film 21 is greater than the thickness of the second insulating film 23. The first insulating film 21 is used to cover the first side surface 13 of the battery cell 10, and the second insulating film 23 is used to cover the second side surface 14 of the battery cell 10. The thickness of the first insulating film 21 is greater than the thickness of the second insulating film 23, so that the bonding strength of the first insulating film 21 is greater, thereby reducing or avoiding the first insulating film 21 from peeling off the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30, and reducing or avoiding the high cost of the insulating film 20. In addition, the thickness of the first insulating film 21 is greater than the thickness of the second insulating film 23, which can reduce or avoid the situation where the thickness of the insulating film 20 is thick and causes a high space occupancy rate of the battery cell 100, thereby effectively utilizing the space.

[0043] Reference Figure 1 According to some embodiments of the present invention, the first insulating film 21 and the second insulating film 23 are made of different materials, and the thickness of the first insulating film 21 is greater than the thickness of the second insulating film 23, so that the bonding strength of the first insulating film 21 is greater, thereby reducing or avoiding the situation where the first insulating film 21 is peeled off from the battery cell 10 during the disassembly process of the battery cell 100 and the module shell 30, and reducing or avoiding the situation where the cost of the insulating film 20 is high. In addition, the thickness of the first insulating film 21 is greater than the thickness of the second insulating film 23, which can reduce or avoid the situation where the thickness of the insulating film 20 is too thick and causes the battery cell 100 to occupy a higher space, thereby effectively utilizing the space reference Figure 1-Figure 2 According to some embodiments of the present invention, the first side surface 13 is adjacent to the second side surface 14, one end of the first insulating film 21 adjacent to the second insulating film 23 is a first edge portion 22, one end of the second insulating film 23 adjacent to the first insulating film 21 is a second edge portion 24, and the first edge portion 22 and the second edge portion 24 are overlapped to form an overlap region 25. The first insulating film 21 is used to cover the first side surface 13 of the battery cell 10, and the second insulating film 23 is used to cover the second side surface 14 of the battery cell 10. The first edge portion 22 of the first insulating film 21 and the second edge portion 24 of the second insulating film 23 are overlapped to form an overlap region 25, so that the insulating film 20 can cover the side surface 12 of the battery cell 10 more tightly, thereby ensuring the insulating effect of the insulating film 20.

[0044] Reference Figure 1-Figure 2According to some embodiments of the present invention, part of the overlapping area 25 covers the first side surface 13 and another part of the overlapping area 25 covers the second side surface 14, and the second edge portion 24 covers the side of the first edge portion 22 away from the first side surface 13. The first edge portion 22 of the first insulating film 21 and the second edge portion 24 of the second insulating film 23 are overlapped to form the overlapping area 25, and the overlapping area 25 covers the first side surface 13 and the second edge portion 24 covers the side of the first edge portion 22 away from the first side surface 13, which can improve the bonding strength between the first insulating film 21 and the first side surface 13, thereby reducing or avoiding the bonding strength between the insulating film 20 and the first side surface 13 of the battery cell 10 being less than the bonding strength of the structural adhesive layer 40 between the first side surface 13 and the module shell 30, resulting in the insulating film 20 being peeled off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30.

[0045] Reference Figure 1-Figure 2 According to some embodiments of the present invention, the first insulating film 21 is the same as the second insulating film 23, the first insulating film 21 is fixed to the first side surface 13 by a first adhesive layer, the second insulating film 23 is fixed to the second side surface 14 by a second adhesive layer, the thickness of the first adhesive layer is greater than the thickness of the second adhesive layer, or the thickness of the first adhesive layer is equal to the thickness of the second adhesive layer. The thickness of the first adhesive layer between the first insulating film 21 and the first side surface 13 is greater than the thickness of the second adhesive layer between the second insulating film 23 and the second side surface 14. The first adhesive layer with a larger thickness can make the bonding strength between the first insulating film 21 and the first side surface 13 larger, thereby reducing or avoiding the occurrence of the first insulating film 21 peeling off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30. At the same time, the second adhesive layer with a smaller thickness can make the space occupancy rate of the battery cell 100 lower, and can effectively utilize the space.

[0046] Reference Figure 1 According to some embodiments of the present invention, the viscosity of the first adhesive layer is greater than that of the second adhesive layer. The viscosity of the first adhesive layer between the first insulating film 21 and the first side surface 13 is greater than that of the second adhesive layer between the second insulating film 23 and the second side surface 14, so that the bonding strength between the first insulating film 21 and the first side surface 13 is greater, thereby reducing or avoiding the first insulating film 21 from peeling off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30.

[0047] Alternatively, the viscosity of the first adhesive layer between the first insulating film 21 and the first side surface 13 is equal to the viscosity of the second adhesive layer between the second insulating film 23 and the second side surface 14 .

[0048] Reference Figure 1-Figure 2According to some embodiments of the present invention, the first insulating film 21 is the same as the second insulating film 23, the first insulating film 21 is fixed to the first side surface 13 by a first adhesive layer, the second insulating film 23 is fixed to the second side surface 14 by a second adhesive layer, the thickness of the first adhesive layer is greater than the thickness of the second adhesive layer, and the viscosity of the first adhesive layer is greater than the viscosity of the second adhesive layer. The thickness of the first adhesive layer between the first insulating film 21 and the first side surface 13 is greater than the thickness of the second adhesive layer between the second insulating film 23 and the second side surface 14, and the viscosity of the first adhesive layer is greater than the viscosity of the second adhesive layer, which can make the bonding strength between the first insulating film 21 and the first side surface 13 greater, thereby reducing or avoiding the occurrence of the first insulating film 21 peeling off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30. At the same time, the second adhesive layer with a smaller thickness can make the space occupancy rate of the battery cell 100 lower, and can effectively utilize the space.

[0049] Reference Figure 1 According to some embodiments of the present invention, the first insulating film 21 and the second insulating film 23 are integrally formed. The first insulating film 21 and the second insulating film 23 are integrally formed, which can simplify the connection process between the insulating film 20 and the side surface 12 of the battery cell 10.

[0050] Reference Figure 1-Figure 2 According to some embodiments of the present invention, the area of ​​the first side 13 is smaller than the area of ​​the second side 14, so that the area of ​​the first insulating film 21 is smaller than the area of ​​the second insulating film 23, thereby reducing or avoiding the occurrence of excessively high costs of the insulating film 20.

[0051] Reference Figure 1-Figure 2 According to some embodiments of the present invention, the area of ​​the first side surface 13 is smaller than the area of ​​the second side surface 14, the first side surfaces 13 are two oppositely arranged, the second side surfaces 14 are two oppositely arranged, the two oppositely arranged first side surfaces 13 are both covered with the first insulating film 21, and the two oppositely arranged second side surfaces 14 are both covered with the second insulating film 23, thereby achieving the insulating effect of the insulating film 20. In addition, the area of ​​the first side surface 13 is smaller than the area of ​​the second side surface 14, the first side surfaces 13 are two oppositely arranged, and the second side surfaces 14 are two oppositely arranged, so that the area of ​​the first insulating film 21 is smaller than the area of ​​the second insulating film 23, thereby reducing or avoiding the situation where the cost of the insulating film 20 is too high.

[0052] Reference Figure 1-Figure 4According to the second embodiment of the present invention, the battery module 200 includes a module shell 30 and the above-mentioned battery cell 100, and the battery cell 100 is disposed in the module shell 30. The battery cell 100 is connected to the module shell 30 through a structural adhesive layer 40, and multiple battery cells 100 are respectively connected to the module shell 30 through the structural adhesive layer 40, and then can be assembled to form a battery module 200.

[0053] The battery module 200 may include a plurality of battery cells 100 , and the plurality of battery cells 100 may be arranged along a third direction.

[0054] According to the battery module 200 of the embodiment of the utility model, by setting the above-mentioned battery cell 100, the insulating film 20 of the battery cell 100 includes a first insulating film 21 and a second insulating film 23, the first insulating film 21 covers the first side surface 13 of the battery cell 10 connected to the module shell 30, and the second insulating film 23 covers the second side surface 14 of the battery cell 10, and the bonding strength between the first insulating film 21 and the first side surface 13 is greater than the bonding strength between the second insulating film 23 and the second side surface 14, so that the bonding strength between the insulating film 20 and the first side surface 13 of the battery cell 10 can be greater, which can reduce or avoid the situation where the insulating film 20 is peeled off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30; in addition, since the bonding strength between the second insulating film 23 and the second side surface 14 is less than the bonding strength between the first insulating film 21 and the first side surface 13, the production cost can be lower.

[0055] The battery pack according to the third embodiment of the present invention includes a battery box and the above-mentioned battery module 200, and the battery module 200 is arranged in the battery box.

[0056] According to the battery pack of the embodiment of the utility model, by setting the above-mentioned battery module 200, the insulating film 20 of the battery cell 100 includes a first insulating film 21 and a second insulating film 23, the first insulating film 21 covers the first side surface 13 of the battery cell 10 connected to the module shell 30, and the second insulating film 23 covers the second side surface 14 of the battery cell 10, and the bonding strength between the first insulating film 21 and the first side surface 13 is greater than the bonding strength between the second insulating film 23 and the second side surface 14, so that the bonding strength between the insulating film 20 and the first side surface 13 of the battery cell 10 can be greater, which can reduce or avoid the situation where the insulating film 20 is peeled off from the battery cell 10 during the disassembly process of the battery cell 100 from the module shell 30; in addition, since the bonding strength between the second insulating film 23 and the second side surface 14 is less than the bonding strength between the first insulating film 21 and the first side surface 13, the production cost can be lower.

[0057] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0058] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that: include: A battery cell, wherein the battery cell has two end surfaces arranged opposite to each other along a first direction and a side surface located between the two end surfaces, the side surface includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other along the second direction, the two second side surfaces are arranged opposite to each other along a third direction, the first direction, the second direction and the third direction are perpendicular to each other, and the first side surface is used to be connected to the module shell through a structural adhesive layer; An insulating film, the insulating film is coated on the side and includes a first insulating film and a second insulating film, the first insulating film covers the first side, the second insulating film covers at least one of the two second side surfaces, and the bonding strength between the first insulating film and the first side surface is greater than the bonding strength between the second insulating film and the second side surface.

2. The battery cell according to claim 1, characterized in that: The first insulating film and the second insulating film are formed independently.

3. The battery cell according to claim 2, characterized in that: The first insulating film and the second insulating film are made of different materials; and / or the thickness of the first insulating film is greater than the thickness of the second insulating film.

4. The battery cell according to claim 2, characterized in that: The first side surface is adjacent to the second side surface, one end of the first insulating film adjacent to the second insulating film is a first edge portion, one end of the second insulating film adjacent to the first insulating film is a second edge portion, and the first edge portion and the second edge portion are overlapped to form an overlapping area.

5. The battery cell according to claim 4, characterized in that: Part of the overlapping area covers the first side surface and another part of the overlapping area covers the second side surface, and the second edge portion covers a side of the first edge portion away from the first side surface.

6. The battery cell according to claim 1, characterized in that: The first insulating film is the same as the second insulating film, the first insulating film is fixed to the first side through a first adhesive layer, and the second insulating film is fixed to the second side through a second adhesive layer, the thickness of the first adhesive layer is greater than or equal to the thickness of the second adhesive layer and / or the viscosity of the first adhesive layer is greater than or equal to the viscosity of the second adhesive layer.

7. The battery cell according to claim 6, characterized in that: The first insulating film and the second insulating film are integrally formed.

8. The battery cell according to claim 1, characterized in that: An area of ​​the first side surface is smaller than an area of ​​the second side surface.

9. A battery module, characterized in that: include: Module shell; The battery cell according to any one of claims 1 to 8, wherein the battery cell is disposed in the module shell.

10. A battery pack, characterized in that: include: Battery box; The battery module according to claim 9, wherein the battery module is disposed in the battery case.

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