Battery monomer, battery and electric equipment

Abstract

The invention relates to the technical field of battery structures, and provides a single battery, a battery and electric equipment, the single battery comprises a shell and an insulation protection layer, and the insulation protection layer is arranged on the inner wall of the shell; according to the battery monomer provided by the embodiment of the invention, the insulating protection layer is arranged on the inner wall of the shell of the battery monomer, and the insulating protection layer can separate the shell from the electrolyte in the shell, so that the probability of contact between the shell and the electrolyte is reduced, and the probability of corrosion breakdown of the shell can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of battery structure, and in particular provides a battery cell, a battery and an electrical device. Background Art

[0002] With the development of electronic and intelligent equipment, people have an increasingly urgent need for secondary energy storage batteries, especially high-energy-density lithium-ion batteries. In related technologies, there is free electrolyte between the shell of the battery cell and the bare cell, and high voltage may be formed between the positive and negative poles of the electrode assembly of the battery cell and the shell, which will cause oxidation of the electrolyte, and the shell will corrode and break down, which will lead to the risk of combustion and explosion of the battery. Summary of the invention

[0003] 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 shell of the battery cell is easily corroded and broken down when in contact with the electrolyte.

[0004] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is:

[0005] 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.

[0006] 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, reduce the probability of contact between the shell and the electrolyte, and thus can reduce the probability of corrosion and breakdown of the shell.

[0007] 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 provided between the insulating protective layer and the end cover.

[0008] 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 avoid welding between the end cover and the shell.

[0009] 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 lower plastic layer is configured to cover at least a portion of the blank gap.

[0010] 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 achieving improved 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, as well as reducing the risk of short circuit between the exposed part of the shell at the blank gap and the electrode assembly.

[0011] In some embodiments, 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.

[0012] 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 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.

[0013] 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 protection layer is Y, 0<Y≤10mm.

[0014] 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.

[0015] 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 protection layer is Y, and 1mm≤Y≤5mm.

[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 or equal to 1 mm and less than or equal to 5 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.

[0017] In some embodiments, the height of the blank gap is X, 2 mm ≤ X ≤ 10 mm.

[0018] 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 influence of the insulating protective layer on the assembly of the end cover.

[0019] In some embodiments, the height of the blank gap is X, 3 mm ≤ X ≤ 5 mm.

[0020] 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 influence of the insulating protective layer on the assembly of the end cover.

[0021] In some embodiments, the insulating protective layer includes at least one of phenolic resin, polyimide, polybenzimidazole, and polyetheretherketone.

[0022] By adopting the above technical solution, the insulating protective layer can include at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone, and the insulating protective layer formed by using the above materials has better insulating protective performance.

[0023] In some embodiments, the thickness of the insulating protective layer is N, 1 μm≤N≤1000 μm.

[0024] By adopting the above-mentioned technical solution, the thickness of the insulating protective layer is set to be greater than or equal to 1μm and less than 1000μm, so that the insulating protective layer has a certain thickness and can play a role in 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.

[0025] In some embodiments, the thickness of the insulating protective layer is N, 50 μm≤N≤500 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 50μm and less than 500μm, so that the insulating protective layer has a certain thickness and can play a role in 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.

[0027] In some embodiments, the battery cell further includes an electrode assembly, and the electrode assembly is accommodated inside the shell.

[0028] By adopting the above technical solution, the electrode assembly is directly accommodated in the shell, and insulation protection is achieved by using an 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.

[0029] In a second aspect, an embodiment of the present application further provides a battery, including the battery as described above or the battery cell as described above.

[0030] 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 shell of the battery cell being corroded and punctured, the probability of the battery burning or exploding can be effectively reduced.

[0031] In a third aspect, an embodiment of the present application further provides an electrical device, comprising a battery as described above.

[0032] 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. Based on 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

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or related technical descriptions will be briefly introduced below. 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 creative work.

[0034] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0035] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0036] Figure 3 A schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application;

[0037] Figure 4 A schematic diagram of the internal structure of a battery cell provided in an embodiment of the present application;

[0038] Figure 5 for Figure 4 A local enlarged schematic diagram of point A.

[0039] Among them, the reference numerals in the figure are:

[0040] Vehicles 1000;

[0041] Battery 100, controller 200, motor 300;

[0042] Box body 10, first part 11, second part 12;

[0043] Battery cell 20, end cover 21, electrode terminal 21a, housing 22, opening 221, electrode assembly 23, pole tab 23a; insulating protective layer 24, blank gap 25, lower plastic layer 26;

[0044] Height direction H. DETAILED DESCRIPTION

[0045] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0046] In the description of the present 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 the present 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 should not be understood as a limitation on the present application.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0050] 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, the battery cells may melt. At this 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 voltage, resulting in the risk of corrosion and breakdown of the shell, which in turn leads to the risk of combustion and explosion of the battery.

[0051] 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 of the battery, 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.

[0052] 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 if the battery cell is blown, 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.

[0053] The battery cell 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 be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0054] 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.

[0055] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may 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 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and 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.

[0056] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve 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.

[0057] Please refer to Figure 2 , Figure 2 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, and the battery cell 20 is contained in the housing 10. The housing 10 is used to provide a storage space for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first part 11 and a second part 12, and the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 can be a hollow structure with one end open, and the first part 11 can be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 can also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the housing 10 formed by the first part 11 and the second part 12 can be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0058] 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 mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0059] Each battery cell 20 may be a secondary battery or a primary battery, or 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.

[0060] Please refer to Figure 3 , Figure 3 The schematic diagram of the exploded structure of the battery cell 20 provided in some embodiments of the present application. The battery cell 20 refers to the smallest unit that constitutes the battery. Figure 3 The battery cell 20 includes an end cover 21, a shell 22, an electrode assembly 23 and other functional components.

[0061] The end cap 21 refers to a component that covers the opening of the shell 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the shell 22 to match the shell 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and reliability can also be improved. Functional components such as electrode terminals 21a can be provided on the end cap 21. The electrode terminal 21a can be used to electrically connect with the electrode assembly 23 to output or input the electrical energy of the battery cell 20; wherein the electrode terminal 21a includes a positive pole, a negative pole, an upper plastic, etc., one end of the positive pole and the negative pole can be directly connected to the bus, and the other end of the positive pole and the negative pole 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, a pressure relief mechanism for releasing the internal pressure of the battery cell 20 when the internal pressure or temperature reaches a threshold value may be provided on the end cap 21. The material of the end cap 21 may also be various, and the material of the end cap 21 may be, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0062] The shell 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte and other components. The shell 22 and the end cap 21 can be independent components, and an opening can be set on the shell 22, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 21 at the opening. Without limitation, the end cap 21 and the shell 22 can also be integrated. Specifically, the end cap 21 and the shell 22 can form a common connection surface before other components are put into the shell, and when the interior of the shell 22 needs to be encapsulated, the end cap 21 covers the shell 22. The shell 22 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0063] The electrode assembly 23 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrode assemblies 23 may be included 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 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 23a connects the electrode terminals to form a current loop.

[0064] According to some embodiments of this application, please refer to Figure 3 and Figure 4 The embodiment of the present application provides a battery cell 20 , including a shell 22 and an insulating protective layer 24 , wherein the insulating protective layer 24 is disposed on the inner wall of the shell 22 .

[0065] It can be understood that the housing 22 can be used to accommodate the electrode assembly 23, electrolyte and other components.

[0066] The inner wall of the shell 22 refers to the wall surface of one side (generally the inner side) of the shell 22 for accommodating the electrode assembly 23, electrolyte and other components.

[0067] The insulating protective layer 24 is an insulating layer structure. The insulating protective layer 24 may 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.

[0068] 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.

[0069] The battery cell 20 provided in the embodiment of the present application has an insulating protective layer 24 disposed 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, reduce the probability of the shell 22 contacting the electrolyte, and thus reduce the probability of the shell 22 being corroded and punctured. At the same time, when the battery cells 20 are combined to form a battery or a battery module for use, even if the battery cell 20 is melted, 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 is disposed on the inner wall of the shell 22 to improve the insulating protection performance of the shell 22, so that the creepage distance between the shell 22 and the electrode assembly 23 contained in the shell 22 can be effectively improved, so that the risk of high-voltage puncture of the shell 22 can be effectively reduced.

[0070] According to some embodiments of this application, please continue to refer to Figures 3 to 5 The shell 22 is provided with an opening 221 , and the battery cell 20 further includes an end cover 21 , which is covered at the opening 221 ; a blank gap 25 is provided between the insulating protective layer 24 and the end cover 21 .

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] According to some embodiments of this 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 . The lower plastic layer 26 is configured to cover at least a portion of the blank gap 25 .

[0077] The lower plastic layer 26 is used to be arranged on the inner wall of the end cover 21 and to insulate and protect the inner wall of the end cover 21. The lower plastic layer 26 can be fixed on the inner wall of the end cover 21 by adhesion. It can be understood that the inner wall of the end cover 21 refers to the wall surface of the end cover 21 facing the housing 22.

[0078] 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 FIG. Figure 5 shown.

[0079] 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 , and the lower plastic layer 26 can be spaced apart 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 .

[0080] When the lower plastic layer 26 completely covers the blank gap 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 .

[0081] In this way, 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.

[0082] According to some embodiments of this 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 disposed on the top of the housing 22 along the height direction H; in any plane parallel to the height direction H, the orthographic projection of the lower plastic layer 26 at least partially overlaps with the orthographic projection of the insulating protective layer 24.

[0083] 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. Figure 4 As shown, the height direction H of the battery cell 20 is the H direction in the figure.

[0084] 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, and thus, 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, and 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 corroded or broken down by high voltage.

[0085] According to some embodiments of this application, please continue to refer to Figure 4 and Figure 5 In any plane parallel to the height direction H, the height of the part where the orthographic projection of the lower plastic layer 26 overlaps with the orthographic projection of the insulating protection layer 24 is Y, 0<Y≤10 mm (hereinafter "mm" is used instead of millimeter).

[0086] Specifically, Y represents the height of the part 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 part in the height direction H, the insulating protective layer 24 can insulate 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 part of the shell 22, thereby reducing the influence of the insulating protective layer 24 on the fixed connection between the shell 22 and the end cover 21, and 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, so that the insulating protective layer 24 can insulate the shell 22 without affecting the connection between the shell 22 and the end cover 21, and 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.

[0087] 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 be 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.

[0088] 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.

[0089] According to some embodiments of this application, please continue to refer to Figure 4 and Figure 5 The height of the part where the orthographic projection of the lower plastic layer 26 overlaps with the orthographic projection of the insulating protection layer 24 is Y, 1mm≤Y≤5mm.

[0090] 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 influence 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.

[0091] According to some embodiments of this application, please continue to refer to Figures 3 to 5 , the height of the blank gap 25 is X, 2mm≤X≤10mm.

[0092] It can be 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 cover 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 shell 22 can be exposed to the insulating protective layer 24 by at least 2 mm in height to improve the fixed connection (such as welding) operation between the end cover 21 and the shell 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 shell 22 to the insulating protective layer 24, so as to improve the insulation protection effect of the insulating protective layer 24 on the shell 22.

[0093] 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, thereby reducing the assembly influence 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.

[0094] According to some embodiments of this application, please continue to refer to Figure 4 and Figure 5 In some embodiments, the height of the blank gap 25 is X, 3mm≤X≤5mm.

[0095] 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 normally perform the fixed connection operation on the end cover 21 and the shell 22.

[0096] According to some embodiments of this application, please continue to refer to Figure 4 and Figure 5 The insulating protective layer 24 includes at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone.

[0097] It can be understood 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.

[0098] In this way, the insulating protection layer 24 may include at least one of phenolic resin, polyimide, polybenzimidazole and polyetheretherketone. The insulating protection layer 24 formed by using the above materials has better insulating protection performance.

[0099] According to some embodiments of this application, please continue to refer to Figure 4 and Figure 5 The thickness of the insulating protective layer 24 is N, 1 micrometer ≤ N ≤ 1000 micrometers (hereinafter, "μm" is used instead of micrometer).

[0100] 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.

[0101] 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 a role in 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 punctured.

[0102] According to some embodiments of this application, please continue to refer to Figures 3 to 5 , the thickness of the insulating protection layer 24 is N, 50μm≤N≤500μm.

[0103] 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 50μm; 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 500μm, 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.

[0104] According to some embodiments of this application, please continue to refer to Figures 3 to 5 The battery cell 20 further includes an electrode assembly 23 , which is accommodated inside the shell 22 .

[0105] 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 structure such as an insulating film, thereby achieving the purpose of reducing costs.

[0106] 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 on the top of the shell 22, and the end cover 21 covers the opening 221 and is fixedly connected to the shell 22 by welding; wherein 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; and The lower plastic layer 26 can cover the blank gap 25, and 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 insulate the shell 22. At the same time, the lower plastic layer 26 can also cover the blank gap 25, that is, the shell 22 exposed at the blank gap 25 is protected, thereby reducing the probability of the electrode assembly 23 (such as a bare battery cell, a transfer sheet, etc.) contained in the shell 22 contacting with the shell 22 and causing a circuit breaker.

[0107] According to some embodiments of this application, please continue to refer to Figures 2 to 5 The embodiment of the present application further provides a battery 100, including the battery cell 20 as described above. The battery 100 uses any of the battery cells 20 described in the above embodiments, which will not be described in detail here.

[0108] According to some embodiments of this 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 introduced in the above embodiments, such as the vehicle 1000, which will not be described in detail here.

[0109] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope 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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