Battery and electric device

Abstract

The utility model is applicable to the technical field of batteries, and provides a battery and a power utilization device, the power utilization device comprises the battery, and the battery comprises a box body, a battery monomer and a fireproof coating. The box body comprises a first part and a second part, the first part and the second part are connected, and a containing cavity is defined between the first part and the second part. The single battery is arranged in the accommodating cavity and is provided with a pressure relief mechanism; a fireproof coating is arranged on the surface, close to the containing cavity, of the first part and / or the second part. The fireproof coating is arranged on the surface, close to the accommodating cavity, of at least one of the first part and the second part of the box body, so that the fireproof coating can block a high-temperature and high-pressure medium which is generated by the single battery and is sprayed out from the pressure relief mechanism in the thermal runaway process of the single battery, and the thermal diffusion of the high-temperature and high-pressure medium is slowed down. Therefore, the problem that the thermal runaway single battery is thermally spread to the adjacent battery can be improved, and the problem that a plurality of batteries explode due to thermal runaway is further improved.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and more specifically, relates to a battery and an electrical device using the same. Background Art

[0002] During the use of a battery cell, thermal runaway is inevitable, generating high-temperature and high-pressure media such as high-temperature and high-pressure gases and flames. Moreover, during the thermal runaway of a battery cell, the generated high-temperature and high-pressure media are ejected from the pressure relief mechanism of the battery cell, and there is a risk of thermal diffusion and thermal spread to adjacent batteries, resulting in a chain reaction of thermal runaway of adjacent batteries, and further leading to explosions of multiple batteries. Summary of the Utility Model

[0003] In view of the above problems, the embodiments of this application provide a battery and an electrical device using the same, which can improve the technical problem of battery thermal diffusion.

[0004] In a first aspect, the embodiments of this application provide a battery, comprising:

[0005] A box body, comprising a first part and a second part, the first part and the second part are connected, and an accommodation cavity is formed by enclosing between the first part and the second part;

[0006] A battery cell, disposed in the accommodation cavity, and the battery cell is provided with a pressure relief mechanism;

[0007] Wherein, a fireproof coating is provided on the surface of at least one of the first part and the second part close to the accommodation cavity.

[0008] For the battery provided by the embodiments of this application, by providing a fireproof coating on the surface of at least one of the first part and the second part of the box body close to the accommodation cavity, during the thermal runaway of the battery cell, the fireproof coating can block the high-temperature and high-pressure media ejected from the pressure relief mechanism of the battery cell, thereby slowing down the thermal diffusion of the high-temperature and high-pressure media. In this way, the problem of thermal spread of the thermal runaway battery cell to adjacent batteries can be improved, and further the problem of chain reaction of thermal runaway of adjacent batteries can be improved. Thus, the problem of explosions of multiple batteries caused by thermal runaway can be improved.

[0009] In some embodiments, at least one of the first part and the second part has a first wall surface on the surface close to the accommodation cavity, the pressure relief mechanism is disposed at the end of the battery cell facing the first wall surface, and at least part of the fireproof coating is disposed at a position on the first wall surface opposite to the pressure relief mechanism.

[0010] In this way, the fireproof coating can effectively block the high-temperature and high-pressure media, so as to effectively improve the problem of thermal diffusion of the high-temperature and high-pressure media, and thus can improve the problem of chain reaction of thermal runaway of adjacent batteries resulting in explosions of multiple batteries.

[0011] In some embodiments, the first wall surface includes a plurality of fireproof regions distributed at intervals, the fireproof regions are disposed opposite to the pressure relief mechanism, and at least a part of the fireproof coating is disposed on the fireproof regions.

[0012] In this way, it is not necessary to provide a fireproof coating on the entire surface of the first wall. On the one hand, the setting of the fireproof coating can be reduced, and on the other hand, it is beneficial to the setting of the anticorrosion layer or other coatings.

[0013] In some embodiments, the first wall surface includes an anticorrosion region, and an anticorrosion layer is provided on the anticorrosion region.

[0014] In this way, the problem of corrosion of the first wall can be improved, which helps to improve the reliability of the battery. Therefore, the problem that the high-temperature and high-pressure medium generated during the thermal runaway process of the battery cell is severely thermally diffused due to the corrosion of the first wall can be improved.

[0015] In some embodiments, at least a part of the fireproof coating is disposed on the surface of the pressure relief mechanism close to the accommodation cavity.

[0016] By disposing at least a part of the fireproof coating on the outer surface of the pressure relief mechanism, the fireproof coating can play roles such as fire prevention, high-temperature resistance, flame retardancy, and heat insulation on the pressure relief mechanism, so as to achieve a protective effect on the pressure relief mechanism. Therefore, thermal runaway protection at the battery cell level can be achieved, thereby reducing the risk of thermal runaway or even explosion of the entire battery.

[0017] In some embodiments, the battery further includes an exhaust structure disposed in the accommodation cavity. The exhaust structure has an exhaust space and an air inlet communicating with the exhaust space, and the air inlet is disposed opposite to the pressure relief mechanism.

[0018] With such a setting, the high-temperature and high-pressure medium generated during the thermal runaway process of the battery cell can enter the exhaust space of the exhaust structure for directional release, which can improve the thermal runaway reaction of the battery cell.

[0019] In some embodiments, the battery further includes a heat insulation structure disposed between the exhaust structure and the pressure relief mechanism, and spaced and opposite to the pressure relief mechanism; the heat insulation structure has a through hole opposite to the pressure relief mechanism, and the through hole is opposite to and communicated with the air inlet.

[0020] By disposing the heat insulation structure opposite to the pressure relief mechanism, the heat insulation structure can achieve protective effects such as fire prevention and heat insulation on the pressure relief mechanism. Therefore, thermal runaway protection at the battery cell level can be achieved, thereby reducing the risk of thermal runaway or even explosion of the entire battery.

[0021] In some embodiments, the battery further includes a partition structure disposed between the battery cell and the exhaust structure and between adjacent pressure relief mechanisms.

[0022] The separation structure can also separate the pressure relief mechanisms of adjacent battery cells. In this way, during the thermal runaway process of a battery cell, when high-temperature and high-pressure media such as high-temperature and high-pressure gases and flames generated by the battery cell spray out from the pressure relief mechanism, the separation structure can effectively block the high-temperature and high-pressure media, so as to improve the problem that the high-temperature and high-pressure media generated by the battery cell experiencing thermal runaway spreads to adjacent battery cells, and further reduce the problem of the chain reaction of adjacent battery cells experiencing thermal runaway. Therefore, thermal runaway protection at the battery cell level can be achieved, thereby reducing the risk of the entire battery experiencing thermal runaway or even explosion.

[0023] In some embodiments, the battery cell further includes an electrode assembly, a housing assembly, and electrode terminals. The electrode assembly is disposed within the housing assembly; the electrode terminals and the pressure relief mechanism are disposed at opposite ends of the housing assembly, or the electrode terminals and the pressure relief mechanism are respectively disposed at one end of the housing assembly.

[0024] With such an arrangement, the layout of the pressure relief mechanism on the battery cell can be very flexible.

[0025] In some embodiments, the fireproof coating is an anti-corrosion coating.

[0026] With such an arrangement, the fireproof coating can also provide a certain anti-corrosion protection effect for the first wall, that is, the first wall has a certain anti-corrosion effect. In this way, the problem of the first wall being corroded can be improved, which helps to improve the reliability of the battery.

[0027] In some embodiments, the thickness of the fireproof coating is ≥0.1 mm and ≤0.9 mm.

[0028] With such an arrangement, on the basis that the fireproof coating has good fireproof, high-temperature resistant, flame retardant, and heat insulation properties, it can have a smaller thickness. In this way, on the basis that there is a predetermined exhaust space between the fireproof coating and the battery cell, the size of the battery in the thickness direction of the fireproof coating can be reduced to reduce the volume of the battery, which helps to improve the energy density of the battery. When the size of the battery in the thickness direction of the fireproof coating is predetermined, the exhaust space between the fireproof coating and the battery cell can be increased, which is beneficial to the discharge of high-temperature and high-pressure media generated during the thermal runaway process of the battery cell, and can improve the explosion problem caused by the aggregation of high-temperature and high-pressure media, thereby improving the reliability of the battery.

[0029] In some embodiments, the thickness of the fireproof coating is ≥0.3 mm and ≤0.7 mm.

[0030] By adopting the above technical solutions, the fireproof coating can have a small thickness on the basis of having good fireproof, high-temperature resistant, flame-retardant, and heat-insulating properties. In this way, on the basis of having a predetermined exhaust space between the fireproof coating and the battery cell, the size of the battery in the thickness direction of the fireproof coating can be reduced, so as to reduce the volume of the battery, which helps to improve the energy density of the battery. When the size of the battery in the thickness direction of the fireproof coating is predetermined, the exhaust space between the fireproof coating and the battery cell can be increased, which is conducive to the discharge of the high-temperature and high-pressure medium generated during the thermal runaway process of the battery cell, and can improve the explosion problem caused by the accumulation of the high-temperature and high-pressure medium, thereby improving the reliability of the battery.

[0031] In a second aspect, an electrical device provided by an embodiment of the present application includes the battery of each of the above embodiments.

[0032] The electrical device provided by the embodiment of the present application, by adopting the batteries of each of the above embodiments, and by providing a fireproof coating on the surface of at least one of the first part and the second part of the box body close to the pressure relief mechanism, during the process of thermal runaway of the battery cell, the fireproof coating can block the high-temperature and high-pressure medium ejected from the pressure relief mechanism generated by the battery cell, thereby slowing down the heat diffusion of the high-temperature and high-pressure medium, that is, the problem of battery heat diffusion can be improved, so as to achieve thermal runaway protection at the battery level. In this way, the problem of thermal spread of the thermal runaway battery cell to adjacent batteries can be improved, and further the problem of the chain reaction of adjacent battery thermal runaway can be improved. In this way, the problem of explosion of multiple batteries due to thermal runaway can be improved, thereby improving the reliability of the electrical device.

[0033] The above description is only an overview of the technical solutions of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically illustrates the specific embodiments of the present application. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0035] Figure 1 Schematic diagram of a vehicle provided by some embodiments of the present application;

[0036] Figure 2 Exploded view of a battery provided by some embodiments of the present application;

[0037] Figure 3 Partial cross-sectional view of the battery provided by some embodiments of the present application;

[0038] Figure 4 is Figure 3 Enlarged view of location A in

[0039] Figure 5 Partial structural view of the battery provided by other embodiments of the present application;

[0040] Figure 6 is Figure 5 Enlarged view of location B in

[0041] Figure 7 Partial cross-sectional view of the battery provided by still other embodiments of the present application;

[0042] Figure 8 is Figure 7 Enlarged view of location C in

[0043] Figure 9 Graph of the temperature-time relationship of the battery provided by Embodiment 1 of the present application;

[0044] Figure 10 Graph of the temperature-time relationship of the battery provided by Comparative Example 1.

[0045] Among them, the reference numerals in the figures are as follows:

[0046] 1000 - vehicle; 100 - battery; 200 - controller; 300 - motor; 10 - battery cell; 11 - electrode assembly; 12 - housing assembly; 121 - housing; 122 - end cap; 13 - electrode terminal; 14 - pressure relief mechanism; 141 - pressure relief portion; 142 - connecting portion; 20 - box body; 201 - accommodating cavity; 202 - first wall surface; 2021 - fireproof area; 2022 - anti-corrosion area; 21 - first part; 22 - second part; 30 - fireproof coating; 30a - first coating; 30b - second coating; 40 - anti-corrosion layer; 50 - heat insulation structure; 501 - through hole; 60 - exhaust structure; 601 - exhaust space; 602 - air inlet; 70 - partition structure; T - first thickness; Z - first direction; Y - second direction; X - third direction. Detailed Description of the Embodiments

[0047] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0048] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0049] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0050] In the description of the present application, the meaning of "a plurality of" is more than two. Unless otherwise specifically defined, "more than two" includes two. Correspondingly, the meaning of "a plurality of groups" is more than two groups, including two groups.

[0051] In the description of the present application, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0052] In the description of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: the existence of A, the simultaneous existence of A and B, and the existence of B. In addition, in the present application, the character " / " generally represents an "or" relationship between the front and rear associated objects.

[0053] Although the present application has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

[0054] In the related art, a battery can be a single physical module including one or more battery cells to provide a higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or in a combined series-parallel connection through a busbar component. The combined series-parallel connection means that there are both series and parallel connections among the multiple battery cells.

[0055] During the use of a battery cell, thermal runaway is inevitable, generating high-temperature and high-pressure media such as high-temperature and high-pressure gases and flames. Moreover, during the thermal runaway of a battery cell, the generated high-temperature and high-pressure media are ejected from the pressure relief mechanism of the battery cell, and there is a risk of thermal diffusion and thermal spread to adjacent batteries, resulting in a chain reaction of thermal runaway of adjacent batteries, and further causing multiple batteries to explode.

[0056] Based on the above considerations, the embodiments of the present application provide a battery and an electrical device. By providing a fireproof coating on at least one of the first part and the second part of the box body near the surface of the accommodation cavity, during the thermal runaway of the battery cell, the fireproof coating can block the high-temperature and high-pressure media ejected from the pressure relief mechanism of the battery cell, thereby slowing down the thermal diffusion of the high-temperature and high-pressure media. In this way, the problem of thermal spread of the thermally runaway battery cell to adjacent batteries can be improved, and further the problem of the chain reaction of thermal runaway of adjacent batteries can be improved. Thus, the problem of explosion of multiple batteries due to thermal runaway can be improved.

[0057] In some embodiments, the battery involved in the embodiments of the present application can be used in an electrical device that uses the battery as a power source.

[0058] The electrical device involved in the embodiments of the present application can be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, a vehicle, a ship, a spacecraft, etc. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, and an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle, and a spaceship, etc. Divided by the power source, the vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc. Divided by the driving mode, the vehicle can be a front-wheel drive vehicle, a rear-wheel drive vehicle, or a four-wheel drive vehicle.

[0059] In other embodiments, the battery involved in the embodiments of the present application can also be used in an energy storage system that uses the battery as an energy storage element. Among them, the energy storage system can include an energy storage container, an energy storage electrical cabinet, etc.

[0060] For ease of description, the embodiments of the present application take the electrical device as a vehicle as an example for illustration.

[0061] In some embodiments, please refer to Figure 1 , Figure 1Schematic diagram of vehicle 1000 provided by some embodiments of the present application. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be disposed at the bottom, head, or tail of the vehicle 1000. The battery 100 can be used to supply power to the vehicle 1000. For example, the battery 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, such as for the working power requirements during the start-up, navigation, and driving of the vehicle 1000.

[0062] In some embodiments, the battery 100 can not only be used as the operating power source of the vehicle 1000, but also be used as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0063] In some embodiments, please refer to Figure 2 , Figure 2 Exploded view of the battery 100 provided by some embodiments of the present application. The battery 100 may include a box body 20 and battery cells 10. The box body 20 is a structure having a receiving cavity 201, and the receiving cavity 201 of the box body 20 is used to accommodate the battery cells 10.

[0064] The box body 20 can adopt various structures. In some embodiments, the box body 20 may include a first part 21 and a second part 22. The first part 21 and the second part 22 cover each other and jointly define the receiving cavity 201 of the box body 20. Among them, the first part 21 may be a hollow structure with an opening at one end, and the second part 22 is a plate-like structure. The second part 22 covers the opening side of the first part 21 so that the first part 21 and the second part 22 jointly define the receiving cavity 201 of the box body 20. Or, please refer to Figure 2 , both the first part 21 and the second part 22 may be hollow structures with an opening at one end. The opening side of the first part 21 covers the opening side of the second part 22 so that the first part 21 and the second part 22 jointly define the receiving cavity 201 of the box body 20. Among them, the box body 20 formed by the first part 21 and the second part 22 can be various shapes, such as a cylinder, a cuboid, etc.

[0065] In some embodiments, please refer to Figure 2, multiple battery cells 10 can form an integral body through series connection, parallel connection or a combination of both, and then the integral body formed by the multiple battery cells 10 is directly accommodated in the accommodation cavity 201 of the box body 20. In some other embodiments, the multiple battery cells 10 can also be first connected in series, parallel or in a combination of both, arranged and fixed to form a battery module, and the battery module is accommodated in the accommodation cavity 201 of the box body 20. In still some other embodiments, the multiple battery cells 10 can also be first connected in series, parallel or in a combination of both, arranged and fixed to form multiple battery modules, and the multiple battery modules are then connected in series, parallel or in a combination of both to form an integral body and are accommodated in the accommodation cavity 201 of the box body 20.

[0066] As an example, multiple battery cells 10 can be fixed by cable ties or the like to form a battery module.

[0067] As another example, multiple battery cells 10 can also be fixed by end plates, side plates or the like to form a battery module.

[0068] In some embodiments, the box body 20 of the battery 100 can be part of the chassis structure of the vehicle 1000. For example, a part of the box body 20 can become at least part of the chassis of the vehicle 1000, or a part of the box body 20 can become at least part of the cross beams and longitudinal beams of the vehicle 1000.

[0069] The battery cell 10 involved in the embodiments of the present application refers to the smallest unit for storing and outputting electric energy. Among them, the battery cell 10 can be a secondary battery or a primary battery. The battery cell 10 can be but is not limited to a metal battery, a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery. The battery cell 10 can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc.

[0070] In some embodiments, please refer to Figure 3 , Figure 3 is a partial cross-sectional view of the battery provided in some embodiments of the present application. Among them, the battery cell 10 can include an electrode assembly 11.

[0071] The electrode assembly 11 is a component in the battery cell 10 where an electrochemical reaction occurs. Among them, the electrode assembly 11 is mainly formed by winding or laminating a positive electrode plate and a negative electrode plate, and a separator is provided between the positive electrode plate and the negative electrode plate. The parts of the positive electrode plate and the negative electrode plate with active substances constitute the main body part of the electrode assembly 11, and the parts of the positive electrode plate and the negative electrode plate without active substances respectively constitute electrode tabs. The electrode tab of the positive electrode plate is the positive electrode tab, and the electrode tab of the negative electrode plate is the negative electrode tab. The positive electrode tab and the negative electrode tab can be located at one end of the main body part together or at opposite ends of the main body part respectively.

[0072] In the battery cell 10, the number of the electrode assemblies 11 can be one or multiple.

[0073] In some cases, the electrode assembly 11 may also be referred to as a bare battery cell, a wound body, a stacked body, etc.

[0074] In some embodiments, the battery cell 10 may further include an electrolyte, which functions to conduct ions between the positive electrode plate and the negative electrode plate. Among them, the electrolyte involved in the embodiments of the present application may be liquid, gel-like or solid.

[0075] In some embodiments, please refer to Figure 3 , the battery cell 10 may further include a housing assembly 12, and the housing assembly 12 is used to define the internal environment of the battery cell 10, and the housing assembly 12 is used to accommodate the electrode assembly 11 and the electrolyte.

[0076] In some embodiments, please refer to Figure 3 , the housing assembly 12 may include a housing 121 and an end cap 122. The housing 121 and the end cap 122 are components used to jointly define the internal environment of the battery cell 10, and the internal environment defined by the housing 121 and the end cap 122 is used to accommodate the electrode assembly 11 and the electrolyte. Among them, the housing 121 and the end cap 122 may be independent components. Specifically, the housing 121 has an opening, and the end cap 122 is covered on the opening of the housing 121 to jointly define the internal environment of the battery cell 10 with the housing 121 and isolate the internal environment of the battery cell 10 from the external environment. Alternatively, the housing 121 and the end cap 122 may also be an integrated structure. Specifically, a common connection surface may be formed between the end cap 122 and the housing 121 before the electrode assembly 11 is put into the housing. When the electrode assembly 11 needs to be encapsulated after being put into the housing, the end cap 122 is then covered on the housing 121.

[0077] Among them, the number of end caps 122 may be one, as Figure 3 shown. Alternatively, the number of end caps 122 may also be two, and the two end caps 122 are respectively provided at opposite ends of the housing 121.

[0078] Among them, the housing 121 may be in a cylindrical, square or other shape, and can be specifically determined according to the specific shape and size of the electrode assembly 11. Moreover, the materials of the housing 121 and the end cap 122 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0079] In some embodiments, please refer to Figure 3 , the battery cell 10 may further include an electrode terminal 13, and the electrode terminal 13 is provided on the housing assembly 12 and connected to the electrode assembly 11. The electrode terminal 13 refers to a component with electrical conductivity. The electrode terminal 13 serves as the current transmission end of the battery cell 10 for transmitting current. Among them, the electrode terminal 13 may be, but is not limited to, a pole column.

[0080] Among them, the electrode terminal 13 can be disposed on the housing 121 of the housing assembly 12, or can be disposed on the end cover 122 of the housing assembly 12.

[0081] In some embodiments, referring to Figure 3 , the electrode terminals 13 are provided in two, and the two electrode terminals 13 are a positive electrode terminal and a negative electrode terminal respectively. The positive electrode terminal is conductively connected to the positive electrode tab of the electrode assembly 11, and the negative electrode terminal is conductively connected to the negative electrode tab of the electrode assembly 11.

[0082] Among them, the positive electrode terminal and the negative electrode terminal can be disposed on the housing 121 simultaneously. Or, as Figure 3 shown, the positive electrode terminal and the negative electrode terminal are disposed on the end cover 122 simultaneously. Or, one of the positive electrode terminal and the negative electrode terminal is disposed on the housing 121, and the other is disposed on the end cover 122.

[0083] Among them, referring to Figure 3 , the positive electrode terminal and the negative electrode terminal can be disposed at the same end of the housing assembly 12. Or, the positive electrode terminal and the negative electrode terminal can be disposed at opposite ends of the housing assembly 12.

[0084] Please refer to Figures 2 to 8 together, Figure 4 is Figure 3 the enlarged view of A in Figure 5 This is a partial structure diagram of the battery 100 provided in some other embodiments of the present application. Figure 6 is Figure 5 the enlarged view of B in Figure 7 This is a partial cross-sectional view of the battery 100 provided in some other embodiments of the present application. Figure 8 is Figure 7 the enlarged view of C in Figures 3 to 6 shown. In some possible designs, as

[0085] The pressure relief mechanism 14 is a mechanism that can release the internal pressure of the battery cell 10 when the internal pressure or temperature of the battery cell 10 reaches a threshold value. For example, when the battery cell 10 is operating normally, the gas pressure inside the battery cell 10 is less than the opening pressure value of the pressure relief mechanism 14, and the pressure relief mechanism 14 is in a closed state, and the gas inside the battery cell 10 is not connected to the gas outside. When the battery cell 10 undergoes thermal runaway under the action of internal and external factors such as overcharging, over-discharging, overheating, and mechanical collision, a large amount of high-temperature and high-pressure gas, flame and other high-temperature and high-pressure media are generated inside the battery cell 10, making the internal pressure of the battery cell 10 greater than the opening pressure value of the pressure relief mechanism 14. The pressure relief mechanism 14 changes from the closed state to the open state, and the high-temperature and high-pressure gas, flame and other high-temperature and high-pressure media inside the battery cell 10 can be discharged outside the battery cell 10 through the pressure relief mechanism 14.

[0086] Among them, the pressure relief mechanism 14 can be a weak structure provided on the battery cell 10, or the pressure relief mechanism 14 can also be a structure such as a pressure valve. When the pressure relief mechanism 14 is a weak structure, the structural strength of the pressure relief mechanism 14 is lower than that of other positions of the battery cell 10. In this way, when the battery cell 10 undergoes thermal runaway, the high-temperature and high-pressure gas, flame and other high-temperature and high-pressure media generated by the battery cell 10 can break through the pressure relief mechanism 14 to be released outside the battery cell 10.

[0087] Among them, the pressure relief mechanism 14 can be provided on the housing assembly 12 of the battery cell 10. As Figure 3 and Figure 4 shown, the pressure relief mechanism 14 can be provided on the end cap 122 of the housing assembly 12; or, as Figure 7 and Figure 8 shown, the pressure relief mechanism 14 can also be provided on the housing 121 of the housing assembly 12.

[0088] In some possible designs, the pressure relief mechanism 14 is integrally connected to the housing assembly 12 of the battery cell 10, and a breakable mark is provided between the pressure relief mechanism 14 and the housing assembly 12, and the breakable mark can be a notch or a break line, etc. Or, the pressure relief mechanism 14 is separately provided on the housing assembly 12.

[0089] In some possible designs, the pressure relief mechanism 14 includes a pressure relief part 141 and a connecting part 142 connected to the outer peripheral wall of the pressure relief part 141. The connecting part 142 is integrally connected to the housing assembly 12 or separately provided on the housing assembly 12. And, the pressure relief part 141 is integrally connected to the connecting part 142, and a breakable mark is provided between the pressure relief part 141 and the connecting part 142, and the breakable mark can be a notch or a break line, etc.; or, the pressure relief part 141 is separately provided on the connecting part 142.

[0090] The fireproof coating 30 refers to a coating made of fireproof materials. Among them, the fireproof materials refer to materials with fireproof properties. When high-temperature and high-pressure media such as high-temperature and high-pressure gases and flames are sprayed onto the fireproof coating 30, the fireproof coating 30 is not easily burned or melted because the fireproof materials have fireproof properties. That is, the fireproof coating 30 is not easily damaged under the action of high-temperature and high-pressure media, so it can isolate and block high-temperature and high-pressure media while maintaining its own structure. Therefore, the fireproof coating 30 has certain fireproof, high-temperature resistant, flame retardant, and heat insulation properties.

[0091] Among them, the fireproof materials can include film-forming substances, carbon sources, fillers, etc. Among them, the film-forming substances can be acrylic resins, epoxy resins, fluoropolymers, etc., and the fillers can be mica powder, muscovite, phlogopite, kaolin, brucite, talc powder, magnesium hydroxide, aluminum hydroxide, nickel-cobalt layered hydroxide, heat-insulating filler glass microspheres, ceramic hollow microspheres, fly ash hollow microspheres, silicon dioxide hollow microspheres, bubble polysilicon hollow microspheres, etc.

[0092] The surface of the first part 21 close to the accommodation cavity 201 is the inner surface of the first part 21, and the surface of the second part 22 close to the accommodation cavity 201 is the inner surface of the second part 22. It can be understood that at least one of the inner surface of the first part 21 and the inner surface of the second part 22 is provided with the fireproof coating 30, that is, the inner surface of the box body 20 is provided with the fireproof coating 30.

[0093] For the convenience of description, the fireproof coating 30 provided on the inner surface of the box body 20 can be defined as the first coating 30a, that is, the fireproof coating 30 can include the first coating 30a. Based on this, the first coating 30a can be provided on the inner surface of the first part 21 of the box body 20 or on the inner surface of the second part 22 of the box body 20.

[0094] In the battery 100 provided by the embodiment of the present application, by providing the fireproof coating 30 on the inner surface of the box body 20 of the battery 100, specifically, at least one of the first part 21 and the second part 22 of the box body 20 is provided with the fireproof coating 30 on the surface close to the accommodation cavity 201, so that during the thermal runaway of the battery cell 10, the fireproof coating 30 can block the high-temperature and high-pressure media ejected from the pressure relief mechanism 14 generated by the battery cell 10, thereby slowing down the heat diffusion of the high-temperature and high-pressure media, that is, the problem of heat diffusion of the battery 100 can be improved to achieve thermal runaway protection at the battery 100 level. In this way, the problem of thermal spread of the thermal runaway battery cell 10 to adjacent batteries 100 can be improved, and further the problem of the chain reaction of thermal runaway of adjacent batteries 100 can be improved, so that the problem of explosion of multiple batteries 100 caused by thermal runaway can be improved.

[0095] It should be added here that, to improve the technical problem of thermal diffusion of the battery 100, in some cases, a mica plate can be arranged in the box body 20, and the mica plate can, to a certain extent, improve the thermal diffusion problem caused during the thermal runaway of the battery cell 10.

[0096] To enable the mica plate to have better heat insulation performance, the thickness of the mica plate is generally relatively large, for example, generally greater than 1 mm, and the density of the mica plate is generally relatively large, for example, generally 2.2 g / cm3. In this way, on the one hand, the mica plate occupies a relatively large space inside the box body 20. On the basis of ensuring a predetermined size of the exhaust space 601 between the mica plate and the battery cell 10, the battery 100 has a relatively large volume; on the basis of ensuring that the battery 100 has a predetermined volume, the exhaust space 601 between the mica plate and the battery cell 10 is relatively small, which easily causes the high-temperature and high-pressure medium to accumulate and lead to an explosion. On the other hand, the arrangement of the mica plate increases the weight of the battery 100. Thus, it is not conducive to improving the energy density of the battery 100.

[0097] In addition, the mica plate is generally fixed in the box body 20 by means of double-sided tape, and the fixing reliability is relatively poor and it is easy to loosen. In this way, during the use of the battery 100, the mica plate is likely to move relative to the box body 20 and generate abnormal noises. Even more seriously, the mica plate falls off from the box body 20, making the mica plate unable to improve the thermal diffusion problem of the battery 100.

[0098] In the battery 100 provided by the embodiment of the present application, since the fireproof coating 30 has good fireproof, high-temperature resistant, flame-retardant, and heat-insulating properties, on the basis that the fireproof coating 30 can better improve the thermal diffusion problem of the battery 100, on the one hand, the thickness of the fireproof coating 30 can be set to be relatively small, so that on the basis of having a predetermined size of the exhaust space 601 between the fireproof coating 30 and the battery cell 10, the size of the battery 100 can be reduced, and further the volume of the battery 100 can be reduced; when the volume of the battery 100 is predetermined, the exhaust space 601 between the fireproof coating 30 and the battery cell 10 can be increased, which is conducive to the discharge of the high-temperature and high-pressure medium and can improve the explosion problem caused by the accumulation of the high-temperature and high-pressure medium, thereby improving the reliability of the battery 100. On the other hand, the fireproof coating 30 can be selected with a relatively small density, for example, it can be but not limited to be set to 1.5 g / cm3, so as to reduce the weight of the battery 100. In this way, the battery 100 can have the advantages of small volume and light weight, which helps to improve the energy density of the battery 100.

[0099] Moreover, the fireproof coating 30 is disposed on the surfaces of the first part 21 and the second part 22 of the box body 20 close to the accommodation cavity 201, that is, the fireproof coating 30 adheres to the inner surface of the box body 20, so that the fireproof coating 30 is combined with the inner surface of the box body 20 by adhesion, so that the fireproof coating 30 can be firmly fixed to the box body 20, which can solve the problems of abnormal noise of the battery 100 caused by the mica plate loosening from the box body 20 and the difficulty of the mica plate to improve the thermal diffusion of the battery 100.

[0100] In addition, based on the good fireproof, high-temperature resistant, flame-retardant and heat-insulating properties of the fireproof coating 30, the box body 20 is not easily melted or collapsed during the thermal runaway of the battery cell 10, so the wall thickness of the box body 20 can be reduced to a certain extent, which is conducive to realizing the lightweight design of the battery 100 and helps to improve the energy density of the battery 100.

[0101] In addition, the fireproof coating 30 can be attached to the inner surface of the box body 20 by spraying, which is convenient for construction, simplifies the processing operation of the battery 100, and can improve the processing efficiency of the battery 100.

[0102] Therefore, for the battery 100 provided by the embodiment of the present application, by providing the fireproof coating 30 on the surface of at least one of the first part 21 and the second part 22 of the box body 20 close to the accommodation cavity 201, the problem of thermal diffusion of the battery 100 during thermal runaway can be effectively and reliably improved, so as to achieve thermal runaway protection at the battery 100 level, and it has the advantages of small volume, lightweight and high processing efficiency, which helps to improve the energy density of the battery 100. And, in some cases, it can also effectively improve the explosion problem caused by the aggregation of high-temperature and high-pressure media.

[0103] In some embodiments, please refer to Figures 3 to 8 together with other drawings. At least one of the first part 21 and the second part 22 is provided with a first wall surface 202 on the surface close to the accommodation cavity 201, the pressure relief mechanism 14 is disposed at the end of the battery cell 10 facing the first wall surface 202, and at least part of the fireproof coating 30 is disposed at a position on the first wall surface 202 opposite to the pressure relief mechanism 14.

[0104] It can be understood that the inner surface of the box body 20 is provided with the first wall surface 202, that is, the first wall surface 202 is at least part of the inner surface of the box body 20, specifically the surface of the box body 20 facing the pressure relief mechanism 14. Among them, the inner surface of the first part 21 may be provided with the first wall surface 202; the inner surface of the second part 22 may also be provided with the first wall surface 202, as Figure 3 and Figure 4 shown. Among them, in the box body 20 of the battery 100, the number of the first wall surfaces 202 may be one or more.

[0105] The pressure relief mechanism 14 is provided at the end of the battery cell 10 facing the first wall surface 202, such that the first wall surface 202 and the pressure relief mechanism 14 are disposed opposite to each other.

[0106] As an example, as Figure 3 and Figure 4 shown, the box body 20 may include a box main body and a cover body. The box main body is a hollow structure with an opening at one end, and the cover body covers the top opening of the box main body to enclose a receiving cavity 201 of the box body 20 with the box main body. Among them, the box main body is the first part 21 of the box body 20, and the cover body is the second part 22 of the box body 20. The first wall surface 202 is provided on the bottom surface of the cover body, and a pressure relief mechanism 14 opposite to the first wall surface 202 is provided on the top of the battery cell 10.

[0107] As another example, the box body 20 may include a box main body and a cover body. The box main body includes a frame and a bottom guard plate provided at the bottom of the frame. The cover body is provided on the top of the frame, and the bottom guard plate, the frame and the cover body enclose a receiving cavity 201 of the box body 20. The box main body is the first part 21 of the box body 20, and the cover body is the second part 22 of the box body 20. The first wall surface 202 is provided on the top surface of the bottom guard plate of the box main body, and a pressure relief mechanism 14 opposite to the first wall surface 202 is provided at the bottom of the battery cell 10.

[0108] The first wall surface 202 and the pressure relief mechanism 14 being opposite means that the orthographic projection of the first wall surface 202 on the battery cell 10 covers at least part of the pressure relief mechanism 14, that is, the orthographic projection of the first wall surface 202 on the battery cell 10 overlaps at least part of the pressure relief mechanism 14. For example, the first wall surface 202 and the pressure relief mechanism 14 are opposite along the first direction Z, that is, the first direction Z is the relative direction of the first wall surface 202 and the pressure relief mechanism 14. The projection of the first wall surface 202 projected onto the battery cell 10 along the first direction Z covers at least part of the pressure relief mechanism 14, that is, the projection of the first wall surface 202 projected onto the battery cell 10 along the first direction Z overlaps at least part of the pressure relief mechanism 14.

[0109] Among them, one end of the box body 20 along the first direction Z is provided with a first wall surface 202. The first wall surface 202 is provided on the inner surface of the first part 21 or the second part 22. One end of the battery cell 10 along the first direction Z facing the first wall surface 202 is provided with a pressure relief mechanism 14, as Figures 3 to 8 shown. Or, opposite ends of the box body 20 along the first direction Z are respectively provided with first wall surfaces 202. The first wall surfaces 202 at both ends are respectively provided on the inner surfaces of the first part 21 and the second part 22. Opposite ends of the battery cell 10 along the first direction Z are respectively provided with pressure relief mechanisms 14, and the first wall surfaces 202 at both ends and the pressure relief mechanisms 14 at opposite ends of the battery cell 10 are respectively disposed opposite to each other.

[0110] Among them, the first wall surface 202 faces the pressure relief mechanism 14, and no other components may be provided in the space between the first wall surface 202 and the pressure relief mechanism 14; other components may also be provided in the space between the first wall surface 202 and the pressure relief mechanism 14. For example, but not limited to, the exhaust structure 60 described below, such as Figure 7 and Figure 8 shown.

[0111] At least part of the fireproof coating 30 is disposed at a position on the first wall surface 202 opposite to the pressure relief mechanism 14, so that the positive projection of the fireproof coating 30 on the battery cell 10 can cover at least part of the pressure relief mechanism 14.

[0112] It can be understood that the first coating 30a is disposed at a position on the first wall surface 202 opposite to the pressure relief mechanism 14.

[0113] With such a setting, at least part of the fireproof coating 30 and the pressure relief mechanism 14 are disposed opposite to each other. Thus, during the thermal runaway process of the battery cell 10, when the high-temperature and high-pressure media such as high-temperature and high-pressure gas and flame generated by the battery cell 10 are ejected from the pressure relief mechanism 14, they can be effectively ejected towards the fireproof coating 30. In this way, the fireproof coating 30 can effectively block the high-temperature and high-pressure media, so as to effectively improve the problem of heat diffusion of the high-temperature and high-pressure media, and thus can improve the problem of chain reaction of thermal runaway of adjacent battery cells 100 resulting in explosion of multiple battery cells 100.

[0114] In some embodiments, the first direction Z may be the height direction of the battery cell 10.

[0115] In some embodiments, such as Figure 3 and Figure 7 shown, the battery cell 10 may also have a length direction and a width direction. The length direction of the battery cell 10 is the second direction Y, and the width direction of the battery cell 10 is the third direction X. Among them, the first direction Z is perpendicular to the second direction Y, the first direction Z is perpendicular to the third direction X, and the second direction Y is perpendicular to the third direction X.

[0116] In some embodiments, please refer to Figure 3 and Figure 4 together, and in combination with other drawings. The fireproof coating 30 may be disposed on the entire surface of the first wall surface 202, rather than only disposed at a position on the first wall surface 202 opposite to the pressure relief mechanism 14, that is, without distinguishing the fireproof area 2021 and the anti-corrosion area 2022 described below.

[0117] In other embodiments, please refer to Figure 5 and Figure 6, and in combination with other attached drawings. The first wall surface 202 includes a plurality of fire prevention areas 2021 distributed at intervals, the fire prevention areas 2021 are disposed opposite to the pressure relief mechanism 14, and at least a part of the fire prevention coating 30 is provided on the fire prevention areas 2021.

[0118] The fire prevention area 2021 refers to the area divided by the first wall surface 202, specifically, the area of the first wall surface 202 disposed opposite to the pressure relief mechanism 14.

[0119] The fire prevention area 2021 is disposed opposite to the pressure relief mechanism 14, which means that the orthographic projection of the fire prevention area 2021 on the battery cell 10 covers at least a part of the pressure relief mechanism 14, that is, the orthographic projection of the fire prevention area 2021 on the battery cell 10 overlaps at least a part of the pressure relief mechanism 14. As an example, the first wall surface 202 and the pressure relief mechanism 14 are disposed opposite to each other along the first direction Z, that is, the first direction Z is the relative direction of the first wall surface 202 and the pressure relief mechanism 14. The projection of the fire prevention area 2021 projected onto the battery cell 10 along the first direction Z covers at least a part of the pressure relief mechanism 14, that is, the projection of the fire prevention area 2021 projected onto the battery cell 10 along the first direction Z overlaps at least a part of the pressure relief mechanism 14.

[0120] It can be understood that the first coating 30a is provided on the fire prevention area 2021.

[0121] In the battery 100, the number of battery cells 10 can be one or more. When the number of battery cells 10 is multiple, a plurality of fire prevention areas 2021 are disposed opposite to the pressure relief mechanisms 14 of the plurality of battery cells 10. Among them, one fire prevention area 2021 can be disposed opposite to the pressure relief mechanism 14 of one battery cell 10, one fire prevention area 2021 can also be disposed opposite to the pressure relief mechanisms 14 of multiple battery cells 10, and a plurality of fire prevention areas 2021 can be disposed opposite to the pressure relief mechanism 14 of one battery cell 10.

[0122] By providing the fire prevention coating 30 on the area of the first wall surface 202 disposed opposite to the pressure relief mechanism 14, when the battery cell 10 undergoes a thermal runaway process, the high-temperature and high-pressure media such as high-temperature and high-pressure gas and flame generated by the battery cell 10 can be effectively ejected towards the fire prevention coating 30 when ejected from the pressure relief mechanism 14. Thus, the fire prevention coating 30 can effectively block the high-temperature and high-pressure media, so as to effectively improve the problem of thermal diffusion of the high-temperature and high-pressure media, and thus can improve the problem of chain reaction of adjacent batteries 100 undergoing thermal runaway and resulting in explosion of multiple batteries 100. In this way, it is not necessary to provide the fire prevention coating 30 on the entire surface of the first wall surface 202. For example, the area of the first wall surface 202 opposite to equipment such as a high-voltage box in the box body 20 can be not provided with the fire prevention coating 30. On the one hand, the setting of the fire prevention coating 30 can be reduced, and on the other hand, it is beneficial to the setting of the anti-corrosion layer 40 or other coatings.

[0123] In some embodiments, the fire prevention area 2021 is disposed opposite to the pressure relief portion 141 of the pressure relief mechanism 14, that is, the fire prevention area 2021 is the area of the first wall surface 202 disposed opposite to the pressure relief portion 141.

[0124] In some other embodiments, please refer to Figure 5 and Figure 6 , and in combination with other drawings. The first wall surface 202 further includes an anti-corrosion area 2022, and an anti-corrosion layer 40 is provided in the anti-corrosion area 2022.

[0125] The anti-corrosion area 2022 refers to the area divided from the first wall surface 202.

[0126] Among them, the anti-corrosion area 2022 may be the area of the first wall surface 202 that is not opposite to the pressure relief mechanism 14. It can be understood that the orthographic projection of the anti-corrosion area 2022 on the battery cell 10 is located outside the pressure relief mechanism 14. The anti-corrosion area 2022 may also be the area of the first wall surface 202 that is opposite to the pressure relief mechanism 14. It can be understood that the orthographic projection of the anti-corrosion area 2022 on the battery cell 10 covers at least a part of the pressure relief mechanism 14.

[0127] The anti-corrosion layer 40 refers to a structural layer with anti-corrosion function, and the anti-corrosion layer 40 can be made of anti-corrosion materials. Among them, the anti-corrosion layer 40 may but is not limited to an electrophoretic layer.

[0128] By providing the anti-corrosion layer 40, a certain anti-corrosion protection effect can be achieved on the first wall surface 202, that is, the first wall surface 202 has a certain anti-corrosion effect. In this way, the problem of corrosion of the first wall surface 202 can be improved, which helps to improve the reliability of the battery 100. Therefore, the problem that the high-temperature and high-pressure medium generated during the thermal runaway of the battery cell 10 diffuses severely due to the corrosion of the first wall surface 202 can be improved.

[0129] In still some other embodiments, please refer to Figure 7 and Figure 8 , and in combination with other drawings. At least a part of the fire prevention coating 30 is provided on the surface of the pressure relief mechanism 14 close to the accommodation cavity 201.

[0130] The surface of the pressure relief mechanism 14 close to the accommodation cavity 201 refers to the outer surface of the pressure relief mechanism 14. Specifically, in the distribution direction of the electrode assembly 11 and the pressure relief mechanism 14, the surface of the pressure relief mechanism 14 on the side away from the electrode assembly 11, that is, the surface of the pressure relief mechanism 14 close to the accommodation cavity 201.

[0131] For the convenience of description, the fire prevention coating 30 provided on the outer surface of the pressure relief mechanism 14 can be defined as the second coating 30b, that is, the fire prevention coating 30 may further include the second coating 30b, and the second coating 30b is provided on the outer surface of the pressure relief mechanism 14.

[0132] At least a part of the fireproof coating 30 is disposed on the surface of the pressure relief mechanism 14 close to the accommodation cavity 201, so that the fireproof coating 30 can play roles such as fire prevention, high temperature resistance, flame retardancy, and heat insulation on the pressure relief mechanism 14, thereby achieving a protective effect on the pressure relief mechanism 14. In this way, during the thermal runaway process of the battery cell 10, when high-temperature and high-pressure media such as high-temperature and high-pressure gas and flame generated by the battery cell 10 are ejected from the pressure relief mechanism 14, the fireproof coating 30 on the pressure relief mechanism 14 of the adjacent battery cell 10 can effectively block the high-temperature and high-pressure media generated by the battery cell 10 that has experienced thermal runaway, so as to improve the problem that the high-temperature and high-pressure media generated by the battery cell 10 that has experienced thermal runaway breaks through the pressure relief mechanism 14 of the adjacent battery cell 10, and further reduce the problem of the chain reaction of thermal runaway of the adjacent battery cell 10. Therefore, thermal runaway protection at the battery cell 10 level can be achieved, thereby reducing the risk of thermal runaway or even explosion of the entire battery 100.

[0133] In some cases, in order to achieve a protective effect on the pressure relief mechanism 14, mica stickers can be provided on the outer surface of the pressure relief mechanism 14, and the mica stickers are fixed to the pressure relief mechanism 14 or the housing assembly 12 by pasting, and there is a risk of falling off. In the embodiment of the present application, by providing the fireproof coating 30 on the outer surface of the pressure relief mechanism 14, the fireproof coating 30 can be attached to the outer surface of the pressure relief mechanism 14, so that the bonding force between the fireproof coating 30 and the pressure relief mechanism 14 can be improved, and the fireproof coating 30 can be stably and firmly fixed to the outer surface of the pressure relief mechanism 14. In this way, the fireproof coating 30 can continuously play a fire prevention role on the outer surface of the pressure relief mechanism 14, thereby solving the problem of the chain reaction of thermal runaway of the adjacent battery cell 10 caused by the thermal diffusion to the adjacent battery cell 10 during the thermal runaway process of the battery cell 10.

[0134] In some embodiments, please refer to Figure 3 、 Figure 4 、 Figure 7 and Figure 8 together, and in combination with other drawings. The battery cell 10 further includes an electrode assembly 11, a housing assembly 12, and an electrode terminal 13, and the electrode assembly 11 is disposed in the housing assembly 12.

[0135] In some possible designs, as Figure 3 and Figure 4 shown, and in combination with other drawings. The electrode terminal 13 and the pressure relief mechanism 14 are disposed at one end of the housing assembly 12.

[0136] It can be understood that the electrode terminal 13 and the pressure relief mechanism 14 are disposed at one end of the housing assembly 12 along the first direction Z.

[0137] To facilitate the arrangement of the battery cell 10 within the box body 20, the electrode terminal 13 is generally disposed at the top of the housing assembly 12. Based on this, both the electrode terminal 13 and the pressure relief mechanism 14 can be disposed at the top of the housing assembly 12, and the top of the box body 20 is provided with a first wall surface 202.

[0138] As an example, as Figure 3 and Figure 4 shown, the box body 20 includes a box main body and a cover body. The box main body is the first part 21 of the box body 20, and the cover body is the second part 22 of the box body 20. The box main body is a hollow structure with an opening at the top, the cover body covers the opening at the top of the box main body, the cover body is provided with a first wall surface 202, and the first wall surface 202 and the pressure relief mechanism 14 are oppositely arranged.

[0139] In some possible designs, as Figure 7 and Figure 8 shown, and in combination with other drawings. The electrode terminal 13 and the pressure relief mechanism 14 are disposed at opposite ends of the housing assembly 12.

[0140] It can be understood that the electrode terminal 13 and the pressure relief mechanism 14 are respectively disposed at opposite ends of the housing assembly 12 along the first direction Z.

[0141] To facilitate the arrangement of the battery cell 10 within the box body 20, one end of the electrode terminal 13 is disposed at the top of the housing assembly 12. Based on this, the pressure relief mechanism 14 is disposed at the bottom of the housing assembly 12, and the bottom of the box body 20 is provided with a first wall surface 202.

[0142] As an example, the box main body is the first part 21 of the box body 20, and the cover body is the second part 22 of the box body 20. The box body 20 includes a box main body and a cover body. The box main body includes a frame and a bottom guard plate disposed at the bottom of the frame, and the cover body covers the top of the frame. The bottom guard plate is provided with a first wall surface 202, and the first wall surface 202 and the pressure relief mechanism 14 are oppositely arranged.

[0143] With such an arrangement, the arrangement of the pressure relief mechanism 14 on the battery cell 10 can be very flexible.

[0144] In some embodiments, please refer to Figure 7 and Figure 8 together, and in combination with other drawings. The battery 100 further includes an exhaust structure 60, and the exhaust structure 60 is disposed within the accommodation cavity 201. The exhaust structure 60 is provided with an exhaust space 601 and an air inlet 602 communicating with the exhaust space 601, and the air inlet 602 and the pressure relief mechanism 14 are oppositely arranged.

[0145] The exhaust structure 60 refers to a structure for discharging the high-temperature and high-pressure medium generated by the battery cell 10 to a predetermined position inside the box body 20 or outside the box body 20.

[0146] The exhaust space 601 refers to the internal space of the exhaust structure 60, and the air inlet 602 refers to an opening for the high-temperature and high-pressure medium discharged from the pressure relief mechanism 14 to enter the exhaust space 601.

[0147] The air inlet 602 and the pressure relief mechanism 14 are oppositely arranged, so that when the high-temperature and high-pressure medium generated inside the battery cell 10 sprays out from the pressure relief mechanism 14, the pressure relief mechanism 14 ruptures and forms an exhaust passage opposite to the air inlet 602, enabling the high-temperature and high-pressure gas sprayed out from the pressure relief mechanism 14 to be released to the air inlet 602 and thus enter the exhaust space 601.

[0148] For ease of description, it is defined that the air inlet 602 and the pressure relief mechanism 14 are oppositely arranged along the first direction Z. At least one end of the box body 20 along the first direction Z is provided with a first wall surface 202. In the first direction Z, the exhaust structure 60 is arranged between the first wall surface 202 and the pressure relief mechanism 14 of the battery cell 10, and the air inlet 602 is arranged at one end of the exhaust structure 60 facing the pressure relief mechanism 14 along the first direction Z.

[0149] With such an arrangement, the high-temperature and high-pressure medium generated during the thermal runaway process of the battery cell 10 can enter the exhaust space 601 of the exhaust structure 60 for directional release, which can improve the thermal runaway reaction of the battery cell 10.

[0150] In some embodiments, please refer to Figure 7 and Figure 8 , and in combination with other drawings. The battery 100 further includes a heat insulation structure 50 arranged inside the box body 20. The heat insulation structure 50 is arranged between the exhaust structure 60 and the pressure relief mechanism 14, and the heat insulation structure 50 is spaced apart and oppositely arranged relative to the pressure relief mechanism 14. The heat insulation structure 50 is provided with a through hole 501, and the through hole 501 is oppositely arranged relative to the pressure relief mechanism 14. The through hole 501 is oppositely arranged and communicated with the air inlet 602.

[0151] The heat insulation structure 50 refers to a component with heat insulation performance, such as but not limited to mica plates, ceramic plates, fiberglass plates, carbon fiber plates, etc.

[0152] Specifically, in the first direction Z, the heat insulation structure 50 is arranged between the exhaust structure 60 and the pressure relief mechanism 14. In the first direction Z, the heat insulation structure 50 is spaced apart and oppositely arranged relative to the pressure relief mechanism 14. The heat insulation structure 50 is formed with a through hole 501 along the first direction Z, so that the through hole 501 and the pressure relief mechanism 14 are spaced apart and oppositely arranged along the first direction Z. The through hole 501 and the air inlet 602 are oppositely arranged and communicated along the first direction Z.

[0153] By adopting the above technical solution, when the battery cell 10 undergoes a thermal runaway process, the high-temperature and high-pressure medium generated can be ejected from the pressure relief mechanism 14 and sprayed towards the through hole 501, and then enter the exhaust space 601 of the exhaust structure 60 through the through hole 501 and the air inlet 602.

[0154] Among them, the heat insulation structure 50 and the pressure relief mechanism 14 are spaced apart, which is conducive to the release of the high-temperature and high-pressure medium ejected from the pressure relief mechanism 14, and can improve the problem that the aggregation of the high-temperature and high-pressure medium causes the explosion of the battery cell 10 or even the battery 100.

[0155] By arranging the heat insulation structure 50 opposite to the pressure relief mechanism 14, the heat insulation structure 50 can provide fire prevention, heat insulation and other protective functions for the pressure relief mechanism 14. In this way, when the battery cell 10 undergoes a thermal runaway process, when the high-temperature and high-pressure medium such as high-temperature and high-pressure gas and flame generated by the battery cell 10 is ejected from the pressure relief mechanism 14, the heat insulation structure 50 spaced apart and opposite to the pressure relief mechanism 14 of the adjacent battery cell 10 can effectively block the high-temperature and high-pressure medium, so as to improve the problem that the high-temperature and high-pressure medium generated by the battery cell 10 undergoing thermal runaway breaks through the pressure relief mechanism 14 of the adjacent battery cell 10, and further reduce the problem of the chain reaction of the adjacent battery cell 10 undergoing thermal runaway. Therefore, the thermal runaway protection at the battery cell 10 level can be realized, and the risk of the entire battery 100 undergoing thermal runaway or even explosion can be reduced.

[0156] In addition, the setting of the heat insulation structure 50 can also improve the problem that the high-temperature and high-pressure medium generated during the thermal runaway process of the battery cell 10 thermally spreads to the opposite battery 100, thereby improving the problem of the chain reaction of the adjacent battery 100 undergoing thermal runaway.

[0157] In some embodiments, please refer to Figure 7 and Figure 8 in combination with other drawings. The battery 100 further includes a partition structure 70 disposed in the accommodation cavity 201. The partition structure 70 is disposed between the battery cell 10 and the exhaust structure 60, and between adjacent pressure relief mechanisms 14.

[0158] The partition structure 70 refers to a structure for separating the battery cell 10 and the exhaust structure 60, and separating adjacent pressure relief mechanisms 14. The partition structure 70 can be made of materials with fire prevention and heat insulation properties such as mica materials, ceramic materials, and glass fiber materials, but is not limited thereto.

[0159] Specifically, in the first direction Z, the partition structure 70 is disposed between the battery cell 10 and the exhaust structure 60. In a direction perpendicular to the first direction Z (such as the second direction Y and the third direction X), the partition structure 70 is also disposed between two adjacent pressure relief mechanisms 14.

[0160] By providing the partition structure 70, the partition structure 70 can separate the battery cell 10 and the exhaust structure 60, so that a certain space is formed between the exhaust structure 60 and the pressure relief mechanism 14 under the action of the partition structure 70, which is beneficial to the release of the high-temperature and high-pressure medium ejected from the pressure relief mechanism 14, and can improve the problem of explosion of the battery cell 10 or even the battery 100 caused by the accumulation of the high-temperature and high-pressure medium. In addition, the partition structure 70 can also separate the pressure relief mechanisms 14 of adjacent battery cells 10. In this way, during the thermal runaway process of the battery cell 10, when the high-temperature and high-pressure medium such as high-temperature and high-pressure gas and flame generated by the battery cell 10 is ejected from the pressure relief mechanism 14, the partition structure 70 can effectively block the high-temperature and high-pressure medium, so as to improve the problem that the high-temperature and high-pressure medium generated by the battery cell 10 with thermal runaway spreads to adjacent battery cells 10, and further reduce the problem of the chain reaction of thermal runaway of the adjacent battery cell 10. Therefore, thermal runaway protection at the battery cell 10 level can be achieved, thereby reducing the risk of thermal runaway or even explosion of the entire battery 100.

[0161] In some embodiments, please refer to Figure 7 and Figure 8 in combination with other drawings. In the first direction Z, the partition structure 70 is disposed between the battery cell 10 and the heat insulation structure 50, so that under the action of the partition structure 70, the heat insulation structure 50 and the pressure relief mechanism 14 can be spaced apart and oppositely disposed along the first direction Z.

[0162] It should be supplemented here that when the pressure relief mechanism 14 and the electrode terminal 13 are respectively disposed at opposite ends of the housing assembly 12 along the first direction Z, the above exhaust structure 60 may be provided between the pressure relief mechanism 14 and the first wall surface 202, the above heat insulation structure 50 may be provided between the exhaust structure 60 and the pressure relief mechanism 14, and the above partition structure 70 may be provided between the heat insulation structure 50 and the battery cell 10. With such an arrangement, it is beneficial to the directional release of the high-temperature and high-pressure medium ejected from the pressure relief mechanism 14, and the problem of the chain reaction of adjacent battery cells 10 being affected by thermal runaway can be improved.

[0163] In some embodiments, the fireproof coating 30 is an anticorrosive coating.

[0164] It can be understood that the fireproof coating 30 also has an anticorrosive effect.

[0165] As an example, the material of the fireproof coating 30 may include glass powder. Under the action of high temperature, the glass powder of the fireproof coating 30 can melt into a film and play an adhesive role, so as to achieve a certain anticorrosive effect.

[0166] With such a setting, the fireproof coating 30 can also achieve a certain anti-corrosion protection effect on the first wall surface 202, that is, the first wall surface 202 has a certain anti-corrosion effect. In this way, the problem of corrosion of the first wall surface 202 can be improved, which helps to improve the reliability of the battery 100. Therefore, the problem that the high-temperature and high-pressure medium generated during the thermal runaway of the battery cell 10 is severely thermally diffused due to the corrosion of the first wall surface 202 can be improved.

[0167] In some embodiments, please refer to Figure 3 and Figure 4 together, and in combination with other drawings. The thickness of the fireproof coating 30 is ≥0.1 mm and ≤0.9 mm.

[0168] The thickness of the fireproof coating 30 is the first thickness T, and 0.1 mm ≤ the first thickness T ≤ 0.9 mm. Specifically, the first thickness T can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, etc.

[0169] As an example, as Figure 3 and Figure 4 shown, the box body 20 includes a first wall surface 202, and the first wall surface 202 is disposed opposite to the pressure relief mechanism 14 along the first direction Z, and the first direction Z is substantially the thickness direction of the first wall surface 202. Based on this, the first thickness T is substantially the dimension of the fireproof coating 30 in the first direction Z.

[0170] With such a setting, on the basis that the fireproof coating 30 has good fireproof, high-temperature resistant, flame retardant, and heat insulation properties, it can have a smaller thickness. In this way, on the basis that there is a predetermined exhaust space 601 between the fireproof coating 30 and the battery cell 10, the size of the battery 100 in the thickness direction of the fireproof coating 30 can be reduced to reduce the volume of the battery 100, which helps to improve the energy density of the battery 100. When the size of the battery 100 in the thickness direction of the fireproof coating 30 is predetermined, the exhaust space 601 between the fireproof coating 30 and the battery cell 10 can be increased, which is beneficial to the discharge of the high-temperature and high-pressure medium generated during the thermal runaway of the battery cell 10, and can improve the explosion problem caused by the aggregation of the high-temperature and high-pressure medium, thereby improving the reliability of the battery 100.

[0171] In some embodiments, please refer to Figure 3 and Figure 4 together, and in combination with other drawings. The thickness of the fireproof coating 30 is ≥0.3 mm and ≤0.7 mm.

[0172] Understandably, 0.3 mm ≤ the first thickness T ≤ 0.7 mm. Specifically, the first thickness T can be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, etc.

[0173] As an example, the first thickness T is 0.3 mm.

[0174] By adopting the above technical solution, the fireproof coating 30 can have a smaller thickness on the basis of having good fireproof, high-temperature resistant, flame-retardant, and heat-insulating properties. In this way, on the basis that there is an exhaust space 601 of a predetermined size between the fireproof coating 30 and the battery cell 10, the size of the battery 100 in the thickness direction of the fireproof coating 30 can be reduced to reduce the volume of the battery 100, which helps to improve the energy density of the battery 100. When the size of the battery 100 in the thickness direction of the fireproof coating 30 is predetermined, the exhaust space 601 between the fireproof coating 30 and the battery cell 10 can be increased, which is beneficial to the discharge of the high-temperature and high-pressure medium generated during the thermal runaway process of the battery cell 10, and can improve the explosion problem caused by the aggregation of the high-temperature and high-pressure medium, thereby improving the reliability of the battery 100.

[0175] Please refer to Figure 1 , the electrical device provided in the embodiment of the present application includes a battery 100. Among them, the battery 100 in this embodiment is the same as the battery 100 in the previous embodiment. For specific details, please refer to the relevant description of the battery 100 in the previous embodiment, which will not be elaborated here.

[0176] For the electrical device provided in the embodiment of the present application, by adopting the battery 100 involved in the above embodiments, and by providing a fireproof coating 30 on the surface of at least one of the first part 21 and the second part 22 of the box body 20 close to the accommodation cavity 201, during the thermal runaway process of the battery cell 10, the fireproof coating 30 can block the high-temperature and high-pressure medium ejected from the pressure relief mechanism 14 generated by the battery cell 10, thereby slowing down the heat diffusion of the high-temperature and high-pressure medium, that is, the problem of heat diffusion of the battery 100 can be improved to achieve thermal runaway protection at the battery 100 level. In this way, the problem of thermal spread of the thermal runaway battery cell 10 to adjacent batteries 100 can be improved, and further the problem of the chain reaction of thermal runaway of adjacent batteries 100 can be improved. In this way, the problem of explosion of multiple batteries 100 due to thermal runaway can be improved, thereby improving the reliability of the electrical device.

[0177] As one of the embodiments of the present application, as Figure 3 and Figure 4As shown and in combination with other drawings. The battery 100 includes a box body 20, battery cells 10, and a fireproof coating 30. The box body 20 includes a first part 21 and a second part 22. The first part 21 and the second part 22 are connected, and an accommodation cavity 201 is formed between the first part 21 and the second part 22 by surrounding. The battery cells 10 are arranged in the accommodation cavity 201. A first wall surface 202 is provided on the surface of the second part 22 of the box body 20 close to the accommodation cavity 201. A pressure relief mechanism 14 is provided at the end of the battery cell 10 facing the first wall surface 202, such that the first wall surface 202 and the pressure relief mechanism 14 are arranged opposite to each other. At least a part of the fireproof coating 30 is provided at a position on the first wall surface 202 opposite to the pressure relief mechanism 14.

[0178] Finally, the battery 100 according to the present application is described as an example of an embodiment, a comparative example, and related test results.

[0179] The battery 100 includes a box body 20 and battery cells 10. The box body 20 includes a first part 21 and a second part 22. The first part 21 and the second part 22 surround to form an accommodation cavity 201, and the battery cells 10 are arranged in the accommodation cavity 201. A first wall surface 202 is provided on the surface of the second part 22 of the box body 20 close to the accommodation cavity 201. A pressure relief mechanism 14 is provided at the end of the battery cell 10 facing the first wall surface 202, such that the first wall surface 202 and the pressure relief mechanism 14 are arranged opposite to each other.

[0180] Example 1:

[0181] Select a fireproof coating 30 with a thickness of 0.3 mm. The fireproof coating 30 is at least provided at a position on the first wall surface 202 opposite to the pressure relief mechanism 14.

[0182] Comparative Example 1:

[0183] Select a mica plate with a thickness of 1.2 mm. The mica plate is at least provided at a position on the first wall surface 202 opposite to the pressure relief mechanism 14.

[0184] Based on the battery 100 provided in Example 1 and Comparative Example 1, the same conditions are used to cause the battery 100 to undergo thermal runaway, and the temperature of the first wall surface 202 and the temperature of the back surface of the first wall surface 202 are respectively measured. Among them, the temperature of the back surface of the first wall surface 202 refers to the temperature of the outer surface of the box body 20 at a position opposite to the first wall surface 202 and far from the accommodation cavity 201.

[0185] Please refer to Figure 9 , Figure 9It is a temperature-time relationship diagram of the battery 100 in Embodiment 1, where L1 is the temperature-time relationship curve of the first wall surface 202, and L2 is the temperature-time relationship curve of the back surface of the first wall surface 202. In Embodiment 1, the measured average temperature of the first wall surface 202 is approximately 1347.4 °C, and the measured average temperature of the back surface of the first wall surface 202 is approximately 328.2 °C.

[0186] Please refer to Figure 10 , Figure 10 It is a temperature-time relationship diagram of the battery 100 in Comparative Example 1, where L3 is the temperature-time relationship curve of the first wall surface 202, and L4 is the temperature-time relationship curve of the back surface of the first wall surface 202. In Comparative Example 1, the measured average temperature of the first wall surface 202 is approximately 1353.9 °C, and the measured average temperature of the back surface of the first wall surface 202 is approximately 318.5 °C.

[0187] It can be seen therefrom that in Embodiment 1 and Comparative Example 1, the difference in the average temperature of the first wall surface 202 is not significant, and the difference in the temperature of the back surface of the first wall surface 202 is also not significant. That is, the fireproof effect of a mica plate with a thickness of 1.2 mm can be obtained by using a fireproof coating 30 with a thickness of 0.3 mm. Therefore, in this embodiment, by providing the fireproof coating 30, the volume of the battery 100 can be reduced or the exhaust space 601 between the fireproof coating 30 and the pressure relief mechanism 14 can be increased.

[0188] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery, characterized in that: include: The box body comprises a first part and a second part, wherein the first part is connected to the second part, and a receiving cavity is formed between the first part and the second part; A battery cell is disposed in the accommodating cavity, and the battery cell is provided with a pressure relief mechanism; Wherein, the first part and / or the second part is provided with a fireproof coating on a surface close to the accommodating cavity.

2. The battery according to claim 1, characterized in that At least one of the first part and the second part is provided with a first wall surface on the surface close to the accommodating cavity, the pressure relief mechanism is provided at the end of the battery cell facing the first wall surface, and at least a part of the fire retardant coating is provided on the first wall surface at a position opposite to the pressure relief mechanism.

3. The battery according to claim 2, characterized in that The first wall surface includes a plurality of fireproof areas distributed at intervals, the fireproof areas are arranged opposite to the pressure relief mechanism, and at least a portion of the fireproof coating is arranged on the fireproof areas.

4. The battery according to claim 2, characterized in that The first wall surface includes an anti-corrosion area, and the anti-corrosion area is provided with an anti-corrosion layer.

5. The battery according to any one of claims 1 to 4, characterized in that: At least a portion of the fire retardant coating is disposed on a surface of the pressure relief mechanism close to the accommodating cavity.

6. The battery according to any one of claims 1 to 4, characterized in that: The battery further comprises an exhaust structure arranged in the accommodating cavity, wherein the exhaust structure is provided with an exhaust space and an air inlet connected to the exhaust space, and the air inlet and the pressure relief mechanism are arranged opposite to each other.

7. The battery according to claim 6, characterized in that The battery also includes a heat insulation structure, which is arranged between the exhaust structure and the pressure relief mechanism, and is spaced from and arranged opposite to the pressure relief mechanism; the heat insulation structure is provided with a through hole opposite to the pressure relief mechanism, and the through hole and the air inlet are arranged opposite to and connected to each other.

8. The battery according to claim 6, characterized in that The battery further includes a partition structure, which is disposed between the battery cell and the exhaust structure and between adjacent pressure relief mechanisms.

9. The battery according to any one of claims 1 to 4, characterized in that: The battery cell further includes an electrode assembly, a shell assembly and an electrode terminal, wherein the electrode assembly is disposed in the shell assembly; the electrode terminal and the pressure relief mechanism are disposed at opposite ends of the shell assembly, or the electrode terminal and the pressure relief mechanism are respectively disposed at one end of the shell assembly.

10. The battery according to any one of claims 1 to 4, characterized in that: The fire retardant coating is an anti-corrosion coating.

11. The battery according to any one of claims 1 to 4, characterized in that: The thickness of the fire retardant coating is ≥0.1mm and ≤0.9mm.

12. The battery according to claim 11, characterized in that The thickness of the fire retardant coating is ≥0.3mm and ≤0.7mm.

13. An electrical device, characterized in that: Comprising a battery according to any one of claims 1-12.

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