Battery cell, battery, and electric device

Abstract

A battery cell (20), a battery (100), and an electrical device are disclosed. The battery cell (20) includes an electrode assembly (22) and a housing assembly (21). The housing assembly (21) is used to house the electrode assembly (22). The housing assembly (21) includes a cover (211) and a housing (212). The housing (212) includes a connecting portion (2121) and a main body portion (2122). The connecting portion (2121) is used to connect the cover (211). A tangible variable absorption area (21221) is formed on the side of the main body portion (2122) near the connecting portion (2121).

Description

Battery cell, battery and electric device

[0001] Cross-reference to related applications

[0002] This application is based on Chinese Patent Application No. 202420817176.5, filed on April 19, 2024, entitled "Battery cell, battery and electric device", which is incorporated by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery cell, a battery and an electric device. BACKGROUND

[0004] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is an important factor for their development.

[0005] A battery generally includes a battery cell, and a housing assembly in the battery cell is used to accommodate an electrode assembly, an electrolyte and the like. The cover of the housing assembly is arranged at the opening of the shell of the housing assembly and connected with the shell to isolate the internal environment of the shell from the external environment of the shell. However, the connection between the shell and the cover is prone to cracking, which causes the battery cell to leak, which is not conducive to improving the reliability of the battery cell.

[0006] SUMMARY

[0007] One of the purposes of the embodiments of the present application is to provide a battery cell, a battery and an electric device, which aims to solve the technical problem that the connection between the shell and the cover of the housing assembly in the related art is prone to cracking, which causes the battery cell to leak.

[0008] To solve the above technical problems, the technical solution adopted by the embodiments of the present application is to provide a battery cell, which includes:

[0009] An electrode assembly;

[0010] A housing assembly for accommodating the electrode assembly, the housing assembly including a cover and a shell, the shell including a connection portion and a main body portion connected with each other, the connection portion being used to connect the cover, and the main body portion being formed with a deformation amount absorbing area on one side close to the connection portion.

[0011] The battery monomer provided by the embodiments of the present application has the beneficial effects that the battery monomer provided by the embodiments of the present application is provided with a deformation amount absorption area on the side of the main body part close to the connecting part, the deformation amount absorption area can absorb the deformation amount of the shell, the deformation amount borne by the connecting part can be reduced, the risk of cracking of the connecting part is effectively reduced, the risk of liquid leakage of the battery monomer is effectively reduced, and the reliability of the battery monomer is effectively improved.

[0012] In some embodiments of the present application, a groove is concavely arranged on the side of the main body part close to the connecting part along the wall thickness direction of the shell, so that the side of the main body part close to the connecting part forms a deformation amount absorption area.

[0013] By adopting the above technical solution, the flexibility of the deformation amount absorption area can be increased, the deformation amount absorption area can better absorb the deformation amount of the shell, the deformation amount of the connecting part is effectively reduced, the risk of cracking of the connecting part is effectively reduced, the risk of liquid leakage of the battery monomer is effectively reduced, and the reliability of the battery monomer is effectively improved.

[0014] In some embodiments of the present application, the ratio of the depth of the groove to the wall thickness of the main body part is 0.05-0.5.

[0015] By adopting the above technical solution, not only can the deformation amount absorption area have good flexibility, but also can have good structural strength, so that the risk of cracking of the deformation amount absorption area is effectively reduced.

[0016] In some embodiments of the present application, the cross section of the groove is in an arc structure.

[0017] By adopting the above technical solution, the local stress borne by the deformation amount absorption area during deformation can be effectively reduced, so that the risk of cracking of the deformation amount absorption area is effectively reduced.

[0018] In some embodiments of the present application, the connecting part includes a first connecting area for connecting the cover body, and the wall thickness of the first connecting area is greater than the wall thickness of the main body part.

[0019] By adopting the above technical solution, compared with the main body part, the wall thickness of the connecting part is greater, the first connecting area can have better structural strength, and the risk of cracking of the connecting part is further reduced.

[0020] In some embodiments of the present application, the ratio of the wall thickness of the first connecting area to the wall thickness of the main body part is greater than or equal to 1.4.

[0021] By adopting the above technical solution, the first connecting area can have sufficient structural strength, and the risk of cracking of the connecting part is further reduced.

[0022] In some embodiments of the present application, the first connecting region has a first inner wall surface for connecting the cover and a first outer wall surface opposite to the first inner wall surface, the main body part has a second inner wall surface and a second outer wall surface opposite to the second inner wall surface, the first inner wall surface and the second inner wall surface are arranged on the same side of the shell assembly, the first inner wall surface is arranged protruding relative to the second inner wall surface, and the first outer wall surface is arranged protruding relative to the second outer wall surface.

[0023] By adopting the above technical solution, the thickening amount of the connecting part relative to the main body part is distributed on the inner side and the outer side of the connecting part. On the one hand, the protruding height of the first inner wall surface relative to the second inner wall surface is not too large, so as to improve the situation that the first inner wall surface interferes with the electrode assembly during the process of the electrode assembly entering the shell. On the other hand, the protruding height of the first outer wall surface relative to the second outer wall surface is not too large, so as to reduce the arrangement gap between the adjacent two battery monomers.

[0024] In some embodiments of the present application, the protruding height of the first inner wall surface relative to the second inner wall surface is 0.1mm-0.5mm; and / or, the protruding height of the first outer wall surface relative to the second outer wall surface is 0.1mm-2.5mm.

[0025] By adopting the above technical solution, the first connecting region has sufficient thickness, and the situation that the first inner wall surface interferes with the electrode assembly during the process of the electrode assembly entering the shell can be improved, and the arrangement gap between the adjacent two battery monomers can be reduced.

[0026] In some embodiments of the present application, the connecting part includes a second connecting region for connecting the main body part, the second connecting region has a third inner wall surface connected between the first inner wall surface and the second inner wall surface, and the protruding height of the third inner wall surface relative to the second inner wall surface gradually decreases in the direction of the first connecting region pointing to the main body part.

[0027] By adopting the above technical solution, the mold can be taken out from the shell along the third inner wall surface during the forming process of the shell, so as to facilitate the mold removal operation after the shell is formed.

[0028] In some embodiments of the present application, the third inner wall surface is an inclined surface, and the angle between the third inner wall surface and the second inner wall surface is 10°-30°.

[0029] By adopting the above technical solution, the inclination angle of the third inner wall surface relative to the second inner wall surface is not too large, and the mold removal operation after the shell is formed is more convenient.

[0030] In some embodiments of the present application, the connecting portion comprises a second connecting area for connecting the body portion, the second connecting area has a third outer wall surface connected between the first outer wall surface and the second outer wall surface, and the protruding height of the third outer wall surface relative to the second outer wall surface gradually decreases in the direction in which the first connecting area points to the body portion.

[0031] By adopting the above technical solution, in the forming process of the shell, the mold can push the material of the shell from the body portion to the first connecting area along the third outer wall surface, so that the material is accumulated in the first connecting area, thereby facilitating the thickening operation of the first connecting area.

[0032] In some embodiments of the present application, the third outer wall surface is an inclined surface, and the angle between the third outer wall surface and the second outer wall surface is 10°-30°.

[0033] By adopting the above technical solution, the moving resistance of the mold can be reduced, the mold can push the material of the shell from the body portion to the first connecting area, and the thickening operation of the first connecting area is facilitated.

[0034] In some embodiments of the present application, the connecting portion comprises a first connecting area and a thermal isolation area, the cover body is welded to the first connecting area, and the thermal isolation area is arranged between the first connecting area and the deformation amount absorbing area.

[0035] By adopting the above technical solution, the heat transferred to the deformation amount absorbing area is effectively reduced, the situation that the flexibility of the deformation amount absorbing area is reduced due to heating is improved, and the risk of cracking of the deformation amount absorbing area is effectively reduced.

[0036] In some embodiments of the present application, the shell is a steel shell; and / or, the cover body is a steel cover body.

[0037] By adopting the above technical solution, the deformation of the shell assembly is effectively improved, the risk of cracking of the connecting portion is effectively reduced, the risk of liquid leakage of the battery monomer is effectively reduced, and the reliability of the battery monomer is effectively improved.

[0038] The embodiments of the present application also provide a battery comprising the battery monomer described in any one of the above embodiments.

[0039] The battery provided by the embodiments of the present application has the beneficial effects that the battery provided by the embodiments of the present application effectively improves the reliability of the battery due to the adoption of the battery monomer described in any one of the above embodiments.

[0040] The embodiments of the present application also provide an electric device comprising the battery.

[0041] The electric device provided by the embodiments of the present application has the beneficial effects that the electric device provided by the embodiments of the present application effectively improves the reliability of the electric device due to the adoption of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] 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 exemplary 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 any creative work.

[0043] FIG1 is a schematic structural diagram of a vehicle provided in an embodiment of the present application;

[0044] FIG2 is a schematic diagram of an exploded structure of a battery in the vehicle shown in FIG1 ;

[0045] FIG3 is a schematic structural diagram of a battery cell in the battery shown in FIG2 ;

[0046] FIG4 is a schematic diagram of the top structure of the battery cell shown in FIG3 ;

[0047] FIG5 is a schematic cross-sectional view of the battery cell shown in FIG4 along line AA;

[0048] FIG6 is an enlarged structural diagram of the battery cell at position B shown in FIG5 ;

[0049] FIG7 is an enlarged structural diagram of a portion C of the battery cell shown in FIG5 .

[0050] Description of reference numerals:

[0051] 1000. Vehicle;

[0052] 100. Battery; 10. Housing; 11. First portion; 12. Second portion; 20. Battery cell; 21. Housing assembly; 211. Cover; 212. Housing; 2121. Connecting portion; 21211. First connecting region; 21212. Second connecting region; 21213. Thermal isolation region; 21214. First inner wall; 21215. First outer wall; 21216. Third inner wall; 21217. Third outer wall; 2122. Main body; 21221. Deformation absorption region; 21222. Groove; 21223. Second inner wall; 21224. Second outer wall; 22. Electrode assembly; 23. Electrode terminal; 24. Pressure relief mechanism;

[0053] 200, controller;

[0054] 300. Motor. DETAILED DESCRIPTION

[0055] In order to make the purposes, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are intended to explain, not to limit, the present application.

[0056] It should be noted that when a component is referred to as being "fixed" or "set" on another component, it can be directly on the other component or indirectly on the other component. When a component is referred to as being "connected" to another component, it can be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first", "second" are only for the purpose of convenient description, and cannot be understood as indicating or implying relative importance or implying the number of technical features. The meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0057] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and the like of various components in the embodiments of the present application shown in the drawings are only exemplary and should not constitute any limitation on the present application.

[0058] A battery cell is the smallest unit of electrical energy storage, which can include a housing assembly for containing an electrode assembly and an electrolyte to isolate the electrode assembly and the electrolyte from the external environment of the battery cell.

[0059] In the related art, the shell usually comprises a cover and a shell body, the electrode assembly and the electrolyte are contained in the shell body, the cover is arranged at the opening of the shell body and is welded with the opening of the shell body to isolate the internal environment of the shell body from the external environment of the shell body. During the charging process of the battery monomer, the electrode assembly will swell, and the swelled electrode assembly will press the shell body, causing the shell body to swell. During the discharging process of the battery monomer, the electrode assembly will shrink, at this time, the pressing force of the electrode assembly acting on the shell body disappears, and the shell body shrinks and recovers under the action of its own elasticity. In other words, during the continuous charging and discharging process of the battery monomer, the shell body will alternately swell and shrink with the electrode assembly. Due to the welding of the cover at the opening of the shell body, the brittleness of the opening of the shell body increases under the influence of heat. After the shell body swells and shrinks multiple times, the opening of the shell body is prone to cracking, causing the internal environment of the shell assembly to communicate with the external environment of the shell assembly through the cracked part of the opening of the shell body, resulting in a liquid leakage of the battery monomer, which is not conducive to improving the reliability of the battery monomer.

[0060] In order to reduce the risk of cracking of the opening of the shell body in the shell assembly, the battery monomer provided by the embodiments of the present application can set a deformation amount absorbing area on one side of the main body part close to the connecting part. The deformation amount absorbing area can absorb the deformation amount of the shell body, and can reduce the deformation amount borne by the connecting part, thereby effectively reducing the risk of cracking of the connecting part, and further effectively reducing the risk of liquid leakage of the battery monomer, and effectively improving the reliability of the battery monomer.

[0061] The technical solutions described in the embodiments of the present application are applicable to batteries and electric devices using batteries. The electric devices can be, but are not limited to, vehicles, mobile phones, portable devices, notebook computers, ships, spacecraft, electric toys and electric tools, etc. The vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or an extended range automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer, etc.

[0062] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a vehicle 1000 provided in an embodiment of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid automobile, or a range extended automobile, etc. The vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000, for example, the battery 100 can be used as an operating power supply of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the working power demand of the vehicle 1000 during starting, navigation, and driving.

[0063] In some embodiments of the present application, the battery 100 can not only be used as an operating power supply of the vehicle 1000, but also be used as a driving power supply of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0064] Referring to FIG. 2, FIG. 2 is an exploded schematic diagram of the battery 100 provided in an embodiment of the present application. The battery 100 includes a box body 10 and a battery cell 20, and the battery cell 20 is accommodated in the box body 10. The box body 10 is used to provide an accommodation space for the battery cell 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 can include a first part 11 and a second part 12, the first part 11 and the second part 12 are overlapped with each other, and the first part 11 and the second part 12 jointly define an accommodation 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-shaped structure, which is arranged on the open side of the second part 12 to jointly define the accommodation space with the second part 12; or the first part 11 and the second part 12 can both be hollow structures with one side open, and the open side of the first part 11 is arranged on the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0065] In some embodiments, the box body 10 can be part of the chassis structure of the vehicle 1000. For example, part of the box body 10 can become at least part of the floor of the vehicle 1000, or part of the box body 10 can become at least part of the cross beam and the longitudinal beam of the vehicle 1000.

[0066] In the battery 100, when the battery cells 20 are multiple, the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection, where the mixed connection means that some of the multiple battery cells 20 are connected in series and some are connected in parallel. The multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and then the whole of the multiple battery cells 20 is accommodated in the case 10; of course, the battery 100 can also be that the multiple battery cells 20 are first connected in series, in parallel, or in a mixed connection to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and are accommodated in the case 10. The battery 100 can also include other structures, for example, the battery 100 can also include a current combing component for realizing the electrical connection between the multiple battery cells 20.

[0067] Each battery cell 20 can be a secondary battery or a primary battery, where the secondary battery means that the battery cell 20 can be activated by charging after being discharged, and the primary battery means that the battery cell 20 cannot be activated by charging after the electrical energy is consumed. The battery cell 20 can also be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., but is not limited thereto. The battery cell 20 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or other shaped battery cell 20, and the prismatic battery cell includes a square battery cell, a blade battery cell, and a multi-prismatic battery cell, such as a hexagonal battery cell, etc., without specific limitation in the present application.

[0068] The battery cell 20 provided by the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0069] In a first aspect, in conjunction with FIGS. 3 to 6, the present application provides a battery cell 20, which includes an electrode assembly 22 and a housing assembly 21, the housing assembly 21 is used to accommodate the electrode assembly 22, the housing assembly 21 includes a cover 211 and a shell 212, the shell 212 includes a connecting part 2121 and a main body part 2122 connected to each other, the connecting part 2121 is used to connect the cover 211, and the main body part 2122 is formed with a deformation amount absorbing area 21221 on the side close to the connecting part 2121.

[0070] The electrode assembly 22 is a component in which electrochemical reactions occur in the battery cell 20. The battery cell 20 can include one or more electrode assemblies 22. The main body of the electrode assembly 22 is made of a positive electrode sheet, a negative electrode sheet, and a separator using a winding process or a stacking process. The positive electrode sheet and the negative electrode sheet can be provided in plural, and the plural positive electrode sheets and the plural negative electrode sheets can be alternately stacked. Adjacent positive electrode sheets and negative electrode sheets are spaced apart to form a slit, and the slit extends through the outer side of the electrode assembly 22 to form a slit opening. The slit is connected to the above-mentioned cavity through the slit opening. The separator is disposed in the slit to insulate and separate the positive electrode sheet and the negative electrode sheet. In some embodiments, the positive electrode sheet can be provided in plural, and the negative electrode sheet can be folded to form a plurality of stacked folded sections. Adjacent folded sections can hold one positive electrode sheet therebetween. In other embodiments, the positive electrode sheet and the negative electrode sheet can be folded to form a plurality of stacked folded sections. In some embodiments, the separator can be provided in plural, and can be disposed between any adjacent positive electrode sheet or negative electrode sheet. In other embodiments, the separator can be continuously provided, and can be disposed between any adjacent positive electrode sheet or negative electrode sheet by being folded or wound. The shape of the electrode assembly 22 can be, but is not limited to, a cylindrical shape, a flat shape, or a polygonal prism shape, etc. In some embodiments, the electrode assembly 22 further includes tabs, and the tabs include a positive tab and a negative tab. The positive tab is connected to the positive electrode sheet, and the negative tab is connected to the negative electrode sheet, to lead out or input current from or to the electrode assembly 22.

[0071] During charging and discharging of the battery cell 20, active ions (e.g., lithium ions) are inserted into and extracted from between the positive electrode sheet and the negative electrode sheet. The separator is disposed between the positive electrode sheet and the negative electrode sheet, and can prevent short circuiting of the positive electrode and the negative electrode, while allowing the active ions to pass therethrough.

[0072] The positive electrode sheet can include a positive current collector and a positive active material disposed on at least one surface of the positive current collector. In some embodiments, the positive current collector has two opposite surfaces in the thickness direction thereof, and the positive active material is disposed on either one or both of the two opposite surfaces of the positive current collector.

[0073] As an example, the positive electrode current collector can employ a metal foil, a composite current collector, or a foamed metal. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, or the like can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy, or the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like). The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, or the like. When the foamed metal is used as the positive electrode, the foamed metal surface can not be provided with a positive electrode active material, and of course, can be provided with a positive electrode active material. As an example, the foamed metal can also be filled or / and deposited with a lithium source material, a potassium metal, or a sodium metal, the lithium source material being a lithium metal and / or a lithium-rich material.

[0074] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a positive electrode active material of the battery cell 20 can also be used. These positive electrode active materials can be used alone only one kind, or two or more kinds in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (which can also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O2), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (which can also be referred to as NCM333), LiNi0.5Co0.2Mn0.3O2 (which can also be referred to as NCM523), LiNi0.5Co0.25Mn0.25O2 (which can also be referred to as NCM211), LiNi0.6Co0.2Mn0.2O2 (which can also be referred to as NCM622), LiNi0.8Co0.1Mn0.1O2 (which can also be referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi0.85Co0.15Al0.05O2), and a modified compound thereof, or the like.

[0075] The negative electrode sheet can include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector. In some embodiments, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two surfaces of the negative electrode current collector.

[0076] As an example, the negative electrode current collector can employ a metal foil, a composite current collector, or a foamed metal. For example, as the metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, or the like can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc.

[0077] As an example, the negative electrode active material can employ a negative electrode active material for the battery cell 20 known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for the battery cell 20 can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0078] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0079] In some embodiments, the separator is a separator film. The present application does not have a particular limitation on the type of the separator film, and any known porous structure separator film having good chemical stability and mechanical stability can be used. For example, the material of the separator film can be, but is not limited to, glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic, etc. The separator film can be a single layer film or a multi-layer composite film. In the case where the separator film is a multi-layer composite film, the materials of the respective layers of the separator film can be the same or different. The separator can be a separate component located between the positive electrode sheet and the negative electrode sheet, or can be attached to the surface of the positive electrode sheet and the surface of the negative electrode sheet.

[0080] The electrolyte serves to conduct ions between the positive electrode sheet and the negative electrode sheet. A portion of the electrolyte is accommodated in the gap of the electrode assembly 22, and another portion of the electrolyte is disposed outside the electrode assembly 22 so that at least a portion of the electrode assembly 22 is soaked in the electrolyte. The type of the electrolyte is not particularly limited in the present application, and can be selected as needed. In some embodiments, the electrolyte can be a liquid electrolyte, and of course, in other embodiments, the electrolyte can also be a gel electrolyte, a solid electrolyte, etc.

[0081] In some embodiments, the battery cell 20 further includes electrode terminals 23, which are components electrically connected to the electrode assembly 22 for outputting or inputting electric energy. The electrode terminals 23 can be disposed in the electrode lead-out holes of the cover body 211, a portion of the electrode terminals 23 is disposed in the internal environment of the battery cell 20 and directly or indirectly connected to the tab of the electrode assembly 22, and another portion of the electrode terminals 23 is disposed in the external environment of the battery cell 20 and connected to components such as the bus component, the sampling device, etc. The number of the electrode terminals 23 can be two, and the two electrode terminals 23 are respectively disposed on opposite sides of the cover body 211, one electrode terminal 23 is connected to the positive tab, and the other electrode terminal 23 is connected to the negative tab. Alternatively, the electrode terminals 23 can have a columnar structure such as a circular column, a prismatic column, etc., or a plate structure such as a circular plate, a square plate, etc., and of course, in other embodiments, the electrode terminals 23 can also have other irregular three-dimensional structures. The electrode terminals 23 can be made of one kind of metal material, or can be made of multiple kinds of metal materials, which can be but are not limited to copper, aluminum, nickel, zinc, iron, etc.

[0082] The housing assembly 21 is used to accommodate the electrode assembly 22 and the electrolyte, etc., so as to isolate the electrode assembly 22 and the electrolyte, etc. from the external environment of the housing assembly 21.

[0083] It should be noted that the battery cell 20 has a height direction, a length direction and a width direction. The height direction of the battery cell 20 can refer to the Z direction shown in FIGS. 3, 5 and 6, and in some embodiments, the height direction of the battery cell 20 can be the lead-out direction of the above-mentioned electrode terminals 23. The width direction of the battery cell 20 can refer to the Y direction shown in FIGS. 3 to 6, and the length direction of the battery cell 20 can refer to the X direction shown in FIGS. 3 and 4. The size of the battery cell 20 along the width direction can be the same as or different from the size of the battery cell 20 along the length direction. The housing assembly 21 defines the shape of the battery cell 20, in other words, the height direction of the battery cell 20 is the height direction of the housing assembly 21, the length direction of the battery cell 20 is the length direction of the housing assembly 21, and the width direction of the battery cell 20 is the width direction of the housing assembly 21.

[0084] The shell 212 is a component for providing an internal environment of the battery cell 20, which can be used to accommodate the electrode assembly 22, electrolyte, and the like. In some embodiments, the shell 212 can be integrally formed, for example, the shell 212 is integrally formed using a drawing process. In other embodiments, the connecting portion 2121 and the main body portion 2122 can be separately formed and then connected to form a whole. The shell 212 can be provided with an opening, and the electrode assembly 22, electrolyte, and the like are accommodated in the internal environment of the shell 212 by covering the opening with the cover 211. Specifically, the shell 212 and the cover 211 can form a common connection surface before other components are accommodated in the shell, and when it is necessary to seal the internal environment of the shell 212, the cover 211 is covered on the opening of the shell 212. The shape of the shell 212 can be, but is not limited to, a rectangular parallelepiped, a cylinder, a hexagonal prism, and the like, and the shape of the cover 211 can be adapted to the shape of the shell 212 to fit the shell 212. The material of the shell 212 can be, but is not limited to, copper, iron, aluminum, carbon steel, stainless steel, aluminum alloy, and the like. The cover 211 can be made of a material having a certain hardness and strength, so that the cover 211 is not easily deformed when subjected to extrusion and impact, and the battery cell 20 can have higher structural strength and improved reliability. The material of the cover 211 can be, but is not limited to, copper, iron, aluminum, carbon steel, stainless steel, aluminum alloy, and the like.

[0085] The connecting portion 2121 constitutes an opening portion of the shell 212, and the cover 211 is covered on the opening and connected to the connecting portion 2121. In some embodiments, the connecting portion 2121 can be welded to the cover 211. Of course, in other embodiments, the connecting portion 2121 can be connected to the cover 211 using other connection methods, such as bonding, and the like.

[0086] In some embodiments, the height of the connecting portion 2121 and the thickness of the cover 211 can not be equal, and at least part of the connecting portion 2121 protrudes toward the main body portion 2122 relative to the cover 211 in the height direction of the shell assembly 21. In the case where the connecting portion 2121 is welded to the cover 211, the portion of the connecting portion 2121 directly opposite the cover 211 is welded to the cover 211, and the heat generated during the welding process can be transferred from the portion of the connecting portion 2121 directly opposite the cover 211 to the protruding portion of the connecting portion 2121 relative to the cover 211.

[0087] In other embodiments, the height of the connecting portion 2121 and the thickness of the cover 211 can be equal, and the top of the connecting portion 2121 and the top of the cover 211 are flush, and the bottom of the connecting portion 2121 and the bottom of the cover 211 are flush in the height direction of the shell assembly 21.

[0088] In some embodiments, the connecting portion 2121 can be arranged to be spaced apart from the electrode assembly 22 in the height direction of the housing assembly 21, in other words, in the case where the electrode assembly 22 swells, the electrode assembly 22 does not directly press the connecting portion 2121.

[0089] The body portion 2122 is a main body part of the housing 212, and is configured to provide an internal environment of the housing assembly 21, in other words, most or all of the electrode assembly 22 is accommodated in the body portion 2122. In some embodiments, the body portion 2122 can include a peripheral wall and a bottom wall, the bottom wall is arranged opposite to the cover 211, and the peripheral wall is connected to the peripheral edge of the bottom wall, and the peripheral wall and the bottom wall together define the internal environment of the housing assembly 21.

[0090] In some embodiments, the deformed amount absorbing region 21221 is arranged to be spaced apart from the electrode assembly 22 in the height direction of the housing assembly 21, in other words, in the case where the electrode assembly 22 swells, the electrode assembly 22 does not directly press the deformed amount absorbing region 21221.

[0091] In some embodiments, the deformed amount absorbing region 21221 is arranged to be spaced apart from the electrode assembly 22 in the height direction of the housing assembly 21, in other words, in the case where the electrode assembly 22 swells, the electrode assembly 22 does not directly press the deformed amount absorbing region 21221.

[0092] In some embodiments, the deformed amount absorbing region 21221 is arranged to be spaced apart from the electrode assembly 22 in the height direction of the housing assembly 21, in other words, in the case where the electrode assembly 22 swells, the electrode assembly 22 does not directly press the deformed amount absorbing region 21221.

[0093] In some embodiments, the structural strength of the deformation amount absorbing region 21221 can be less than that of the connecting portion 2121, so that the deformation amount absorbing region 21221 is more likely to deform than the connecting portion 2121. In the case where the electrode assembly 22 expands, the electrode assembly 22 presses the case 212, so that the case 212 deforms by expansion. In the case where the electrode assembly 22 shrinks, the pressing force of the electrode assembly 22 acting on the case 212 disappears, and the case 212 shrinks to recover. Since the structural strength of the deformation amount absorbing region 21221 is less than that of the connecting portion 2121, and the deformation amount absorbing region 21221 is located on the side of the main body portion 2122 close to the connecting portion 2121, most of the deformation amount of the case 212 is concentrated on the deformation amount absorbing region 21221, and only a small amount of deformation amount is transmitted to the connecting portion 2121, that is, the connecting portion 2121 deforms slightly, or even no deformation amount is transmitted to the connecting portion 2121, that is, the connecting portion 2121 does not deform.

[0094] In some embodiments, the battery cell 20 further includes a pressure relief mechanism 24, which is a mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The pressure relief mechanism 24 can be mounted on the cover 211 or the case 212. In the case where the pressure relief mechanism 24 is mounted on the cover 211, the pressure relief mechanism 24 is disposed between the two electrode terminals 23. In the case where the pressure relief mechanism 24 is mounted on the case 212, the pressure relief mechanism 24 can be mounted on the wall of the case 212 opposite to the cover 211.

[0095] The case 212 in the battery cell 20 provided by the embodiments of the present application includes the connecting portion 2121, the deformation amount absorbing region 21221, and the main body portion 2122. During the charging and discharging of the battery cell 20, the case 212 expands with the expansion of the electrode assembly 22 and shrinks with the shrinkage of the electrode assembly 22. Since the deformation amount absorbing region 21221 is connected between the connecting portion 2121 and the main body portion 2122, the deformation amount of the case 212 is absorbed by the deformation amount absorbing region 21221, which can reduce the deformation amount borne by the connecting portion 2121, thereby effectively reducing the risk of cracking of the connecting portion 2121, and further effectively reducing the risk of liquid leakage of the battery cell 20, and effectively improving the reliability of the battery cell 20.

[0096] In some embodiments of the present application, referring to FIG. 6, a groove 21222 is recessed on the side of the main body portion 2122 close to the connecting portion 2121 along the wall thickness direction of the case 212, so that the side of the main body portion 2122 close to the connecting portion 2121 forms the deformation amount absorbing region 21221.

[0097] In some embodiments, the recess 21222 can be an annular groove and arranged around the inner environment of the shell assembly 21. The recess 21222 can be arranged on the outer wall surface of the main body portion 2122 or the inner wall surface of the main body portion 2122. The cross-sectional shape of the recess 21222 can be, but is not limited to, arc-shaped, square-shaped, triangular-shaped, etc.

[0098] By adopting the above technical solution, the structural strength of the deformation amount absorbing area 21221 can be less than that of the connecting portion 2121, the flexibility of the deformation amount absorbing area 21221 can be increased, the deformation amount absorbing area 21221 can better absorb the deformation amount of the shell 212, the deformation amount of the connecting portion 2121 can be effectively reduced, the risk of cracking of the connecting portion 2121 can be effectively reduced, the risk of liquid leakage of the battery monomer 20 can be effectively reduced, and the reliability of the battery monomer 20 can be effectively improved.

[0099] In some embodiments of the present application, referring to FIG. 7, the ratio of the depth H1 of the recess 21222 to the wall thickness H2 of the main body portion 2122 is 0.05-0.5.

[0100] The depth H1 of the recess 21222 refers to the dimension of the recess 21222 along the wall thickness direction of the shell 212. The ratio of the depth H1 of the recess 21222 to the wall thickness H2 of the main body portion 2122 can be determined according to actual application needs, and can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0101] By adopting the above technical solution, not only can the deformation amount absorbing area 21221 have good flexibility, but also can have good structural strength, thereby effectively reducing the risk of cracking of the deformation amount absorbing area 21221.

[0102] In some embodiments of the present application, referring to FIG. 6, the cross-section of the recess 21222 is arc-shaped.

[0103] By adopting the above technical solution, compared with structures with corners such as square-shaped, triangular-shaped, etc., the cross-sectional shape of the recess 21222 is arranged as an arc-shaped structure, which can effectively reduce the local stress borne by the deformation amount absorbing area 21221 during deformation, thereby effectively reducing the risk of cracking of the deformation amount absorbing area 21221.

[0104] Of course, in other embodiments, other ways can also be adopted to reduce the structural strength of the deformation-amount absorbing region 21221, so that the structural strength of the deformation-amount absorbing region 21221 is less than the structural strength of the connecting portion 2121. For example, the deformation-amount absorbing region 21221 can be designed to be thinned, or the deformation-amount absorbing region 21221 of the main body portion 2122 can be made of a low-strength material.

[0105] In some embodiments of the present application, referring to FIGS. 6 and 7, the connecting portion 2121 includes a first connecting region 21211 for connecting the cover body 211, and the wall thickness H5 of the first connecting region 21211 is greater than the wall thickness H2 of the main body portion 2122.

[0106] It can be understood that the first connecting region 21211 is a part of the connecting portion 2121 for connecting the cover body 211. In some embodiments, the wall thickness of each part of the first connecting region 21211 can be equal, and the wall thickness of each part of the main body portion 2122 except the deformation-amount absorbing region 21221 can be equal. In the present embodiment, the wall thickness H2 of the main body portion 2122 refers to the wall thickness of each part of the main body portion 2122 except the deformation-amount absorbing region 21221. The maximum wall thickness of the deformation-amount absorbing region 21221 can be equal to or different from the wall thickness of each part of the main body portion 2122. For example, in the case where the deformation-amount absorbing region 21221 is provided with the groove 21222, the maximum wall thickness of the deformation-amount absorbing region 21221 can be equal to the wall thickness of each part of the main body portion 2122.

[0107] By adopting the above technical solution, compared with the main body portion 2122, the connecting portion 2121 has a greater wall thickness, so that the connecting portion 2121 has better structural strength, thereby further reducing the risk of cracking of the connecting portion 2121.

[0108] In some embodiments of the present application, the ratio of the wall thickness H5 of the first connecting region 21211 to the wall thickness H2 of the main body portion 2122 is greater than or equal to 1.4.

[0109] The ratio of the wall thickness H5 of the first connecting region 21211 to the wall thickness H2 of the main body portion 2122 can be determined according to actual application needs, and can be 1.4, 1.5, 1.6, 1.7, 1.8, etc.

[0110] By adopting the above technical solution, the connecting portion 2121 can have sufficient structural strength, thereby further reducing the risk of cracking of the connecting portion 2121.

[0111] In some embodiments of the present application, referring to FIG. 6, the first connecting area 21211 has a first inner wall surface 21214 for connecting the cover 211 and a first outer wall surface 21215 opposite to the first inner wall surface 21214, the main body part 2122 has a second inner wall surface 21223 and a second outer wall surface 21224 opposite to the second inner wall surface 21223, the first inner wall surface 21214 and the second inner wall surface 21223 are arranged on the same side of the shell assembly 21, the first inner wall surface 21214 is arranged protruding relative to the second inner wall surface 21223, and the first outer wall surface 21215 is arranged protruding relative to the second outer wall surface 21224.

[0112] The first inner wall surface 21214 is a surface of the first connecting area 21211 facing the internal environment of the shell assembly 21, and correspondingly, the first outer wall surface 21215 is a surface of the first connecting area 21211 facing away from the internal environment of the shell assembly 21. Similarly, the second inner wall surface 21223 is a surface of the main body part 2122 facing the internal environment of the shell assembly 21, and correspondingly, the second outer wall surface 21224 is a surface of the main body part 2122 facing away from the internal environment of the shell assembly 21. The first inner wall surface 21214 is arranged protruding relative to the second inner wall surface 21223, which means that the inner side of the first connecting area 21211 protrudes towards the internal environment of the shell assembly 21 relative to the inner side of the main body part 2122, and similarly, the first outer wall surface 21215 is arranged protruding relative to the second outer wall surface 21224, which means that the outer side of the first connecting area 21211 protrudes towards the external environment of the shell assembly 21 relative to the outer side of the main body part 2122. In some embodiments, in the case where the plurality of battery monomers 20 are arranged in sequence, the first outer wall surfaces 21215 of two adjacent battery monomers 20 can abut each other.

[0113] By adopting the above technical solution, the thickening amount of the connecting part 2121 relative to the main body part 2122 is distributed on the inner side and the outer side of the connecting part 2121, on the one hand, the protruding height of the first inner wall surface 21214 relative to the second inner wall surface 21223 is not too large, so as to improve the situation that the first inner wall surface 21214 interferes with the electrode assembly 22 during the process of entering the shell, and on the other hand, the protruding height of the first outer wall surface 21215 relative to the second outer wall surface 21224 is not too large, so as to reduce the arrangement gap between two adjacent battery monomers 20.

[0114] In some embodiments of the present application, referring to FIG. 6, the protruding height H3 of the first inner wall surface 21214 relative to the second inner wall surface 21223 is 0.1-0.5 mm.

[0115] The protruding height H3 of the first inner wall surface 21214 relative to the second inner wall surface 21223 can be determined according to actual application needs, and can be 0.1, 0.2, 0.3, 0.4, 0.5, etc.

[0116] By adopting the technical scheme, the first connecting area 21211 has sufficient thickness, and the interference between the first inner wall surface 21214 and the electrode assembly 22 during the process of the electrode assembly 22 entering the shell can be improved.

[0117] In some embodiments of the present application, referring to FIG. 6, the protruding height H4 of the first outer wall surface 21215 relative to the second outer wall surface 21224 is 0.1 mm-2.5 mm.

[0118] The protruding height H4 of the first outer wall surface 21215 relative to the second outer wall surface 21224 can be determined according to actual application needs, and can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, etc.

[0119] By adopting the technical scheme, the first connecting area 21211 has sufficient thickness, and the interference between the first inner wall surface 21214 and the electrode assembly 22 during the process of the electrode assembly 22 entering the shell can be improved.

[0120] In some embodiments of the present application, referring to FIG. 6, the connecting part 2121 includes a second connecting area 21212 for connecting the main body part 2122, the second connecting area 21212 has a third inner wall surface 21216 connected between the first inner wall surface 21214 and the second inner wall surface 21223, and the protruding height of the third inner wall surface 21216 relative to the second inner wall surface 21223 gradually decreases in the direction in which the first connecting area 21211 points to the main body part 2122.

[0121] The second connecting area 21212 is a part for connecting the first connecting area 21211 and the main body part 2122. The third inner wall surface 21216 is a surface of the second connecting area 21212 facing the internal environment of the shell assembly 21, and the protruding height of the third inner wall surface 21216 relative to the second inner wall surface 21223 gradually decreases in the direction in which the first connecting area 21211 points to the main body part 2122, that is, the third inner wall surface 21216 can serve as a transition surface from the second inner wall surface 21223 to the first inner wall surface 21214.

[0122] By adopting the technical scheme, during the forming process of the shell 212, the mold can be taken out from the shell 212 along the third inner wall surface 21216, facilitating the mold removal operation after the shell 212 is formed.

[0123] In some embodiments of the present application, referring to FIG. 7, the third inner wall surface 21216 is an inclined surface, and the angle between the third inner wall surface 21216 and the second inner wall surface 21223 is 10°-30°.

[0124] The angle between the third inner wall surface 21216 and the second inner wall surface 21223 can be determined according to actual application requirements, and can be 10°, 15°, 20°, 25°, 30°, etc.

[0125] By adopting the above technical solution, the inclination angle of the third inner wall surface 21216 relative to the second inner wall surface 21223 can be not too large, and it is more convenient to perform the mold stripping operation after the shell 212 is formed.

[0126] In some embodiments of the present application, referring to FIG. 6, the second connecting area 21212 has a third outer wall surface 21217 connected between the first outer wall surface 21215 and the second outer wall surface 21224, and in the direction in which the first connecting area 21211 points to the main body part 2122, the protruding height of the third outer wall surface 21217 relative to the second outer wall surface 21224 gradually decreases.

[0127] The third outer wall surface 21217 is a surface of the second connecting area 21212 facing the external environment of the shell assembly 21, and in the direction in which the first connecting area 21211 points to the main body part 2122, the protruding height of the third outer wall surface 21217 relative to the second outer wall surface 21224 gradually decreases, that is, the third outer wall surface 21217 can serve as a transition surface from the second outer wall surface 21224 to the first outer wall surface 21215.

[0128] By adopting the above technical solution, in the forming process of the shell 212, the mold can push the material of the shell 212 from the main body part 2122 to the first connecting area 21211 along the third outer wall surface 21217, so that the material is accumulated in the first connecting area 21211, thereby facilitating the thickening operation of the first connecting area 21211.

[0129] In some embodiments of the present application, referring to FIG. 7, the third outer wall surface 21217 is an inclined surface, and the angle between the third outer wall surface 21217 and the second outer wall surface 21224 is 10°-30°.

[0130] The angle between the third outer wall surface 21217 and the second outer wall surface 21224 can be determined according to actual application requirements, and can be 10°, 15°, 20°, 25°, 30°, etc.

[0131] By adopting the above technical solution, the moving resistance of the mold can be reduced, the material of the shell 212 can be pushed from the main body part 2122 to the first connecting area 21211 by the mold, and the thickening operation of the first connecting area 21211 is more convenient.

[0132] In some embodiments of the present application, referring to FIG. 6, the connecting portion 2121 comprises a first connecting area 21211 and a thermal isolation area 21213, the cover 211 is welded to the first connecting area 21211, and the thermal isolation area 21213 is arranged between the first connecting area 21211 and the deformation amount absorbing area 21221.

[0133] The thermal isolation area 21213 can serve as a heat transfer buffer area between the first connecting area 21211 and the deformation amount absorbing area 21221, that is, during the welding process of the cover 211 and the first connecting area 21211, heat is first transferred to the thermal isolation area 21213, and at least most of the heat is absorbed by the thermal isolation area 21213, only a small part of the heat is transferred to the deformation amount absorbing area 21221, or even no heat is transferred to the deformation amount absorbing area 21221, thereby effectively reducing the adverse effects of heat on the deformation amount absorbing area 21221.

[0134] In some embodiments, in the case where the connecting portion 2121 comprises a second connecting area 21212, the second connecting area 21212 can be used as the above-mentioned thermal isolation area 21213, in other words, the second connecting area 21212 and the thermal isolation area 21213 can be the same part of the connecting portion 2121.

[0135] By adopting the above technical solution, the heat transferred to the deformation amount absorbing area 21221 is effectively reduced, the situation that the flexibility of the deformation amount absorbing area 21221 is reduced due to heat is improved, and thus the risk of cracking of the deformation amount absorbing area 21221 is effectively reduced.

[0136] In some embodiments of the present application, referring to Figs. 5-7, the housing assembly 21 comprises a cover 211 and a shell 212, the shell 212 comprises a connecting portion 2121 and a main body portion 2122 connected to each other, the connecting portion 2121 is used to connect the cover 211, and the main body portion 2122 is recessed with a groove 21222 on a side close to the connecting portion 2121 along a wall thickness direction of the shell 212, so that the side of the main body portion 2122 close to the connecting portion 2121 forms a deformation amount absorbing area 21221. The connecting portion 2121 comprises a first connecting area 21211 used to connect the cover 211 and a second connecting area 21212 used to connect the main body portion 2122. The wall thickness H5 of the first connecting area 21211 is greater than the wall thickness H2 of the main body portion 2122. The first connecting area 21211 has a first inner wall surface 21214 used to connect the cover 211 and a first outer wall surface 21215 arranged opposite to the first inner wall surface 21214, the main body portion 2122 has a second inner wall surface 21223 and a second outer wall surface 21224 arranged opposite to the second inner wall surface 21223, the first inner wall surface 21214 and the second inner wall surface 21223 are arranged on the same side of the housing assembly 21, the first inner wall surface 21214 is arranged protruding relative to the second inner wall surface 21223, and the first outer wall surface 21215 is arranged protruding relative to the second outer wall surface 21224. The second connecting area 21212 has a third inner wall surface 21216 connected between the first inner wall surface 21214 and the second inner wall surface 21223 and a third outer wall surface 21217 connected between the first outer wall surface 21215 and the second outer wall surface 21224, in a direction of the first connecting area 21211 pointing to the main body portion 2122, the protruding height of the third inner wall surface 21216 relative to the second inner wall surface 21223 gradually decreases, and the protruding height of the third outer wall surface 21217 relative to the second outer wall surface 21224 gradually decreases. The second connecting area 21212 can be used as a heat isolation area 21213 to hinder heat transfer to the deformation amount absorbing area 21221.

[0137] In some embodiments of the present application, the shell 212 is a steel shell.

[0138] In other words, the material of the shell 212 is steel, for example, the material of the shell 212 is carbon steel, stainless steel, etc.

[0139] In some embodiments of the present application, the cover 211 is a steel cover.

[0140] In other words, the material of the cover 211 is steel, for example, the material of the cover 211 is carbon steel, stainless steel, etc.

[0141] In some embodiments of the present application, the shell 212 is a steel shell, and the cover 211 is a steel cover.

[0142] In other words, the material of the shell 212 and the material of the cover 211 are both steel, and the material of the shell 212 and the material of the cover 211 can be the same steel material, for example, the material of the shell 212 and the material of the cover 211 are both carbon steel, or for example, the material of the shell 212 and the material of the cover 211 are both stainless steel.

[0143] By adopting the above technical solutions, the deformation of the shell assembly 21 is effectively improved, thereby effectively reducing the risk of cracking of the connecting portion 2121, and further effectively reducing the risk of liquid leakage of the battery monomer 20, and effectively improving the reliability of the battery monomer 20.

[0144] In a second aspect, referring to FIG. 2, the embodiment of the present application provides a battery 100, which comprises the battery monomer 20 described in any of the above embodiments.

[0145] The battery 100 provided by the embodiment of the present application effectively improves the reliability of the battery 100 because the battery monomer 20 described in any of the above embodiments is used.

[0146] In a third aspect, referring to FIG. 1, the embodiment of the present application provides a power-consuming device, which comprises the battery 100 described above.

[0147] The power-consuming device provided by the embodiment of the present application effectively improves the reliability of the power-consuming device because the battery 100 described above is used.

[0148] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized by, The battery cell comprises: an electrode assembly; a housing assembly for accommodating the electrode assembly, the housing assembly comprising a cover and a shell, the shell comprising a connecting portion and a main body portion connected to each other, the connecting portion being used for connecting the cover, and the main body portion being formed with a deformation-amount absorbing area on a side close to the connecting portion.

2. The battery cell of claim 1, wherein, The main body portion is recessed with a groove in a wall thickness direction of the shell on the side close to the connecting portion, so that the main body portion is formed with the deformation-amount absorbing area on the side close to the connecting portion.

3. The battery cell of claim 2, wherein, A ratio of a depth of the groove to a wall thickness of the main body portion is 0.05-0.

5.

4. The battery cell of claim 3, wherein, A cross section of the groove is in an arc shape.

5. The battery cell according to any one of claims 1-4, characterized in that, The connecting portion comprises a first connecting area for connecting the cover, and a wall thickness of the first connecting area is greater than a wall thickness of the main body portion.

6. The battery cell of claim 5, wherein, A ratio of the wall thickness of the first connecting area to the wall thickness of the main body portion is greater than or equal to 1.

4.

7. The battery cell of claim 6, wherein, The first connecting area has a first inner wall surface for connecting the cover and a first outer wall surface arranged opposite to the first inner wall surface, the main body portion has a second inner wall surface and a second outer wall surface arranged opposite to the second inner wall surface, the first inner wall surface and the second inner wall surface are arranged on the same side of the housing assembly, the first inner wall surface is arranged protruding relative to the second inner wall surface, and the first outer wall surface is arranged protruding relative to the second outer wall surface.

8. The battery cell according to claim 7, wherein a protruding height of the first inner wall surface relative to the second inner wall surface is 0.1 mm-0.5 mm; and / or a protruding height of the first outer wall surface relative to the second outer wall surface is 0.1 mm-2.5 mm.

9. The battery cell according to claim 7 or 8, characterized in that, The connecting portion comprises a second connecting area for connecting the main body portion, the second connecting area has a third inner wall surface connected between the first inner wall surface and the second inner wall surface, and a protruding height of the third inner wall surface relative to the second inner wall surface gradually decreases in a direction of the first connecting area pointing to the main body portion.

10. The battery cell of claim 9, wherein, The third inner wall surface is a bevel, and an angle between the third inner wall surface and the second inner wall surface is 10°-30°.

11. The battery cell according to any one of claims 7-10, characterized in that, The connecting portion comprises a second connecting area for connecting the main body portion, the second connecting area has a third outer wall surface connected between the first outer wall surface and the second outer wall surface, and a protruding height of the third outer wall surface relative to the second outer wall surface gradually decreases in a direction of the first connecting area pointing to the main body portion.

12. The battery cell of claim 11, wherein, The third outer wall surface is a bevel, and an angle between the third outer wall surface and the second outer wall surface is 10°-30°.

13. The battery cell of any one of claims 1-4, wherein, The connecting portion comprises the first connecting area and a thermal isolation area, the cover is welded to the first connecting area, and the thermal isolation area is arranged between the first connecting area and the deformation-amount absorbing area.

14. The battery cell according to any one of claims 1-13, wherein the shell is a steel shell; and / or the cover is a steel cover.

15. A battery, characterized by The battery comprises the battery cell according to any one of claims 1-14.

16. An electrical device, characterized by The electric device comprises the battery according to claim 15.

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