Battery cell, battery and electric device

Abstract

A battery cell (100), a battery (10) and an electric device, which relate to the technical field of batteries. The battery cell (100) comprises a casing (110), wherein a pressure relief valve (150) is arranged on the casing (110), the pressure relief valve (150) comprises a valve opening portion (152) and a weakened portion (153), and the valve opening portion (152) is connected to the casing (110) by means of the weakened portion (153). At least part of the pressure relief valve (150) is made of a first shape memory alloy; once the temperature reaches a deformation temperature, the first shape memory alloy deforms, such that the weakened portion (153) cracks, and the valve opening portion (152) is opened, thereby preventing the situation where, during thermal runaway in the battery cell (100), due to a rapid temperature rise, other parts of the battery cell (100) other than the pressure relief valve (150) become weaker and crack or melt prior to the pressure relief valve (150), resulting in a high-temperature gas inside the battery cell (100) being released from the other parts. The pressure relief valve (150) can respond to the air pressure and / or temperature in the battery cell (100) so as to be opened, such that the pressure relief valve (150) is opened in the early stage of the thermal runaway of the battery cell (100), thereby reducing the risk of explosion of the battery cell (100) and improving the reliability of the battery (10).

Description

Battery monomer, battery and electric device

[0001] Cross-reference to related applications

[0002] The present application claims priority to Chinese Patent Application No. 202421384302.9, filed on June 18, 2024, entitled "Battery monomer, battery and electric device", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, in particular to a battery monomer, 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] With the popularity of electric vehicles and the improvement of energy density, electric vehicle fire accidents occur from time to time, and most of the electric vehicle fire accidents are caused by thermal runaway of the battery. Therefore, how to improve the reliability of the battery is an urgent technical problem in the battery technology.

[0006] SUMMARY

[0007] The present application provides a battery monomer, a battery and an electric device, which can improve the reliability of the battery.

[0008] The present application is achieved by the following technical solutions:

[0009] In a first aspect, the present application provides a battery monomer, which comprises a shell, the shell is provided with a explosion-proof valve, the explosion-proof valve comprises an opening valve part and a weak part, the opening valve part and the shell are connected through the weak part, the explosion-proof valve is at least partially made of a first shape memory alloy, the first shape memory alloy is used to deform after reaching a deformation temperature to cause the weak part to crack and the opening valve part to open.

[0010] According to the shell of the embodiments of the present application, at least part of the explosion-proof valve is made of the first shape memory alloy. When the temperature reaches the deformation temperature of the first shape memory alloy, the first shape memory alloy deforms to cause the weak part to crack and the opening valve part to open, so that the explosion-proof valve is preferentially automatically opened. When the battery monomer is in thermal runaway, due to the rapid increase in temperature, other parts of the battery monomer except the explosion-proof valve become weaker and crack or melt before the explosion-proof valve, which causes the high-temperature gas in the battery monomer to be discharged from other parts. The explosion-proof valve of the present application can respond to the gas pressure and / or temperature in the battery monomer to open, thereby opening in the early stage of thermal runaway of the battery monomer, reducing the risk of explosion of the battery monomer, and further improving the reliability of the battery.

[0011] According to some embodiments of the present application, the shell comprises a shell body, and the explosion-proof valve is arranged at the bottom of the shell body.

[0012] In the above scheme, the explosion-proof valve is arranged at the bottom of the shell body. The explosion-proof valve can respond to the gas pressure and / or temperature in the battery monomer to open, thereby opening in the early stage of thermal runaway of the battery monomer, reducing the risk of explosion of the battery monomer, and further improving the reliability of the battery.

[0013] According to some embodiments of the present application, the opening valve part is made of the first shape memory alloy.

[0014] In the above scheme, by making the opening valve part made of the first shape memory alloy, when the temperature reaches the deformation temperature of the first shape memory alloy, the opening valve part can deform and exert a force on the weak part, so that the weak part cracks and the opening valve part opens, thereby causing the explosion-proof valve to be preferentially automatically opened.

[0015] According to some embodiments of the present application, the explosion-proof valve is made of the first shape memory alloy.

[0016] In the above scheme, by making the entire explosion-proof valve made of the first shape memory alloy, when the temperature reaches the deformation temperature of the first shape memory alloy, the entire explosion-proof valve can deform, so that the weak part is bent and cracked, the opening valve part is opened, and the explosion-proof valve is preferentially automatically opened.

[0017] According to some embodiments of the present application, the explosion-proof valve further comprises a connecting part connected to the shell, and the opening valve part and the connecting part are connected through the weak part.

[0018] According to some embodiments of the present application, the connecting part comprises a connecting block and a pressing block. The connecting block and the opening valve part are connected through the weak part, the pressing block is at least partially arranged in the connecting block, and the pressing block is made of the first shape memory alloy.

[0019] In the above scheme, by making the extrusion block made of the first shape memory alloy, when the temperature reaches the shape deformation temperature of the first shape memory alloy, the extrusion block can be deformed and apply force to the weak part, so that the weak part is cracked, the valve opening part is opened, and the explosion-proof valve is automatically opened preferentially.

[0020] According to some embodiments of the present application, the connecting part includes at least two extrusion blocks, which are oppositely arranged with the valve opening part as the center.

[0021] In the above scheme, the oppositely arranged at least two extrusion blocks can be deformed and apply force to different positions of the weak part after reaching the shape deformation temperature of the first shape memory alloy, so that the weak part is cracked faster, the valve opening part is opened, and the explosion-proof valve is automatically opened preferentially.

[0022] According to some embodiments of the present application, one end of the extrusion block is arranged in the connecting block, and the other end is arranged in the valve opening part, and the extrusion block is used to be deformed and bent to open the valve opening part after reaching the shape deformation temperature.

[0023] In the above scheme, by making one end of the extrusion block arranged in the connecting block and the other end arranged in the valve opening part, when the temperature reaches the shape deformation temperature of the first shape memory alloy, the extrusion block can be deformed and bent and apply a pushing force to the valve opening part, causing the weak part to be cracked and the valve opening part to be opened, so that the explosion-proof valve is automatically opened preferentially.

[0024] According to some embodiments of the present application, the extrusion block is partially arranged in the weak part, and the extrusion block is used to be deformed and pierce the weak part after reaching the shape deformation temperature.

[0025] In the above scheme, by making the extrusion block partially arranged in the weak part, when the temperature reaches the shape deformation temperature of the first shape memory alloy, the extrusion block can be deformed and pierce the weak part, so that the weak part is cracked and the valve opening part is opened, so that the explosion-proof valve is automatically opened preferentially.

[0026] According to some embodiments of the present application, the thickness of the weak part is less than the thickness of the connecting part and the valve opening part.

[0027] In the above scheme, by making the thickness of the weak part less than the thickness of the connecting part and the valve opening part, the weak part can be cracked more easily than the connecting part and the valve opening part.

[0028] According to some embodiments of the present application, the weak part is a notch formed between the connecting part and the valve opening part.

[0029] In the above scheme, the notch is convenient to process and is conducive to forming the explosion-proof valve at low cost.

[0030] According to some embodiments of the present application, the first shape memory alloy includes a nickel-titanium alloy, a copper-zinc alloy, a copper-aluminum-nickel alloy, a copper-molybdenum-nickel alloy, or a copper-gold-zinc alloy.

[0031] In the above scheme, by selecting the first shape memory alloy described above, when the temperature reaches the shape change temperature of the first shape memory alloy, the valve opening part can be deformed and exert a force on the weak part, causing the weak part to crack and the valve opening part to open, so that the explosion-proof valve is preferentially automatically opened.

[0032] According to some embodiments of the present application, the battery cell further includes a support, the shell has an inner wall for forming a cavity for accommodating the electrode assembly, and the support is arranged on the inner wall of the explosion-proof valve and / or the inner wall of the shell. The support is made of a second shape memory alloy, and the support is used to be deformed into a protruding structure to support the electrode assembly after reaching the shape change temperature.

[0033] In the above scheme, by making the support made of a second shape memory alloy, when the temperature reaches the shape change temperature of the second shape memory alloy, the support can be deformed into a protruding structure, and the protruding structure is used to lift the electrode assembly in the battery, preventing the electrode assembly from abutting against the explosion-proof valve to cause the explosion-proof valve to be blocked. This is conducive to the discharge of high-temperature gas in the battery cell that has undergone thermal runaway, thereby reducing the explosion caused by the electrode assembly blocking the explosion-proof valve.

[0034] According to some embodiments of the present application, the explosion-proof valve further includes at least two supports, and the at least two supports are arranged opposite to each other with the valve opening part as the center.

[0035] In the above scheme, the at least two supports arranged opposite to each other can be deformed into protruding structures respectively after reaching the shape change temperature of the second shape memory alloy, and cooperate with each other to lift the electrode assembly in the battery, thereby increasing the gap between the electrode assembly and the explosion-proof valve, and more conducive to the discharge of high-temperature gas in the battery cell that has undergone thermal runaway.

[0036] According to some embodiments of the present application, the second shape memory alloy includes a nickel-titanium alloy, a copper-zinc alloy, a copper-aluminum-nickel alloy, a copper-molybdenum-nickel alloy, or a copper-gold-zinc alloy.

[0037] In the above scheme, by selecting the second shape memory alloy described above, when the temperature reaches the shape change temperature of the second shape memory alloy, the support can be deformed into a protruding structure, thereby lifting the electrode assembly in the battery and reducing the explosion caused by the electrode assembly blocking the explosion-proof valve.

[0038] In a second aspect, the embodiments of the present application provide a battery, which includes the battery cell in the above embodiments.

[0039] In a third aspect, the embodiments of the present application provide a power utilization device, which comprises the battery cell or the battery in the above embodiments, and the battery cell or the battery is used to provide electric energy.

[0040] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0042] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application.

[0043] FIG. 2 is an exploded view of a battery provided by some embodiments of the present application.

[0044] FIG. 3 is an exploded view of a battery cell provided by some embodiments of the present application.

[0045] FIG. 4 is a sectional view of a first kind of shell when the valve opening part is not opened, provided by some embodiments of the present application.

[0046] FIG. 5 is a sectional view of the first kind of shell when the valve opening part is opened, provided by some embodiments of the present application.

[0047] FIG. 6 is a sectional view of a second kind of shell when the valve opening part is not opened, provided by some embodiments of the present application.

[0048] FIG. 7 is a sectional view of the second kind of shell when the valve opening part is opened, provided by some embodiments of the present application.

[0049] FIG. 8 is a sectional view of a third kind of shell when the valve opening part is not opened, provided by some embodiments of the present application.

[0050] FIG. 9 is a sectional view of the third kind of shell when the valve opening part is opened, provided by some embodiments of the present application.

[0051] FIG. 10 is a sectional view of a fourth kind of shell when the valve opening part is not opened, provided by some embodiments of the present application.

[0052] FIG. 11 is a sectional view of the fourth kind of shell when the valve opening part is opened, provided by some embodiments of the present application.

[0053] FIG. 12 is a structural schematic diagram of an inner wall of the first kind of shell, provided by some embodiments of the present application.

[0054] Fig. 13 is a cross-sectional view of the fifth shell according to some embodiments of the present application when the valve opening part is not opened.

[0055] Fig. 14 is a cross-sectional view of the fifth shell according to some embodiments of the present application when the valve opening part is opened.

[0056] Fig. 15 is a cross-sectional view of the battery cell internal support when not deformed according to some embodiments of the present application.

[0057] Fig. 16 is a cross-sectional view of the battery cell internal support when deformed according to some embodiments of the present application.

[0058] Fig. 17 is a structural schematic view of the inner wall of the second shell according to some embodiments of the present application.

[0059] Fig. 18 is a structural schematic view of the inner wall of the third shell according to some embodiments of the present application. DETAILED DESCRIPTION

[0060] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0061] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the present application; the terms “include” and “have” and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover not exclusive inclusion. The terms “first”, “second” and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, and are not intended to describe a particular order or primary and secondary relationship.

[0062] Reference to an "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As will be apparent to those of ordinary skill in the art, embodiments described in this application can be combined with one another.

[0063] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "attaching" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0064] The term "and / or" in this application is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this application generally represents that the front and rear associated objects have an "or" relationship.

[0065] "Multiple" appearing in this application means more than two (including two), and similarly, "multiple groups" means more than two groups (including two groups), and "multiple pieces" means more than two pieces (including two pieces).

[0066] In some embodiments, the battery can be a battery module, and when there are multiple battery monomers, the multiple battery monomers are arranged and fixed to form a battery module.

[0067] In some embodiments, the battery can be a battery pack, and the battery pack includes a box body and a battery monomer, and the battery monomer or the battery module is contained in the box body.

[0068] In some embodiments, the box body can be part of the chassis structure of the vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0069] 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.

[0070] In the embodiments of the application, the battery monomer can be a secondary battery, which refers to a battery monomer that can be activated by charging after discharging to continue to use.

[0071] The battery cell can be, but is not limited to, 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.

[0072] The battery cell generally includes an electrode assembly. The electrode assembly includes a cathode, an anode, and a separator. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are intercalated and deintercalated between the cathode and the anode. The separator is disposed between the cathode and the anode, and can function to prevent short circuiting of the cathode and the anode while allowing the active ions to pass through.

[0073] In some embodiments, the cathode can be a cathode sheet, which can include a cathode current collector and a cathode active material disposed on at least one surface of the cathode current collector.

[0074] As an example, the cathode current collector has two surfaces opposite in the thickness direction thereof, and the cathode active material is disposed on either one or both of the two surfaces of the cathode current collector.

[0075] As an example, the cathode current collector can be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. with a silver plating treatment on the surface thereof 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 (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0076] As an example, the cathode active material can include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a cathode active material for a battery can also be used.

[0077] In some embodiments, the anode can be an anode sheet, which can include an anode current collector.

[0078] As an example, the anode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver plating treatment on the surface thereof, stainless steel with a silver plating treatment on the surface thereof, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be used.

[0079] In some embodiments, the anode current collector has two surfaces opposite in the thickness direction thereof, and the anode active material is disposed on either one or both of the two surfaces of the anode current collector.

[0080] As an example, the negative active material can employ a negative active material for a battery that is publicly known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can be selected from at least one of elemental tin, tin oxide compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative active material for a battery can also be used. These negative active materials can be used alone or in combination of two or more.

[0081] In some embodiments, the separator is a separator film. The type of the separator film is not particularly limited, and any publicly known porous structure separator film having good chemical stability and mechanical stability can be used.

[0082] As an 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. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. In the case of the multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate member located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0083] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes, and functions to transport ions and separate the positive and negative electrodes.

[0084] In some embodiments, the electrode assembly has a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound to have the jelly-roll structure.

[0085] In some embodiments, the electrode assembly has a stack structure.

[0086] In some embodiments, the battery cell can include a case. The case is used to package the electrode assembly and other components such as the electrolyte. The case can be a steel case, an aluminum case, a plastic case (e.g., polypropylene), a composite metal case (e.g., copper-aluminum composite case), or an aluminum-plastic film, etc.

[0087] In some embodiments, the case includes a cap and a case body, and the case body has an opening, and the cap closes the opening to form a sealed space for accommodating the electrode assembly and the electrolyte, etc. The case body can have one or more openings. The cap can also have one or more openings.

[0088] In some embodiments, at least one electrode terminal is arranged on the shell, and the electrode terminal is electrically connected with the tab of the electrode assembly. The electrode terminal can be directly connected with the tab or indirectly connected with the tab through an adapter. The electrode terminal can be arranged on the end cover or the shell.

[0089] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes, the prismatic battery cell including a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal prismatic battery cell, and the like, without specific limitation in the embodiments of the present application.

[0090] At present, from the development of market situation, the battery has been widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as electric tools, unmanned aerial vehicles, energy storage equipment and other fields. With the continuous expansion of the field of battery use, the demand of its market is also increasing.

[0091] The development of battery technology needs to consider many design factors, such as energy density, discharge capacity, charge-discharge rate and other performance parameters. In addition, with the change of battery use environment, the reliability of the battery is also one of the key factors to be considered.

[0092] When the battery cell is in thermal runaway, the temperature inside the battery cell rises, and a large amount of high-temperature gas is generated. If the high-temperature gas cannot be discharged in time, the battery cell will explode. The battery cell usually uses an explosion-proof valve to release the high-temperature gas generated when the battery cell is in thermal runaway. When the gas pressure in the battery cell reaches the pressure threshold that the explosion-proof valve can withstand, the explosion-proof valve opens to release the high-temperature gas. At present, the explosion-proof valve can only respond to the gas pressure inside the battery cell, and cannot respond to the temperature rise inside the battery cell.

[0093] However, when the battery cell is in thermal runaway, the temperature inside the battery cell rises faster than the gas pressure. Other parts of the battery cell except the explosion-proof valve become weaker and crack or melt before the explosion-proof valve, causing the high-temperature gas in the battery cell to be discharged from other parts. The explosion-proof valve cannot be normally opened, the high-temperature gas cannot be discharged from the preset position, and other battery cells that do not occur thermal runaway are affected.

[0094] Based on the above considerations, in order to improve the reliability of the battery, the embodiments of the present application provide a battery cell, which comprises a shell, and an explosion-proof valve arranged on the shell. The explosion-proof valve comprises an opening valve part and a weak part, and the opening valve part and the shell are connected through the weak part. The explosion-proof valve is at least partially made of a first shape memory alloy. The first shape memory alloy is used to deform when the deformation temperature is reached, so that the weak part cracks and the opening valve part opens.

[0095] The first shape memory alloy is used to make at least part of the explosion-proof valve. When the temperature reaches the shape memory temperature of the first shape memory alloy, the first shape memory alloy deforms to cause the weak part to crack and the valve opening part to open, so that the explosion-proof valve is preferentially automatically opened, and the risk of explosion of the battery monomer is reduced. When the battery monomer is in thermal runaway, due to the rapid rise in temperature, other parts of the battery monomer except the explosion-proof valve become weaker and crack or melt before the explosion-proof valve, causing high-temperature gas in the battery monomer to be discharged from other parts. The explosion-proof valve of the present application can respond to the gas pressure and / or temperature in the battery monomer to open, thereby opening in the early stage of thermal runaway of the battery monomer, reducing the risk of explosion of the battery monomer, and thereby improving the reliability of the battery.

[0096] The battery disclosed in the embodiments of the present application can be used in, but is not limited to, an electric device such as a vehicle, a ship or an aircraft. The power supply system of the electric device can be composed of the battery disclosed in the present application.

[0097] The embodiments of the present application provide an electric device using a battery as a power source. The electric device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric vehicle, a ship, a spacecraft, etc. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy, an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0098] The following embodiments are described with reference to a vehicle as an example of an electric device of an embodiment of the present application for convenience of description.

[0099] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1 provided by some embodiments of the present application. The vehicle 1 can be a fuel automobile, a gas automobile or a new energy automobile, which can be a pure electric vehicle, a hybrid electric vehicle or a range extended electric vehicle, etc. The vehicle 1 is internally provided with a battery 10, which can be arranged at the bottom, the head or the tail of the vehicle 1. The battery 10 can be used for power supply of the vehicle 1, for example, the battery 10 can be used as an operating power source of the vehicle 1, for example, for the working power demand of the circuit system of the vehicle 1, such as for the starting, navigation and running of the vehicle 1.

[0100] The vehicle 1 can further include a controller 11 and a motor 12, and the controller 11 is used to control the battery 10 to supply power to the motor 12, for example, for the working power demand of the vehicle 1 during starting, navigation and driving.

[0101] In some embodiments of the present application, the battery 10 can not only be used as an operating power source of the vehicle 1, but also be used as a driving power source of the vehicle 1, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1.

[0102] Please refer to FIG. 2, which is an exploded view of the battery 10 according to some embodiments of the present application. The battery 10 includes a battery cell 100 and a case 200, and the battery cell 100 is accommodated in the case 200. The case 200 is configured to provide a space for accommodating the battery cell 100, and the case 200 can have various structures. In some embodiments, the case 200 can include a first sub-case 201 and a second sub-case 202, and the first sub-case 201 and the second sub-case 202 are coupled to each other to define a space for accommodating the battery cell 100. The second sub-case 202 can be a hollow structure with an opening 121 at one end, and the first sub-case 201 can be a plate structure. The first sub-case 201 is coupled to the opening 121 of the second sub-case 202 to define the space for accommodating the battery cell 100 together with the second sub-case 202. Alternatively, the first sub-case 201 and the second sub-case 202 can both be hollow structures with an opening 121 at one end, and the opening 121 of the first sub-case 201 is coupled to the opening 121 of the second sub-case 202.

[0103] In the battery 10, the battery cell 100 can be multiple, and the multiple battery cells 100 can be connected in series, in parallel, or in a mixed manner. The mixed manner means that the multiple battery cells 100 are connected in series and in parallel. The multiple battery cells 100 can be directly connected in series, in parallel, or in a mixed manner, and then the multiple battery cells 100 are accommodated in the case 200. Alternatively, the multiple battery cells 100 can be connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole, and the whole is accommodated in the case 200. The battery 10 can further include other structures, for example, the battery 10 can further include a busbar component for electrically connecting the multiple battery cells 100.

[0104] The battery cell 100 can be a secondary battery or a primary battery, and the battery cell 100 can be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.

[0105] Please refer to FIG. 3, which is an exploded view of the battery cell 100 according to some embodiments of the present application. As shown in FIG. 3, the battery cell 100 includes an outer shell 110, an electrode assembly 170, and an electrode terminal. The outer shell 110 includes a housing 120 and an end cap 130, and the housing 120 has an opening 121. The end cap 130 seals the opening 121 to isolate the internal environment of the battery cell 100 from the external environment.

[0106] The shell 120 is a component for fitting the end cover 130 to form an internal environment of the battery cell 100, wherein the formed internal environment can be used to accommodate the electrode assembly 170, electrolyte and other components. The shell 120 and the end cover 130 can be independent components. The shell 120 can be of various shapes and sizes. Specifically, the shape of the shell 120 can be determined according to the specific shape and size of the electrode assembly 170. The material of the shell 120 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0107] The end cover 130 refers to a component that covers the opening 121 of the shell 120 to isolate the internal environment of the battery cell 100 from the external environment. Without limitation, the shape of the end cover 130 can be adapted to the shape of the shell 120 to fit the shell 120. Optionally, the end cover 130 can be made of a material with certain hardness and strength (such as aluminum alloy), so that the end cover 130 is not easily deformed when subjected to extrusion collision, so that the battery cell 100 can have higher structural strength, and the reliability can also be improved. The end cover 130 can be provided with functional components such as electrode terminals. The electrode terminals can be used to electrically connect with the electrode assembly 170 for outputting or inputting the electrical energy of the battery cell 100. The material of the end cover 130 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not specially limited in the embodiments of the present application. In some embodiments, an insulating structure can also be provided on the inner side of the end cover 130, which can be used to isolate the electrical connection components 151 in the shell 120 from the end cover 130 to reduce the risk of short circuit. Exemplarily, the insulating structure can be plastic, rubber, etc.

[0108] The electrode assembly 170 is a component in which electrochemical reactions occur in the battery cell 100. One or more electrode assemblies 170 can be contained in the shell 120. The electrode assembly 170 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and generally has a separator film between the positive electrode sheet and the negative electrode sheet, which is used to separate the positive electrode sheet and the negative electrode sheet to reduce the risk of internal short circuit of the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet have a portion of active material constituting the main body of the electrode assembly 170, and a portion of the positive electrode sheet and the negative electrode sheet without active material each constitutes a tab. The positive electrode tab and the negative electrode tab can be located at one end of the main body or at two ends of the main body, respectively.

[0109] Please refer to FIG. 3-11, FIG. 4 is a cross-sectional view of the first shell 110 provided by some embodiments of the present application when the valve opening part 152 is not opened, FIG. 5 is a cross-sectional view of the first shell 110 provided by some embodiments of the present application when the valve opening part 152 is opened, FIG. 6 is a cross-sectional view of the second shell 110 provided by some embodiments of the present application when the valve opening part 152 is not opened, FIG. 7 is a cross-sectional view of the second shell 110 provided by some embodiments of the present application when the valve opening part 152 is opened, FIG. 8 is a cross-sectional view of the third shell 110 provided by some embodiments of the present application when the valve opening part 152 is not opened, FIG. 9 is a cross-sectional view of the third shell 110 provided by some embodiments of the present application when the valve opening part 152 is opened, FIG. 10 is a cross-sectional view of the fourth shell 110 provided by some embodiments of the present application when the valve opening part 152 is not opened, and FIG. 11 is a cross-sectional view of the fourth shell 110 provided by some embodiments of the present application when the valve opening part 152 is opened.

[0110] The embodiments of the present application provide a battery monomer 100, which comprises a shell 110, the shell 110 is provided with a explosion-proof valve 150, the explosion-proof valve 150 comprises a valve opening part 152 and a weak part 153, the valve opening part 152 and the shell 110 are connected through the weak part 153, the explosion-proof valve 150 is at least partially made of a first shape memory alloy, the first shape memory alloy is used to deform after reaching a deformation temperature to make the weak part 153 crack and the valve opening part 152 open.

[0111] The valve opening part 152 is a structure for opening the explosion-proof valve 150 when the battery monomer 100 has thermal runaway.

[0112] The weak part 153 is a structure connecting the shell 110 and the valve opening part 152, the weak part 153 refers to a weak part of the explosion-proof valve 150, when the explosion-proof valve 150 is subjected to high temperature and high pressure, the weak part 153 cracks more preferentially than the valve opening part 152, so that the valve opening part 152 opens.

[0113] Shape memory alloy (SMA) is a material composed of two or more metal elements that has shape memory effect (SME) through thermoelasticity and martensitic phase transformation and its inverse transformation. Shape memory alloy is the best material in shape memory materials in terms of shape memory performance.

[0114] The first shape memory alloy has at least two shapes, a first shape before the first shape memory alloy reaches a deformation temperature, when the first shape memory alloy is in the first shape, the first shape memory alloy cannot exert a force on the opening valve portion 152 to open it; a second shape after the first shape memory alloy reaches the deformation temperature, when the first shape memory alloy is in the transition from the first shape to the second shape or the first shape memory alloy is in the second shape, the first shape memory alloy can exert a force on the opening valve portion 152 to open it.

[0115] The technical solution of the embodiment of the application uses the first shape memory alloy to manufacture at least part of the explosion-proof valve 150. When the temperature reaches the deformation temperature of the first shape memory alloy, the first shape memory alloy deforms to cause the weak portion 153 to crack, and the opening valve portion 152 opens, so that the explosion-proof valve 150 is preferentially automatically opened, reducing the situation that when the battery monomer 100 is in thermal runaway, due to rapid temperature rise, other parts of the battery monomer 100 except the explosion-proof valve 150 become weaker and crack or melt before the explosion-proof valve 150, causing high-temperature gas in the battery monomer 100 to be discharged from other parts. The explosion-proof valve 150 of the application can respond to the gas pressure and / or temperature in the battery monomer 100 to open, so as to open in the early stage of thermal runaway of the battery monomer 100, reduce the risk of explosion of the battery monomer 100, and further improve the reliability of the battery 10.

[0116] It should be noted that the explosion-proof valve 150 of the application is opened by responding to the gas pressure and / or temperature in the battery monomer 100 in the following way: when the gas pressure in the battery monomer 100 preferentially reaches the pressure threshold that the explosion-proof valve 150 can withstand, the explosion-proof valve 150 is subjected to high pressure in the battery monomer 100 to cause the opening valve portion 152 to open; when the temperature in the battery monomer 100 preferentially reaches the deformation temperature of the first shape memory alloy, the first shape memory alloy deforms to cause the weak portion 153 to crack, and the opening valve portion 152 opens.

[0117] In some embodiments, the explosion-proof valve 150 can be arranged on the bottom of the shell 120 or the end cover 130.

[0118] In some embodiments, the shell 110 includes a shell 120, and the explosion-proof valve 150 is arranged on the bottom of the shell 120.

[0119] The explosion-proof valve 150 arranged on the bottom of the shell 120 can respond to the gas pressure and / or temperature in the battery monomer 100 to open, so as to open in the early stage of thermal runaway of the battery monomer 100, reduce the risk of explosion of the battery monomer 100, and further improve the reliability of the battery 10.

[0120] Please refer to FIGS. 4-5, in some embodiments, the valve opening part 152 is made of the first shape memory alloy.

[0121] The valve opening part 152 has at least two shapes. When the temperature inside the battery monomer 100 is lower than the deformation temperature of the first shape memory alloy, the valve opening part 152 is in the first shape, i.e. the valve opening part 152 is stably connected to the connecting part 151 through the weak part 153, and the valve opening part 152 does not exert force on the weak part 153, and the valve opening part 152 is in the closed state; when the temperature inside the battery monomer 100 is higher than the deformation temperature of the first shape memory alloy, the valve opening part 152 is in the second shape, i.e. the valve opening part 152 deforms and exerts force on the weak part 153, so that the weak part 153 is broken, and the valve opening part 152 is opened.

[0122] The technical scheme of the embodiment of the present application is that the valve opening part 152 is made of the first shape memory alloy, when the temperature reaches the deformation temperature of the first shape memory alloy, the valve opening part 152 can deform and exert force on the weak part 153, so that the weak part 153 is broken, and the valve opening part 152 is opened, so that the explosion-proof valve 150 is preferentially automatically opened.

[0123] In some other embodiments of the present application, the connecting part 151 can also be made of the first shape memory alloy.

[0124] In this embodiment, the connecting part 151 has at least two shapes. When the temperature inside the battery monomer 100 is lower than the deformation temperature of the first shape memory alloy, the connecting part 151 is in the first shape, i.e. the connecting part 151 is stably connected to the valve opening part 152 through the weak part 153, and the connecting part 151 does not exert force on the weak part 153, and the valve opening part 152 is in the closed state; when the temperature inside the battery monomer 100 is higher than the deformation temperature of the first shape memory alloy, the connecting part 151 is in the second shape, i.e. the connecting part 151 deforms and exerts force on the weak part 153, so that the weak part 153 is broken, and the valve opening part 152 is opened.

[0125] Please refer to FIGS. 6-7, in some embodiments, the explosion-proof valve 150 is made of the first shape memory alloy.

[0126] The explosion-proof valve 150 has at least two shapes. When the temperature in the battery monomer 100 is lower than the deformation temperature of the first shape memory alloy, the explosion-proof valve 150 has a first shape, i.e., the opening valve part 152 is stably connected to the connecting part 151 through the weak part 153, the weak part 153 stably connects the opening valve part 152 and the connecting part 151, and the opening valve part 152 is in a closed state. When the temperature in the battery monomer 100 is higher than the deformation temperature of the first shape memory alloy, the explosion-proof valve 150 is in a transition process from the first shape to a second shape. The explosion-proof valve 150 can generate internal stress, so that the weak part 153 is bent and broken, and the opening valve part 152 is opened.

[0127] The technical scheme of the embodiment of the present application is that the entire explosion-proof valve 150 is made of the first shape memory alloy. When the temperature reaches the deformation temperature of the first shape memory alloy, the entire explosion-proof valve 150 can be deformed, so that the weak part 153 is bent and broken, and the opening valve part 152 is opened, so that the explosion-proof valve 150 is preferentially automatically opened.

[0128] In some embodiments, the explosion-proof valve 150 further includes the connecting part 151, the connecting part 151 is connected to the shell 110, and the opening valve part 152 and the connecting part 151 are connected through the weak part 153.

[0129] The connecting part 151 is a structure for connecting the shell 110, and the connecting manner of the connecting part 151 includes bonding, welding, etc.

[0130] It should be noted that the entire explosion-proof valve 150 can be integrally formed, and then the weak part 153 is formed on the explosion-proof valve 150, and the opening valve part 152 and the connecting part 151 are divided. Then, the entire explosion-proof valve 150 is connected to the shell 110. Please refer to FIGS. 8-11. In some embodiments, the connecting part 151 includes a connecting block 1511 and an extrusion block 1512. The connecting block 1511 and the opening valve part 152 are connected through the weak part 153. The extrusion block 1512 is at least partially arranged on the connecting block 1511, and the extrusion block 1512 is made of the first shape memory alloy.

[0131] The connecting block 1511 is a structure for connecting the shell 110, and the connecting manner of the connecting block 1511 includes bonding, welding, etc.

[0132] The extrusion block 1512 is a structure for deforming to open the opening valve part 152.

[0133] The technical scheme of the embodiment of the present application is that the extrusion block 1512 is made of the first shape memory alloy, when the temperature reaches the deformation temperature of the first shape memory alloy, the extrusion block 1512 can deform and exert force on the weak part 153, so that the weak part 153 is broken, the valve opening part 152 is opened, and thus the explosion-proof valve 150 is preferentially automatically opened.

[0134] Please refer to FIG. 12, which is a structural schematic diagram of an inner wall of a first shell 110 according to some embodiments of the present application. In some embodiments, the connecting part 151 includes at least two extrusion blocks 1512, which are oppositely arranged with the valve opening part 152 as the center.

[0135] In the embodiment shown in FIG. 12, the connecting part 151 includes four extrusion blocks 1512, which are located on both sides of the valve opening part 152, and each side of the valve opening part 152 is provided with two extrusion blocks 1512. Among them, the extrusion block 1512 located on the left side of the valve opening part 152 can deform and exert force on the left side of the weak part 153 after reaching the deformation temperature of the first shape memory alloy, so that the left side of the weak part 153 is broken faster. The extrusion block 1512 located on the right side of the valve opening part 152 can deform and exert force on the right side of the weak part 153 after reaching the deformation temperature of the first shape memory alloy, so that the right side of the weak part 153 is broken faster.

[0136] The technical scheme of the embodiment of the present application is that the at least two oppositely arranged extrusion blocks 1512 can respectively deform and exert force on different positions of the weak part 153 after reaching the deformation temperature of the first shape memory alloy, so that the weak part 153 is broken faster, the valve opening part 152 is opened, and thus the explosion-proof valve 150 is preferentially automatically opened.

[0137] Please refer to FIGS. 8-9. In some embodiments, one end of the extrusion block 1512 is arranged at the connecting block 1511, and the other end is arranged at the valve opening part 152. The extrusion block 1512 is used to deform and bend to open the valve opening part 152 after reaching the deformation temperature.

[0138] The extrusion block 1512 has at least two shapes. When the temperature in the battery monomer 100 is lower than the deformation temperature of the first shape memory alloy, the extrusion block 1512 is in the first shape, that is, the extrusion block 1512 does not exert force on the connecting part 151 and the valve opening part 152, and the valve opening part 152 is in the closed state. When the temperature in the battery monomer 100 is higher than the deformation temperature of the first shape memory alloy, the extrusion block 1512 is in the second shape, that is, the extrusion block 1512 deforms and bends outwardly of the battery monomer 100 and exerts a pushing force on the valve opening part 152, causing the weak part 153 to break and the valve opening part 152 to open.

[0139] In some embodiments, the way in which the extrusion block 1512 is configured to deform and bend to open the valve opening 152 when the deformation temperature is reached includes prying open the valve opening 152, pushing open the valve opening 152, and the like.

[0140] The technical solution of the embodiments of the present application enables the extrusion block 1512 to be arranged at one end of the connecting block 1511 and at the other end of the valve opening 152. When the temperature reaches the deformation temperature of the first shape memory alloy, the extrusion block 1512 can deform and bend and apply a pushing force to the valve opening 152, causing the weak portion 153 to break open and the valve opening 152 to open, thereby causing the explosion-proof valve 150 to automatically open preferentially.

[0141] Please refer to FIGS. 10-11. In some embodiments, the extrusion block 1512 is partially arranged at the weak portion 153. The extrusion block 1512 is configured to deform and pierce the weak portion 153 when the deformation temperature is reached.

[0142] The extrusion block 1512 has at least two shapes. When the temperature inside the battery monomer 100 is lower than the deformation temperature of the first shape memory alloy, the extrusion block 1512 is in the first shape, i.e., the extrusion block 1512 does not apply a force to the connecting portion 151 and the valve opening 152, and the valve opening 152 is in a closed state. When the temperature inside the battery monomer 100 is higher than the deformation temperature of the first shape memory alloy, the extrusion block 1512 is in the second shape, i.e., the extrusion block 1512 deforms and the side of the extrusion block 1512 facing the weak portion 153 is formed into a sharp structure. The sharp structure can pierce the weak portion 153, causing the weak portion 153 to break open and the valve opening 152 to open.

[0143] The technical solution of the embodiments of the present application enables the extrusion block 1512 to be partially arranged at the weak portion 153. When the temperature reaches the deformation temperature of the first shape memory alloy, the extrusion block 1512 can deform and pierce the weak portion 153, causing the weak portion 153 to break open and the valve opening 152 to open, thereby causing the explosion-proof valve 150 to automatically open preferentially.

[0144] In some embodiments, the thickness of the weak portion 153 is less than the thickness of the connecting portion 151 and the valve opening 152.

[0145] The technical solution of the embodiments of the present application enables the thickness of the weak portion 153 to be less than the thickness of the connecting portion 151 and the valve opening 152, thereby enabling the weak portion 153 to break open more easily than the connecting portion 151 and the valve opening 152.

[0146] In some embodiments, the weak portion 153 is a notch formed between the connecting portion 151 and the valve opening 152.

[0147] The notch is a groove-shaped structure formed between the connecting portion 151 and the valve opening 152.

[0148] When the weak portion 153 is a notch, the entire explosion-proof valve 150 can be integrally formed, and then the notch is formed by etching at least one side of the explosion-proof valve 150.

[0149] The technical solution of the embodiment of the present application is convenient for processing the notch and is conducive to forming the explosion-proof valve 150 at low cost.

[0150] In some embodiments, the first shape memory alloy includes a nickel-titanium alloy, a copper-zinc alloy, a copper-aluminum-nickel alloy, a copper-molybdenum-nickel alloy, or a copper-gold-zinc alloy.

[0151] It should be noted that the material of the first shape memory alloy is not limited to the above memory alloys, and any material that can meet the shape requirements of the present application at low and high temperatures can be used.

[0152] The technical solution of the embodiment of the present application selects the first shape memory alloy described above. When the temperature reaches the deformation temperature of the first shape memory alloy, the valve opening portion 152 can be deformed and apply a force to the weak portion 153, so that the weak portion 153 is broken, the valve opening portion 152 is opened, and the explosion-proof valve 150 is preferentially automatically opened.

[0153] Please refer to FIGS. 13-16. FIG. 13 is a cross-sectional view of a fifth shell 110 provided by some embodiments of the present application when the valve opening portion 152 is not opened. FIG. 14 is a cross-sectional view of the fifth shell 110 provided by some embodiments of the present application when the valve opening portion 152 is opened. FIG. 15 is a cross-sectional view of an internal support 160 of a battery monomer 100 before the internal support 160 is deformed. FIG. 16 is a cross-sectional view of the internal support 160 of the battery monomer 100 after the internal support 160 is deformed.

[0154] In some embodiments, the battery monomer 100 further includes a support 160, the shell 110 has an inner wall for forming a cavity for accommodating the electrode assembly 170, the support 160 is arranged on the inner wall of the explosion-proof valve 150 and / or the inner wall of the shell 110, the support 160 is made of a second shape memory alloy, and the support 160 is used to be deformed into a convex structure to support the electrode assembly 170 after reaching a deformation temperature.

[0155] The support 160 is a structure for supporting the electrode assembly 170 inside the battery monomer 100 at a high temperature.

[0156] The support 160 has at least two shapes. When the temperature in the battery monomer 100 is lower than the deformation temperature of the second shape memory alloy, the support 160 is in the first shape, that is, the support 160 closely adheres to the shell 110 in a thin structure. When the temperature in the battery monomer 100 is higher than the deformation temperature of the second shape memory alloy, the support 160 is in the second shape, that is, the support 160 is deformed to form a convex structure, and the convex structure is used to lift the electrode assembly 170 in the battery 10.

[0157] It should be noted that the support 160 can be arranged on the inner wall of the shell 110, or arranged on the inner wall of the connecting portion 151, or partially arranged on the inner wall of the shell 110 and partially arranged on the inner wall of the connecting portion 151.

[0158] The technical scheme of the embodiment of the application is that the support 160 is made of the second shape memory alloy. When the temperature reaches the deformation temperature of the second shape memory alloy, the support 160 can be deformed to form a convex structure, and the convex structure is used to lift the electrode assembly 170 in the battery 10, so as to prevent the electrode assembly 170 from abutting against the explosion-proof valve 150 and causing the explosion-proof valve 150 to be blocked, and facilitate the discharge of high-temperature gas in the battery monomer 100 that has thermal runaway, thereby reducing the explosion caused by the electrode assembly 170 blocking the explosion-proof valve 150.

[0159] Please refer to FIG. 17, which is a structural schematic diagram of the inner wall of a second shell provided by some embodiments of the application. In some embodiments, the explosion-proof valve 150 further includes at least two supports 160, and the at least two supports 160 are oppositely arranged with the valve opening portion 152 as the center.

[0160] In the embodiment as shown in FIG. 17, the explosion-proof valve 150 includes four supports 160, and the four supports 160 are located on both sides of the explosion-proof valve 150. Each side of the explosion-proof valve 150 is provided with two supports 160. Among them, the support 160 located on the left side of the explosion-proof valve 150 can be deformed to form a convex structure after reaching the deformation temperature of the second shape memory alloy, so as to support the electrode assembly 170 in the battery monomer 100 from the left side. The support 160 located on the right side of the explosion-proof valve 150 can be deformed to form a convex structure after reaching the deformation temperature of the second shape memory alloy, so as to support the electrode assembly 170 in the battery monomer 100 from the right side.

[0161] The technical scheme of the embodiment of the application is that the at least two oppositely arranged supports 160 can be deformed to form convex structures after reaching the deformation temperature of the second shape memory alloy, and cooperate with each other to lift the electrode assembly 170 in the battery 10, so as to increase the gap between the electrode assembly 170 and the explosion-proof valve 150, and more facilitate the discharge of high-temperature gas in the battery monomer 100 that has thermal runaway.

[0162] In some embodiments, the second shape memory alloy includes a nickel-titanium alloy, a copper-zinc alloy, a copper-aluminum-nickel alloy, a copper-molybdenum-nickel alloy, or a copper-gold-zinc alloy.

[0163] It should be noted that the material of the second shape memory alloy is not limited to the above shape memory alloys, and any material that can meet the shape requirements of the present application at low and high temperatures can be used.

[0164] By selecting the second shape memory alloy described above, when the temperature reaches the deformation temperature of the second shape memory alloy, the support 160 can be deformed into a convex structure, thereby lifting the electrode assembly 170 in the battery 10, and reducing the explosion caused by the electrode assembly 170 blocking the explosion-proof valve 150.

[0165] Referring to FIGS. 6-7, the present application provides a battery monomer 100, which includes a shell 110, the shell 110 including a housing 120, an explosion-proof valve 150 disposed at the bottom of the housing 120, the explosion-proof valve 150 including an opening valve portion 152 and a weak portion 153, the opening valve portion 152 and the shell 110 being connected by the weak portion 153, the explosion-proof valve 150 being made of a first shape memory alloy, the first shape memory alloy being used to deform after reaching a deformation temperature to cause the weak portion 153 to crack and the opening valve portion 152 to open.

[0166] Please refer to FIGS. 8-9 and 12-17, the battery cell 100 provided by the embodiment of the application includes a shell 110, the shell 110 includes a casing 120, an explosion-proof valve 150 is arranged at the bottom of the casing 120, the explosion-proof valve 150 includes a connecting part 151, an opening valve part 152 and a weak part 153, the weak part 153 is a notch formed between the connecting part 151 and the opening valve part 152, the connecting part 151 is connected to the shell 110, the connecting part 151 includes a connecting block 1511 and four extrusion blocks 1512, the extrusion blocks 1512 are made of a first shape memory alloy, the connecting block 1511 and the opening valve part 152 are connected through the weak part 153, one end of the extrusion block 1512 is arranged at the connecting block 1511, the other end is arranged at the opening valve part 152, the four extrusion blocks 1512 are located at both sides of the opening valve part 152, two extrusion blocks 1512 are arranged at each side of the opening valve part 152, wherein the extrusion block 1512 located at the left side of the opening valve part 152 can be deformed after reaching the deformation temperature of the first shape memory alloy and apply a force to the left side of the weak part 153, so that the left side of the weak part 153 is broken faster, the extrusion block 1512 located at the right side of the opening valve part 152 can be deformed after reaching the deformation temperature of the first shape memory alloy and apply a force to the right side of the weak part 153, so that the right side of the weak part 153 is broken faster. The battery cell 100 further includes four supporting pieces 160, the shell 110 has an inner wall for forming a cavity for accommodating an electrode assembly 170, the supporting pieces 160 are arranged at the inner wall of the connecting part 151, the supporting pieces 160 are made of a second shape memory alloy, the four supporting pieces 160 are located at both sides of the explosion-proof valve 150, two supporting pieces 160 are arranged at each side of the explosion-proof valve 150, wherein the supporting piece 160 located at the left side of the explosion-proof valve 150 can be deformed to become a convex structure after reaching the deformation temperature of the second shape memory alloy, thereby supporting the electrode assembly 170 in the battery cell 100 from the left side, the supporting piece 160 at the right side of the explosion-proof valve 150 can be deformed to become a convex structure after reaching the deformation temperature of the second shape memory alloy, thereby supporting the electrode assembly 170 in the battery cell 100 from the right side.

[0167] Although the application has been described with reference to the preferred embodiments, various modifications can be made to the application without departing from the scope of the application. In particular, the technical features mentioned in each of the embodiments can be combined in any manner as long as there is no structural conflict. The 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 battery cell, wherein, The battery cell comprises a shell, and an explosion-proof valve is arranged on the shell, wherein the explosion-proof valve comprises an opening valve part and a weak part, the opening valve part and the shell are connected through the weak part, the explosion-proof valve is at least partially made of a first shape memory alloy, the first shape memory alloy is used to deform after reaching a deformation temperature to cause the weak part to crack, and the opening valve part is opened.

2. The battery cell of claim 1, wherein, The shell comprises a shell body, and the explosion-proof valve is arranged at the bottom of the shell body.

3. The battery cell of claim 1 or 2, wherein, The opening valve part is made of the first shape memory alloy.

4. The battery cell of any one of claims 1-3, wherein, The explosion-proof valve is made of the first shape memory alloy.

5. The battery cell of any one of claims 1-4, wherein, The explosion-proof valve further comprises a connecting part, the connecting part is connected to the shell, and the opening valve part and the connecting part are connected through the weak part.

6. The battery cell of claim 5, wherein, The connecting part comprises a connecting block and a pressing block, the connecting block and the opening valve part are connected through the weak part, the pressing block is at least partially arranged on the connecting block, and the pressing block is made of the first shape memory alloy.

7. The battery cell of claim 6, wherein, The connecting part comprises at least two pressing blocks, and the at least two pressing blocks are oppositely arranged with the opening valve part as the center.

8. The battery cell of claim 6 or 7, wherein, One end of the pressing block is arranged on the connecting block, and the other end of the pressing block is arranged on the opening valve part, and the pressing block is used to deform and bend to open the opening valve part after reaching the deformation temperature.

9. The battery cell of any one of claims 6-8, wherein, The pressing block is partially arranged on the weak part, and the pressing block is used to deform to pierce the weak part after reaching the deformation temperature.

10. The battery cell of any one of claims 5-9, wherein, The thickness of the weak part is smaller than the thickness of the connecting part and the opening valve part.

11. The battery cell of claim 10, wherein, The weak part is a notch formed between the connecting part and the opening valve part.

12. The battery cell according to any one of claims 1 to 9, wherein, The first shape memory alloy comprises a nickel-titanium alloy, a copper-zinc alloy, a copper-aluminum-nickel alloy, a copper-molybdenum-nickel alloy, or a copper-gold-zinc alloy.

13. The battery cell according to any one of claims 1 to 9, wherein, The battery cell further comprises a support, the shell has an inner wall for forming an electrode assembly accommodating cavity, the support is arranged on the inner wall of the explosion-proof valve and / or the inner wall of the shell, and the support is made of a second shape memory alloy, the support is used to deform to form a convex structure to support the electrode assembly after reaching a deformation temperature.

14. The battery cell of claim 13, wherein, The explosion-proof valve further comprises at least two supports, and the at least two supports are oppositely arranged with the opening valve part as the center.

15. The battery cell of claim 13 or 14, wherein, The second shape memory alloy comprises a nickel-titanium alloy, a copper-zinc alloy, a copper-aluminum-nickel alloy, a copper-molybdenum-nickel alloy, or a copper-gold-zinc alloy.

16. A battery, wherein, The battery comprises the battery cell according to any one of claims 1 to 15.

17. An electrical device, comprising: The electric device comprises the battery cell according to any one of claims 1 to 15 or the battery according to claim 16, and the battery cell or the battery is used to provide electric energy.

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