Battery and electric device

Abstract

The utility model discloses a battery and an electric device. The battery comprises a battery monomer and a box body, and the battery monomer is accommodated in the box body. And a pressure relief mechanism is arranged on one side of the single battery along the first direction. The box body comprises a first box wall, the pressure relief mechanism faces the first box wall in the first direction, and a concave part is arranged on the side, facing the pressure relief mechanism, of the first box wall. In the first direction, the recess at least partially overlaps the pressure relief mechanism. When the single battery is in thermal runaway, the pressure relief mechanism actuates and releases substances of the single battery, so that the risk of explosion of the single battery is reduced. The concave part can avoid the pressure relief mechanism when the pressure relief mechanism is actuated, so that the interference of the first box wall on the pressure relief mechanism is reduced, the pressure relief rate is increased, and the reliability of the battery is improved.

Description

Technical Field

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

[0002] Batteries are widely used in electronic devices, such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0003] How to improve battery reliability is a research direction in battery technology. Utility Model Content

[0004] The present application provides a battery and an electrical device, which can improve reliability.

[0005] In a first aspect, the present application provides a battery, comprising a battery cell and a box body, wherein the battery cell is contained in the box body. A pressure relief mechanism is provided on one side of the battery cell along a first direction. The box body comprises a first box wall, the pressure relief mechanism faces the first box wall along the first direction, and a recess is provided on one side of the first box wall facing the pressure relief mechanism. In the first direction, the recess at least partially overlaps with the pressure relief mechanism.

[0006] When the battery cell is in thermal runaway, the pressure relief mechanism is activated and releases the substance of the battery cell, thereby reducing the risk of battery cell explosion. The recess can avoid the pressure relief mechanism when the pressure relief mechanism is activated, thereby reducing the interference of the first box wall on the pressure relief mechanism, increasing the pressure relief rate, and improving the reliability of the battery.

[0007] In some embodiments, the pressure relief mechanism includes a pressure relief zone, which includes a main body and a weak portion arranged around the main body. In the first direction, the projection of the pressure relief zone is located within the projection of the recessed portion. When the weak portion ruptures, the recessed portion can avoid the entire main body and provide a holding space for the main body, thereby reducing the shielding of the pressure relief channel by the main body and improving the pressure relief efficiency.

[0008] In some embodiments, the battery further comprises a protective layer, at least part of which is contained in the recess. In a first direction, the protective layer at least partially overlaps with the pressure relief mechanism; the recess comprises an escape space between the protective layer and the pressure relief mechanism in the first direction.

[0009] The substances released by the battery cell during thermal runaway act on the protective layer, which can reduce the thermal shock on the first box wall and the heat transferred to the first box wall, reduce the risk of the first box wall being melted through, and improve the reliability of the battery. The protective layer only fills a part of the concave part and forms an escape space, which can reduce the interference of the protective layer on the pressure relief mechanism, increase the pressure relief rate, and improve the reliability of the battery.

[0010] In some embodiments, the protective layer is contained in the recess and connected to the first box wall. In the first direction, the depth of the recess is greater than the thickness of the protective layer, thereby forming an escape space.

[0011] In some embodiments, the battery includes a plurality of battery cells. In a first direction, the protective layer overlaps with the pressure relief mechanisms of at least two battery cells. The protective layer can withstand the high-temperature substances released by at least two battery cells, thereby reducing the number of protective layers and reducing the difficulty of assembly.

[0012] In some embodiments, the battery includes a plurality of battery cells; there are a plurality of protective layers, and the plurality of protective layers are arranged one by one corresponding to the pressure relief mechanisms of the plurality of battery cells. The protective layers can be flexibly arranged according to the positions of the pressure relief mechanisms, thereby reducing the overall amount of protective layers and improving the energy density of the battery cells.

[0013] In some embodiments, the battery includes a plurality of battery cells. In the first direction, the recess overlaps with the pressure relief mechanisms of at least two battery cells. The recess can at least avoid the pressure relief mechanisms of two battery cells, thereby reducing the number of recesses and reducing the difficulty of forming the first box wall.

[0014] In some embodiments, the battery includes at least one battery column, the battery column includes at least two battery cells arranged along the second direction, the first direction is perpendicular to the second direction, and in the first direction, the projections of the pressure relief mechanisms of the battery cells of the battery column are all located within the projection of the recess.

[0015] The concave portion can increase the exhaust space inside the box and improve the exhaust efficiency. When the battery cell is in thermal runaway, the material discharged from the battery cell can enter the concave portion, which can guide the material flow, thereby reducing the accumulation of the material, reducing the risk of the pressure relief channel of the battery cell being blocked and the risk of the first box wall being melted through, improving the exhaust efficiency, reducing the risk of sealing failure, and improving reliability.

[0016] In some embodiments, there are multiple recesses and multiple battery cells, and the pressure relief mechanisms of the multiple battery cells are arranged in a one-to-one correspondence with the multiple recesses.

[0017] In some embodiments, the first box wall includes a plurality of recesses spaced apart along the second direction, a partition is provided between adjacent recesses, the second direction is perpendicular to the first direction; the partition is provided with a channel connecting adjacent recesses. By providing the partition, the structural strength of the first box wall can be improved. When a battery cell thermally runs away and releases high-temperature substances, the high-temperature substances can flow through the channels in the plurality of recesses, thereby reducing the accumulation of high-temperature substances.

[0018] In some embodiments, the first box wall includes a wall body and a convex portion, the convex portion protrudes from a side of the wall body away from the battery cell, and the concave portion is recessed relative to a surface of the wall body facing the battery cell and corresponds to the position of the convex portion.

[0019] By providing the convex part, the restriction on the depth of the concave part can be reduced, so as to increase the distance between the first box wall and the pressure relief mechanism and improve the exhaust space. The concave and convex parts form a concave-convex structure, which can improve the structural strength of the first box wall and has little effect on the weight of the first box wall, thereby improving the reliability and energy density of the battery.

[0020] In some embodiments, the wall body and the protrusion are integrally formed to reduce assembly processes and improve sealing performance.

[0021] In some embodiments, the first box wall includes a wall body and a cover plate, the wall body has a through hole, and the cover plate is connected to the wall body and covers the through hole. The cover plate and the hole wall of the through hole define a recess. The wall body and the cover plate are independently formed, which can simplify the forming process of the first box wall.

[0022] In some embodiments, at least a portion of the cover plate is accommodated in the through hole. The through hole can provide space for the cover plate, thereby reducing the maximum size of the first box wall in the first direction and improving space utilization.

[0023] In some embodiments, the through hole includes a first hole segment and a second hole segment, the first hole segment is located on a side of the second hole segment away from the battery cell, and the first hole segment has a bottom surface surrounding the second hole segment. The battery also includes a protective layer, the protective layer is accommodated in the first hole segment, and in the axial direction of the through hole, the bottom surface at least partially overlaps with the protective layer. The bottom surface of the first hole segment can limit the protective layer, reducing the risk of the protective layer falling onto the pressure relief mechanism.

[0024] In a second aspect, the present application provides an electrical device, which includes a battery provided by any embodiment of the first aspect, and the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0026] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0027] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0028] Figure 3 A schematic cross-sectional view of a battery provided in some embodiments of the present application;

[0029] Figure 4 for Figure 3 An enlarged schematic diagram at the circle frame;

[0030] Figure 5 for Figure 2A schematic diagram of the first box wall and the protective layer shown at another angle;

[0031] Figure 6 Schematic diagram of a first box wall and a protective layer of a battery provided in some other embodiments of the present application;

[0032] Figure 7 A schematic diagram of a first box wall and a protective layer of a battery provided in some other embodiments of the present application;

[0033] Figure 8 A schematic diagram of a first box wall and a protective layer of a battery provided in some further embodiments of the present application;

[0034] Fig. 9 for Figure 8 An enlarged schematic diagram at the circle frame;

[0035] Fig.10 A partial cross-sectional schematic diagram of a battery provided in some other embodiments of the present application;

[0036] Fig.11 A partial cross-sectional schematic diagram of a battery provided in some other embodiments of the present application;

[0037] Fig.12 Schematic diagram of an explosion of a battery provided in some other embodiments of the present application.

[0038] The following are the descriptions of the reference numerals:

[0039] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor;

[0040] 10. Battery cell; 10a. Battery array; 11. Shell; 111. Shell; 112. End cover; 12. Electrode assembly; 13. Pressure relief mechanism; 131. Pressure relief area; 131 a. Main body; 131 b. Weak part; 132. Connecting part;

[0041] 20, box body; 20a, first box body; 20b, second box body; 21, first box wall; 211, recess; 211 a, bottom surface of recess; 212, wall body; 2121, through hole; 2122, first hole section; 2123, second hole section; 2124, bottom surface; 213, convex part; 213a, top surface; 214, partition; 214a, channel; 215, cover plate; 22, first cavity; 23, second cavity;

[0042] 30. Protective layer; 40. Explosion-proof valve; G. Avoidance space;

[0043] X, second direction; Y, third direction; Z, first direction. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0046] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0047] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0049] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0050] The term "plurality" used in the present application refers to two or more (including two).

[0051] In the embodiments of the present application, a battery may refer to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0052] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0053] As an example, the battery cells may be lithium ion battery cells, sodium ion battery cells, sodium lithium ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium sulfur battery cells, magnesium ion battery cells, nickel hydrogen battery cells, nickel cadmium battery cells, lead storage battery cells, etc.

[0054] As an example, the battery cell may 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 includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery.

[0055] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0056] Batteries generally include a casing for enclosing one or more battery cells. The casing can reduce the risk of liquid or other foreign matter affecting the battery cells.

[0057] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0058] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0059] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0060] The pressure relief mechanism on the battery cell has an important impact on the reliability of the battery cell. For example, when a short circuit or overcharge occurs, thermal runaway may occur inside the battery cell, causing a sudden increase in pressure. In this case, the pressure relief mechanism can be activated to release the internal pressure to the outside to prevent the battery cell from exploding or catching fire.

[0061] The pressure relief mechanism may be an element or component that is activated when a battery cell reaches a certain condition. For example, the pressure relief mechanism may be an element or component that is activated to release the internal pressure and / or internal substances when the internal pressure or internal temperature of the battery cell reaches a predetermined threshold. The threshold design varies according to different design requirements. The threshold may depend on one or more materials of the positive electrode sheet, negative electrode sheet, electrolyte and separator in the battery cell.

[0062] The pressure relief mechanism may be in the form of an explosion-proof valve, an air valve, a pressure relief valve or a safety valve, and may specifically be a pressure-sensitive element or structure, that is, when the internal pressure of the battery cell reaches a predetermined threshold, the pressure relief mechanism performs an action or a weak area provided in the pressure relief mechanism ruptures, thereby forming a pressure relief channel for internal pressure relief. Alternatively, the pressure relief mechanism may also be a temperature-sensitive element or structure, that is, when the internal temperature of the battery cell reaches a predetermined threshold, the pressure relief mechanism performs an action, thereby forming a pressure relief channel for internal pressure relief. Alternatively, the pressure relief mechanism may also be a component that can be actively actuated. For example, the pressure relief mechanism may be actuated upon receiving a control signal from the battery.

[0063] The pressure relief mechanism may also be in other forms. For example, the pressure relief mechanism may be a relatively low-strength structure on the outer shell of the battery cell. When the battery cell is in thermal runaway, the relatively low-strength structure cracks or deforms to form a pressure relief channel for internal pressure relief. For example, the pressure relief mechanism may be a weld mark on the outer shell of the battery cell.

[0064] The "actuation" mentioned in this application means that the pressure relief mechanism is in action or activated to a certain state, so that the internal pressure and / or internal substances of the battery cell can be released. The action produced by the pressure relief mechanism may include but is not limited to: at least a part of the pressure relief mechanism is ruptured, broken, torn or opened, etc. When the pressure relief mechanism is actuated, the high-temperature and high-speed substances inside the battery cell will be discharged from the actuated part as emissions. In this way, the battery cell can be depressurized under controllable pressure, thereby avoiding potential more serious accidents.

[0065] The emissions from the battery cells mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-speed gases produced by the reaction, flames, etc.

[0066] In order to improve the space utilization inside the battery, the distance between the box wall and the pressure relief mechanism is usually reduced; however, when the battery cell experiences thermal runaway, the box wall may block the pressure relief mechanism, thereby reducing the pressure relief efficiency of the battery cell and affecting the reliability of the battery.

[0067] In view of this, an embodiment of the present application provides a technical solution, which provides a recess on the box wall of the box body to avoid the pressure relief mechanism of the battery cell when the battery cell thermally runs away, so that the battery cell can release pressure in time and improve the reliability of the battery.

[0068] The battery cells described in the embodiments of the present application are suitable for use in batteries and electrical devices using the batteries.

[0069] The battery cells, batteries and electrical devices disclosed in the embodiments of the present application can be used in electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0070] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0071] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0072] like Figure 1 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0073] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0074] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0075] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application; Figure 3 A schematic cross-sectional view of a battery provided in some embodiments of the present application; Figure 4 for Figure 3 An enlarged schematic diagram at the circle frame; Figure 5 for Figure 2 A schematic diagram of the first box wall and the protective layer at another angle is shown.

[0076] Reference Figures 2 to 5 The embodiment of the present application provides a battery 2, which includes a battery cell 10 and a box body 20, and the battery cell 10 is accommodated in the box body 20.

[0077] In the battery 2, there can be one or more battery cells 10. If there are more than one battery cell 10, the battery cells 10 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the battery cells 10 are both connected in series and in parallel. The battery cells 10 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the battery cells 10 can be accommodated in the box 20; of course, the battery cells 10 can also be connected in series, in parallel, or in mixed connection to form a battery module, and then the battery modules can be connected in series, in parallel, or in mixed connection to form a whole, and then accommodated in the box 20.

[0078] The box 20 may be an outer envelope of the battery 2, and the battery cell 10 is located inside the outer envelope. The box 20 may block external foreign matter (such as liquid or particles), thereby reducing the influence of the external foreign matter on the charging or discharging of the battery cell 10.

[0079] In some embodiments, the box body 20 may include a first box body portion 20 a and a second box body portion 20 b , the first box body portion 20 a and the second box body portion 20 b cover each other, and the first box body portion 20 a and the second box body portion 20 b together define an accommodation space for accommodating the battery cell 10 .

[0080] In some examples, the second box body 20b may be a hollow structure with one end open, the first box body 20a is a plate-like structure, and the first box body 20a covers the open side of the second box body 20b to form a box body 20 with a storage space. In other examples, the first box body 20a and the second box body 20b may also be hollow structures with one side open, and the open side of the first box body 20a covers the open side of the second box body 20b to form a box body 20 with a storage space.

[0081] The first box body 20a and the second box body 20b can be in various shapes, such as a cylinder, a cuboid, etc.

[0082] In some embodiments, the battery 2 further includes a sealant (not shown), which may be disposed between the first box body 20a and the second box body 20b to improve the sealing after the first box body 20a and the second box body 20b are connected. For example, the sealant may be a sealant or a sealing ring.

[0083] In some embodiments, the battery cell 10 includes a housing 11 and an electrode assembly 12 accommodated in the housing 11 .

[0084] The housing 11 is a hollow structure, and a space for accommodating the electrode assembly 12 and the electrolyte is formed therein. The shape of the housing 11 can be determined according to the specific shape of the electrode assembly 12. For example, if the electrode assembly 12 is a rectangular parallelepiped structure, a rectangular housing can be selected; if the electrode assembly 12 is a cylindrical structure, a cylindrical housing can be selected.

[0085] As an example, the housing 11 includes a shell 111 and an end cover 112 . The shell 111 has an opening, and the end cover 112 is used to cover the opening.

[0086] The housing 111 is a component used to cooperate with the end cover 112 to form an internal cavity of the battery cell 10 . The formed internal cavity can be used to accommodate the electrode assembly 12 , electrolyte, and other components.

[0087] The housing 111 and the end cap 112 may be independent components. For example, an opening may be provided on the housing 111 , and the end cap 112 may cover the opening to form an internal cavity of the battery cell 10 .

[0088] The shell 111 can be in various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism shape, etc. Specifically, the shape of the shell 111 can be determined according to the specific shape and size of the electrode assembly 12. The shell 111 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0089] The shape of the end cap 112 can be adapted to the shape of the shell 111 to match the shell 111. The material of the end cap 112 can be the same as or different from the material of the shell 111. Optionally, the end cap 112 can be made of a material with a certain hardness and strength (for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cap 112 is not easily deformed when squeezed and collided, so that the battery cell 10 can have a higher structural strength and the reliability performance can also be improved.

[0090] The end cover 112 is connected to the housing 111 by welding, bonding, clamping or other methods.

[0091] The housing 111 may be open at one end or at both ends. In some examples, the housing 111 may be a structure with one end open, and one end cap 112 is provided and covers the housing 111. In other examples, the housing 111 may be a structure with two ends open, and two end caps 112 are provided, and the two end caps 112 cover the two openings of the housing 111 respectively.

[0092] In some embodiments, the battery cell 10 includes a pressure relief mechanism 13. Exemplarily, the pressure relief mechanism 13 can be actuated to release the gas in the housing 11 when the internal pressure or temperature of the battery cell 10 reaches a threshold.

[0093] In some embodiments, the pressure relief mechanism 13 is disposed on the housing 11 .

[0094] In some embodiments, the pressure relief mechanism 13 is disposed on the end cover 112. In some examples, the pressure relief mechanism 13 and the end cover 112 are independently formed components, and the pressure relief mechanism 13 and the end cover 112 can be connected by welding, bonding or other methods. In other examples, the pressure relief mechanism 13 and the end cover 112 are an integrally formed structure.

[0095] In some embodiments, the pressure relief mechanism 13 is disposed on the housing 111. In some examples, the pressure relief mechanism 13 and the housing 111 are independently formed components, and the pressure relief mechanism 13 and the housing 111 can be connected by welding, bonding or other methods. In other examples, the pressure relief mechanism 13 and the housing 111 are an integrally formed structure.

[0096] In some embodiments, the battery 2 includes a box body 20 and a battery cell 10 contained in the box body 20. A pressure relief mechanism 13 is provided on one side of the battery cell 10 along a first direction Z. The box body 20 includes a first box wall 21, and the pressure relief mechanism 13 faces the first box wall 21 along the first direction Z. A recess 211 is provided on one side of the first box wall 21 facing the pressure relief mechanism 13, and in the first direction Z, the recess 211 at least partially overlaps with the pressure relief mechanism 13.

[0097] As an example, the first box wall 21 may be a top wall located on the upper side of the battery cell 10 , a bottom wall located on the lower side of the battery cell 10 , or a side wall of the box body 20 located on one side of the battery cell 10 .

[0098] As an example, the first box wall 21 may be a part of the first box body portion 20 a or a part of the second box body portion 20 b .

[0099] The first box wall 21 can be in a flat plate shape, a curved plate shape or other shapes.

[0100] The first box wall 21 may be an integrally formed structure, or may be formed by connecting a plurality of independent components.

[0101] The battery cell 10 may be one or more. Exemplarily, there are more than one battery cell 10. Optionally, the pressure relief mechanisms 13 of the more than one battery cell 10 are all facing the first box wall 21.

[0102] The first box wall 21 may have one recess 211 or may have a plurality of recesses 211 .

[0103] In some examples, in the first direction Z, the recess 211 partially overlaps with the pressure relief mechanism 13; in other words, the projection of the recess 211 along the first direction Z partially overlaps with the projection of the pressure relief mechanism 13 along the first direction Z. In other examples, in the first direction Z, the recess 211 completely overlaps with the pressure relief mechanism 13; in other words, the projection of the recess 211 along the first direction Z completely overlaps with the projection of the pressure relief mechanism 13 along the first direction Z.

[0104] Optionally, in the first direction Z, the projection of the pressure relief mechanism 13 is located within the projection of the recess 211 .

[0105] As an example, there are multiple battery cells 10 , and one recess 211 may overlap with the pressure relief mechanism 13 of only one battery cell 10 in the first direction Z, or may overlap with the pressure relief mechanisms 13 of multiple battery cells 10 in the first direction Z at the same time.

[0106] When the battery cell 10 is in thermal runaway, the pressure relief mechanism 13 is activated and releases the substance of the battery cell 10, thereby reducing the risk of explosion of the battery cell 10. The recess 211 can avoid the pressure relief mechanism 13 when the pressure relief mechanism 13 is activated, thereby reducing the interference of the first box wall 21 on the pressure relief mechanism 13, increasing the pressure relief rate, and improving the reliability of the battery 2.

[0107] In addition, the recess 211 can also reduce the weight of the box 20 and improve the energy density of the battery 2 .

[0108] In some embodiments, the first direction Z may be parallel to the vertical direction. When the battery 2 is installed in an electrical device, the first box wall 21 may be located at the lower side of the battery cell 10 or at the upper side of the battery cell 10 .

[0109] In some embodiments, the pressure relief mechanism 13 includes a pressure relief area 131 , and the pressure relief area 131 includes a main body 131 a and a weak portion 131 b disposed around the main body 131 a .

[0110] The weak portion 131b is a relatively weak portion of the pressure relief mechanism 13, which is a portion that is easily broken, shattered, torn or opened. Exemplarily, the strength of the pressure relief mechanism 13 is less than the strength of the portion of the pressure relief mechanism 13 near the weak portion 131b.

[0111] The weak portion 131 b can be ruptured when the internal pressure or temperature of the battery cell 10 reaches a threshold value to release the substance in the outer case 11 .

[0112] In some examples, the present application may provide a groove, notch or other structure in a predetermined area of ​​the pressure relief mechanism 13 to reduce the local strength of the pressure relief mechanism 13, thereby forming a weak portion 131 b on the pressure relief mechanism 13. For example, a thinning process is performed on a predetermined area of ​​the pressure relief mechanism 13, and the thinned portion of the pressure relief mechanism 13 forms the weak portion 131 b. In other examples, a material process may be performed on a predetermined area of ​​the pressure relief mechanism 13, so that the strength of the area is weaker than that of other areas. In other words, the area is the weak portion 131 b.

[0113] In some examples, the weak portion 131b is annular and surrounds the main body 131a. In other examples, the two ends of the weak portion 131b are not closed, and the connecting line of the two ends of the weak portion 131b and the weak portion 131b together define the main body 131a, for example, the weak portion 131b is U-shaped.

[0114] After at least a portion of the weak portion 131 b is ruptured, the main body portion 131 a may be turned over or fly out under the internal pressure of the battery cell 10 .

[0115] In some embodiments, the pressure relief mechanism 13 only includes the pressure relief area 131 ; the pressure relief mechanism 13 and the end cover 112 are integrally formed, or the pressure relief mechanism 13 and the housing 111 are integrally formed.

[0116] In other embodiments, the pressure relief mechanism 13 further includes a connecting portion 132, and the weak portion 131 b connects the main body 131 a and the connecting portion 132. The connecting portion 132 is connected to the housing 11. For example, the connecting portion 132 is welded to the end cover 112 or the housing 111.

[0117] In some embodiments, in the first direction Z, the projection of the pressure relief area 131 is located within the projection of the recess 211 .

[0118] Exemplarily, the pressure relief area 131 may be a portion of the pressure relief mechanism 13 that is used to open and form a pressure relief channel.

[0119] When the weak portion 131b is broken, the recessed portion 211 can avoid the entire main body portion 131a and provide an accommodation space for the main body portion 131a, thereby reducing the shielding of the pressure relief channel by the main body portion 131a and improving the pressure relief efficiency.

[0120] In some embodiments, in the first direction Z, the projection of the pressure relief mechanism 13 is located within the projection of the recess 211 .

[0121] In some embodiments, the battery 2 further includes a protective layer 30, at least part of which is accommodated in the recess 211. In the first direction Z, the protective layer 30 at least partially overlaps with the pressure relief mechanism 13. The recess 211 includes an escape space G between the protective layer 30 and the pressure relief mechanism 13 in the first direction Z.

[0122] The protection layer 30 may be entirely accommodated in the recess 211 , or only partially accommodated in the recess 211 .

[0123] In some examples, in the first direction Z, the protective layer 30 partially overlaps with the pressure relief mechanism 13; in other words, the projection of the protective layer 30 along the first direction Z partially overlaps with the projection of the pressure relief mechanism 13 along the first direction Z. In other examples, in the first direction Z, the protective layer 30 completely overlaps with the pressure relief mechanism 13; in other words, the projection of the protective layer 30 along the first direction Z completely overlaps with the projection of the pressure relief mechanism 13 along the first direction Z. Optionally, in the first direction Z, the projection of the pressure relief mechanism 13 is located within the projection of the protective layer 30.

[0124] As an example, there are multiple battery cells 10 , and the protective layer 30 may overlap with the pressure relief mechanism 13 of only one battery cell 10 in the first direction Z, or may overlap with the pressure relief mechanisms 13 of multiple battery cells 10 in the first direction Z at the same time.

[0125] The substances released by the battery cell 10 in thermal runaway act on the protective layer 30, and the protective layer 30 can reduce the thermal shock on the first box wall 21 and reduce the heat transferred to the first box wall 21, thereby reducing the risk of the first box wall 21 being melted through and improving the reliability of the battery 2. The protective layer 30 only fills a part of the recess 211 and forms an escape space G, which can reduce the interference of the protective layer 30 with the pressure relief mechanism 13, increase the pressure relief rate, and improve the reliability of the battery 2.

[0126] In some embodiments, the protective layer 30 includes a high temperature resistant material. Exemplarily, the protective layer 30 includes at least one of mica, carbon fiber and aerogel. The protective layer 30 has good thermal shock resistance, thereby reducing the risk of the protective layer 30 being punched through. Optionally, the melting point of the protective layer 30 is greater than the melting point of the first box wall 21.

[0127] In some embodiments, the protective layer 30 includes an insulating material. For example, the protective layer 30 includes at least one of aluminum oxide and silicon nitride. The protective layer 30 can have an insulating effect, thereby reducing the risk of conduction between the battery cell 10 and the box body 20.

[0128] In some embodiments, the protective layer 30 includes a buffer material. Exemplarily, the protective layer 30 includes at least one of foam and silicone rubber. The protective layer 30 can play a buffering function. When the battery 2 is subjected to external impact, the battery cell 10 may contact the protective layer 30 due to vibration. The protective layer 30 can play a buffering role by deformation, thereby reducing the risk of damage to the battery cell 10 and improving reliability.

[0129] In some embodiments, the protective layer 30 is accommodated in the recess 211, thereby improving space utilization. During assembly, the recess 211 can also play a positioning role.

[0130] One recess 211 can accommodate one protective layer 30 or multiple protective layers 30 at the same time.

[0131] In some embodiments, the protection layer 30 is connected to the first box wall 21 to reduce the risk of the protection layer 30 falling off when the battery 2 is subjected to external impact.

[0132] In some embodiments, in the first direction Z, the depth of the recess 211 is greater than the thickness of the protective layer 30 , thereby forming an escape space G.

[0133] In some embodiments, the protective layer 30 may be bonded to the first box wall 21. For example, the protective layer 30 is bonded to the bottom surface 211a of the recess.

[0134] In some embodiments, the battery 2 includes a plurality of battery cells 10. In the first direction Z, the protective layer 30 overlaps with the pressure relief mechanisms 13 of at least two battery cells 10. The protective layer 30 can withstand the high-temperature substances released by at least two battery cells 10, thereby reducing the number of protective layers 30 and reducing the difficulty of assembly.

[0135] In some embodiments, the plurality of battery cells 10 are arranged in one or more rows.

[0136] In some embodiments, the battery 2 includes at least one battery column 10 a , and the battery column 10 a includes at least two battery cells 10 arranged along a second direction X. The first direction Z is perpendicular to the second direction X.

[0137] In the first direction Z, the protective layer 30 overlaps with the pressure relief mechanisms 13 of the battery cells 10 of the battery column 10 a. The protective layer 30 can separate the pressure relief mechanisms 13 of a column of battery cells 10 from the first box wall 21 .

[0138] In some embodiments, in the first direction Z, the projections of all the pressure relief mechanisms 13 of a battery column 10 a are located within the projection of a protective layer 30 .

[0139] In some embodiments, the battery 2 includes a plurality of battery columns 10 a , and the plurality of battery columns 10 a are arranged along a third direction Y. Exemplarily, the third direction Y is perpendicular to the first direction Z and the second direction X.

[0140] In some embodiments, there are multiple protective layers 30 , and the multiple protective layers 30 are arranged along the third direction Y. Exemplarily, the number of protective layers 30 is the same as the number of battery columns 10 a , and the multiple protective layers 30 are arranged in one-to-one correspondence with the multiple battery columns 10 a .

[0141] In some embodiments, the battery 2 includes a plurality of battery cells 10 . In the first direction Z, the recess 211 overlaps with the pressure relief mechanisms 13 of at least two battery cells 10 .

[0142] The recessed portion 211 can at least avoid the pressure relief mechanisms 13 of two battery cells 10 , thereby reducing the number of recessed portions 211 and lowering the difficulty of forming the first box wall 21 .

[0143] In some embodiments, the battery 2 includes at least one battery column 10 a, the battery column 10 a includes at least two battery cells 10 arranged along the second direction X, and the first direction Z is perpendicular to the second direction X. In the first direction Z, the projections of the pressure relief mechanisms 13 of the battery cells 10 of the battery column 10 a are all located within the projection of the recess 211 .

[0144] The recessed portion 211 can simultaneously avoid the pressure relief mechanisms 13 of a row of battery cells 10 arranged along the second direction X.

[0145] The recess 211 can also increase the exhaust space inside the box body 20 and improve the exhaust efficiency. When the battery cell 10 is in thermal runaway, the material discharged from the battery cell 10 can enter the recess 211, and the recess 211 can guide the material flow, thereby reducing the accumulation of the material, reducing the risk of the pressure relief channel of the battery cell 10 being blocked and the risk of the first box wall 21 being melted through, improving the exhaust efficiency, reducing the risk of sealing failure, and improving reliability.

[0146] Exemplarily, the recess 211 can guide particles discharged from the battery cell 10 , thereby reducing particles attached to other normal battery cells 10 , reducing the risk of failure and ignition of other normal battery cells 10 , and slowing down heat spread.

[0147] In some embodiments, the battery 2 further includes an explosion-proof valve 40 disposed on the box 20. After the explosion-proof valve 40 is activated, the material in the recess 211 can be discharged to the outside of the box 20, thereby reducing the risk of fire and explosion of the battery 2.

[0148] In some embodiments, a plurality of recesses 211 are arranged along the third direction Y, and a protective layer 30 is disposed in each recess 211 .

[0149] In some embodiments, the recess 211 extends along the second direction X. For example, a cross section of the recess 211 perpendicular to the second direction X may be rectangular, trapezoidal, triangular, semicircular, semi-elliptical or other shapes.

[0150] Exemplarily, there are multiple recesses 211 , and the cross-sections of the multiple recesses 211 may be the same or different.

[0151] In some embodiments, the first box wall 21 includes a wall body 212 and a protrusion 213 , wherein the protrusion 213 protrudes from a side of the wall body 212 away from the battery cell 10 , and the recess 211 is recessed relative to the surface of the wall body 212 facing the battery cell 10 and corresponds to the position of the protrusion 213 .

[0152] The wall body 212 and the protrusion 213 may be integrally formed, or connected by bonding, welding or other methods.

[0153] One protrusion 213 may be provided with one concave portion 211 correspondingly, or a plurality of concave portions 211 may be formed correspondingly.

[0154] By providing the convex portion 213, the limitation on the depth of the concave portion 211 can be reduced, so as to increase the distance between the first box wall 21 and the pressure relief mechanism 13 and improve the exhaust space. The concave portion 211 and the convex portion 213 form a concave-convex structure, which can improve the structural strength of the first box wall 21, and the concave-convex structure has little effect on the weight of the first box wall 21, thereby improving the reliability and energy density of the battery 2.

[0155] The concave-convex structure can improve the structural strength of the first box wall 21 and reduce abnormal noise generated by the battery 2 under vibration conditions.

[0156] In some embodiments, the wall body 212 and the protrusion 213 are integrally formed to reduce assembly processes and improve sealing performance.

[0157] Exemplarily, the first box wall 21 may be manufactured by a stamping process.

[0158] In some alternative embodiments, the wall body 212 and the protrusion 213 are welded.

[0159] In some embodiments, the area of ​​the top surface 213a of the convex portion is S1, and the area of ​​the pressure relief mechanism 13 is S2.

[0160] Exemplarily, the top surface 213 a of the convex portion may be a plane perpendicular to the first direction Z. The area of ​​the pressure relief mechanism 13 may be the area of ​​the projection of the pressure relief mechanism 13 along the first direction Z.

[0161] In some embodiments, the battery column 10 a includes n battery cells 10 , where n is a positive integer greater than or equal to 2. 1≤S1 / (n×S2)≤5.

[0162] In the embodiment of the present application, S1 / (n×S2) is limited to be less than or equal to 5, so as to reduce the weight increment of the battery 2 and reduce the range of the protruding area of ​​the first box wall 21, so as to facilitate the adaptation of the battery 2 to the vehicle. S1 / (n×S2) is limited to be greater than or equal to 1, so as to improve the ability of the concave portion 211 to collect and guide airflow and reduce the impact of the high-temperature material formed by the battery cells 10 on other components.

[0163] In some embodiments, S1 / (n×S2) is 1, 2, 3, 4 or 5.

[0164] In some embodiments, the energy density of the battery cell 10 is E Wh / kg, and the wall thickness of the protrusion 213 is d mm. 0.0016≤E / d≤0.005.

[0165] For example, d may be the minimum distance between the top surface 213a of the convex portion and the bottom surface 211a of the concave portion along the first direction Z. For example, the battery cell 10 has a standard label with capacity and platform voltage, E=(capacity×platform voltage) / weight of the battery cell.

[0166] In the embodiment of the present application, E / d is limited to 0.0016-0.005, which can balance the strength of the first box wall 21 and the weight of the first box wall 21, reduce the loss of energy density, and improve the overall structural strength of the battery 2.

[0167] In some embodiments, E / d is 0.0016, 0.002, 0.0025, 0.003, 0.0035, 0.004, 0.0045, or 0.005.

[0168] Figure 6 Schematic diagram of the first box wall and protective layer of a battery provided in some other embodiments of the present application.

[0169] Reference Figure 6 In some embodiments, the battery 2 includes a plurality of battery cells 10. There are a plurality of protective layers 30, and the plurality of protective layers 30 are arranged in one-to-one correspondence with the pressure relief mechanisms 13 of the plurality of battery cells 10.

[0170] The embodiment of the present application can flexibly set the protective layer 30 according to the position of the pressure relief mechanism 13, thereby reducing the overall usage of the protective layer 30 and improving the energy density of the battery cell 10.

[0171] In some embodiments, one protective layer 30 may be disposed corresponding to one recess 211 , or multiple protective layers 30 may be disposed simultaneously.

[0172] In some embodiments, a plurality of protective layers 30 are arranged in an array.

[0173] Exemplarily, the plurality of recesses 211 are arranged in one-to-one correspondence with the plurality of battery columns 10 a. At least two protection layers 30 arranged along the second direction X are arranged in each recess 211 .

[0174] Figure 7 A schematic diagram of a first box wall and a protective layer of a battery provided in some further embodiments of the present application.

[0175] like Figure 7 As shown, in some embodiments, there are multiple recesses 211 and multiple battery cells 10 , and the pressure relief mechanisms 13 of the multiple battery cells 10 are arranged in a one-to-one correspondence with the multiple recesses 211 .

[0176] In some embodiments, a protective layer 30 is disposed in each recess 211 .

[0177] In some embodiments, the number of the concave portions 211 is the same as the number of the convex portions 213, and they are arranged in a one-to-one correspondence. For example, adjacent convex portions 213 are arranged at intervals.

[0178] In some embodiments, the area of ​​the top surface 213a of the convex portion is S1, and the area of ​​the pressure relief mechanism 13 is S2. 1≤S1 / S2≤5.

[0179] Figure 8 A schematic diagram of a first box wall and a protective layer of a battery provided in some further embodiments of the present application; Fig. 9 for Figure 8 Enlarged diagram of the circle.

[0180] Reference Figure 8 and Fig. 9 In some embodiments, the first box wall 21 includes a plurality of recesses 211 spaced apart along the second direction X, and partitions 214 are disposed between adjacent recesses 211. By providing the partitions 214, the structural strength of the first box wall 21 can be improved.

[0181] In some embodiments, the partition plate 214 is provided with a channel 214a communicating with adjacent recesses 211. Exemplarily, the channel 214a includes a notch, a groove, a through hole or other structures.

[0182] When a battery cell 10 thermally runs away and releases high-temperature substances, the high-temperature substances can flow through the channels 214 a in the plurality of recesses 211 , thereby reducing the accumulation of the high-temperature substances.

[0183] Fig.10 A partial cross-sectional schematic diagram of a battery provided for some other embodiments of the present application.

[0184] like Fig.10As shown, in some embodiments, the first box wall 21 includes a wall body 212 and a cover plate 215, the wall body 212 has a through hole 2121, and the cover plate 215 is connected to the wall body 212 and covers the through hole 2121. The cover plate 215 and the hole wall of the through hole 2121 define a recess 211.

[0185] The cover plate 215 may be located outside the wall body 212 , or may be at least partially accommodated in the through hole 2121 .

[0186] The cover plate 215 may be in a flat plate shape, a curved plate shape, or other shapes.

[0187] The embodiment of the present application can simplify the molding process of the first box wall 21 .

[0188] In some embodiments, the cover plate 215 is a flat plate.

[0189] In some embodiments, the battery 2 further includes a protective layer 30, and the protective layer 30 is located on the inner side of the cover plate 215. Exemplarily, the protective layer 30 is bonded to the cover plate 215.

[0190] In some embodiments, at least a portion of the protection layer 30 is accommodated in the through hole 2121 , thereby improving space utilization.

[0191] In some embodiments, the through hole 2121 includes a first hole segment 2122 and a second hole segment 2123, the first hole segment 2122 is located on a side of the second hole segment 2123 away from the battery cell 10, and the first hole segment 2122 has a bottom surface 2124 surrounding the second hole segment 2123. The battery 2 also includes a protective layer 30, which is accommodated in the first hole segment 2122, and in the axial direction of the through hole 2121, the bottom surface 2124 at least partially overlaps with the protective layer 30.

[0192] The shapes of the first hole section 2122 and the second hole section 2123 may be the same or different. For example, the first hole section 2122 and the second hole section 2123 are both round holes, or one of the first hole section 2122 and the second hole section 2123 is a round hole and the other is a square hole.

[0193] Exemplarily, the axial direction of the through hole 2121 is parallel to the first direction Z.

[0194] The bottom surface 2124 of the first hole section 2122 can limit the protective layer 30 to reduce the risk of the protective layer 30 falling onto the pressure relief mechanism 13.

[0195] Fig.11 A partial cross-sectional schematic diagram of a battery provided in some other embodiments of the present application.

[0196] like Fig.11As shown, in some embodiments, at least a portion of the cover plate 215 is accommodated in the through hole 2121. The through hole 2121 can provide space for the cover plate 215, thereby reducing the maximum size of the first box wall 21 in the first direction Z and improving space utilization.

[0197] In some embodiments, the cover plate 215 is entirely accommodated in the through hole 2121 to further increase space utilization.

[0198] In some embodiments, the protection layer 30 is sandwiched between the cover plate 215 and the bottom surface 2124 .

[0199] Fig.12 Schematic diagram of an explosion of a battery provided in some other embodiments of the present application.

[0200] In some embodiments, the second box body 20b has a first cavity 22 and a second cavity 23 arranged at intervals, the battery cell 10 is accommodated in the first cavity 22, and the recess 211 connects the first cavity 22 and the second cavity 23. When the battery cell 10 thermally runs away, the recess 211 can introduce high-temperature substances into the second cavity 23, thereby reducing the impact of the high-temperature substances on other battery cells 10 and slowing down the spread of heat.

[0201] In some embodiments, the explosion-proof valve 40 is disposed on the outer wall of the second box body 20b for enclosing the second cavity 23. When the battery cell 10 thermally runs away, the explosion-proof valve 40 can discharge the material in the second cavity 23, thereby reducing the risk of battery 2 explosion and improving the reliability of battery 2.

[0202] According to some embodiments of the present application, the present application further provides an electric device, including the battery 2 of any of the above embodiments, the battery 2 is used to provide electric energy for the electric device. The electric device can be any of the above devices or systems using the battery 2.

[0203] Reference Figures 2 to 5 An embodiment of the present application provides a battery 2 , which includes a box body 20 , a plurality of battery cells 10 , and a plurality of protective layers 30 .

[0204] A pressure relief mechanism 13 is provided on one side of the battery cell 10 along the first direction Z. The box body 20 includes a first box wall 21 , and the pressure relief mechanism 13 faces the first box wall 21 along the first direction Z.

[0205] The battery 2 includes a plurality of battery columns 10a, each battery column 10a includes at least two battery cells 10 arranged along the second direction X, and the plurality of battery columns 10a are arranged along the third direction Y. The first direction Z, the second direction X, and the third direction Y are perpendicular to each other.

[0206] A plurality of recesses 211 are provided on one side of the first box wall 21 facing the pressure relief mechanism 13 . Each recess 211 extends along the second direction X. The plurality of recesses 211 are arranged at intervals along the third direction Y. The number of recesses 211 is the same as the number of battery arrays 10 a .

[0207] The plurality of recesses 211 are disposed in one-to-one correspondence with the plurality of battery columns 10 a. Specifically, in the first direction Z, the projections of the pressure relief mechanisms 13 of all the battery cells 10 of a battery column 10 a are located within the projection of a corresponding recess 211 .

[0208] Each recess 211 contains a protective layer 30; in the first direction Z, the projections of the pressure relief mechanisms 13 of all battery cells 10 of a battery column 10a are located within the projection of a corresponding protective layer 30. The recess 211 includes an escape space G between the protective layer 30 and the pressure relief mechanism 13 in the first direction Z.

[0209] The first box wall 21 includes a wall body 212 and a plurality of protrusions 213. Each protrusion 213 protrudes from a side of the wall body 212 away from the battery cell 10. The recesses 211 are recessed relative to the surface of the wall body 212 facing the battery cell 10. The plurality of recesses 211 and the plurality of protrusions 213 are arranged one by one.

[0210] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present 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, characterized in that: include: A battery cell, wherein a pressure relief mechanism is provided on one side of the battery cell along a first direction; A box body, wherein the battery cell is accommodated in the box body, the box body includes a first box wall, the pressure relief mechanism faces the first box wall along the first direction, a recess is provided on one side of the first box wall facing the pressure relief mechanism, and in the first direction, the recess at least partially overlaps with the pressure relief mechanism.

2. The battery according to claim 1, characterized in that The pressure relief mechanism comprises a pressure relief area, and the pressure relief area comprises a main body and a weak part arranged around the main body; In the first direction, a projection of the pressure relief area is located within a projection of the recessed portion.

3. The battery according to claim 1, characterized in that The battery further includes a protective layer, at least a portion of which is accommodated in the recess; In the first direction, the protective layer at least partially overlaps with the pressure relief mechanism; and the recess includes an escape space located between the protective layer and the pressure relief mechanism in the first direction.

4. The battery according to claim 3, characterized in that The protective layer is contained in the recess and connected to the first box wall; In the first direction, the depth of the recess is greater than the thickness of the protective layer.

5. The battery according to claim 3, characterized in that The battery comprises a plurality of battery cells; In the first direction, the protective layer overlaps with the pressure relief mechanisms of at least two of the battery cells.

6. The battery according to claim 3, characterized in that The battery comprises a plurality of battery cells; there are a plurality of protective layers, and the plurality of protective layers are arranged in one-to-one correspondence with the pressure relief mechanisms of the plurality of battery cells.

7. The battery according to any one of claims 1 to 6, characterized in that: The battery includes a plurality of battery cells; in the first direction, the recess overlaps with the pressure relief mechanisms of at least two of the battery cells.

8. The battery according to claim 7, characterized in that The battery comprises at least one battery column, wherein the battery column comprises at least two battery cells arranged along a second direction, wherein the first direction is perpendicular to the second direction; In the first direction, projections of the pressure relief mechanisms of the battery cells of the battery column are all located within the projection of the recess.

9. The battery according to any one of claims 1, 2, 3, 4 and 6, characterized in that There are a plurality of the recesses and a plurality of the battery cells, and the pressure relief mechanisms of the plurality of the battery cells are arranged in a one-to-one correspondence with the plurality of the recesses.

10. The battery according to any one of claims 1 to 6, characterized in that: The first box wall includes a plurality of recesses spaced apart along a second direction, a partition is provided between adjacent recesses, the second direction is perpendicular to the first direction; the partition is provided with a channel communicating with adjacent recesses.

11. The battery according to any one of claims 1 to 6, characterized in that: The first box wall includes a wall body and a convex portion, the convex portion protrudes from a side of the wall body away from the battery cell, and the concave portion is recessed relative to a surface of the wall body facing the battery cell and corresponds to the position of the convex portion.

12. The battery according to claim 11, characterized in that The wall body and the convex portion are integrally formed.

13. The battery according to any one of claims 1 to 6, characterized in that: The first box wall comprises a wall body and a cover plate, the wall body has a through hole, and the cover plate is connected to the wall body and covers the through hole; The cover plate and the hole wall of the through hole define the recess.

14. The battery according to claim 13, characterized in that At least a portion of the cover plate is received in the through hole.

15. The battery according to claim 13, characterized in that The through hole comprises a first hole segment and a second hole segment, the first hole segment is located at a side of the second hole segment away from the battery cell, and the first hole segment has a bottom surface surrounding the second hole segment; The battery further includes a protective layer, which is accommodated in the first hole segment. In the axial direction of the through hole, the bottom surface at least partially overlaps with the protective layer.

16. An electrical device, characterized in that: The invention comprises a battery according to any one of claims 1 to 15, wherein the battery is used to provide electrical energy.

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