Battery cell, battery and electrical device

Abstract

The present application provides a battery cell (20), a battery (100) and an electrical device. The battery cell (20) comprises a housing (21), an electrode assembly (22), a first insulating protective layer (23), and a second insulating protective layer (24). The first insulating protective layer (23) is provided on the inner wall of the housing (21), and the second insulating protective layer (24) is configured to cover at least part of the electrode assembly (22). The battery cell (20) provided in embodiments of the present application uses the first insulating protective layer (23) and the second insulating protective layer (24) to separate the housing (21) from the electrode assembly (22), so as to improve the creepage distance between the housing (21) and the electrode assembly (22), and achieve the purpose of improving the breakdown voltage resistance between the housing (21) and the electrode assembly (22), thereby effectively improving the high-voltage breakdown resistance of the housing (21), and further reducing the probability of combustion or explosion of the battery cell (20).

Description

Battery cells, batteries and electrical equipment

[0001] This application refers to Chinese patent application No. 202311264181.4 filed on September 27, 2023, entitled “Battery Cell, Battery and Electrical Equipment”, which is incorporated into this application in its entirety by reference. Technical Field

[0002] The present application relates to the technical field of battery structures, and in particular provides a battery cell, a battery, and an electrical device. Background Art

[0003] With the development of electronic and intelligent devices, the demand for secondary energy storage batteries, especially high-energy-density lithium-ion batteries, is becoming increasingly urgent. In related technologies, multiple battery cells are connected in series and then in parallel to form a group. However, multiple battery cells connected in series generate high voltage. If one battery cell fuses, high voltage will be generated between the positive and negative poles in the battery cell's electrode assembly and the outer casing. This will cause the outer casing of the battery cell to corrode and break down due to lithium deposition under high pressure. At the same time, the electrolyte will oxidize and generate heat, which may lead to the risk of combustion and explosion.

[0004] Application Contents

[0005] The purpose of the embodiments of the present application is to provide a battery cell, a battery and an electrical device, aiming to solve the problem in the related art that the outer shell of the battery cell is prone to high-voltage breakdown in a high-voltage environment.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are:

[0007] In one aspect, an embodiment of the present application provides a battery cell comprising a shell, an electrode assembly, a first insulating protective layer, and a second insulating protective layer. A accommodating cavity is formed in the shell, the electrode assembly is disposed in the accommodating cavity, the first insulating protective layer is disposed on the inner wall of the shell, and the second insulating protective layer is configured to cover at least a portion of the electrode assembly.

[0008] Beneficial effects of the embodiments of the present application: The battery cell provided in the embodiments of the present application has a first insulating protective layer on the inner wall of the shell, and the inner wall of the shell is insulated and protected by the first insulating protective layer, thereby reducing the contact probability between the shell and the electrolyte in the accommodating cavity. At the same time, a second insulating protective layer is coated on at least part of the electrode assembly, and the electrode assembly is insulated and protected by the second insulating protective layer. The first insulating protective layer and the second insulating protective layer are used to separate the shell and the electrode assembly to increase the creepage distance between the shell and the electrode assembly, which can achieve the purpose of increasing the breakdown voltage between the shell and the electrode assembly, thereby effectively improving the high-voltage breakdown resistance of the shell, and thereby reducing the probability of combustion or explosion of the battery cell.

[0009] In some embodiments, on any plane parallel to the height direction of the battery cell, the sum of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer includes the orthographic projection of the electrode assembly.

[0010] By adopting the above-mentioned technical solution, the sum of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer can include the orthographic projection of the electrode assembly, that is, the first insulating protective layer and the second insulating protective layer can jointly play an insulating protection role, and the first insulating protective layer and the second insulating protective layer can completely separate the electrode assembly and the outer shell, effectively improving the breakdown voltage between the outer shell and the electrode assembly, thereby improving the high-voltage breakdown resistance of the outer shell and reducing the probability of high-voltage breakdown of the outer shell.

[0011] In some embodiments, on any plane parallel to the height direction of the battery cell, the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer at least partially overlap.

[0012] By adopting the above-mentioned technical solution, the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer at least partially overlap, which can ensure the degree of separation of the first insulating protective layer and the second insulating protective layer from the outer shell and the electrode assembly, further improve the breakdown voltage between the outer shell and the electrode assembly, and thus further improve the high-voltage breakdown resistance of the outer shell.

[0013] In some embodiments, the housing includes a shell and an end cover, a accommodating cavity with an opening is formed on the shell, and the end cover is arranged at the opening; the first insulating protective layer is arranged on the inner wall of the shell, and there is an avoidance gap between the first insulating protective layer and the end cover.

[0014] By adopting the above-mentioned technical solution, the end cover is arranged at the opening of the shell to form a seal, and an avoidance gap is set between the first insulating protective layer and the end cover to avoid welding between the end cover and the shell. On the basis of the first insulating protective layer insulating and protecting the shell, the influence of the first insulating protective layer on the connection operation of the shell and the end cover is reduced.

[0015] In some embodiments, the battery cell further includes a lower plastic layer, which is disposed on the inner wall of the end cover, and the second insulating protective layer is at least partially connected to the lower plastic layer.

[0016] By adopting the above-mentioned technical solution, the second insulating protective layer is connected to the lower plastic layer provided on the inner wall of the end cover, and the electrode assembly is synchronously insulated and protected by the lower plastic layer and the second insulating protective layer, thereby effectively improving the insulating protection effect of the electrode assembly. At the same time, the second insulating protective layer is connected to the lower plastic layer. When the end cover and the shell are assembled, the second insulating protective layer can be directly sleeved and covered on at least part of the electrode assembly, thereby effectively improving the convenience of assembly.

[0017] In some embodiments, on any plane parallel to the height direction of the battery cell, the overlapping height of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer is M, and the inner wall height of the shell is Z, where 0.01Z≤M≤0.96Z.

[0018] By adopting the above-mentioned technical solution, the overlapping height of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer is set to be between 0.01 times and 0.96 times the inner wall height of the shell. The first insulating protective layer and the second insulating protective layer can work together between the shell and the electrode assembly to increase the breakdown voltage between the shell and the electrode assembly, thereby achieving the purpose of improving the high-voltage breakdown resistance of the shell.

[0019] In some embodiments, 0.1Z≤M≤0.7Z.

[0020] By adopting the above-mentioned technical solution, the overlapping height of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer is set to be between 0.1 times and 0.7 times the inner wall height of the shell, so that the first insulating protective layer and the second insulating protective layer can work together between the shell and the electrode assembly and improve the breakdown voltage between the shell and the electrode assembly, and the material consumption of the first insulating protective layer and the second insulating protective layer is relatively reduced, thereby achieving the purpose of reducing costs.

[0021] In some embodiments, M ≥ 10 mm.

[0022] By adopting the above-mentioned technical solution, the overlapping height of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer is set to be greater than or equal to 10 mm, so that the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer have a sufficient overlapping height, so that the first insulating protective layer and the second insulating protective layer can effectively separate the shell and the electrode assembly, so as to achieve the purpose of improving the breakdown voltage between the shell and the electrode assembly.

[0023] In some embodiments, the height of the first insulating protective layer is X, the height of the inner wall of the shell is Z, and 0.3Z≤X≤0.98Z.

[0024] By adopting the above-mentioned technical solution, the height of the first insulating protective layer is set to between 0.3 times and 0.98 times the height of the inner wall of the outer shell, so that the first insulating protective layer has an insulating protection effect on the inner wall of the outer shell, effectively improving the breakdown voltage between the outer shell and the electrode assembly.

[0025] In some embodiments, 0.5Z≤X≤0.9Z.

[0026] By adopting the above-mentioned technical solution, the height of the first insulating protective layer is set to between 0.5 times and 0.9 times the height of the inner wall of the shell. This allows the first insulating protective layer to provide insulation protection for the shell while using relatively less material, thereby achieving the purpose of reducing costs.

[0027] In some embodiments, X <Z-3mm。

[0028] By adopting the above-mentioned technical solution, the height of the first insulating protective layer is set to be 3 mm less than the height of the inner wall of the outer shell, so that the first insulating protective layer can fully cover and protect the inner wall of the outer shell, effectively improving the breakdown voltage between the outer shell and the electrode assembly, and thus improving the high-voltage breakdown resistance of the shell.

[0029] In some embodiments, the height of the second insulating protective layer is Y, the height of the inner wall of the shell is Z, and 0.05Z≤Y≤0.98Z.

[0030] By adopting the above-mentioned technical solution, the height of the second insulating protective layer is set to between 0.05 times and 0.98 times the height of the inner wall of the outer shell, so that the second insulating protective layer can cover at least part of the electrode assembly, effectively improving the breakdown voltage between the outer shell and the electrode assembly, and thus improving the high-voltage breakdown resistance of the shell.

[0031] In some embodiments, 0.2Z≤Y≤0.8Z.

[0032] By adopting the above-mentioned technical solution, the height of the second insulating protective layer is set to between 0.2 times and 0.8 times the height of the inner wall of the outer shell, so that the second insulating protective layer can be covered on at least part of the electrode assembly, and the material used in the second insulating protective layer is relatively reduced, thereby achieving the purpose of reducing costs.

[0033] In some embodiments, the first insulating protective layer includes at least one of phenolic resin, polyimide, polybenzimidazole, and polyetheretherketone.

[0034] By adopting the above technical solution, the first insulating protective layer can include at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone. The first insulating protective layer formed by using the above materials has better insulating protective performance.

[0035] In some embodiments, the second insulating protective layer is a thermoplastic polymer layer.

[0036] By adopting the above technical solution, the second insulating protective layer adopts a thermoplastic polymer layer, which is easy to process and shape and has good dimensional stability.

[0037] In some embodiments, the second insulating shield comprises at least one of polyethylene, polypropylene, polyurethane, nylon, polyvinylidene fluoride, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polytetrafluoroethylene, and polyethylene terephthalate.

[0038] By adopting the above technical solution, the second insulating protective layer can include at least one of polyethylene, polypropylene, polyurethane, nylon, polyvinylidene fluoride, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polytetrafluoroethylene and polyethylene terephthalate. The second insulating protective layer formed using the above materials has better insulating protection performance.

[0039] In some embodiments, the thickness of the first insulating protective layer is N, and 1 μm≤N≤1000 μm.

[0040] By adopting the above-mentioned technical solution, the thickness of the first insulating protective layer is set to be greater than or equal to 1μm and less than 1000μm, so that the first insulating protective layer has a certain thickness and can play a role in insulating and protecting the outer shell, so that the first insulating protective layer can increase the breakdown voltage between the outer shell and the electrode assembly, thereby improving the high-voltage breakdown resistance of the outer shell.

[0041] In some embodiments, the thickness of the first insulating protective layer is N, and 50 μm≤N≤500 μm.

[0042] By adopting the above technical solution, the thickness of the first insulating protective layer is set to be greater than or equal to 50μm and less than 500μm, which can ensure that the first insulating protective layer has better insulating protection performance while having a relatively low space occupancy rate.

[0043] In some embodiments, the thickness of the second insulating protective layer is P, 10 μm≤P≤2000 μm.

[0044] By adopting the above-mentioned technical solution, the thickness of the second insulating protective layer is set to be greater than or equal to 10μm and less than 2000μm, so that the second insulating protective layer has a certain thickness and can play a role in insulating and protecting the outer shell, so that the second insulating protective layer can increase the breakdown voltage between the outer shell and the electrode assembly, thereby improving the high-voltage breakdown resistance of the outer shell.

[0045] In some embodiments, the second insulating protective layer has a thickness P, 50 μm≤P≤500 μm.

[0046] By adopting the above technical solution, the thickness of the second insulating protective layer is set to be greater than or equal to 50μm and less than 500μm, which can ensure that the second insulating protective layer has better insulating protection performance while having a relatively low space occupancy rate.

[0047] In a second aspect, an embodiment of the present application further provides a battery comprising the battery cell as described above.

[0048] Beneficial effects of the embodiments of the present application: The battery provided by the embodiments of the present application includes the above-mentioned battery cell. On the basis that the shell of the battery cell has better resistance to high-voltage breakdown, the probability of combustion or explosion of the battery can be effectively reduced.

[0049] In a third aspect, an embodiment of the present application further provides an electrical device comprising the battery as described above.

[0050] Beneficial effects of the embodiments of the present application: The electrical equipment provided by the embodiments of the present application includes the above-mentioned battery. On the basis of the low probability of combustion or explosion of the battery, the probability of combustion or explosion of the electrical equipment is also low. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0052] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0053] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0054] FIG3 is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application;

[0055] FIG4 is a schematic diagram of the internal structure of a battery cell provided in some embodiments of the present application;

[0056] FIG5 is a partial enlarged schematic diagram of point A in FIG4 .

[0057] Detailed description of the drawings: Vehicle 1000; Battery 100, Controller 200, Motor 300; Housing 10, First Part 11, Second Part 12; Battery Cell 20, Housing 21, Accommodation Chamber 21a, End Cap 211, Electrode Terminal 211a, Shell 212, Electrode Assembly 22, Tab 22a, First Insulating Protective Layer 23, Avoidance Gap 231, Second Insulating Protective Layer 24, Lower Plastic Layer 25; Height Direction H. DETAILED DESCRIPTION

[0058] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0059] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0061] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0062] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0063] Battery cells are generally connected in series or in parallel to form battery modules or batteries for use; during the operation of the battery or battery module, multiple battery cells connected in series will generate high voltage. When one of the battery cells melts, a high voltage will be generated between the positive and negative poles in the electrode assembly of the battery cell and the shell, which will cause the shell of the battery cell to corrode and break down due to lithium deposition under high voltage. At the same time, the electrolyte will also oxidize and generate heat, which will lead to the risk of combustion and explosion.

[0064] Based on the above considerations, in order to solve the problem that the outer shell of the battery cell is prone to high-voltage breakdown in a high-voltage environment, a battery cell is designed, and a first insulating protective layer is provided on the inner wall of the outer shell. The first insulating protective layer is provided to insulate the inner wall of the outer shell, thereby reducing the probability of contact between the outer shell and the electrolyte in the accommodating cavity. At the same time, a second insulating protective layer is coated on at least part of the electrode assembly, and the electrode assembly is insulated by providing the second insulating protective layer. The first insulating protective layer and the second insulating protective layer are used to separate the outer shell and the electrode assembly to increase the creepage distance between the outer shell and the electrode assembly, thereby achieving the purpose of increasing the breakdown voltage between the outer shell and the electrode assembly, thereby effectively improving the high-voltage breakdown resistance of the shell, and thereby reducing the probability of combustion or explosion of the battery cell.

[0065] The battery cells disclosed in the embodiments of the present application can be used in electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements. Electrical devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric vehicles, ships, spacecraft, and the like. Electric toys may include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0066] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0067] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0068] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0069] Please refer to Figure 2, which is an exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a storage space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open. The first portion 11 can be a plate-like structure, with the first portion 11 overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0070] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0071] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0072] Please refer to Figure 3, which shows an exploded schematic diagram of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 is the smallest unit of a battery. As shown in Figure 3, a battery cell 20 includes a housing 21, an electrode assembly 22, and other functional components. The housing 21 includes an end cap 211 and a casing 212.

[0073] The end cap 211 is a component that covers the opening of the housing 212 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 211 can be adapted to the shape of the housing 212 to match the housing 212. Optionally, the end cap 211 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This makes the end cap 211 less likely to deform when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved reliability. Functional components such as electrode terminals 211a can be provided on the end cap 211. The electrode terminal 211a can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy from the battery cell 20; wherein the electrode terminal 211a includes a positive electrode post, a negative electrode post, an upper plastic, etc., one end of the positive electrode post and the negative electrode post can be directly connected to the bus bar, and the other end of the positive electrode post and the negative electrode post can be connected to one of the poles of the adjacent battery cell 20 in the battery 100 or the battery module. In some embodiments, the end cap 211 can also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 211 can also be various, for example, the material of the end cap 211 includes but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0074] The housing 212 is a component that cooperates with the end cap 211 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 22, electrolyte, and other components. The housing 212 and the end cap 211 can be separate components. An opening can be provided in the housing 212, and the end cap 211 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 211 and the housing 212 can be integrated. Specifically, the end cap 211 and the housing 212 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 212 is to be enclosed, the end cap 211 is placed over the housing 212. The housing 212 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 212 can be determined based on the specific shape and size of the electrode assembly 22. The housing 212 can be made of a variety of materials, including, but not limited to, copper, iron, aluminum, stainless steel, and aluminum alloys.

[0075] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained in the housing 212. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 22, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 22a. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tab 22a connects the electrode terminals to form a current loop.

[0076] According to some embodiments of the present application, please refer to Figures 3 to 5. The embodiments of the present application provide a battery cell 20, including a shell 21, an electrode assembly 22, a first insulating protective layer 23 and a second insulating protective layer 24. A accommodating cavity 21a is formed in the shell 21, the electrode assembly 22 is arranged in the accommodating cavity 21a, the first insulating protective layer 23 is arranged on the inner wall of the shell 21, and the second insulating protective layer 24 is configured to cover at least part of the electrode assembly 22.

[0077] It can be understood that the inner wall of the outer shell 21 refers to the side wall of the outer shell 21 forming the accommodating cavity 21a; the accommodating cavity 21a is used to accommodate the electrode assembly 22, and the first insulating protective layer 23 is arranged on the inner wall of the outer shell 21, so the first insulating protective layer 23 can play an insulating and protective role on the inner wall of the outer shell 21, and can increase the creepage distance between the outer shell 21 and the electrode assembly 22.

[0078] The first insulating protective layer 23 is an insulating layer structure. The first insulating protective layer 23 may be, but is not limited to, an insulating coating, an insulating film, an insulating adhesive layer, etc., and may be fixed to the inner wall of the housing 21 by coating, bonding, etc. Specifically, the first insulating protective layer 23 may completely cover the inner wall of the housing 21; alternatively, the first insulating protective layer 23 may cover a portion of the inner wall of the housing 21, leaving another portion of the inner wall of the housing 21 exposed to the first insulating protective layer 23 according to assembly requirements.

[0079] The first insulating protective layer 23 is used to be arranged on the inner wall of the outer shell 21. Optionally, the first insulating protective layer 23 can completely cover the inner wall of the outer shell 21, including covering the inner bottom wall, inner side wall and inner top wall; or, the first insulating protective layer 23 can also cover part of the inner wall of the outer shell 21. For example, the first insulating protective layer 23 can cover at least one of the inner bottom wall, inner side wall and inner top wall; or, the first insulating protective layer 23 can also cover at least part of at least one of the inner bottom wall, inner side wall and inner top wall.

[0080] The second insulating protective layer 24 is an insulating layer structure. The second insulating protective layer 24 can be, but is not limited to, an insulating coating, an insulating film, an insulating adhesive layer, etc., and can be wrapped around the electrode assembly 22 by coating, bonding, etc., or connected to the housing 21 by heat sealing, bonding, etc. When the housing 21 and the electrode assembly 22 are assembled, the second insulating protective layer 24 can be sleeved on at least a portion of the electrode assembly 22. The second insulating protective layer 24 can be used in conjunction with the first insulating protective layer 23 to effectively improve the breakdown voltage between the housing 21 and the electrode assembly 22.

[0081] The second insulating protective layer 24 is used to cover at least a portion of the electrode assembly 22; optionally, the second insulating protective layer 24 can be covered on the main body of the electrode assembly 22. For example, the second insulating protective layer 24 can completely cover the outer surface of the main body of the electrode assembly 22, or the second insulating protective layer 24 can only cover a portion of the outer surface of the main body of the electrode assembly 22, and the other uncovered portion of the main body of the electrode assembly 22 can be separated from the inner wall of the outer shell 21 by the first insulating protective layer 23.

[0082] The battery cell 20 provided in the embodiment of the present application has a first insulating protective layer 23 provided on the inner wall of the outer shell 21. The first insulating protective layer 23 is provided to insulate and protect the inner wall of the outer shell 21, thereby reducing the probability of contact between the outer shell 21 and the electrolyte in the accommodating cavity 21a. At the same time, a second insulating protective layer 24 is coated on at least part of the electrode assembly 22, and the electrode assembly 22 is insulated and protected by providing the second insulating protective layer 24. The first insulating protective layer 23 and the second insulating protective layer 24 are used to separate the outer shell 21 and the electrode assembly 22 to increase the creepage distance between the outer shell 21 and the electrode assembly 22, thereby achieving the purpose of increasing the breakdown voltage between the outer shell 21 and the electrode assembly 22, thereby effectively improving the high-voltage breakdown resistance of the shell, and thereby reducing the probability of combustion or explosion of the battery cell 20.

[0083] According to some embodiments of the present application, referring to Figures 3 to 5, on any plane parallel to the height direction H of the battery cell 20, the sum of the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 includes the orthographic projection of the electrode assembly 22.

[0084] The orthographic projection of the first insulating protective layer 23 on any plane parallel to the height direction H of the battery cell 20 refers to the projection of the first insulating protective layer 23 perpendicular to the height direction H; it can be understood that the height direction H of the battery cell 20 is the height direction of the outer shell 21. When the outer shell 21 has a side wall with a planar structure, the orthographic projection of the first insulating protective layer 23 on any plane parallel to the height direction H of the battery cell 20 includes the projection on the side wall with a planar structure.

[0085] Similarly, the orthographic projection of the second insulating protective layer 24 on any plane parallel to the height direction H of the battery cell 20 refers to the projection of the second insulating protective layer 24 perpendicular to the height direction H. When the outer shell 21 has a side wall with a planar structure, the orthographic projection of the second insulating protective layer 24 on any plane parallel to the height direction H of the battery cell 20 includes the projection on the side wall with a planar structure.

[0086] The orthographic projection of the electrode assembly 22 on any plane parallel to the height direction H of the battery cell 20 refers to the projection of the electrode assembly 22 along the direction perpendicular to the height direction H. When the outer shell 21 has a side wall with a planar structure, the orthographic projection of the electrode assembly 22 on any plane parallel to the height direction H of the battery cell 20 includes the projection on the side wall with a planar structure.

[0087] On any plane parallel to the height direction H of the battery cell 20, the sum of the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 includes the orthographic projection of the electrode assembly 22, that is, the first insulating protective layer 23 and the second insulating protective layer 24 can act together between the outer shell 21 and the electrode assembly 22 along the height direction H perpendicular to the battery cell 20, so that the first insulating protective layer 23 and the second insulating protective layer 24 can cover the electrode assembly 22 along the height direction H perpendicular to the battery cell 20, and the electrode assembly 22 is not exposed to the combination of the first insulating protective layer 23 and the second insulating protective layer 24 along the height direction H perpendicular to the battery cell 20. The outer shell 21 and the electrode assembly 22 are separated on opposite sides of the first insulating protective layer 23 and the second insulating protective layer 24, thereby effectively improving the breakdown voltage between the outer shell 21 and the electrode assembly 22, and thereby effectively improving the high-voltage breakdown resistance of the outer shell 21.

[0088] Optionally, along the height direction H of the battery cell 20, the insulation protection measures between the two ends of the outer shell 21 and the electrode assembly 22 can be achieved by covering the opposite ends of the inner wall of the outer shell 21 in the height direction H of the battery cell 20 with a first insulation protection layer 23, or by covering the ends of the electrode assembly 22 in the height direction H of the battery cell 20 with a second insulation protection layer 24, or by using other insulation structures to be arranged between the electrode assembly 22 and the inner wall of the outer shell 21 for insulation protection.

[0089] In this way, the sum of the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 can include the orthographic projection of the electrode assembly 22, that is, the first insulating protective layer 23 and the second insulating protective layer 24 can jointly play an insulating protection role, and the first insulating protective layer 23 and the second insulating protective layer 24 can completely separate the electrode assembly 22 and the outer shell 21, effectively improving the breakdown voltage between the outer shell 21 and the electrode assembly 22, so as to improve the high-voltage breakdown resistance of the outer shell 21 and reduce the probability of high-voltage breakdown of the outer shell 21.

[0090] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , on any plane parallel to the height direction H of the battery cell 20 , the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 at least partially overlap.

[0091] It can be understood that the first insulating protective layer 23 and the second insulating protective layer 24 can jointly play an insulating and protective role along the height direction H perpendicular to the battery cell 20. The first insulating protective layer 23 and the second insulating protective layer 24 can completely separate the electrode assembly 22 and the outer shell 21. At the same time, the first insulating protective layer 23 and the second insulating protective layer 24 at least partially overlap along the height direction H perpendicular to the battery cell 20, that is, it can ensure that the electrode assembly 22 will not be exposed to the outer shell 21 along the height direction H perpendicular to the battery cell 20, further improving the breakdown voltage between the outer shell 21 and the electrode assembly 22, thereby further improving the high-voltage breakdown resistance of the outer shell 21.

[0092] According to some embodiments of the present application, please refer to Figures 3 to 5, the outer shell 21 includes a shell body 212 and an end cover 211, and a accommodating cavity 21a with an opening is formed on the shell body 212, and the end cover 211 is covered at the opening; the first insulating protective layer 23 is arranged on the inner wall of the shell body 212, and an avoidance gap 231 is provided between the first insulating protective layer 23 and the end cover 211.

[0093] The avoidance gap 231 refers to the gap formed between the first insulating protective layer 23 on the inner wall of the shell 212 and the end cover 211 . The inner wall of the shell 212 can be exposed from the avoidance gap 231 .

[0094] In this arrangement, the end cover 211 is covered at the opening of the shell 212 to form a seal, and an avoidance gap 231 is set between the first insulating protective layer 23 and the end cover 211 to avoid welding between the end cover 211 and the shell 212. On the basis of the first insulating protective layer 23 insulating and protecting the shell 212, the influence of the first insulating protective layer 23 on the connection operation between the shell 212 and the end cover 211 is reduced.

[0095] Optionally, the specific setting positions of the first insulating protective layer 23 and the second insulating protective layer 24 can be that the first insulating protective layer 23 covers the inner wall of the shell 212, including the inner bottom wall and the inner side wall of the shell 212, and the first insulating protective layer 23 is on the inner side wall of the shell 212 and forms an avoidance gap 231 with the opening; the second insulating protective layer 24 is coated on the main body of the electrode assembly 22, for example, the second insulating protective layer 24 can completely cover the main body of the electrode assembly 22, or the second insulating protective layer 24 can partially cover the main body of the electrode assembly 22 along any end in the height direction H of the battery cell 20.

[0096] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the battery cell 20 further includes a lower plastic layer 25 , which is disposed on the inner wall of the end cover 211 , and the second insulating protective layer 24 is at least partially connected to the lower plastic layer 25 .

[0097] The lower plastic layer 25 is disposed on the inner wall of the end cap 211 and is used to insulate and protect the inner wall of the end cap 211. The lower plastic layer 25 can be fixed to the inner wall of the end cap 211 by adhesion. It is understood that the inner wall of the end cap 211 refers to the wall surface of the end cap 211 facing the housing 212.

[0098] The second insulating protective layer 24 can be partially connected to the lower plastic layer 25, such as partially connected or connected in a spaced manner; alternatively, the second insulating protective layer 24 can also be sealed to the lower plastic layer 25, that is, the second insulating protective layer 24 and the lower plastic layer 25 are continuously sealed, such as by a full hot-melt sealing connection. Using this sealing connection method can further increase the creepage distance between the electrode assembly 22 and the housing 212, thereby further improving the high-voltage breakdown resistance of the housing 212. Optionally, the connection method between the second insulating protective layer 24 and the lower plastic layer 25 can be, but is not limited to, hot-melt fixing, adhesive fixing, etc.

[0099] It can be understood that the second insulating protective layer 24 is connected to the lower plastic layer 25, that is, the second insulating protective layer 24 and the end cap 211 are connected to form a whole through the lower plastic layer 25. When the end cap 211 is assembled with the shell 212, the second insulating protective layer 24 provided on the end cap 211 can move toward the main body of the electrode assembly 22 and be mounted on the main body of the electrode assembly 22, effectively improving the convenience of assembly. At the same time, the first insulating protective layer 23 is provided on the inner wall of the shell 212, and the first insulating protective layer 23 forms an avoidance gap 231 between the end cap 211. At this time, the second insulating protective layer 24 can cover the blank gap in the height direction H perpendicular to the battery cell 20, effectively improving the breakdown voltage between the shell 212 and the electrode assembly 22, thereby improving the high-voltage breakdown resistance of the shell 212.

[0100] According to some embodiments of the present application, please refer to Figures 3 to 5. On any plane parallel to the height direction H of the battery cell 20, the overlapping height of the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 is M, and the inner wall height of the outer shell 21 is Z, where 0.01Z≤M≤0.96Z.

[0101] Specifically, Z represents the height of the inner wall of the outer shell 21, that is, the distance between the inner bottom wall and the inner top wall of the outer shell 21. M represents the overlapping height of the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 on any plane parallel to the height direction H of the battery cell 20. In this embodiment, it can be considered as the height of the portion where the orthographic projection of the first insulating protective layer 23 on the side wall of the outer shell 21 and the orthographic projection of the second insulating protective layer 24 on the side wall of the outer shell 21 overlap.

[0102] The range of the overlap height M is set to be greater than or equal to 0.01 times the height Z of the inner wall of the shell 21, that is, the orthographic projection of the first insulating protective layer 23 on the side wall of the shell 21 and the orthographic projection of the second insulating protective layer 24 on the side wall of the shell 21 overlap, and the first insulating protective layer 23 and the second insulating protective layer 24 can jointly protect the shell 21 to improve the high-voltage breakdown resistance of the shell 21. At the same time, the range of the overlap height M is set to be less than or equal to 0.96 times the height Z of the inner wall of the shell 21, that is, the range of M is limited to between 0.01 times and 0.96 times the height of the inner wall of the shell 21. The first insulating protective layer 23 and the second insulating protective layer 24 can jointly act between the shell 212 and the electrode assembly 22 to increase the breakdown voltage between the shell 21 and the electrode assembly 22, thereby achieving the purpose of improving the high-voltage breakdown resistance of the shell 212.

[0103] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , 0.1Z≤M≤0.7Z.

[0104] In this way, the overlapping height M of the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 on any plane parallel to the height direction H of the battery cell 20 is set to between 0.1 times and 0.7 times the inner wall height Z of the outer shell 21, so that the first insulating protective layer 23 and the second insulating protective layer 24 can act together between the shell 212 and the electrode assembly 22 and improve the breakdown voltage between the outer shell 21 and the electrode assembly 22, and the material used in the first insulating protective layer 23 and the second insulating protective layer 24 is relatively reduced, thereby achieving the purpose of reducing costs.

[0105] According to some embodiments of the present application, please refer to Figures 3 to 5, M≥10mm.

[0106] In this way, the overlapping height of the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24 is set to be greater than or equal to 10 mm, so that there is a sufficient overlapping height between the orthographic projection of the first insulating protective layer 23 and the orthographic projection of the second insulating protective layer 24, so that the first insulating protective layer 23 and the second insulating protective layer 24 can effectively separate the shell 212 and the electrode assembly 22, so as to achieve the purpose of improving the breakdown voltage between the shell 21 and the electrode assembly 22.

[0107] According to some embodiments of the present application, referring to FIG. 3 and FIG. 4 , the height of the first insulating protective layer 23 is X, the height of the inner wall of the housing 21 is Z, and 0.3Z≤X≤0.98Z.

[0108] Specifically, X represents the height of the first insulating protective layer 23. The range of the height X of the first insulating protective layer 23 is set to be greater than or equal to 0.03 times the height Z of the inner wall of the outer shell 21, that is, the first insulating protective layer 23 can cover at least a portion of the inner wall of the outer shell 21. At the same time, the range of the height X of the first insulating protective layer 23 is set to be less than or equal to 0.98 times the height Z of the inner wall of the outer shell 21, that is, the height of the first insulating protective layer 23 is set to be between 0.3 times and 0.98 times the height of the inner wall of the outer shell 21. This enables the first insulating protective layer 23 to have an insulating protective effect on the inner wall of the outer shell 21, effectively improving the breakdown voltage between the outer shell 21 and the electrode assembly 22.

[0109] According to some embodiments of the present application, please refer to FIG. 3 and FIG. 4 , 0.5Z≤X≤0.9Z.

[0110] In this way, the height of the first insulating protective layer 23 is set to between 0.5 times and 0.9 times the inner wall height of the shell 21. This can ensure that the first insulating protective layer 23 can insulate and protect the shell 21 while using relatively less material, thereby achieving the purpose of reducing costs.

[0111] According to some embodiments of the present application, please refer to FIG3 and FIG4, X <Z-3mm。

[0112] In this way, the height of the first insulating protective layer 23 is set to be 3 mm less than the inner wall height of the outer shell 21, so that the first insulating protective layer 23 can fully cover and protect the inner wall of the outer shell 21, effectively improving the breakdown voltage between the outer shell 21 and the electrode assembly 22.

[0113] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the height of the second insulating protective layer 24 is Y, the height of the inner wall of the housing 21 is Z, and 0.05Z≤Y≤0.98Z.

[0114] Specifically, Y represents the height of the second insulating protective layer 24. The range of the height X of the second insulating protective layer 24 is set to be greater than or equal to 0.05 times the height Z of the inner wall of the outer shell 21, that is, the first insulating protective layer 23 can cover at least part of the inner wall of the outer shell 21. At the same time, the range of the height Y of the second insulating protective layer 24 is set to be less than or equal to 0.98 times the height Z of the inner wall of the outer shell 21, that is, the height of the second insulating protective layer 24 is set to be between 0.05 times and 0.98 times the height of the inner wall of the outer shell 21, so that the second insulating protective layer 24 can insulate and isolate the main body of the electrode assembly 22, separate the main body from the outer shell 21, effectively improve the breakdown voltage between the outer shell 21 and the electrode assembly 22, and thus improve the high-voltage breakdown resistance of the shell 212.

[0115] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , 0.2Z≤Y≤0.8Z.

[0116] In this way, the height of the second insulating protective layer 24 is set to between 0.2 times and 0.8 times the height of the inner wall of the outer shell 21, so that the second insulating protective layer 24 can be covered on at least a part of the electrode assembly 22, and the material used in the second insulating protective layer 24 is relatively reduced, thereby achieving the purpose of reducing costs.

[0117] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the first insulating protective layer 23 includes at least one of phenolic resin, polyimide, polybenzimidazole, and polyetheretherketone.

[0118] It is understandable that the first insulating protective layer 23 may include one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone; or the first insulating protective layer 23 may also include multiple ones of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone.

[0119] In this configuration, the first insulating protective layer 23 may include at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone. The first insulating protective layer 23 formed using the above materials has better insulating protective performance.

[0120] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the second insulating protective layer 24 is a thermoplastic polymer layer.

[0121] In this configuration, the second insulating protective layer 24 is made of a thermoplastic polymer layer, which is easy to process and shape and has good dimensional stability.

[0122] According to some embodiments of the present application, referring to Figures 3 to 5, the second insulating protective layer 24 includes at least one of polyethylene, polypropylene, polyurethane, nylon, polyvinylidene fluoride, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polytetrafluoroethylene and polyethylene terephthalate.

[0123] It can be understood that the second insulating protective layer 24 can include one of polyethylene, polypropylene, polyurethane, nylon, polyvinylidene fluoride, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polytetrafluoroethylene and polyethylene terephthalate; or, the second insulating protective layer 24 can also include multiple of polyethylene, polypropylene, polyurethane, nylon, polyvinylidene fluoride, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polytetrafluoroethylene and polyethylene terephthalate.

[0124] In this manner, the second insulating protective layer 24 may include at least one of polyethylene, polypropylene, polyurethane, nylon, polyvinylidene fluoride, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polytetrafluoroethylene and polyethylene terephthalate. The second insulating protective layer 24 formed using the above materials has better insulating protective performance.

[0125] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the thickness of the first insulating protective layer 23 is N, 1 micron≤N≤1000 microns (hereinafter, “μm” is used instead of micron).

[0126] Specifically, the thickness N of the first insulating protective layer 23 is set to be greater than or equal to 1 μm to ensure that the first insulating protective layer 23 has sufficient thickness to improve the insulating protection performance of the first insulating protective layer 23; at the same time, the thickness N of the first insulating protective layer 23 is set to be less than or equal to 1000 μm. On the premise of ensuring the first insulating protection performance, the thickness N of the first insulating protective layer 23 is controlled not to exceed 1000 μm to reduce the space occupied by the first insulating protective layer 23 inside the shell 21.

[0127] In this way, the thickness of the first insulating protective layer 23 is set to be greater than or equal to 1μm and less than 1000μm, so that the first insulating protective layer 23 has a certain thickness and can play a role in insulating and protecting the outer shell 21, so that the first insulating protective layer 23 can increase the breakdown voltage between the outer shell 21 and the electrode assembly 22, so as to improve the high-voltage breakdown resistance of the outer shell 21.

[0128] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the thickness of the first insulating protection layer 23 is N, and 50 μm≤N≤500 μm.

[0129] It can be understood that in order to further optimize the insulation performance of the first insulating protective layer 23, the thickness N of the first insulating protective layer 23 is set to be greater than or equal to 50 μm; at the same time, in order to further optimize the space occupancy rate of the first insulating protective layer 23, the thickness N of the first insulating protective layer 23 is set to be less than or equal to 500 μm, so that the first insulating protective layer 23 has better insulation protection performance while the space occupancy rate of the first insulating protective layer 23 is relatively low.

[0130] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the thickness of the second insulating protection layer 24 is P, and 10 μm≤P≤2000 μm.

[0131] Specifically, the thickness P of the second insulating protective layer 24 is set to be greater than or equal to 10 μm to ensure that the second insulating protective layer 24 has sufficient thickness to improve the insulating protection performance of the second insulating protective layer 24; at the same time, the thickness P of the second insulating protective layer 24 is set to be less than or equal to 2000 μm. On the premise of ensuring the second insulating protection performance, the thickness P of the second insulating protective layer 24 is controlled not to exceed 2000 μm to reduce the space occupied by the second insulating protective layer 24 inside the shell 21.

[0132] According to some embodiments of the present application, referring to FIG. 3 to FIG. 5 , the thickness of the second insulating protection layer 24 is P, 50 μm≤P≤500 μm.

[0133] It can be understood that in order to further optimize the insulation performance of the second insulating protective layer 24, the thickness P of the second insulating protective layer 24 is set to be greater than or equal to 50 μm; at the same time, in order to further optimize the space occupancy rate of the second insulating protective layer 24, the thickness P of the second insulating protective layer 24 is set to be less than or equal to 500 μm, so that the second insulating protective layer 24 has better insulation protection performance while the space occupancy rate of the second insulating protective layer 24 is relatively low.

[0134] For example, in some specific embodiments, the battery cell 20 includes an outer shell 21 and an electrode assembly 22, and the outer shell 21 includes a shell 212 and an end cover 211 covering the opening; the inner wall of the shell 212 is coated with a first insulating protective coating, and an avoidance gap 231 is formed between the first insulating protective coating and the end cover 211 covering the opening. The first insulating protective coating can cover most of the inner wall of the shell 212, and the inner wall of the shell 212 is only exposed at the avoidance gap 231 to facilitate the welding assembly operation between the end cover 211 and the shell 212; the inner wall of the end cover 211 is covered with a lower plastic layer 25, and a second insulating protective film is fully hot-melt-sealed on the lower plastic layer 25. The second insulating protective film is a cylindrical structure with one end open, and the sealed end of the second insulating protective film is connected to the lower plastic layer 25; when assembling the end cover 211 and the shell 212, The second insulating protective film can be sleeved on the main body of the electrode assembly 22, so that the second insulating protective film can cover part of the main body of the electrode assembly 22; at this time, the first insulating protective coating and the second insulating protective film overlap in the height direction H perpendicular to the battery cell 20, that is, the first insulating protective coating and the second insulating protective film can jointly insulate the shell 212 and the electrode assembly 22, separating the shell 212 and the electrode assembly 22 on opposite sides of the first insulating protective coating and the second insulating protective film, effectively improving the breakdown voltage between the shell 212 and the electrode assembly 22, and thereby improving the high-voltage breakdown resistance of the shell 212.

[0135] According to some embodiments of the present application, referring to Figures 2 to 4, the present application also provides a battery 100 including the above-mentioned battery cell 20. The battery 100 uses any of the battery cells 20 described in the above embodiments, which will not be described in detail here.

[0136] According to some embodiments of the present application, please continue to refer to Figures 1 and 2. The present application also provides an electric device, including the battery 100 as described above. The electric device can be any electric device described in the above embodiments, such as a vehicle 1000, which will not be repeated here.

[0137] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: A housing having a receiving cavity formed therein; an electrode assembly, wherein the electrode assembly is disposed in the accommodating cavity; A first insulating protective layer, wherein the first insulating protective layer is disposed on an inner wall of the shell; as well as A second insulating protective layer is configured to cover at least a portion of the electrode assembly.

2. The battery cell according to claim 1, characterized in that: On any plane parallel to the height direction of the battery cell, the sum of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer includes the orthographic projection of the electrode assembly.

3. The battery cell according to claim 1 or 2, characterized in that: On any plane parallel to the height direction of the battery cell, the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer at least partially overlap.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The shell includes a shell and an end cover, the shell is formed with the accommodating cavity having an opening, and the end cover is arranged at the opening; the first insulating protective layer is arranged on the inner wall of the shell, and there is an avoidance gap between the first insulating protective layer and the end cover.

5. The battery cell according to claim 4, characterized in that: The battery cell further includes a lower plastic layer, which is disposed on the inner wall of the end cover, and the second insulating protective layer is at least partially connected to the lower plastic layer.

6. The battery cell according to claim 3, characterized in that: On any plane parallel to the height direction of the battery cell, the overlapping height of the orthographic projection of the first insulating protective layer and the orthographic projection of the second insulating protective layer is M, and the inner wall height of the shell is Z, wherein 0.01Z≤M≤0.96Z.

7. The battery cell according to claim 6, characterized in that: 0.1Z≤M≤0.7Z.

8. The battery cell according to claim 6 or 7, characterized in that: M≥10mm.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The height of the first insulating protective layer is X, the height of the inner wall of the shell is Z, and 0.3Z≤X≤0.98Z.

10. The battery cell according to claim 8, characterized in that: 0.5Z≤X≤0.9Z.

11. The battery cell according to claim 9 or 10, characterized in that: X <Z-3mm。 12. The battery cell according to any one of claims 1 to 11, characterized in that: The height of the second insulating protective layer is Y, the height of the inner wall of the shell is Z, and 0.05Z≤Y≤0.98Z.

13. The battery cell according to claim 12, characterized in that: 0.2Z≤Y≤0.8Z.

14. The battery cell according to any one of claims 1 to 13, characterized in that: The first insulating protective layer includes at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone.

15. The battery cell according to any one of claims 1 to 14, characterized in that: The second insulating protective layer is a thermoplastic polymer layer.

16. The battery cell according to claim 15, characterized in that: The second insulating protective layer includes at least one of polyethylene, polypropylene, polyurethane, nylon, polyvinylidene fluoride, polystyrene, polymethyl methacrylate, polyvinyl chloride, polycarbonate, polytetrafluoroethylene and polyethylene terephthalate.

17. The battery cell according to any one of claims 1 to 16, characterized in that: The thickness of the first insulating protection layer is N, 1 μm≤N≤1000 μm.

18. The battery cell according to claim 17, characterized in that: The thickness of the first insulating protection layer is N, 50 μm≤N≤500 μm.

19. The battery cell according to any one of claims 1 to 18, characterized in that: The thickness of the second insulating protection layer is P, 10 μm≤P≤2000 μm.

20. The battery cell according to claim 19, characterized in that: The thickness of the second insulating protection layer is P, 50 μm≤P≤500 μm.

21. A battery, characterized in that: include: A battery cell as claimed in any one of claims 1 to 20.

22. An electrical equipment, characterized in that: include: The battery as claimed in claim 21.

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