Battery cell, battery, and electrical device

Abstract

Provided are a battery cell (20), a battery (100), and an electrical device. The battery cell (20) comprises a casing (22) and an insulating protective layer (24); and the insulating protective layer (24) is arranged on an inner wall of the casing (22). In the battery cell (20) provided in the embodiments of the present application, by means of the provision of the insulating protective layer (24) on the inner wall of the casing of the battery cell (20), the insulating protective layer (24) can separate the casing (22) from the electrolyte inside the casing (22), thereby reducing the probability of contact between the casing (22) and the electrolyte, and thus the probability of corrosion and breakdown of the casing (22) is reduced.

Description

Battery cells, batteries and electrical equipment

[0001] This application refers to Chinese Patent Application No. 202311264196.0, 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, free electrolyte exists between the battery cell's casing and the bare cell. This can lead to high voltage between the positive and negative poles of the battery cell's electrode assembly and the casing, causing electrolyte oxidation and corrosion and breakdown of the casing, which can 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 battery cell shell is easily corroded and broken down when in contact with the electrolyte.

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

[0007] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell and an insulating protective layer, wherein the insulating protective layer is disposed on an inner wall of the shell.

[0008] Beneficial effects of the embodiments of the present application: The battery cell provided in the embodiments of the present application, by arranging an insulating protective layer on the inner wall of the shell of the battery cell, the insulating protective layer can separate the shell from the electrolyte inside the shell, thereby reducing the probability of contact between the shell and the electrolyte, thereby reducing the probability of the shell being corroded and punctured.

[0009] In some embodiments, an opening is provided on the shell, and the battery cell further includes an end cover, which is provided at the opening; and a blank gap is left between the insulating protective layer and the end cover.

[0010] By adopting the above technical solution, the end cover can be covered at the opening of the shell to form a seal, and a blank gap is provided between the insulating protective layer and the end cover to facilitate avoiding welding between the end cover and the shell.

[0011] In some embodiments, the battery cell further includes a lower plastic layer, which is disposed on the inner wall of the end cover and is configured to cover at least a portion of the blank gap.

[0012] By adopting the above-mentioned technical solution, the insulation protection capability of the end cover is improved by arranging a lower plastic layer on the inner wall of the end cover, and the lower plastic layer can cover at least part of the blank gap, thereby improving the protection of the exposed shell at the blank gap, further reducing the probability of contact between the shell and the electrolyte, and further reducing the probability of corrosion and breakdown of the shell, and reducing the risk of short circuit between the exposed part of the shell at the blank gap and the electrode assembly.

[0013] In some embodiments, the battery cell has a height direction, and the end cap is arranged at the top of the shell along the height direction; in any plane parallel to the height direction, the orthographic projection of the lower plastic layer and the orthographic projection of the insulating protective layer at least partially overlap.

[0014] By adopting the above technical solution, the orthographic projection of the lower plastic layer and the orthographic projection of the insulating protective layer partially overlap in any plane parallel to the height direction, that is, the combination of the lower plastic layer and the insulating protective layer can completely cover the inner wall of the shell, effectively separating the inner wall of the shell from the electrolyte inside, thereby reducing the probability of contact between the shell and the electrolyte, and further reducing the probability of corrosion and breakdown of the shell.

[0015] In some embodiments, in any plane parallel to the height direction, the height of the portion where the orthographic projection of the lower plastic layer overlaps with the orthographic projection of the insulating protective layer is Y, and 0<Y≤10 mm.

[0016] By adopting the above-mentioned technical solution, the overlapping height Y of the orthographic projection of the lower plastic layer and the orthographic projection of the insulating protective layer is set to be greater than 0 mm and less than or equal to 10 mm, so that the lower plastic layer and the insulating protective layer can be partially stacked to cover the inner wall of the shell, and the inner wall of the shell and the internal electrolyte can be separated, thereby reducing the probability of contact between the shell and the electrolyte, and further reducing the probability of corrosion and breakdown of the shell, while also reducing the risk of contact short circuit between the inner wall of the shell and the electrode assembly.

[0017] In some embodiments, the height of the portion where the orthographic projection of the lower plastic layer overlaps with the orthographic projection of the insulating protective layer is Y, and 1 mm ≤ Y ≤ 5 mm.

[0018] By adopting the above-mentioned technical solution, the overlapping height Y of the orthographic projection of the lower plastic layer and the orthographic projection of the insulating protective layer is set to be greater than or equal to 1 mm and less than or equal to 5 mm. This allows the lower plastic layer and the insulating protective layer to be partially stacked to cover the inner wall of the shell, and can separate the inner wall of the shell from the internal electrolyte, thereby reducing the probability of contact between the shell and the electrolyte, and further reducing the probability of corrosion and breakdown of the shell.

[0019] In some embodiments, the height of the blank gap is X, 2 mm ≤ X ≤ 10 mm.

[0020] By adopting the above-mentioned technical solution, the height of the blank gap is set to be greater than or equal to 2 mm and less than or equal to 10 mm, so that within the height range of the blank gap, the end cover can be normally welded and fixed at the opening of the shell, reducing the impact of the insulating protective layer on the assembly of the end cover.

[0021] In some embodiments, the height of the blank gap is X, and 3 mm ≤ X ≤ 5 mm.

[0022] By adopting the above-mentioned technical solution, the height of the blank gap is set to be greater than or equal to 3 mm and less than or equal to 5 mm, so that within the height range of the blank gap, the end cover can be normally welded and fixed at the opening of the shell, reducing the impact of the insulating protective layer on the assembly of the end cover.

[0023] In some embodiments, the insulating protective layer includes at least one of phenolic resin, polyimide, polybenzimidazole, and polyetheretherketone.

[0024] By adopting the above technical solution, the insulating protective layer can include at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone. The insulating protective layer formed by using the above materials has better insulating protective performance.

[0025] In some embodiments, the thickness of the insulating protective layer is N, and 1 μm≤N≤1000 μm.

[0026] By adopting the above-mentioned technical solution, the thickness of the insulating protective layer is set to be greater than or equal to 1 μm and less than 1000 μm, so that the insulating protective layer has a certain thickness and can play the role of separating the shell and the electrolyte. Therefore, the insulating protective layer can reduce the probability of electrolyte contact with electrolyte, thereby reducing the probability of corrosion and breakdown of the shell.

[0027] In some embodiments, the thickness of the insulating protective layer is N, and 50 μm≤N≤500 μm.

[0028] By adopting the above-mentioned technical solution, the thickness of the insulating protective layer is set to be greater than or equal to 50 μm and less than 500 μm, so that the insulating protective layer has a certain thickness and can play the role of separating the shell and the electrolyte, so that the insulating protective layer can reduce the probability of electrolyte contact with electrolyte, thereby reducing the probability of corrosion and breakdown of the shell.

[0029] In some embodiments, the battery cell further includes an electrode assembly, which is housed inside the housing.

[0030] By adopting the above technical solution, the electrode assembly is directly accommodated in the shell, and insulation protection is achieved by using the insulating protective layer arranged on the inner wall of the shell, and the insulating structure on the surface of the electrode assembly is eliminated, thereby achieving the purpose of reducing costs.

[0031] In a second aspect, an embodiment of the present application further provides a battery, comprising the battery as described above or the battery cell as described above.

[0032] Beneficial effects of the embodiments of the present application: The battery provided by the embodiments of the present application includes the above-mentioned battery cells. On the basis of the low probability of the battery cell shell being corroded and punctured, the probability of the battery burning or exploding can be effectively reduced.

[0033] In a third aspect, an embodiment of the present application further provides an electrical device comprising the battery as described above.

[0034] 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

[0035] 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.

[0036] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0037] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0038] FIG3 is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application;

[0039] FIG4 is a schematic diagram of the internal structure of a battery cell provided in an embodiment of the present application;

[0040] FIG5 is a partial enlarged schematic diagram of point A in FIG4 .

[0041] Detailed description of the drawings: Vehicle 1000; Battery 100, Controller 200, Motor 300; Housing 10, First Part 11, Second Part 12; Battery Cell 20, End Cap 21, Electrode Terminal 21a, Housing 22, Opening 221, Electrode Assembly 23, Tab 23a; Insulating Protective Layer 24, Blank Space 25, Lower Plastic Layer 26; Height Direction H. DETAILED DESCRIPTION

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] Battery cells are generally connected in series or parallel to form battery modules or batteries for use; during the operation of the battery or battery module, the battery cells may melt, at which time high voltage may be generated between the electrode assembly and the shell of the battery cell. At the same time, due to the presence of electrolyte between the shell of the battery cell and the bare battery cell inside the shell, the electrolyte will oxidize under high pressure, resulting in the risk of corrosion and breakdown of the shell, and then the risk of combustion and explosion of the battery.

[0048] Based on the above considerations, in order to solve the problem that the shell of the battery cell is prone to corrosion and breakdown when it comes into contact with the electrolyte during use, a battery cell is designed. By providing an insulating protective layer on the inner wall of the shell of the battery cell, the insulating protective layer can separate at least part of the inner wall of the shell from the electrolyte, so as to reduce the probability of contact between the electrolyte and the shell, thereby effectively reducing the probability of corrosion and breakdown of the shell.

[0049] In such a battery cell, since an insulating protective layer is provided on the inner wall of the shell, the probability of direct contact between the electrolyte and the shell is low, and therefore the probability of the shell being corroded and punctured by the electrolyte is also low; at the same time, even in the case of a battery cell meltdown, a high-voltage environment is generated between the positive and negative poles of the electrode assembly of the battery cell and the shell. Since an insulating protective layer is provided on the inner wall of the shell, the insulation performance of the shell can be effectively improved, thereby increasing the creepage distance between the bare battery cell inside the shell and the shell, thereby reducing the probability of high-voltage breakdown of the shell.

[0050] 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 can 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 can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, among others.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] Please refer to Figure 3, which is a schematic diagram of the exploded structure of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery. As shown in Figure 3, a battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0058] The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, giving the battery cell 20 greater structural strength and improved reliability. Functional components such as electrode terminals 21a can be provided on the end cap 21. The electrode terminals 21a can be used to electrically connect to the electrode assembly 23 to output or input electrical energy to the battery cell 20. The electrode terminals 21a include a positive electrode post, a negative electrode post, and a plastic cover. One end of the positive and negative electrode posts can be directly connected to the busbar, while the other ends of the positive and negative electrode posts can be connected to one of the electrodes of adjacent battery cells 20 in the battery 100 or battery module. In some embodiments, the end cap 21 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 may also be made of a variety of materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and the like.

[0059] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be enclosed, the end cap 21 is placed over the housing 22. The housing 22 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 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0060] The electrode assembly 23 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 22. The electrode assembly 23 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 23, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 23a. The positive and negative electrode tabs 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 tabs 23a connect the electrode terminals to form a current loop.

[0061] According to some embodiments of the present application, please refer to Figures 3 and 4. The embodiments of the present application provide a battery cell 20, including a shell 22 and an insulating protective layer 24. The insulating protective layer 24 is arranged on the inner wall of the shell 22.

[0062] It can be understood that the housing 22 can be used to accommodate the electrode assembly 23, electrolyte and other components.

[0063] The inner wall of the shell 22 refers to the wall surface on one side (generally the inner side) of the shell 22 for accommodating the electrode assembly 23, electrolyte and other components.

[0064] The insulating protective layer 24 is an insulating layer structure. The insulating protective layer 24 can be, but is not limited to, an insulating coating, an insulating film, an insulating adhesive layer, etc., and is fixed to the inner wall of the housing 22 by coating, bonding, etc.

[0065] Specifically, the insulating protective layer 24 can completely cover the inner wall of the shell 22 so as to completely separate the shell 22 and the electrolyte contained inside the shell 22; or, the insulating protective layer 24 can only cover part of the inner wall of the shell 22, for example, the insulating protective layer 24 leaves a blank at the edge of the inner wall of the shell 22, that is, the insulating protective layer 24 does not cover the edge of the inner wall of the shell 22, and the edge of the inner wall of the shell 22 is exposed, thereby facilitating the connection operation between the shell 22 and external equipment.

[0066] The battery cell 20 provided in the embodiment of the present application has an insulating protective layer 24 provided on the inner wall of the shell 22 of the battery cell 20. The insulating protective layer 24 can separate the shell 22 from the electrolyte inside the shell 22, reducing the probability of contact between the shell 22 and the electrolyte, thereby reducing the probability of corrosion and breakdown of the shell 22. At the same time, when the battery cells 20 are combined to form a battery or battery module for use, even if the battery cell 20 melts, resulting in a high-voltage environment between the positive and negative poles of the battery cell 20 and the shell 22, the insulating protective layer 24 provided on the inner wall of the shell 22 improves the insulation protection performance of the shell 22. Therefore, the creepage distance between the shell 22 and the electrode assembly 23 contained in the shell 22 is effectively increased, thereby effectively reducing the risk of high-voltage breakdown of the shell 22.

[0067] According to some embodiments of the present application, please continue to refer to Figures 3 to 5. An opening 221 is set on the shell 22, and the battery cell 20 also includes an end cover 21, which is covered at the opening 221; a blank gap 25 is left between the insulating protective layer 24 and the end cover 21.

[0068] It can be understood that the end cap 21 can cover the opening 221 of the shell 22 and enclose the shell 22 to form a sealed internal environment, wherein the formed internal environment can be used to accommodate the electrode assembly 23, electrolyte and other components.

[0069] Specifically, the connection method between the end cover 21 and the shell 22 can be that the end cover 21 is fixedly covered on the opening 221 of the shell 22 by welding, or the end cover 21 can also be fixedly connected to the shell 22 and covered on the opening 221 by bonding, screwing, snapping, etc.

[0070] Among them, the above-mentioned blank gap 25 refers to the area in the shell 22 where the insulating protective layer 24 is not set. Specifically, it can be the gap between the insulating protective layer 24 and the end cover 21, that is, the gap between the end surface of the insulating protective layer 24 facing the end cover 21 and the surface of the end cover 21 facing the insulating protective layer 24.

[0071] It can be understood that a portion of the insulating protective layer 24 can form a blank gap 25 with the end cover 21, and at the same time, another portion of the insulating protective layer 24 can be in contact with the end cover 21; or, a blank gap 25 is formed between the insulating protective layer 24 as a whole and the end cover 21, that is, the distance between any point on the end surface of the insulating protective layer 24 facing the end cover 21 and the surface of the end cover 21 facing the insulating protective layer 24 is greater than 0.

[0072] In this way, by setting the blank gap 25, the portion of the shell 22 located at the opening 221 can be exposed to the insulating protective layer 24 at the blank gap 25, so that there is sufficient operating space when the end cover 21 and the shell 22 are fixedly connected by welding or the like, thereby reducing the influence of the insulating protective layer 24 on the connection operation between the end cover 21 and the shell 22.

[0073] According to some embodiments of the present application, please continue to refer to Figures 3 to 5 , the battery cell 20 further includes a lower plastic layer 26 , which is disposed on the inner wall of the end cover 21 and is configured to cover at least a portion of the blank gap 25 .

[0074] The lower plastic layer 26 is disposed on the inner wall of the end cap 21 and is used to insulate and protect the inner wall of the end cap 21. The lower plastic layer 26 can be fixed to the inner wall of the end cap 21 by adhesion. It is understood that the inner wall of the end cap 21 refers to the wall surface of the end cap 21 facing the housing 22.

[0075] It can be understood that when the end cover 21 is covered on the opening 221 of the shell 22, the lower plastic layer 26 on the inner wall of the end cover 21 will extend into the interior of the shell 22; at the same time, a blank gap 25 is provided between the insulating coating provided on the inner wall of the shell 22 and the end cover 21, so the lower plastic layer 26 can cover at least part of the blank gap 25; for example, the lower plastic layer 26 can cover part of the blank gap 25, or the lower plastic layer 26 can completely cover the blank gap 25, and the lower plastic layer 26 overlaps with the insulating protective layer 24, as shown in Figure 5.

[0076] The lower plastic layer 26 covering the blank gap 25 means that at least a portion of the lower plastic layer 26 can extend into the area of ​​the blank gap 25 . The lower plastic layer 26 can be spaced from the inner wall of the shell 22 , or the lower plastic layer 26 can also abut against the inner wall of the shell 22 .

[0077] When the lower plastic layer 26 completely covers the blank space 25 and overlaps with the insulating protective layer 24 , the lower plastic layer 26 may abut against the insulating protective layer 24 , or the lower plastic layer 26 may be spaced apart from the insulating protective layer 24 .

[0078] In this manner, the lower plastic layer 26 can cover at least part of the blank gap 25 to reduce the probability of the inner wall of the shell 22 exposed at the blank gap 25 contacting the electrolyte, thereby further reducing the probability of corrosion breakdown of the shell 22. While reducing the influence of the insulating protective layer 24 on the fixed connection between the end cover 21 and the shell 22 through the blank gap 25, it can also effectively reduce the probability of corrosion breakdown of the shell 22 contacting the electrolyte, and reduce the risk of short circuit between the part of the shell 22 exposed at the blank gap 25 and the electrode assembly 23.

[0079] According to some embodiments of the present application, please continue to refer to Figures 3 to 5. The battery cell 20 has a height direction H, and the end cover 21 is arranged on the top of the shell 22 along the height direction H; in any plane parallel to the height direction H, the orthographic projection of the lower plastic layer 26 and the orthographic projection of the insulating protective layer 24 at least partially overlap.

[0080] It can be understood that the height direction H of the battery cell 20 refers to the direction from the housing 22 to the end cover 21 . As shown in FIG. 4 , the height direction H of the battery cell 20 is the H direction in the figure.

[0081] It can be understood that the opening 221 of the shell 22 is located at the top of the shell 22 along the height direction H. Therefore, the end cover 21 is correspondingly arranged at the top of the shell 22 along the height direction H to cover the opening 221. At the same time, the blank gap 25 between the insulating protective layer 24 and the end cover 21 is the height difference between the top of the insulating protective layer 24 along the height direction H and the inner wall of the end cover 21. Therefore, in any plane parallel to the height direction H, the orthographic projection of the lower plastic layer 26 and the orthographic projection of the insulating protective layer 24 at least partially overlap, that is, the lower plastic layer 26 and the insulating protective layer 24 have an overlapping portion in the height direction H of the shell 22. The lower plastic layer 26 and the insulating protective layer 24 can jointly protect the inner wall of the shell 22, effectively improving the insulation protection effect of the inner wall of the shell 22, thereby reducing the probability of the shell 22 being broken down by corrosion or high voltage.

[0082] According to some embodiments of the present application, please continue to refer to Figures 4 and 5. In any plane parallel to the height direction H, the height of the portion where the orthographic projection of the lower plastic layer 26 overlaps with the orthographic projection of the insulating protective layer 24 is Y, 0<Y≤10 mm (hereinafter "mm" is used instead of millimeters).

[0083] Specifically, Y represents the height of the portion where the orthographic projection of the lower plastic layer 26 overlaps with the orthographic projection of the insulating protective layer 24 in the height direction H. The range of Y is set to be greater than 0, that is, the lower plastic layer 26 and the insulating protective layer 24 have an overlapping portion in the height direction H. The insulating protective layer 24 can insulate and protect the inner wall of the shell 22, and a blank gap 25 is formed between the insulating protective layer 24 and the end cover 21 to expose a portion of the shell 22, thereby reducing the impact of the insulating protective layer 24 on the fixed connection between the shell 22 and the end cover 21. At the same time, the lower plastic layer 26 on the end cover 21 can cover the blank gap 25 and extend along the height direction H of the battery cell 20 to overlap with the insulating protective layer 24, thereby enabling the insulating protective layer 24 to insulate and protect the shell 22 without affecting the connection between the shell 22 and the end cover 21. The lower plastic layer 26 can also protect the shell 22 exposed at the blank gap 25, thereby reducing the risk of short circuit caused by contact between the shell 22 and the electrolyte or the electrode assembly 23.

[0084] At the same time, the range of Y is set to be less than or equal to 10 mm. On the basis that the lower plastic layer 26 and the insulating protective layer 24 have an overlapping portion in the height direction H, the height Y of the overlapping portion is limited to less than or equal to 10 mm, so as to reduce the influence of the lower plastic layer 26 on the electrode assembly 23 contained in the shell 22, and reduce the probability of interference between the lower plastic layer 26 and the electrode assembly 23.

[0085] In this way, the overlapping height Y of the orthographic projection of the lower plastic layer 26 and the orthographic projection of the insulating protective layer 24 is set to be greater than 0 mm and less than or equal to 10 mm, so that the lower plastic layer 26 and the insulating protective layer 24 can be partially stacked to cover the inner wall of the shell 22, and the inner wall of the shell 22 and the internal electrolyte can be separated, thereby reducing the probability of contact between the shell 22 and the electrolyte, and further reducing the probability of corrosion and breakdown of the shell 22, while also reducing the risk of contact short circuit between the inner wall of the shell 22 and the electrode assembly 23.

[0086] According to some embodiments of the present application, please continue to refer to FIG. 4 and FIG. 5 , the height of the portion where the orthographic projection of the lower plastic layer 26 overlaps with the orthographic projection of the insulating protective layer 24 is Y, 1mm≤Y≤5mm.

[0087] It can be understood that in order to improve the protective effect of the lower plastic layer 26 and the insulating protective layer 24 on the shell 22, and further reduce the impact of the lower plastic layer 26 on the electrode assembly 23, the overlapping height Y of the orthographic projection of the lower plastic layer 26 and the orthographic projection of the insulating protective layer 24 can be set to be greater than or equal to 1 mm and less than or equal to 5 mm, so that the lower plastic layer 26 and the insulating protective layer 24 fully overlap in the height direction H of the battery cell 20.

[0088] According to some embodiments of the present application, please continue to refer to Figures 3 to 5 , the height of the blank gap 25 is X, 2mm≤X≤10mm.

[0089] It is understood that the height X of the blank gap 25 refers to the distance between the top of the insulating protective layer 24 and the side surface of the end cap 21 facing the insulating protective layer 24 in the height direction H of the battery cell 20. The height X of the blank gap 25 is set to be greater than or equal to 2 mm so that the housing 22 can be exposed above the insulating protective layer 24 by at least 2 mm, thereby improving the fixed connection (e.g., welding) between the end cap 21 and the housing 22. At the same time, the height X of the blank gap 25 is set to be less than or equal to 10 mm to optimize the degree of exposure of the housing 22 from the insulating protective layer 24, thereby improving the insulation protection effect of the insulating protective layer 24 on the housing 22.

[0090] In this way, the height of the blank gap 25 is set to be greater than or equal to 2 mm and less than or equal to 10 mm, so that within the height range of the blank gap 25, the end cover 21 can be normally welded and fixed at the opening 221 of the shell 22, reducing the assembly impact of the insulating protective layer 24 on the end cover 21, and the insulating protective layer 24 can better insulate and protect the shell 22.

[0091] According to some embodiments of the present application, please continue to refer to FIG. 4 and FIG. 5 . In some embodiments, the height of the blank gap 25 is X, 3 mm ≤ X ≤ 5 mm.

[0092] It can be understood that in order to further improve the fixed connection operation between the end cover 21 and the shell 22, and to further optimize the insulation protection effect of the insulating protective layer 24 on the shell 22, the height of the blank gap 25 can be set to be greater than or equal to 3 mm and less than or equal to 5 mm, so as to achieve that the insulating protective layer 24 can better insulate the shell 22 on the basis of being able to perform the fixed connection operation between the end cover 21 and the shell 22 normally.

[0093] According to some embodiments of the present application, please continue to refer to FIG. 4 and FIG. 5 , the insulating protective layer 24 includes at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone.

[0094] It is understandable that the insulating protective layer 24 may include one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone; or, the insulating protective layer 24 may also include multiple ones of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone.

[0095] In this configuration, the insulating protective layer 24 may include at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone. The insulating protective layer 24 formed using the above materials has better insulating protective performance.

[0096] According to some embodiments of the present application, please continue to refer to FIG. 4 and FIG. 5 , the thickness of the insulating protective layer 24 is N, 1 micron≤N≤1000 microns (hereinafter “μm” is used instead of micron).

[0097] Specifically, the thickness N of the insulating protective layer 24 is set to be greater than or equal to 1 μm to ensure that the insulating protective layer 24 has sufficient thickness to improve the insulating protection performance of the insulating protective layer 24; at the same time, the thickness N of the insulating protective layer 24 is set to be less than or equal to 1000 μm. On the premise of ensuring the insulating protection performance, the thickness N of the insulating protective layer 24 is controlled not to exceed 1000 μm to reduce the space occupied by the insulating protective layer 24 inside the shell 22.

[0098] In this way, the thickness of the insulating protective layer 24 is set to be greater than or equal to 1μm and less than 1000μm, so that the insulating protective layer 24 has a certain thickness and can play the role of separating the shell 22 and the electrolyte, so that the insulating protective layer 24 can reduce the probability of electrolyte contact with electrolyte, thereby reducing the probability of the shell 22 being corroded and broken down.

[0099] According to some embodiments of the present application, please continue to refer to FIG. 3 to FIG. 5 , the thickness of the insulating protection layer 24 is N, 50 μm≤N≤500 μm.

[0100] It can be understood that in order to further optimize the insulation performance of the insulating protective layer 24, the thickness N of the 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 insulating protective layer 24, the thickness N of the insulating protective layer 24 is set to be less than or equal to 500 μm, so that the insulating protective layer 24 has better insulation protection performance while the space occupancy rate of the insulating protective layer 24 is relatively low.

[0101] According to some embodiments of the present application, please continue to refer to FIG. 3 to FIG. 5 , the battery cell 20 further includes an electrode assembly 23 , and the electrode assembly 23 is accommodated inside the shell 22 .

[0102] It can be understood that by providing an insulating protective layer 24 on the inner wall of the shell 22, while the insulating protective layer 24 can separate the shell 22 and the electrolyte contained inside the shell 22, the insulating protective layer 24 can also improve the creepage between the electrode assembly 23 and the shell 22 to meet the insulation requirements between the electrode assembly 23 and the shell 22; thereby, the insulating structure on the surface of the electrode assembly 23 can be eliminated, that is, there is no need to again cover the surface of the electrode assembly 23 with an insulating film or other insulating structure, thereby achieving the purpose of reducing costs.

[0103] For example, in some specific embodiments, the battery cell 20 includes a shell 22 and an end cover 21. The inner wall of the shell 22 is coated with an insulating protective coating, and the inner wall of the end cover 21 is affixed with a lower plastic layer 26. In the height direction H of the battery cell 20, an opening 221 is formed at the top of the shell 22. The end cover 21 covers the opening 221 and is fixedly connected to the shell 22 by welding. The insulating protective coating forms a blank gap 25 between the end cover 21 in the height direction H, so that the shell 22 can be exposed from the blank gap 25. At the same time, the lower plastic layer 26 can cover the blank gap 25. Moreover, the lower plastic layer 26 can overlap with the insulating protective coating in the height direction H, so that the insulating protective coating can reduce the impact on the welding of the shell 22 and the end cover 21 through the blank gap 25, and provide insulation protection for the shell 22. At the same time, the lower plastic layer 26 can also cover the blank gap 25, that is, protect the shell 22 exposed at the blank gap 25, and reduce the probability of the electrode assembly 23 (such as bare battery cells, adapters, etc.) contained in the shell 22 contacting the shell 22 and causing a circuit breaker.

[0104] According to some embodiments of the present application, please continue to refer to Figures 2 to 5. 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 repeated here.

[0105] According to some embodiments of the present application, please continue to refer to Figures 1 to 5. The present application also provides an electric device, including the battery cell 20 as described above, or including the battery 100 as described above. The electric device can be any electric device described in the above embodiments, such as the vehicle 1000, and will not be repeated here.

[0106] 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: case; as well as An insulating protective layer is arranged on the inner wall of the shell.

2. The battery cell according to claim 1, characterized in that: The shell is provided with an opening, and the battery cell further comprises an end cover, which is arranged at the opening; and a blank gap is provided between the insulating protective layer and the end cover.

3. The battery cell according to claim 2, characterized in that: The battery cell further includes a lower plastic layer, which is disposed on the inner wall of the end cover and is configured to cover at least a portion of the blank gap.

4. The battery cell according to claim 3, characterized in that: The battery cell has a height direction, and the end cover is arranged at the top of the shell along the height direction; in any plane parallel to the height direction, the orthographic projection of the lower plastic layer and the orthographic projection of the insulating protective layer at least partially overlap.

5. The battery cell according to claim 4, characterized in that: In any plane parallel to the height direction, the height of the portion where the orthographic projection of the lower plastic layer overlaps with the orthographic projection of the insulating protection layer is Y, 0<Y≤10mm.

6. The battery cell according to claim 4, characterized in that: The height of the portion where the orthographic projection of the lower plastic layer overlaps with the orthographic projection of the insulating protection layer is Y, 1mm≤Y≤5mm.

7. The battery cell according to any one of claims 2 to 6, characterized in that: The height of the blank gap is X, 2mm≤X≤10mm.

8. The battery cell according to claim 7, characterized in that: The height of the blank gap is X, 3mm≤X≤5mm.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The insulating protective layer includes at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The thickness of the insulating protection layer is N, 1 μm≤N≤1000 μm.

11. The battery cell according to claim 10, characterized in that: The thickness of the insulating protection layer is N, 50 μm≤N≤500 μm.

12. The battery cell according to any one of claims 1 to 11, characterized in that: Also includes: An electrode assembly is accommodated in the shell.

13. A battery, characterized in that: include: A battery cell as claimed in any one of claims 1 to 12.

14. An electrical device, characterized in that: include: A battery cell as claimed in any one of claims 1 to 12 or a battery as claimed in claim 13.

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