Battery cell, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly and a pressure relief mechanism, and the shell comprises a first wall; the electrode assembly is arranged in the shell; the pressure relief mechanism is arranged on the first wall and comprises a first connecting part, a weak part, a second connecting part and a protruding part which are connected in sequence, the weak part is arranged on the periphery of the second connecting part, the weak part is configured to be damaged to release pressure when pressure in the shell reaches a threshold value, the first connecting part is located on the outer side of the weak part and connected with the first wall, and the second connecting part is located on the outer side of the protruding part. The protruding part comprises an arc-shaped part and a flat part, the arc-shaped part protrudes out of the side, back to the electrode assembly, of the second connecting part, and the flat part is arranged at the end, back to the electrode assembly, of the arc-shaped part. The energy density of the battery device is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery device and a power utilization device. BACKGROUND

[0002] In recent years, with the rapid development of new energy technology, new energy vehicles are increasingly widely used and gradually replace traditional fuel vehicles to become one of the mainstream transportation tools. As the power source of new energy vehicles, power batteries are one of the core equipment of new energy vehicles, and therefore the safety performance of power batteries has become the focus of attention.

[0003] In the development of battery technology, how to improve the energy density of the battery device is a research direction in the battery technology. CONTENT OF THE INVENTION

[0004] The embodiments of the present application provide a battery monomer, a battery device and a power utilization device, which can improve the energy density of the battery device.

[0005] In a first aspect, the embodiments of the present application provide a battery monomer, which comprises a shell, an electrode assembly and a pressure relief mechanism, the shell comprises a first wall; the electrode assembly is arranged inside the shell; the pressure relief mechanism is arranged on the first wall, and comprises a first connecting portion, a weak portion, a second connecting portion and a raised portion connected in sequence, the weak portion is arranged on the outer periphery of the second connecting portion, the weak portion is configured to be damaged to release pressure when the pressure inside the shell reaches a threshold value, the first connecting portion is located outside the weak portion and connected to the first wall, and the raised portion comprises an arc-shaped portion and a flat portion, the arc-shaped portion protrudes from one side of the second connecting portion away from the electrode assembly, and the flat portion is arranged at one end of the arc-shaped portion away from the electrode assembly.

[0006] In the above scheme, if the battery monomer has thermal runaway and the internal gas pressure is too large, the weak portion can be damaged under the impact of the pressure, so that the raised portion can be separated from the first wall, and the high-pressure gas is discharged to the outside of the shell. Since the arc-shaped portion of the raised portion protrudes outward, it can to some extent avoid fatigue fracture caused by repeated expansion of the arc-shaped portion under the action of internal pressure, thereby preventing the defect of reducing the opening pressure of the pressure relief mechanism to some extent. By arranging the flat portion at one end of the arc-shaped portion away from the electrode assembly, the height of the entire raised portion is reduced, and when the battery device is assembled, the pressure relief mechanism does not occupy other space, thereby improving the space utilization rate of the battery device and improving the energy density of the battery device.

[0007] In some embodiments, the flat portion does not protrude from the surface of the first wall away from the electrode assembly.

[0008] In the above scheme, the flat part does not protrude from the outer surface of the first wall, thereby avoiding the height of the pressure relief mechanism exceeding the height of the first wall of the shell to a certain extent, and further improving the energy density of the battery device.

[0009] In some embodiments, the first connecting part includes a bending part and a first connecting sub-part, the bending part bends from the first wall to the direction of the electrode assembly; the bending part is connected to the weak part through the first connecting sub-part.

[0010] In the above scheme, the bending part is formed by bending in the direction of the electrode assembly first, and then the weak part is connected through the first connecting sub-part, further reducing the height of the pressure relief mechanism, thereby further improving the energy density of the battery device.

[0011] In some embodiments, the bending part is integrally formed with the first wall.

[0012] In the above scheme, by integrally forming the pressure relief mechanism with the shell, the strength and sealing performance of the battery monomer can be improved.

[0013] In some embodiments, the first connecting part further includes a second connecting sub-part, the bending part is connected to the second connecting sub-part, and the second connecting sub-part is fixed to the first wall.

[0014] In the above scheme, the second connecting sub-part is used to fix the pressure relief mechanism to the first wall, reducing the difficulty of process manufacturing.

[0015] In some embodiments, the outer surface of the second connecting sub-part away from the electrode assembly is flush with the outer surface of the first wall.

[0016] In the above scheme, by setting the outer surface of the second connecting sub-part and the outer surface of the first wall to be flush with each other, the space occupied by the pressure relief mechanism during assembly of the battery device can be further reduced, thereby further improving the energy density of the battery device.

[0017] In some embodiments, the first wall is provided with a through hole corresponding to the pressure relief mechanism, and the shell further includes a step part, the step part is arranged on the side of the first wall facing the electrode assembly, and the second connecting sub-part is overlapped with the part of the step part exposed to the through hole.

[0018] In the above scheme, by setting the step part and the second connecting sub-part to overlap, the connection strength of the pressure relief mechanism and the shell can be improved, thereby increasing the stability of the battery monomer.

[0019] In some embodiments, the step part is arranged in a ring around the through hole, which can further improve the connection strength of the pressure relief mechanism and the shell, thereby further increasing the stability of the battery monomer.

[0020] In some embodiments, the flat part extends in the first direction, and the first direction is the length direction of the pressure relief mechanism.

[0021] In the above solution, by extending the flat part along the length direction of the pressure relief mechanism, the stress of the flat part can be made more uniform, thereby further preventing the defect of reducing the opening pressure of the pressure relief mechanism to a certain extent.

[0022] In some embodiments, the flat part is arranged at the region of the central axis of the pressure relief mechanism along the first direction.

[0023] In the above solution, by arranging the flat part at the region of the central axis of the pressure relief mechanism along the first direction, the pressure can be dispersed, the supporting force can be improved, and the stability of the overall structure of the raised part can be enhanced.

[0024] In some embodiments, the arc-shaped part is arranged in a ring around the circumference of the flat part.

[0025] In the above solution, by arranging the arc-shaped part on the circumferential side of the flat part, the pressure can be uniformly dispersed, and the fatigue resistance of the pressure relief mechanism can be further improved.

[0026] In some embodiments, the width of the flat part along the second direction is L1, the width of the pressure relief mechanism along the second direction is L2, and L1 and L2 satisfy: 1 / 20≤L1 / L2≤1 / 4; wherein the second direction is the width direction of the pressure relief mechanism.

[0027] In the above solution, by limiting the ratio of the width of the flat part to the width of the pressure relief mechanism within a suitable range, the defect of reducing the opening pressure of the pressure relief mechanism can be further prevented, and the height of the pressure relief mechanism can be further avoided to affect the energy density of the battery device.

[0028] In some embodiments, L1 and L2 satisfy: 1 / 10≤L1 / L2≤1 / 6.

[0029] In the above solution, by further limiting the ratio of the width of the flat part to the width of the pressure relief mechanism, the opening pressure of the pressure relief mechanism and the energy density of the battery device can be further balanced.

[0030] In some embodiments, in the third direction, there is a gap between the outer surface of the first wall and the side of the flat part away from the electrode assembly; wherein the third direction is the thickness direction of the first wall.

[0031] In the above solution, by arranging a gap between the outer surface of the first wall and the side of the flat part away from the electrode assembly, the risk of the height of the pressure relief mechanism being too high due to the tolerance during process manufacturing can be reduced.

[0032] In some embodiments, the gap between the outer surface of the first wall and the side of the flat part away from the electrode assembly is H, and H satisfies: 0.05≤H≤0.5.

[0033] In the above scheme, by limiting the range of the gap, the risk of the height of the pressure relief mechanism being too high due to the tolerance during process manufacturing can be further reduced to a certain extent.

[0034] In some embodiments, H satisfies: 0.1≤H≤0.3.

[0035] In the above scheme, by further limiting the range of the gap, the risk of the height of the pressure relief mechanism being too high can be further avoided.

[0036] In some embodiments, the weak part is arranged in a ring around the circumference of the arc-shaped part, improving the uniformity of the pressure impact and reducing the risk of excessive local pressure.

[0037] In some embodiments, the material of the first wall includes at least one of stainless steel and carbon steel; and the material of the pressure relief mechanism includes at least one of stainless steel and carbon steel.

[0038] In the above technical scheme, stainless steel and carbon steel have high strength, which can effectively improve the structural strength of the first wall and the pressure relief mechanism, reduce the risk of deformation of the first wall and the pressure relief mechanism under stress, and is conducive to reducing the risk of the pressure relief mechanism opening the valve to relieve pressure in advance, and is conducive to improving the service life and reliability of the battery monomer. In addition, using at least one of stainless steel and carbon steel to manufacture the first wall can appropriately reduce the thickness of the first wall, which is conducive to increasing the internal space of the shell and thus increasing the energy density under the same volume.

[0039] In a second aspect, the embodiments of the present application also provide a battery device, which includes the battery monomer of any of the above embodiments.

[0040] In a third aspect, the embodiments of the present application also provide a power consumption device, which includes the battery device, and the battery device is used to provide electric energy.

[0041] The power consumption device provided by the embodiments of the present application has the same technical effects as the battery provided by the above embodiments, and thus will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0043] Figure 1 It is a structural schematic diagram of a vehicle of some embodiments of the present application;

[0044] Figure 2 It is an exploded view of a battery device of some embodiments of the present application;

[0045] Figure 3 Structure diagram of a battery module according to some embodiments of the present application;

[0046] Figure 4 Exploded structure diagram of a battery cell according to some embodiments of the present application;

[0047] Figure 5 Partial exploded structure diagram of a battery cell according to some embodiments of the present application;

[0048] Figure 6 Structure diagram of a pressure relief mechanism according to some embodiments of the present application;

[0049] Figure 7 Structure diagram of a pressure relief mechanism according to some embodiments of the present application from another angle;

[0050] Figure 8 Sectional view diagram of a battery cell according to some embodiments of the present application;

[0051] Figure 9 is an enlarged view diagram of A of Figure 8

[0052] Figure 10 Partial exploded structure diagram of a battery cell according to some embodiments of the present application;

[0053] Figure 11 Top view diagram of a battery cell according to some embodiments of the present application;

[0054] Figure 12 Top view diagram of a pressure relief mechanism according to some embodiments of the present application;

[0055] Figure 13 Structure diagram of a pressure relief mechanism according to some embodiments of the present application from another angle.

[0056] BRIEF DESCRIPTION OF THE DRAWINGS

[0057] 1000, vehicle; 100, battery device; 200, controller; 300, motor; 10, upper cover; 30, box body; 400, battery module; 20, battery cell; 22, housing; 21, end cap; 23, electrode assembly; 24, outer shell; 241, first wall; 242, through hole; 243, stepped portion; 40, pressure relief mechanism; 41, weak portion; 42, raised portion; 421, arc portion; 422, flat portion; 43, bent portion; 44, first connecting sub-portion; 45, second connecting sub-portion; 46, first connecting portion; 47, second connecting portion; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0058] ​The embodiments of the present application will be described in further detail below with reference to the drawings and examples. The detailed description and drawings of the following examples are illustrative only and are not intended to limit the scope of the present application, that is, the present application is not limited to the described examples.

[0059] In the description of the present application, it should be noted that the meaning of "a plurality of" is two or more unless otherwise specified; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer" and the like is only for the purpose of facilitating the description of the present application and simplifying the description, and is not intended to 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 limiting the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable range of error. "Parallel" is not strictly parallel, but within the allowable range of error.

[0060] In the present application, the phrase "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0061] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0062] "Plurality" appearing in the present application means two or more (including two).

[0063] In the present application, the battery cell can include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium-sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, etc., and the present application embodiments are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc., and the present application embodiments are not limited thereto.

[0064] The battery referred to in the embodiments of the present application can include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel, or in a hybrid manner through a busbar component.

[0065] In some embodiments, the battery can be a battery module; when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0066] In some embodiments, the battery can be a battery pack, which includes a case and battery cells, and the battery cells or battery modules are contained in the case.

[0067] In some embodiments, the case can be part of the chassis structure of the vehicle. For example, part of the case can be at least part of the floor of the vehicle, or part of the case can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0068] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0069] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting while allowing the active ions to pass through.

[0070] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0071] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0072] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, silver surface treated stainless steel, copper, aluminum, nickel, carbon, carbon, nickel, or titanium, etc. can be used. 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, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0073] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials can also be used. These positive electrode active materials can be used alone or in combination with two or more.

[0074] In some embodiments, the positive electrode can employ a foamed carbon or a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, or foamed alloy, etc. When the foamed metal is used as the positive electrode, the surface of the foamed metal can be free of the positive electrode active material, or can be provided with the positive electrode active material. As an example, the foamed metal can 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.

[0075] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0076] As an example, the negative electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, silver surface treated stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. 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 polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0077] As an example, the negative electrode sheet can include the negative electrode current collector and the negative electrode active material provided on at least one surface of the negative electrode current collector.

[0078] As an example, the negative electrode current collector has two opposite surfaces in the thickness direction thereof, and the negative electrode active material is provided on either one or both of the two opposite surfaces of the negative electrode current collector.

[0079] As an example, the negative electrode active material can employ a negative electrode active material known in the art for use in a battery cell. As an example, the negative electrode active material can include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc.

[0080] In some embodiments, the negative electrode can employ a foamed carbon or a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, or foamed alloy, etc. When the foamed metal is used as the negative electrode sheet, the surface of the foamed metal can be free of the negative electrode active material, or can be provided with the negative electrode active material.

[0081] As an example, the foamed metal can 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.

[0082] 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.

[0083] In some embodiments, the electrode assembly further comprises a separator film disposed between the positive electrode and the negative electrode. The type of the separator film is not particularly limited in the present application, and any known porous separator film having good chemical stability and mechanical stability can be used.

[0084] For example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic.

[0085] In some embodiments, the battery cell further comprises an electrolyte, which functions to conduct ions between the positive electrode and the negative electrode. The type of the electrolyte is not particularly limited in the present application, and can be selected as needed. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0086] In some embodiments, the electrode assembly has a roll structure. The positive electrode sheet and the negative electrode sheet are rolled to form the roll structure.

[0087] In some embodiments, the electrode assembly has a stack structure.

[0088] A plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked.

[0089] For example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet can be folded to form a plurality of folded segments that are stacked. One positive electrode sheet can be sandwiched between adjacent folded segments.

[0090] For example, both the positive electrode sheet and the negative electrode sheet can be folded to form a plurality of folded segments that are stacked.

[0091] For example, a plurality of separator films can be provided, and each of the plurality of separator films can be disposed between any adjacent positive electrode sheet or negative electrode sheet.

[0092] For example, the separator film can be continuously provided and disposed between any adjacent positive electrode sheet or negative electrode sheet by folding or rolling.

[0093] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0094] In some embodiments, the electrode assembly is provided with a tab, which can guide current out of the electrode assembly. The tab includes a positive tab and a negative tab.

[0095] The battery cell further comprises a housing, which forms an accommodation cavity inside to accommodate the electrode assembly. The housing can protect the electrode assembly from the outside to avoid foreign matter affecting the charging or discharging of the electrode assembly.

[0096] The battery cell generates gas during charging and discharging. When the battery cell is damaged or fails, for example, the battery cell experiences thermal runaway, the battery cell generates gas rapidly, and the internal pressure of the battery cell increases rapidly. The high-pressure gas in the battery cell is generally discharged through a pressure relief mechanism. However, the existing pressure relief mechanism protrudes from the first wall of the shell of the battery cell during the forming process, resulting in an excessive height of the pressure relief mechanism, which occupies other space of the battery device and reduces the energy density of the battery device.

[0097] To solve the above technical problems, the embodiments of the present application provide a battery cell. If the battery cell experiences thermal runaway and the internal pressure is too high, the weak part can be damaged under the impact of the pressure, so that the protruding part can be separated from the first wall, and the high-pressure gas can be discharged to the outside of the shell. Because the arc-shaped part of the protruding part protrudes outward, the arc-shaped part can be prevented from repeatedly expanding and fatigue fracture under the action of the internal pressure to a certain extent, thereby preventing the defect of reducing the opening pressure of the pressure relief mechanism to a certain extent. By providing a flat part at one end of the arc-shaped part away from the electrode assembly, the flat part does not protrude from the outer surface of the first wall, thereby preventing the height of the pressure relief mechanism from exceeding the height of the first wall of the shell to a certain extent. When the battery device is assembled, the pressure relief mechanism does not occupy other space, thereby improving the space utilization rate of the battery device and improving the energy density of the battery device.

[0098] The technical solutions described in the embodiments of the present application are applicable to an electrode assembly, a battery cell including an electrode assembly, a battery including a battery cell, and a power consumption device using a battery.

[0099] The power consumption device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, and an electric tool, 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 a range extended 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 machine, 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 assembling 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. The embodiments of the present application do not specially limit the above power consumption devices.

[0100] The following embodiments are described by taking the power consumption device as a vehicle for example for convenience of description.

[0101] Please refer to Figure 1 , Figure 1A structural schematic diagram of a vehicle is provided for some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle, which can be a pure electric vehicle, a hybrid vehicle, or a range extended vehicle, etc. The vehicle 1000 is internally provided with a battery device 100, which can be arranged at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000, for example, the battery device 100 can be used as an operating power source of the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300, the controller 200 being used to control the battery device 100 to supply power to the motor 300, for example, for the working power demand of the vehicle 1000 during starting, navigation and driving.

[0102] In some embodiments of the present application, the battery device 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000.

[0103] Please refer to Figure 2 , Figure 2 An exploded view of the device is provided for some embodiments of the present application. The battery device 100 includes a battery box and a battery cell 20. In some embodiments, the battery box can include an upper cover 10 and a box 30, the upper cover 10 and the box 30 are covered with each other, and the upper cover 10 and the box 30 together define a containing cavity for containing the battery cell 20. The box 30 can be a hollow structure with one end open, and the upper cover 10 can be a plate structure, the upper cover 10 is covered on the open side of the box 30, so that the upper cover 10 and the box 30 together define the containing cavity; the upper cover 10 and the box 30 can also be hollow structures with one side open, and the open side of the upper cover 10 is covered on the open side of the box 30. Of course, the battery box formed by the upper cover 10 and the box 30 can have various shapes, such as a cylinder, a cuboid, etc.

[0104] Figure 3 A structural schematic diagram of the battery module is provided for some embodiments of the present application. In the battery device 100, the battery cell 20 can be multiple, and the multiple battery cells 20 can be connected in series, in parallel or in mixed connection, the mixed connection means that the multiple battery cells 20 are connected in series and in parallel. The multiple battery cells 20 can be directly connected in series, in parallel or in mixed connection, and then the whole of the multiple battery cells 20 is contained in the box; of course, the battery device 100 can also be in the form that the multiple battery cells 20 are first connected in series, in parallel or in mixed connection to form a battery module 400, and the multiple battery modules 400 are connected in series, in parallel or in mixed connection to form a whole, and are contained in the box. The battery device 100 can also include other structures, for example, the battery device 100 can also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0105] Each battery cell 20 can be a secondary battery cell or a primary battery cell; can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 20 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0106] Figure 4 is a partially exploded structural schematic diagram of a battery cell according to some embodiments of the present application. The end cover 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cover 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cover 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that the end cover 21 is not easily deformed when subjected to extrusion and collision, so that the battery cell 20 can have higher structural strength, and the safety performance can also be improved. The end cover 21 can be provided with functional components such as the electrode terminal 26. The electrode terminal 26 can be used to electrically connect with the electrode assembly 23 for outputting or inputting the electrical energy of the battery cell 20. In some embodiments, the end cover 21 can also be provided with a pressure relief mechanism for relieving the internal pressure of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cover 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations thereon. In some embodiments, an insulating piece can also be provided on the inner side of the end cover 21, which can be used to isolate the electrical first connecting component in the housing 22 from the end cover 21 to reduce the risk of short circuit. For example, the insulating piece can be plastic, rubber, etc.

[0107] Figure 5 is a partially exploded structural schematic diagram of a battery cell according to some embodiments of the present application. Figure 6 is a structural schematic diagram of a pressure relief mechanism according to some embodiments of the present application. Figure 7 is another angle of a structural schematic diagram of a pressure relief mechanism according to some embodiments of the present application.

[0108] Please refer to Figures 5-7In a first aspect, the embodiments of the present application provide a battery cell 20, the battery cell 20 comprising a housing 24, an electrode assembly 23 and a pressure relief mechanism 40, the housing 24 comprising a first wall 241; the electrode assembly 23 being disposed inside the housing 24; the pressure relief mechanism 40 being disposed on the first wall 241, the pressure relief mechanism 40 comprising a first connecting portion 46, a weak portion 41, a second connecting portion 47 and a raised portion 42 connected in sequence, the weak portion 41 being disposed on the outer periphery of the second connecting portion 47, the weak portion 41 being configured to be broken to release pressure when the pressure inside the housing 24 reaches a threshold value, the first connecting portion 46 being located on the outside of the weak portion 41 and connected to the first wall 241, the raised portion 42 comprising an arc-shaped portion 421 and a flat portion 422, the arc-shaped portion 421 protruding from one side of the second connecting portion 47 away from the electrode assembly 23, the flat portion 422 being disposed at one end of the arc-shaped portion 421 away from the electrode assembly 23.

[0109] The pressure relief mechanism 40 refers to a component for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The threshold value can be determined according to the design requirements of the battery cell 20. The above-mentioned threshold value can depend on the material of one or several of the positive plate, the negative plate, the electrolyte and the separator in the battery cell 20. Alternatively, the pressure relief mechanism 40 can take the form of a rupture disc, a gas valve, a pressure relief valve and a safety valve, etc.

[0110] The weak portion 41 can be a notch disposed on the side of the pressure relief mechanism 40 away from the electrode assembly 23; or the weak portion 41 is made of a material that is more fragile than the raised portion 42; or the weak portion 41 and the raised portion 42 are made of the same material, but the thickness of the weak portion 41 is set to be smaller than the thickness of the raised portion 42.

[0111] The weak portion 41 can be disposed in a ring shape along the circumference of the raised portion 42, or a plurality of weak portions 41 can be arranged at intervals on the outer periphery of the raised portion 42.

[0112] The arc-shaped portion 421 of the raised portion 42 protrudes away from the electrode assembly 23, and the arc-shaped portion 421 is a concave portion on the side facing the electrode assembly 23, rather than a solid structure. The arc-shaped portion 421 protrudes away from the electrode assembly 23 relative to the second connecting portion 47, rather than bending towards the internal space of the battery cell 20. This arrangement is to avoid fatigue fracture of the arc-shaped portion 421 caused by repeated expansion under the action of the internal pressure of the battery cell 20 to some extent, and can prevent the defect of the pressure relief mechanism 40 opening and the pressure decreasing to some extent.

[0113] When the internal pressure or temperature of the battery cell 20 is below the threshold value, the weak portion 41 does not act, and the pressure relief mechanism 40 is not opened, so that the internal environment of the battery cell 20 is isolated from the external environment. When the internal pressure or temperature of the battery cell 20 reaches the threshold value, the weak portion 41 is broken, and the raised portion 42 is separated from the shell 24, so that the internal environment of the battery cell 20 is communicated with the external environment, thereby releasing the internal pressure of the battery cell 20 to the external environment of the battery cell 20.

[0114] The first connecting portion 46 is located outside the weak portion 41, and can be arranged in a ring around the periphery of the weak portion 41, or a plurality of first connecting portions 46 are arranged at intervals on the periphery of the weak portion 41.

[0115] The first wall 241 of the shell 24 can be a top wall, a side wall or a bottom wall of the shell 24, that is, the pressure relief mechanism 40 can be arranged on any side of the shell 24. The pressure relief mechanism 40 can be an integral molding structure with the shell 24, that is, the pressure relief mechanism 40 is an integral structure with the shell 24, or the pressure relief mechanism 40 and the shell 24 can be arranged as independent structures and fixedly connected by welding, bonding, clamping or the like. That is, the first connecting portion 46 can be an integral molding structure with the first wall 241, or the first connecting portion 46 and the first wall 241 are fixedly connected by welding, bonding, clamping or the like.

[0116] The flat portion 422 is a planar structure, neither recessed toward one side of the electrode assembly 23 nor protruded away from one side of the electrode assembly 23. The flat portion 422 is arranged at one end of the arc-shaped portion 421 away from the electrode assembly 23, that is, the flat portion 422 is arranged at the highest position of the protrusion of the arc-shaped portion 421.

[0117] In the above scheme, if the battery cell 20 occurs thermal runaway and the internal gas pressure is too large, the weak portion 41 can be broken under the impact of the pressure, so that the raised portion 42 can be separated from the first wall 241, and the high-pressure gas is discharged to the outside of the shell 24. Since the arc-shaped portion 421 of the raised portion 42 protrudes outward, it can to some extent avoid the fatigue fracture of the arc-shaped portion 421 due to repeated expansion under the action of the internal pressure, thereby preventing the defect of the opening pressure of the pressure relief mechanism 40 being reduced to some extent. By arranging the flat portion 422 at one end of the arc-shaped portion 421 away from the electrode assembly 23, the height of the entire raised portion 42 is reduced, and when the battery device 100 is assembled, the pressure relief mechanism 40 does not occupy other space, thereby improving the space utilization of the battery device 100 and improving the energy density of the battery device 100.

[0118] In some embodiments, the flat portion 422 does not protrude from the surface of the first wall 241 away from the electrode assembly 23.

[0119] The flat portion 422 is arranged not to protrude from the outer surface of the first wall 241, so that the entire protruding portion 42 does not exceed the height of the first wall 241 of the outer shell 24.

[0120] In the above scheme, the flat portion 422 is arranged not to protrude from the outer surface of the first wall 241, so that the height of the pressure relief mechanism 40 does not exceed the height of the first wall 241 of the outer shell 24 to a certain extent, further improving the energy density of the battery device 100.

[0121] In some embodiments, the first connecting portion 46 includes a bending portion 43 and a first connecting sub-portion 44, the bending portion 43 being bent from the first wall 241 towards the electrode assembly 23; the bending portion 43 is connected to the weak portion 41 through the first connecting sub-portion 44.

[0122] The bending portion 43 can be directly connected to the first wall 241 of the outer shell 24, or can be connected to other parts of the pressure relief mechanism 40. The bending portion 43 is bent and extends towards the inside of the battery cell 20.

[0123] One end of the first connecting sub-portion 44 is connected to the bending portion 43, and the other end is connected to the weak portion 41. The first connecting sub-portion 44 can be planar, parallel to the first wall 241, or can have an angle with the plane of the first wall 241.

[0124] The weak portion 41 can be a notch formed by a laser etching process, which uses a high-energy-density laser beam to irradiate the surface of the material. The energy of the laser makes the material vaporize or melt instantaneously, thereby forming a precise notch on the material. Or use a sharp knife or mold to physically score the surface of the material.

[0125] In the above scheme, the bending portion 43 is first bent in the direction of the electrode assembly 23, and then the weak portion 41 is connected through the first connecting sub-portion 44, and the arc-shaped portion 421 protrudes outward, further reducing the height of the pressure relief mechanism 40, thereby further improving the energy density of the battery device 100.

[0126] In some embodiments, the bending portion 43 is integrally formed with the first wall 241.

[0127] That is, the bending portion 43 is directly connected to the first wall 241 of the outer shell 24, and the pressure relief mechanism 40 is integrally formed with the outer shell 24.

[0128] When the bending portion 43 is integrally formed with the first wall 241, there is no gap or interface due to the connection in the structure of the outer shell 24 of the battery cell 20. This is very important for maintaining the sealing of the internal environment of the battery cell 20. Because the battery cell 20 contains chemical substances such as electrolyte inside, good sealing can prevent electrolyte leakage to a certain extent, and avoid performance degradation and potential safety hazards of the battery.

[0129] The integral structure makes the connection between the bending part 43 and the first wall 241 stronger. When the battery cell 20 is subjected to external impact, vibration or internal pressure change, this high-strength connection can ensure the stability of the pressure relief mechanism 40. Compared with other connection methods (such as welding, gluing, etc.), the integral bending part 43 and the first wall 241 can better withstand these external forces and prevent the pressure relief mechanism 40 from failing due to loosening or damage of the first connection part.

[0130] In the above scheme, by integrating the pressure relief mechanism 40 with the shell 24, the strength and sealing performance of the battery cell 20 can be improved.

[0131] In some embodiments, the first connecting part 46 further comprises a second connecting sub-part 45, the bending part 43 is connected with the second connecting sub-part 45, and the second connecting sub-part 45 is fixed with the first wall 241.

[0132] The pressure relief mechanism 40 and the shell 24 are respectively independent components. The second connecting sub-part 45 can be connected and fixed with the first wall 241 of the shell 24 by welding, bonding or clamping, etc.

[0133] In the above scheme, the second connecting sub-part 45 is used to fix the pressure relief mechanism 40 with the first wall 241, reducing the difficulty of process manufacturing.

[0134] Figure 8 is a cross-sectional view of a battery cell according to some embodiments of the present application; Figure 9 is an enlarged view of A of Figure 8 Please refer to

[0135] and Figure 8 In some embodiments, the outer surface of the second connecting sub-part 45 away from the electrode assembly 23 is flush with the outer surface of the first wall 241. Figure 9 In the above scheme, by setting the outer surface of the second connecting sub-part 45 and the outer surface of the first wall 241 to be flush with each other, the space occupied by the pressure relief mechanism 40 during assembly of the battery device 100 can be further reduced, thereby further improving the energy density of the battery device 100.

[0136]

[0137] is an enlarged view of A of Figure 9 Figure 8 Figure 10 is another exploded structural schematic view of a battery cell according to some embodiments of the present application.

[0138] Please refer to Figure 9 and Figure 10 ​​In some embodiments, the first wall 241 is provided with a through hole 242 corresponding to the pressure relief mechanism 40, and the housing 24 further comprises a stepped portion 243, which is arranged on the side of the first wall 241 facing the electrode assembly 23, and the second connecting sub-portion 45 is overlapped on the stepped portion 243 exposed to the through hole 242.

[0139] The first wall 241 is provided with a through hole 242 corresponding to the pressure relief mechanism 40, which provides a gas discharge channel for the pressure relief mechanism 40 when releasing the internal pressure of the battery monomer 20. When the internal pressure of the battery monomer 20 reaches the threshold value and needs to be relieved, the gas can be discharged to the outside of the battery monomer 20 through the through hole 242.

[0140] Part of the stepped portion 243 is covered by the first wall 241, and the other part is not covered by the first wall 241 and is exposed by the through hole 242. The edge of the second connecting sub-portion 45 can be placed on the upper side of the part of the stepped portion 243 exposed to the through hole 242, and then the second connecting sub-portion 45 is welded with the stepped portion 243. Alternatively, the second connecting sub-portion 45 and the stepped portion 243 can also be connected by bonding, clamping or the like.

[0141] In the above scheme, by arranging the stepped portion 243 to overlap with the second connecting sub-portion 45, the connection strength of the pressure relief mechanism 40 and the housing 24 can be improved, thereby increasing the stability of the battery monomer 20.

[0142] In some embodiments, the stepped portion 243 is arranged in a ring shape along the circumference of the through hole 242.

[0143] In the above scheme, by arranging the stepped portion 243 in a ring shape along the circumference of the through hole 242, the connection strength of the pressure relief mechanism 40 and the housing 24 can be further improved, thereby further increasing the stability of the battery monomer 20.

[0144] Figure 11 is a top view of a battery monomer according to some embodiments of the present application.

[0145] As shown in Figure 11 In some embodiments, the flat portion 422 extends in a first direction X, which is the length direction of the pressure relief mechanism 40.

[0146] The pressure relief mechanism 40 can be rectangular, elliptical or the like, and the flat portion 422 also extends in the length direction of the pressure relief mechanism 40 to increase the area of the flat portion 422 as much as possible.

[0147] In the above scheme, by extending the flat portion 422 in the length direction of the pressure relief mechanism 40, the stress of the flat portion 422 can be more uniform, thereby further preventing the defect of reducing the opening pressure of the pressure relief mechanism 40 to some extent.

[0148] In some embodiments, the flat portion 422 is disposed in the region of the pressure relief mechanism 40 along the central axis of the first direction X.

[0149] The flat portion 422 extends along the central axis of the pressure relief mechanism in the first direction X, and the flat portion 422 is also symmetrical along the central axis, and is located exactly in the middle of the pressure relief mechanism.

[0150] The central axis region is where the pressure relief mechanism 40 experiences concentrated stress when subjected to internal pressure. Providing a flat section 422 here allows for a more even distribution of pressure across the curved section 421 and the entire raised section 42 structure. Compared to the absence of a flat section 422 or its placement in other locations, this avoids stress concentration at specific points or areas of the curved section 421, thereby further enhancing the overall stability of the raised section 42 structure and reducing the risk of localized cracking or abnormal deformation under pressure.

[0151] The flat portion 422, located in the central axis region, provides better support for the entire raised portion 42. When the internal pressure of the battery cell 20 increases, the arc-shaped portion 421 will be subjected to outward pressure. The flat portion 422 in the central axis region acts as a "stabilizer," helping to maintain the shape and position of the arc-shaped portion 421, preventing excessive deformation or twisting of the arc-shaped portion 421, and enabling the raised portion 42 to better withstand pressure, thus ensuring the structural integrity of the pressure relief mechanism 40 when the pressure relief threshold is not reached.

[0152] In the above solution, by placing the flat portion 422 in the region of the pressure relief mechanism 40 along the central axis of the first direction X, the pressure can be dispersed, the support force can be improved, and the overall stability of the raised portion 42 can be enhanced.

[0153] In some embodiments, the arcuate portion 421 is arranged around the circumference of the flat portion 422.

[0154] When the internal pressure of the battery cell 20 increases, the arc-shaped portion 421 surrounding it can evenly distribute the pressure to the area around the flat portion 422. This can prevent the pressure from concentrating in a local area to a certain extent, allowing the entire pressure relief mechanism 40 to withstand the internal pressure more effectively, reducing the risk of structural damage caused by excessive local stress, and thus enhancing the stability of the pressure relief mechanism 40 under high pressure.

[0155] The curved portion 421 surrounds the flat portion 422, making the structure of the entire raised portion 42 more continuous and complete, and the connection between the curved portion 421 and the flat portion 422 more stable. Under pressure, they can work together to resist deformation and failure. The curved shape of the curved portion 421 itself has a certain degree of elasticity and toughness, and the surrounding arrangement can further improve the fatigue resistance of the entire structure and reduce the possibility of cracks or fractures under repeated pressure.

[0156] In the above solution, by setting the arc-shaped part 421 on the periphery of the flat part 422, the pressure can be evenly distributed, further improving the fatigue resistance of the pressure relief mechanism.

[0157] Figure 12 This is a top view of a pressure relief mechanism according to some embodiments of this application.

[0158] like Figure 12 As shown, in some embodiments, the width of the flat portion 422 along the second direction Y is L1, and the width of the pressure relief mechanism 40 along the second direction Y is L2. L1 and L2 satisfy: 1 / 20≤L1 / L2≤1 / 4; wherein, the second direction Y is the width direction of the pressure relief mechanism 40.

[0159] L1 / L2 can be any value between 1 / 20 and 1 / 4. For example, L1 / L2 can be 1 / 20, 1 / 18, 1 / 15, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, or 1 / 4.

[0160] After obtaining the battery cell 20, the width direction Y (second direction) of the pressure relief mechanism 40 can be determined first. Observe the shape of the pressure relief mechanism 40 on the outer casing 24 of the battery cell 20. Take the main long axis direction of the pressure relief mechanism 40 as the first direction X, and the direction perpendicular to it is the second direction Y. The width of the flat part 422 and the pressure relief mechanism 40 along the second direction Y can be measured using vernier calipers, digital calipers, or high-precision optical microscopes or industrial cameras with macro shooting capabilities.

[0161] For example, the battery cell 20 is fixed on a fixture, and the focal length and position of an optical microscope or industrial camera are adjusted so that the shooting angle is parallel to the second direction Y. Using the software's measuring tools, the edges of the pressure relief mechanism 40 and the flat portion 422 are marked along the second direction Y. The software will automatically calculate their widths in the second direction Y based on the conversion relationship between pixels and actual dimensions. Alternatively, calipers can be used for measurement. The two measuring jaws of the calipers are placed along the second direction Y, aligned with the edges of the flat portion 422 and the pressure relief mechanism 40 along the second direction Y, and the values ​​displayed on the calipers are read.

[0162] When the flat portion 422 and the pressure relief mechanism 40 have different width values ​​at different positions along the second direction Y, the maximum width of the flat portion 422 along the second direction Y can be taken as L1, and the maximum width of the pressure relief mechanism 40 along the second direction Y can be taken as L2. Alternatively, the average width of the flat portion 422 along the second direction Y can be taken as L1, and the average width of the pressure relief mechanism 40 along the second direction Y can be taken as L2. The average width can be calculated by dividing the sum of the maximum width value and the minimum width value by 2.

[0163] In the above solution, by limiting the ratio of the width of the flat portion 422 to the width of the pressure relief mechanism 40 within a suitable range, it is possible to further prevent the defect of reduced opening pressure of the pressure relief mechanism 40, and also to further avoid the pressure relief mechanism 40 being too high, which would affect the energy density of the battery device 100.

[0164] In some embodiments, L1 and L2 satisfy: 1 / 10 ≤ L1 / L2 ≤ 1 / 6.

[0165] L1 / L2 can be any value between 1 / 10 and 1 / 6. For example, L1 / L2 can be 1 / 10, 1 / 9, 1 / 8, 1 / 7, or 1 / 6.

[0166] In the above scheme, by further limiting the ratio of the width of the flat portion 422 to the width of the pressure relief mechanism 40, the opening pressure of the pressure relief mechanism 40 and the energy density of the battery device 100 can be further balanced.

[0167] Figure 13 This is a structural schematic diagram of the pressure relief mechanism of some embodiments of this application from another angle.

[0168] like Figure 13 As shown, in some embodiments, there is a gap between the outer surface of the first wall 241 and the side of the flat portion 422 away from the electrode assembly 23 along the third direction Z; wherein the third direction Z is the thickness direction of the first wall 241.

[0169] In other words, the outer surface of the first wall 241 protrudes from the flat portion 422.

[0170] In the above solution, by setting a gap between the outer surface of the first wall 241 and the side of the flat portion 422 away from the electrode assembly 23, the risk of excessive height of the pressure relief mechanism 40 due to tolerance during manufacturing can be reduced.

[0171] In some embodiments, the gap between the outer surface of the first wall 241 and the side of the flat portion 422 away from the electrode assembly 23 is H, where H satisfies: 0.05≤H≤0.5.

[0172] In other words, the height H of the outer surface of the first wall 241 protruding from the flat portion 422 is denoted by H.

[0173] H can be any value between 0.05 and 0.5. For example, H can be 0.05, 0.07, 0.09, 0.1, 0.2, 0.3, 0.4, or 0.5.

[0174] In the above solution, by limiting the range of the gap, the risk of excessive height of the pressure relief mechanism 40 caused by tolerance during manufacturing process can be further reduced to a certain extent.

[0175] In some embodiments, H satisfies: 0.1 ≤ H ≤ 0.3.

[0176] H can be any value between 0.1 and 0.3. For example, H can be 0.1, 0.13, 0.15, 0.2, 0.25, or 0.3.

[0177] In the above scheme, by further limiting the range of the gap, the risk of the pressure relief mechanism 40 being too high can be further avoided.

[0178] In some embodiments, the weak portion 41 is arranged around the circumference of the arcuate portion 421.

[0179] When the internal pressure or temperature of the battery cell 20 reaches a threshold, the weak part 41 is destroyed, and the arc-shaped part 421 can be separated from the outer casing 24, so that the internal environment of the battery cell 20 is connected to the external environment, thereby releasing the internal pressure of the battery cell 20 to the external environment of the battery cell 20.

[0180] In the above solution, by arranging the weak part 41 around the circumference of the arc-shaped part 421, the uniformity of pressure impact is improved and the risk of excessive local pressure is reduced.

[0181] In some embodiments, the material of the first wall 241 includes at least one of stainless steel and carbon steel. The material of the pressure relief mechanism 40 includes at least one of stainless steel and carbon steel.

[0182] The material of the first wall 241 can be carbon steel or stainless steel, etc., and the carbon steel can be low carbon steel, medium carbon steel or high carbon steel. It should be noted that the material of the first wall 241 includes at least one of stainless steel and carbon steel. If the first wall 241 is the end cap 21 of the outer shell 24, then the material of the end cap 21 includes at least one of stainless steel and carbon steel; if the first wall 241 is a wall in the shell 22, then the material of the shell 22 includes at least one of stainless steel and carbon steel.

[0183] In this embodiment, by setting the material of the first wall 241 to include at least one of stainless steel and carbon steel, since steel has the characteristic of high strength, the first wall 241 made of steel has better strength, so that the first wall 241 can be made thinner under the condition of a certain burst pressure of the battery cell 20, which is beneficial to save the space occupied by the first wall 241.

[0184] The pressure relief mechanism 40 can be made of carbon steel or stainless steel, and the carbon steel can be low-carbon steel, medium-carbon steel, or high-carbon steel. For example, the material of the pressure relief mechanism 40 can be 304 stainless steel, 305 stainless steel, 316 stainless steel, etc. Stainless steel and carbon steel have high strength, which can effectively improve the structural strength of the first wall 241 and the pressure relief mechanism 40, reduce the risk of deformation of the first wall 241 and the pressure relief mechanism 40 under stress, and help reduce the risk of premature valve opening and pressure relief of the pressure relief mechanism 40, which is beneficial to improving the service life and reliability of the battery cell 20. In addition, using at least one of stainless steel and carbon steel to manufacture the first wall 241 can appropriately reduce the thickness of the first wall 241, which is beneficial to increase the internal space of the outer casing 24 within the same volume, thereby increasing the energy density.

[0185] Optionally, the material of the first wall 241 includes at least one of SU304 stainless steel, SU305 stainless steel, or SU316L stainless steel. The material of the pressure relief mechanism 40 includes at least one of SU304 stainless steel, SU305 stainless steel, or SU316L stainless steel.

[0186] 304 stainless steel, 305 stainless steel, and 316L stainless steel have advantages such as corrosion resistance, high temperature resistance, and good processing performance. The first wall 241 and the pressure relief mechanism 40 made of 304 stainless steel, 305 stainless steel, or 316L stainless steel have high strength, which can reduce the risk of deformation of the first wall 241 and the pressure relief mechanism 40 under stress. This is beneficial to reducing the risk of premature valve opening and pressure relief of the pressure relief mechanism 40, improving the service life and reliability of the battery cell 20, and improving the consistency of the explosion pressure of multiple battery cells 20.

[0187] Secondly, embodiments of this application also provide a battery device 100, including a battery cell 20 of any of the above embodiments.

[0188] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device 100, which is used to provide electrical energy.

[0189] According to some embodiments of this application, a battery cell 20 is provided. The battery cell 20 includes a housing 24, an electrode assembly 23, and a pressure relief mechanism 40. The housing 24 includes a first wall 241. The electrode assembly 23 is disposed inside the housing 24. The pressure relief mechanism 40 is disposed on the first wall 241 and includes a first connecting portion 46, a weak portion 41, and a raised portion 42 connected in sequence. The weak portion 41 is disposed on the outer periphery of the raised portion 42 and is configured to be broken to release pressure when the pressure inside the housing 24 reaches a threshold. The first connecting portion 46 is located outside the weak portion 41 and connects to the first wall 241. The raised portion 42 includes an arcuate portion 421 and a flat portion 422. The arcuate portion 421 protrudes from the side of the weak portion 41 facing away from the electrode assembly 23, and the flat portion 422 is disposed at the end of the arcuate portion 421 facing away from the electrode assembly 23. The flat portion 422 does not protrude from the surface of the first wall 241 facing away from the electrode assembly 23.

[0190] The battery device 100 provided according to the embodiments of this application includes the battery cell 20 provided in the embodiments. Since the battery device 100 provided in the embodiments of this application adopts the battery cell 20 provided in the above embodiments, it has the same technical effect, which will not be repeated here.

[0191] The electrical device provided according to the embodiments of this application includes the battery device 100 provided in the above embodiments, and the battery device 100 is used to provide electrical energy.

[0192] The power supply device provided according to the embodiments of this application has the same technical effect as the battery device 100 provided in the embodiments of this application, and will not be described again here.

[0193] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: The outer shell, including the first wall; The electrode assembly is disposed inside the housing; A pressure relief mechanism is disposed on the first wall. The pressure relief mechanism includes a first connecting portion, a weak portion, a second connecting portion, and a raised portion connected in sequence. The weak portion is disposed on the outer periphery of the second connecting portion. The weak portion is configured to be broken to release the pressure when the pressure inside the housing reaches a threshold. The first connecting portion is located outside the weak portion and is connected to the first wall. The raised portion includes an arcuate portion and a flat portion. The arcuate portion protrudes from the side of the second connecting portion opposite to the electrode assembly. The flat portion is disposed at the end of the arcuate portion opposite to the electrode assembly.

2. The battery cell according to claim 1, wherein, The flat portion does not protrude from the surface of the first wall opposite to the electrode assembly.

3. The battery cell according to claim 1, wherein, First connecting part: The bent portion bends from the first wall toward the electrode assembly; The first connecting sub-part connects the bent portion to the weak portion.

4. The battery cell according to claim 3, wherein, The bent portion is integrally formed with the first wall.

5. The battery cell according to claim 3, wherein, The first connecting portion further includes a second connecting sub-portion, the bent portion is connected to the second connecting sub-portion, and the second connecting sub-portion is fixed to the first wall.

6. The battery cell according to claim 5, wherein, The second connecting part is flush with the outer surface of the first wall, away from the outer surface of the electrode assembly.

7. The battery cell according to claim 5, wherein, The first wall has a through hole corresponding to the pressure relief mechanism. The housing also includes a stepped portion, which is located on the side of the first wall facing the electrode assembly. The second connecting portion overlaps the part of the stepped portion that is exposed in the through hole.

8. The battery cell according to claim 7, wherein, The stepped portion is arranged around the circumference of the through hole.

9. The battery cell according to any one of claims 1-8, wherein, The flat portion extends along a first direction, which is the length direction of the pressure relief mechanism.

10. The battery cell according to claim 9, wherein, The flat portion is disposed in the region of the pressure relief mechanism along the central axis in the first direction.

11. The battery cell according to claim 10, wherein, The arc-shaped portion is arranged around the circumference of the flat portion.

12. The battery cell according to claim 9, wherein, The width of the flat portion along the second direction is L1, and the width of the pressure relief mechanism along the second direction is L2. L1 and L2 satisfy: 1 / 20≤L1 / L2≤1 / 4; wherein, the second direction is the width direction of the pressure relief mechanism.

13. The battery cell according to claim 12, wherein, The L1 and L2 satisfy: 1 / 10≤L1 / L2≤1 / 6.

14. The battery cell according to claim 1, wherein, Along a third direction, there is a gap between the outer surface of the first wall and the side of the flat portion away from the electrode assembly; wherein, the third direction is the thickness direction of the first wall.

15. The battery cell according to claim 14, wherein, The gap between the outer surface of the first wall and the side of the flat portion away from the electrode assembly is H, wherein H satisfies: 0.05≤H≤0.

5.

16. The battery cell according to claim 15, wherein, The condition H satisfies: 0.1 ≤ H ≤ 0.

3.

17. The battery cell according to claim 1, wherein, The weak part is arranged around the circumference of the arc-shaped part.

18. The battery cell according to any one of claims 1-17, wherein, The material of the first wall includes at least one of stainless steel and carbon steel; the material of the pressure relief mechanism includes at least one of stainless steel and carbon steel.

19. A battery device, wherein, Includes the battery cell according to any one of claims 1-18.

20. An electrical appliance, wherein, Includes the battery device according to claim 19, the battery device being used to provide electrical energy.

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