Battery cell, battery device, and electric device

Abstract

The utility model provides a single battery, a battery device and a power utilization device, the single battery comprises a shell and an electrode assembly, the shell comprises a shell and an end cover, the shell is provided with an opening, the end cover covers the opening and is connected with the shell, the shell and the end cover are enclosed to form an accommodating cavity, and the electrode assembly is accommodated in the accommodating cavity. The shell comprises a first wall, and the first wall intersects with the end cover and comprises a wall body and a buffering part which are connected with each other. The buffer portion is flexibly connected between the wall body and the end cap in a deformable manner. According to the battery monomer provided by the invention, the expansion force of the electrode assembly or the acting force of an external load borne by the connecting part of the end cover and the shell is reduced, so that the risk of cracking of the connecting part of the end cover and the shell is reduced, and the reliability of the battery monomer is improved.

Description

Technical Field

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

[0002] Battery cells are widely used in electronic devices, such as mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc.

[0003] In the development of battery cell technology, in addition to improving the performance of battery cells, the reliability of battery cells is also an issue that needs to be considered. Therefore, how to improve the reliability of battery cells is an ongoing problem in battery technology. Summary of the Utility Model

[0004] The present application provides a battery cell, a battery device, and an electrical device to improve the reliability of the battery cell.

[0005] The present application is implemented by the following technical solutions:

[0006] In a first aspect, the battery cell provided by the present application includes a housing and an electrode assembly. The housing includes a housing body and an end cap. The housing body has an opening, and the end cap covers the opening and is connected to the housing body. The housing body and the end cap enclose a receiving cavity, and the electrode assembly is received in the receiving cavity. The housing body includes a first wall, the first wall intersects with the end cap, and includes a wall body and a buffer portion connected to each other. The buffer portion is flexibly connected between the wall body and the end cap in a deformable manner.

[0007] For the battery cell provided by the embodiment of the present application, by providing that the first wall of the housing body has a buffer portion and a wall body, and setting the buffer portion to be flexibly connected between the wall body and the end cap in a deformable manner, when the first wall is subjected to the expansion force of the electrode assembly or an external load, the buffer portion first deforms to buffer the external acting force, reduce the magnitude of the expansion force of the electrode assembly or the acting force of the external load borne by the connection between the end cap and the housing body, and further reduce the risk of cracking at the connection between the end cap and the housing body. Thus, it is beneficial to improve the reliability of the battery cell.

[0008] According to some embodiments of the present application, the wall body and the buffer portion are integrally formed.

[0009] In the above solution, it is beneficial to improve the connection strength between the wall body and the buffer portion, and it is beneficial to simplify the manufacturing process of the housing body.

[0010] According to some embodiments of the present application, the buffer portion includes an arc-shaped sub-portion, the arc-shaped sub-portion is connected to the wall body and is bent.

[0011] In the above solution, the buffer part is provided with an arc-shaped sub-part, and the arc-shaped sub-part is bent, which is beneficial to reducing the structural and technological difficulties of the buffer part, and is beneficial to improving the buffering effect of the buffer part on the expansion force of the electrode assembly, further reducing the magnitude of the force borne by the connection between the first wall and the end cover, and reducing the risk of connection failure between the first wall and the end cover.

[0012] According to some embodiments of the present application, the arc-shaped sub-part protrudes from the side of the wall body facing the accommodation cavity.

[0013] In the above solution, during the grouping process of the battery cells, the buffer part does not occupy additional external space of the battery cells, and the first walls of the battery cells can be attached to each other, which is convenient for the grouping of the battery cells and is beneficial to improving the energy density of the battery device.

[0014] According to some embodiments of the present application, along the thickness direction of the wall body, there is a first gap between the wall body and the electrode assembly, and the orthographic projection of the surface of the arc-shaped sub-part facing the electrode assembly on the end cover is located within the orthographic projection of the first gap on the end cover.

[0015] In the above solution, the orthographic projection of the surface of the arc-shaped sub-part facing the electrode assembly on the end cover is located within the orthographic projection of the first gap on the end cover, which is beneficial to reducing the risk of the buffer part scratching the electrode assembly during the process of loading the electrode assembly into the housing, and is beneficial to improving the smoothness of the electrode assembly entering the housing.

[0016] According to some embodiments of the present application, the buffer part further includes a transition sub-part, the transition sub-part is arc-shaped, and connects the wall body and the arc-shaped sub-part, and the centers of curvature of the transition sub-part and the arc-shaped sub-part are respectively located on both sides of the first wall.

[0017] In the above solution, setting the buffer part to further include a transition sub-part is beneficial to further improving the buffering effect of the buffer part on the expansion force of the electrode assembly, and is beneficial to improving the smoothness of the connection between the buffer part and the wall body, and is beneficial to reducing the phenomenon of stress concentration at the connection between the buffer part and the wall body, thereby being beneficial to improving the structural strength of the first wall.

[0018] According to some embodiments of the present application, the electrode assembly includes an electrode body and a tab, the tab is led out from the end of the electrode body, and the orthographic projection of the electrode body on the first wall is located inside the wall body.

[0019] In the above solution, it is beneficial to more fully exert the buffering effect of the buffer part on the expansion force of the battery cell, further reduce the destructive force borne by the connection between the first wall and the end cover, and reduce the risk of cracking between the first wall and the end cover.

[0020] According to some embodiments of the present application, the buffer part is strip-shaped.

[0021] In the above solution, when the buffer part is under the action of the expansion force of the electrode assembly, it can generate a greater deformation, which is beneficial to further improving the buffering effect of the buffer part on the expansion force of the electrode assembly, further reducing the magnitude of the force borne by the connection between the first wall and the end cover, and being conducive to further reducing the risk of cracking at the connection between the first wall and the end cover.

[0022] According to some embodiments of the present application, the electrode assembly includes two first surfaces opposite to each other in a first direction and two second surfaces opposite to each other in a second direction. The first surfaces connect the two second surfaces. The first direction, the second direction, and the thickness direction of the end cover are perpendicular to each other in pairs. The area of the first surface is larger than the area of the second surface, and at least one first surface is disposed opposite to the first wall.

[0023] In the above solution, it is more convenient to buffer the expansion force of the electrode assembly through the deformation of the buffer part of the first wall, thereby reducing the magnitude of the expansion force of the electrode assembly borne by the connection between the housing and the end cover, and reducing the risk of cracking at the connection between the housing and the end cover.

[0024] According to some embodiments of the present application, at least one second surface is disposed opposite to the first wall.

[0025] In the above solution, the amount of deformation that the buffer part of the first wall can generate is increased, and the deformation directions of different first walls can also intersect. When the electrode assembly expands, the buffer parts of multiple first walls can generate a greater amount of deformation and more diverse deformation directions, which is further beneficial for the buffer part to reduce the expansion force of the electrode assembly on the first wall by generating deformation, and further reducing the risk of cracking at the connection between the housing and the end cover.

[0026] According to some embodiments of the present application, the housing includes two first sub-walls opposite to each other in a first direction and two second sub-walls opposite to each other in a second direction. The first sub-walls connect the two second sub-walls. The first direction, the second direction, and the thickness direction of the end cover are perpendicular to each other in pairs. The surface area of the first sub-wall is larger than the surface area of the second sub-wall. At least one first sub-wall forms the first wall. In the above solution, during the process of generating deformation, the buffer part of the first wall can generate a greater deformation, which is beneficial to improving the buffering effect of the buffer part on the expansion force of the electrode assembly or external load, and further reducing the risk of cracking at the connection between the first wall and the end cover.

[0027] According to some embodiments of the present application, at least one second sub-wall forms the first wall.

[0028] In the above solution, the directions of the buffer parts of the first sub-wall and the second sub-wall for buffering the deformation of the electrode assembly intersect, which further improves the buffering effect of the housing on the expansion force of the electrode assembly, and further reduces the risk of cracking at the connection between the first wall and the end cover.

[0029] According to some embodiments of the present application, both of the two first sub-walls and the two second sub-walls include a first wall, the buffer portions of adjacent first sub-wall and second sub-wall are connected to each other, and a plurality of buffer portions enclose to form a ring shape.

[0030] In the above solution, during the process of the electrode assembly expanding towards any side, there is a corresponding buffer portion to buffer the acting force of the electrode assembly on the connection between the first wall and the end cover by deforming. Thus, it is beneficial to greatly reduce the risk of cracking at the connection between the first wall and the end cover.

[0031] According to some embodiments of the present application, the housing is welded to the end cover.

[0032] In the above solution, the welded connection has a high connection strength and good sealing performance. Thus, it is beneficial to improve the connection strength between the housing and the end cover, and is further beneficial to improve the sealing performance of the accommodation cavity, and further beneficial to improve the reliable performance of the battery cell.

[0033] According to some embodiments of the present application, the housing is welded to the end cover to form a weld mark, and the buffer portion is located on the side of the weld mark facing away from the end cover.

[0034] In the above solution, it is beneficial to reduce the magnitude of the expansion force of the electrode assembly borne at the welded connection between the first wall and the end cover, and further reduce the risk of cracking at the welded connection between the housing and the end cover.

[0035] According to some embodiments of the present application, the electrode assembly includes an electrode body and a tab, and the tab is led out from the end of the electrode body facing the end cover. The minimum distance between the edge of the orthographic projection of the electrode body on the first wall and the edge of the weld mark in the thickness direction of the end cover is d, and the maximum dimension of the buffer portion in the thickness direction of the end cover is L, and 0.8 ≤ L / d ≤ 1.

[0036] In the above solution, setting the orthographic projection of the electrode body on the first wall to be on the side of the buffer portion facing away from the end cover and setting 0.8 ≤ L / d ≤ 1 is beneficial to further improve the buffering effect of the buffer portion on the expansion force of the electrode assembly, and further reduce the risk of cracking at the connection between the housing and the end cover caused by the expansion of the electrode assembly.

[0037] In a second aspect, the battery device provided by the embodiments of the present application includes the battery cell provided by any of the above embodiments.

[0038] Since the battery device provided by the embodiments of the present application adopts the battery cell provided by any of the above embodiments, it has the same technical effects and will not be elaborated here.

[0039] In a third aspect, the electrical device provided by the embodiments of the present application includes the battery cell or the battery device provided by any of the above embodiments, and the battery device is used to provide electrical energy.

[0040] The power consumption device provided by the embodiment of the present application has the same technical effects because it adopts the battery cell or battery device provided by any of the above embodiments, and thus will not be elaborated here.

[0041] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. Brief Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1 Structural schematic diagram of the vehicle provided by the embodiment of the present application;

[0044] Figure 2 Structural schematic diagram of the battery device provided by the embodiment of the present application;

[0045] Figure 3 Structural schematic diagram of the battery module in the battery device provided by the embodiment of the present application;

[0046] Figure 4 Explosion structural schematic diagram of the battery cell provided by the embodiment of the present application;

[0047] Figure 5 Mechanical schematic diagram of the battery cell provided by the embodiment of the present application;

[0048] Figure 6 Cross-sectional structural schematic diagram of the battery cell provided by the embodiment of the present application.

[0049] In the drawings, the drawings are not necessarily drawn to scale.

[0050] Explanation of the reference numerals:

[0051] 1 - Vehicle;

[0052] 10 - Battery device; 111 - First sub - box body; 112 - Second sub - box body; 11 - Box body; 1a - Motor; 1b - Controller;

[0053] 20 - Battery module;

[0054] 30 - Battery cell; 31 - Housing; 31a - Accommodating cavity; 311 - Shell; 3111 - First sub - wall; 3112 - Second sub - wall; 311a - Opening; 312 - End cap; 313 - First wall; 3131 - Wall body; 3132 - Buffer part; 3132a - Arc - shaped sub - part; 3132b - Transition sub - part; 32 - Electrode assembly; 321 - Electrode body; 321a - First surface; 321b - Second surface; 322 - Tab; 33 - Welding mark; 34 - Electrode terminal

[0055] X - First direction; Y - Second direction. Detailed implementation manners

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0057] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs; the terms used in the description of the present application in the specification are only for the purpose of describing specific embodiments, and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above - mentioned drawings are intended to cover non - exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above - mentioned drawings are used to distinguish different objects, rather than to describe a specific order or primary - secondary relationship.

[0058] Referring to "embodiments" in the present application means that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments.

[0059] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "joined", and "attached" 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. 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.

[0060] In this application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0061] In this application, "a plurality of" means two or more (including two). Similarly, "a plurality of groups" means two or more groups (including two groups), and "a plurality of sheets" means two or more sheets (including two sheets).

[0062] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, parallel, or in a hybrid connection through a busbar component.

[0063] In some embodiments, the battery cell assembly is usually formed by arranging a plurality of battery cells. As an example, the battery cell assembly can be a battery module, and the battery module is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with cable ties.

[0064] In some embodiments, the battery apparatus can be a battery pack, and the battery pack includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body.

[0065] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box body by fixing the battery module in the box body.

[0066] As an example, the battery cell assembly can also be accommodated in the box body by directly fixing a plurality of battery cells to the box body.

[0067] In some embodiments, the box body can be part of the chassis structure of a vehicle. For example, part of the box body can become at least part of the floor of the vehicle, or part of the box body can become at least part of the crossbeam and longitudinal beam of the vehicle.

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

[0069] In the embodiments of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can be activated by charging after discharging and can be used continuously.

[0070] The battery cell may be, but is not limited to, a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc.

[0071] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive and negative electrodes and at the same time allow the active ions to pass through.

[0072] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0073] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0074] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, carbon electrode, carbon, nickel, or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0075] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as the positive electrode active material of the battery cell may also be used.

[0076] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0077] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, carbon electrode, carbon, nickel, or titanium, etc. may be used.

[0078] In some embodiments, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0079] As an example, the negative electrode active material can be a negative electrode active material for battery cells known in the art. As an example, the negative electrode active material can include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. The silicon-based materials can be selected from at least one of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based materials can be selected from at least one of elemental tin, tin oxides, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as the negative electrode active material of battery cells can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0080] In some embodiments, the separator is an insulating film. The present application does not particularly limit the type of the insulating film, and any well-known porous structure insulating film with good chemical stability and mechanical stability can be selected.

[0081] As an example, the main material of the insulating film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The insulating film can be a single-layer film or a multi-layer composite film, without particular limitation. When the insulating film is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surfaces of the positive and negative electrodes.

[0082] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions to transport ions and isolate the positive and negative electrodes.

[0083] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0084] In some embodiments, the electrode assembly is a stacked structure.

[0085] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0086] In some embodiments, the housing includes an end cap and a housing body. The housing body is provided with an opening, and the end cap closes the opening to form a sealed space for accommodating components such as the electrode assembly and the electrolyte. The housing body can be provided with one or more openings. One or more end caps can also be provided.

[0087] In some embodiments, at least one electrode terminal is provided on the outer casing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0088] In some embodiments, a pressure relief valve is provided on the outer casing. The pressure relief valve is used to release the internal pressure of the battery cell.

[0089] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch 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 multi-prismatic battery cell, and the multi-prismatic battery cell is, for example, a hexagonal prism battery cell, etc. There is no particular limitation in the embodiments of the present application.

[0090] The outer casing of the battery cell generally includes a housing and an end cap. During the manufacturing process of the battery cell, usually after the electrode assembly is installed in the housing, the end cap is then covered and connected to the housing. The end cap is usually connected to the housing by processes such as welding. The connection between the end cap and the housing is usually a relatively weak structure of the outer casing. However, during the cyclic operation of the battery cell, the electrode assembly will inevitably expand to a certain extent. The expansion force generated during the expansion process of the battery assembly will act on the housing, and then act on the connection between the housing and the end cap. As the expansion force of the electrode assembly increases and reaches the level of breaking the connection force between the housing and the end cap, it will cause the connection between the housing and the end cap of the battery cell to crack. Thus, it seriously affects the reliable performance of the battery cell.

[0091] In view of this, the battery cell provided by the present application includes an outer casing and an electrode assembly. The outer casing includes a housing and an end cap. The housing has an opening, and the end cap covers the opening and is connected to the housing. The housing and the end cap enclose a receiving cavity, and the electrode assembly is received in the receiving cavity. The housing includes a first wall, the first wall is connected to the end cap, and includes a wall body and a buffer portion. The buffer portion is flexibly connected between the wall body and the end cap in a deformable manner.

[0092] For the battery cell provided by the embodiments of the present application, by providing the first wall of the housing with a buffer portion and a wall body, and setting the buffer portion to be flexibly connected between the wall body and the end cap in a deformable manner, so that when the first wall is subjected to the expansion force of the electrode assembly, or when the first wall is subjected to external loads such as vibration or impact force of external loads, the buffer portion first deforms to buffer the expansion force of the electrode assembly or the action of external loads, reduce the magnitude of the force borne at the connection between the end cap and the first wall, and further reduce the risk of cracking at the connection between the end cap and the first wall. Thus, it is beneficial to improve the reliable performance of the battery cell.

[0093] The technical solutions described in the embodiments of the present application are applicable to battery cells, battery devices including battery cells, and electrical devices using battery devices.

[0094] The battery device disclosed in the embodiments of the present application can be but is not limited to being used in electrical devices such as vehicles, ships, or aircraft. The power supply system of the electrical device can be composed of the battery device disclosed in the present application.

[0095] The embodiments of the present application provide an electrical device using a battery device as a power source. The electrical device can be but is not limited to mobile phones, tablet computers, laptop computers, electric toys, electric tools, electric bicycles, electric motorcycles, electric vehicles, ships, spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0096] For the convenience of description in the following embodiments, a vehicle is taken as an example of an electrical device in an embodiment of the present application for illustration.

[0097] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of vehicle 1 provided by the embodiments of the present application. Vehicle 1 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 vehicle, or an extended-range vehicle, etc. A battery device 10 is disposed inside vehicle 1. The battery device 10 can be disposed at the bottom, head, or tail of vehicle 1. The battery device 10 can be used for power supply of vehicle 1. For example, the battery device 10 can be used as an operating power source of vehicle 1 for the electrical system of vehicle 1, such as for the working power requirements during the start-up, navigation, and operation of vehicle 1.

[0098] Vehicle 1 may further include a controller 1b and a motor 1a. The controller 1b is used to control the battery device 10 to supply power to the motor 1a, such as for the working power requirements during the start-up, navigation, and driving of vehicle 1.

[0099] In some embodiments of the present application, the battery device 10 can not only be used as an operating power source of vehicle 1 but also as a driving power source of vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for vehicle 1.

[0100] Please refer to Figure 2 and Figure 3 , Figure 2 which is a schematic structural diagram of the battery device 10 provided by the embodiments of the present application, Figure 3Schematic diagram of the structure of the battery module 20 in the battery device 10 provided by the embodiment of the present application. The battery device 10 includes a box body 11 and battery cells 30, and the battery cells 30 are accommodated in the box body 11. Among them, the box body 11 is used to provide an accommodation space for the battery cells 30, and the box body 11 can adopt various structures. In some embodiments, the box body 11 may include a first sub-box body 111 and a second sub-box body 112. The first sub-box body 111 and the second sub-box body 112 cover each other, and the first sub-box body 111 and the second sub-box body 112 jointly define an accommodation space for accommodating the battery cells 30. The second sub-box body 112 may be a hollow structure with one end open, and the first sub-box body 111 may be a plate-like structure. The first sub-box body 111 covers the open side of the second sub-box body 112 so that the first sub-box body 111 and the second sub-box body 112 jointly define an accommodation space; the first sub-box body 111 and the second sub-box body 112 may also both be hollow structures with one side open, and the open side of the first sub-box body 111 covers the open side of the second sub-box body 112.

[0101] In the battery device 10, there may be multiple battery cells 30, and the multiple battery cells 30 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 30. The multiple battery cells 30 can be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 30 is accommodated in the box body 11; of course, in the battery device 10, multiple battery cells 30 can also be first connected in series, in parallel, or in a mixed connection to form the form of a battery module 20, and then multiple battery modules 20 are connected in series, in parallel, or in a mixed connection to form a whole and are accommodated in the box body 11. The battery device 10 may further include other structures. For example, the battery device 10 may further include a busbar component for realizing the electrical connection among the multiple battery cells 30.

[0102] Among them, the battery cell 30 can be a secondary battery or a primary battery; the battery cell 30 can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.

[0103] Please refer to Figure 4 , Figure 4 Schematic diagram of the explosion structure of the battery cell 30 provided by the embodiment of the present application. As Figure 4 shown, the battery cell 30 includes a housing 31, an electrode assembly 32, and electrode terminals 34. The housing 31 includes a shell 311 and an end cap 312. The shell 311 has an opening 311a, and the end cap 312 closes the opening 311a to isolate the internal environment of the battery cell 30 from the external environment.

[0104] The housing 311 is a component for cooperating with the end cap 312 to form the internal environment of the battery cell 30. Among them, the formed internal environment can be used to accommodate the electrode assembly 32, the electrolyte, and other components. The housing 311 and the end cap 312 can be independent components. The housing 311 can be of various shapes and sizes. Specifically, the shape of the housing 311 can be determined according to the specific shape and size of the electrode assembly 32. The material of the housing 311 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0105] The end cap 312 is a component that covers the opening 311a of the housing 311 to isolate the internal environment of the battery cell 30 from the external environment. Without limitation, the shape of the end cap 312 can be adapted to the shape of the housing 311 to cooperate with the housing 311. Optionally, the end cap 312 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 312 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 30 to have higher structural strength and improved reliability. Functional components such as the electrode terminal 34 can be provided on the end cap 312. The electrode terminal 34 can be used to electrically connect to the electrode assembly 32 for outputting or inputting the electrical energy of the battery cell 30. The material of the end cap 312 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this. In some embodiments, an insulating structure can also be provided on the inner side of the end cap 312. The insulating structure can be used to isolate the electrical connection components in the housing 311 from the end cap 312 to reduce the risk of short circuit. Exemplarily, the insulating structure can be plastic, rubber, etc.

[0106] The electrode assembly 32 is a component in the battery cell 30 where an electrochemical reaction occurs. The housing 311 can contain one or more electrode assemblies 32. The electrode assembly 32 is mainly formed by winding or laminating a positive electrode plate and a negative electrode plate, and usually an isolation film is provided between the positive electrode plate and the negative electrode plate. The isolation film is used to separate the positive electrode plate and the negative electrode plate to prevent internal short circuit 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 electrode body 321 of the electrode assembly 32, and the parts of the positive electrode plate and the negative electrode plate without active substances respectively constitute the electrode tabs 322. The positive electrode tab and the negative electrode tab can be located at one end of the electrode body 321 together or at both ends of the electrode body 321 respectively. During the charge and discharge process of the battery cell 30, the positive active substance and the negative active substance react with the electrolyte, and the electrode tabs 322 are connected to the electrode terminals 34 to form a current loop.

[0107] In the first aspect, as Figure 4 and Figure 5As shown in the figure, the battery cell 30 provided by the present application includes a housing 31 and an electrode assembly 32. The housing 31 includes a shell 311 and an end cap 312. The shell 311 has an opening 311a. The end cap 312 covers the opening 311a and is connected to the shell 311. The shell 311 and the end cap 312 enclose a receiving cavity 31a, and the electrode assembly 32 is received in the receiving cavity 31a. The shell 311 includes a first wall 313. The first wall 313 is connected to the end cap 312 and includes a wall body 3131 and a buffer portion 3132. The buffer portion 3132 is flexibly connected between the wall body 3131 and the end cap 312 in a deformable manner.

[0108] The housing 31 includes a shell 311 and an end cap 312. The shell 311 has an opening 311a. Optionally, the shell 311 may have one opening 311a, or the shell 311 may have two openings 311a. The two openings 311a may be disposed opposite to or adjacent to each other. Correspondingly, the housing 31 may have one or two end caps 312, and the end cap 312 is disposed in one-to-one correspondence with the opening 311a of the shell 311.

[0109] The end cap 312 is connected to the shell 311. Optionally, the end cap 312 and the end of the shell 311 may be connected together by welding, bonding or other means to form a sealed receiving cavity 31a.

[0110] The shell 311 includes a first wall 313. Optionally, the shell 311 may include one, two, three or four first walls 313, which can be set according to actual needs. The first wall 313 is connected to the end cap 312, and the first wall 313 may be disposed adjacent to the end cap 312.

[0111] The electrode assembly 32 is received in the receiving cavity 31a. During the cyclic operation, the electrode assembly 32 will inevitably expand. The expansion of the electrode assembly 32 acts on the first wall 313, generating an expansion force on the first wall 313. In addition, during the operation of the battery cell 30, it will also inevitably be subjected to external impacts or vibrations and other external loads, and the external loads will also reach the connection between the first wall 313 and the end cap 312.

[0112] The first wall 313 includes a wall body 3131 and a buffer portion 3132. Optionally, the wall body 3131 and the buffer portion 3132 may be integrally formed, and only the corresponding structure and shape are processed at the position corresponding to the buffer portion 3132. Of course, it is also possible to set the wall body 3131 and the buffer portion 3132 to be formed separately and then connected together, which can be set according to actual needs.

[0113] When the electrode assembly 32 expands or is under the action of an external load, it will exert a force on the first wall 313. Since the buffer portion 3132 is connected to the wall body 3131, the expansion force of the electrode assembly 32 on the first wall 313 will be transmitted to the wall body 3131 and the buffer portion 3132. Since the buffer portion 3132 is flexibly connected to the wall body 3131 and the end cover 312 in a deformable manner, the buffer portion 3132 can undergo flexible deformation under the action of the expansion force of the electrode assembly 32. Then, the buffer portion 3132 can buffer the expansion force of the electrode assembly 32 or an external load through its own deformation, reducing the risk that the expansion force of the electrode assembly 32 or the external load acts on the connection between the housing 311 and the end cover 312 and causes the connection between the housing 311 and the end cover 312 to fail.

[0114] Optionally, the buffer portion 3132 can be disposed opposite to the electrode body 321 of the electrode assembly 32, or the buffer portion 3132 can be offset from the electrode body 321 of the electrode assembly 32. The buffer portion 3132 can be disposed on one side of the first wall 313 close to the end cover 312.

[0115] Under the action of the expansion force of the electrode assembly 32 or an external load, the deformation generated by the buffer portion 3132 can be elastic deformation or plastic deformation. The form of the deformation generated by the buffer portion 3132 can be bending deformation, tensile deformation, etc.

[0116] The structural form of the buffer portion 3132 can be any form that can generate deformation under the action of an external force. The buffer portion 3132 can be curved, concave, convex, etc.

[0117] Optionally, during the expansion of the electrode assembly 32, under the action of the expansion force of the electrode assembly 32, the wall body 3131 can generate deformation to further relieve the expansion force of the electrode assembly 32, or the wall body 3131 does not generate deformation, and only the deformation of the buffer portion 3132 buffers the expansion force of the electrode assembly 32.

[0118] Optionally, one first wall 313 can have one, two or more buffer portions 3132, and the specific positions of different buffer portions 3132 can be set as needed.

[0119] The battery cell 30 provided by the embodiment of the present application is provided with a buffer portion 3132 and a wall body 3131 on the first wall 313 of the housing 311, and the buffer portion 3132 is deformably and flexibly connected between the wall body 3131 and the end cap 312. When the first wall 313 is subjected to the expansion force of the electrode assembly 32 or an external load, the buffer portion 3132 deforms first to buffer the external acting force, reduce the magnitude of the expansion force of the electrode assembly 32 or the acting force of the external load borne by the connection between the end cap 312 and the housing 311, and further reduce the risk of cracking at the connection between the end cap 312 and the housing 311. In this way, it is beneficial to improve the reliable performance of the battery cell 30.

[0120] In some embodiments, as Figure 4 and Figure 5 shown, the wall body 3131 and the buffer portion 3132 are integrally formed.

[0121] If the wall body 3131 and the buffer portion 3132 are integrally formed, the buffer portion 3132 can be formed by processes such as stamping. In this way, it is beneficial to improve the connection strength between the wall body 3131 and the buffer portion 3132 and simplify the manufacturing process of the housing 311.

[0122] In some embodiments, as Figure 5 described, the buffer portion 3132 includes an arc-shaped sub-portion 3132a. One end of the arc-shaped sub-portion 3132a is connected to the wall body 3131, and the other end of the arc-shaped sub-portion 3132a is connected to the end cap 312.

[0123] The buffer portion 3132 includes an arc-shaped sub-portion 3132a. The arc-shaped sub-portion 3132a is connected to the wall body 3131. The arc-shaped sub-portion 3132a can be integrally formed with the wall body 3131 and can be formed into a curved arc-shaped sub-portion 3132a through processes such as stamping. The arc-shaped sub-portion 3132a can be bent towards the side of the accommodation cavity 31a, or the arc-shaped sub-portion 3132a can be bent away from the accommodation cavity 31a. Of course, it can also be set that a part of the arc-shaped sub-portion 3132a is bent towards the accommodation cavity 31a and the other part is bent away from the accommodation cavity 31a. The buffer portion 3132 can include one or more arc-shaped sub-portion 3132a. The bending directions, curvature radii, etc. of different arc-shaped sub-portion 3132a can be the same or different and can be set according to actual needs.

[0124] Optionally, the surface of the arc-shaped sub-portion 3132a can be a part of a cylindrical shape, or the surface of the arc-shaped sub-portion 3132a can be a part of an ellipsoidal shape or a spherical shape.

[0125] The arc-shaped sub-part 3132a is bent. When the arc-shaped sub-part 3132a is under the action of the expansion force of the electrode assembly 32, the arc-shaped sub-part 3132a can, by means of deformation, provide more space for the expansion of the electrode assembly 32, such as the increase of the radius of curvature at various parts of the arc-shaped sub-part 3132a, so that the electrode assembly 32 can have more expansion space, reduce the action of the expansion force of the electrode assembly 32 on the first wall 313, and further reduce the action of the expansion force of the electrode assembly 32 on the connection between the first wall 313 and the end cover 312.

[0126] After the electrode assembly 32 expands and recovers, the acting force of the electrode assembly 32 on the arc-shaped sub-part 3132a decreases, and the arc-shaped sub-part 3132a can recover its deformation under the action of its own elastic force. When the electrode assembly 32 expands again during subsequent cyclic operation, the arc-shaped sub-part 3132a can deform again.

[0127] Therefore, setting the buffer part 3132 to include the arc-shaped sub-part 3132a and setting the arc-shaped sub-part 3132a to be bent is beneficial to reducing the structural and technological difficulty of the buffer part 3132, and is beneficial to improving the buffering effect of the buffer part 3132 on the expansion force of the electrode assembly 32, further reducing the magnitude of the force borne by the connection between the first wall 313 and the end cover 312, and reducing the risk of connection failure between the first wall 313 and the end cover 312.

[0128] In some embodiments, as Figure 4 and Figure 6 described, the arc-shaped sub-part 3132a protrudes towards the side of the accommodation cavity 31a with respect to the wall body 3131.

[0129] During the forming process of the arc-shaped sub-part 3132a, it can be bent towards the side of the accommodation cavity 31a.

[0130] In this way, during the grouping process of the battery cells 30, the buffer part 3132 does not occupy additional external space of the battery cells 30, and the first walls 313 of the battery cells 30 can be mutually attached, which is convenient for the grouping of the battery cells 30 and is beneficial to improving the energy density of the battery device 10.

[0131] In some embodiments, along the thickness direction of the wall body 3131, there is a first gap between the wall body 3131 and the electrode assembly 32, and the orthographic projection of the surface of the arc-shaped sub-part 3132a facing the electrode assembly 32 on the end cover 312 is located within the orthographic projection of the first gap on the end cover 312.

[0132] If the orthographic projection of the surface of the arc-shaped sub-part 3132a facing the electrode assembly 32 on the end cap 312 is within the orthographic projection of the first gap on the end cap 312, then the orthographic projection of the surface of the arc-shaped sub-part 3132a facing the electrode assembly 32 in the thickness direction of the end cap falls within the first gap. During the process of installing the electrode assembly 32 into the housing 311, it is beneficial to reduce the risk of the buffer part 3132 scraping the electrode assembly 32 and improve the smoothness of the electrode assembly 32 entering the housing.

[0133] In some embodiments, as Figure 6 shown, the buffer part 3132 further includes a transition sub-part 3132b. The transition sub-part 3132b is arc-shaped and connects the wall body 3131 and the arc-shaped sub-part 3132a. The centers of curvature of the transition sub-part 3132b and the arc-shaped sub-part 3132a are respectively located on both sides of the first wall 313.

[0134] The transition sub-part 3132b can be circular arc-shaped, and the radius of curvature of the transition sub-part 3132b can be the same as or different from the radius of curvature of the arc-shaped sub-part 3132a. Since the transition sub-part 3132b is curved, during the expansion process of the electrode assembly 32, the transition sub-part 3132b can also provide a certain buffering effect for the expansion of the electrode assembly 32 by deforming.

[0135] And since the centers of curvature of the transition sub-part 3132b and the arc-shaped sub-part 3132a are respectively located on both sides of the first wall 313, the connection between the transition sub-part 3132b and the arc-shaped sub-part 3132a and the wall body 3131 is smoother, which is beneficial to reducing the phenomenon of stress concentration at the connection between the buffer part 3132 and the wall body 3131.

[0136] Therefore, setting the buffer part 3132 to also include the transition sub-part 3132b is beneficial to further improving the buffering effect of the buffer part 3132 on the expansion force of the electrode assembly 32, improving the smoothness of the connection between the buffer part 3132 and the wall body 3131, reducing the phenomenon of stress concentration at the connection between the buffer part 3132 and the wall body 3131, and thus beneficial to improving the structural strength of the first wall 313.

[0137] In some embodiments, as Figure 4 and Figure 6 shown, the electrode assembly 32 includes an electrode body 321 and a tab 322. The tab 322 is led out from the end of the electrode body 321, and the orthographic projection of the electrode body 321 on the first wall 313 is located inside the wall body 3131.

[0138] The orthographic projection of the electrode body 321 on the first wall 313 is located inside the wall body 3131, so the orthographic projection of the electrode body 321 on the first wall 313 does not overlap with the buffer portion 3132. In other words, the buffer portion 3132 is not disposed opposite to the electrode body 321. Also, since the orthographic projection of the electrode body 321 on the first wall 313 is located on the side of the buffer portion 3132 facing away from the end cap 312, when the electrode assembly 32 expands, the expansion force of the electrode assembly 32 needs to pass through the buffer portion 3132 during the process of being transmitted to the connection between the first wall 313 and the end cap 312. Specifically, the expansion force of the electrode assembly 32 will first be transmitted to the wall body 3131, and then from the wall body 3131 to the buffer portion 3132. The buffer portion 3132 can reduce the magnitude of the expansion force of the electrode assembly 32 borne by the first wall 313 by means of deformation, and then it will be transmitted to the connection between the first wall 313 and the end cap 312.

[0139] Therefore, with such a setting, it is beneficial to more fully exert the buffering effect of the buffer portion 3132 on the expansion force of the battery cell 30, further reduce the destructive force borne by the connection between the first wall 313 and the end cap 312, and reduce the risk of cracking between the first wall 313 and the end cap 312.

[0140] In some embodiments, as Figure 4 and Figure 5 shown, the buffer portion 3132 is strip-shaped.

[0141] If the buffer portion 3132 is strip-shaped, the buffer portion 3132 can extend a preset distance along the extending direction. The extending direction of the buffer portion 3132 can be perpendicular to the thickness direction of the corresponding first wall 313 and the thickness direction of the end cap 312 respectively. Of course, the extending direction of the buffer portion 3132 can also be other directions. The distance that the buffer portion 3132 extends can be the same as the dimension of the first wall 313 along the extending direction. When the buffer portion 3132 includes an arc-shaped sub-portion 3132a, the arc-shaped sub-portion 3132a can be semi-cylindrical.

[0142] It can be understood that when the housing 311 includes a plurality of first walls 313, the extending directions of the buffer portions 3132 of different first walls 313 are not the same. Therefore, the extending directions of the buffer portions 3132 of different first walls 313 are not the same.

[0143] Since the buffer portion 3132 is strip-shaped, when the buffer portion 3132 is acted on by the expansion force of the electrode assembly 32, it can generate greater deformation, which is beneficial to further improving the buffering effect of the buffer portion 3132 on the expansion force of the electrode assembly 32, further reducing the magnitude of the force borne by the connection between the first wall 313 and the end cap 312, and being beneficial to further reducing the risk of cracking at the connection between the first wall 313 and the end cap 312.

[0144] In some embodiments, as Figure 4 shown, the electrode assembly 32 includes two first surfaces 321a opposite to each other along the first direction X and two second surfaces 321b opposite to each other along the second direction Y. The first surfaces 321a connect the two second surfaces 321b. The first direction X, the second direction Y, and the thickness direction of the end cap 312 are perpendicular to each other in pairs. The area of the first surface 321a is larger than the area of the second surface 321b. At least one first surface 321a is disposed opposite to the first wall 313.

[0145] Optionally, any one of the first surfaces 321a can be disposed opposite to the first wall 313, or both of the first surfaces 321a can be disposed opposite to the first wall 313.

[0146] Since the area of the first surface 321a of the electrode assembly 32 is larger than the area of the second surface 321b, during the expansion of the electrode assembly 32, it is easier to generate an expansion force in the direction perpendicular to the first surface 321a on the first surface 321a. By disposing at least one first surface 321a opposite to the first wall 313, the expansion force of the electrode assembly 32 can be buffered more conveniently through the deformation of the buffer portion 3132 of the first wall 313, thereby reducing the magnitude of the expansion force of the electrode assembly 32 borne by the connection between the housing 311 and the end cap 312 and reducing the risk of cracking at the connection between the housing 311 and the end cap 312.

[0147] In some embodiments, as Figure 4 shown, at least one second surface 321b is disposed opposite to the first wall 313.

[0148] Optionally, any one of the second surfaces 321b can be disposed opposite to the first wall 313, or both of the second surfaces 321b can be disposed opposite to the first wall 313.

[0149] Since the first surface 321a and the second surface 321b can intersect, the first wall 313 opposite to the first surface 321a and the first wall 313 opposite to the second surface 321b can intersect. Thus, the deformation directions of the buffer portions 3132 of the first wall 313 opposite to the first surface 321a and the first wall 313 opposite to the second surface 321b can intersect. In this way, the amount of deformation that the buffer portion 3132 of the first wall 313 can generate is increased, and the deformation directions of different first walls 313 can also intersect. When the electrode assembly 32 expands, the buffer portions 3132 of multiple first walls 313 can generate a larger amount of deformation and more diverse deformation directions, which is further beneficial for the buffer portion 3132 to reduce the expansion force of the electrode assembly 32 on the first wall 313 by generating deformation, and further reduces the risk of cracking at the connection between the housing 311 and the end cap 312.

[0150] In some embodiments, such as Figure 4 and Figure 5 shown, the housing 311 includes two first sub-walls 3111 opposite to each other along the first direction X and two second sub-walls 3112 opposite to each other along the second direction Y. The first sub-walls 3111 connect the two second sub-walls 3112. The first direction X, the second direction Y, and the thickness direction of the end cap 312 are perpendicular to each other pairwise. The surface area of the first sub-walls 3111 is greater than the surface area of the second sub-walls 3112. At least one of the first sub-walls 3111 forms the first wall 313.

[0151] Since the surface area of the first sub-walls 3111 is greater than the surface area of the second sub-walls 3112, the dimension of the first sub-walls 3111 along the second direction Y is greater than the dimension of the second sub-walls 3112 along the first direction X.

[0152] Since the first sub-walls 3111 form the first wall 313, at least a part of the first sub-walls 3111 is the first wall 313. The first sub-walls 3111 include a buffer portion 3132 and a wall body 3131. Optionally, one of the first sub-walls 3111 can be set to form the first wall 313, or two of the first sub-walls 3111 can be set to both form the first wall 313.

[0153] Since the surface area of the first sub-walls 3111 is greater than the surface area of the second sub-walls 3112, and at least one of the first sub-walls 3111 forms the first wall 313, during the process of deformation of the buffer portion 3132 of the first wall 313, a greater deformation can be generated, which is beneficial to improving the buffering effect of the buffer portion 3132 on the expansion force of the electrode assembly 32 or an external load, and further reducing the risk of cracking at the connection between the first wall 313 and the end cap 312.

[0154] In some embodiments, such as Figure 4 and Figure 5 shown, at least one of the second sub-walls 3112 forms the first wall 313.

[0155] Since the second sub-walls 3112 form the first wall 313, at least a part of the second sub-walls 3112 is the first wall 313. In other words, the buffer portion 3132 and the wall body 3131 are part of the second sub-walls 3112.

[0156] Optionally, one of the second sub-walls 3112 can be set to form the first wall 313, or two of the second sub-walls 3112 can be set to both form the first wall 313.

[0157] Thus, at least one first sub-wall 3111 and at least one second sub-wall 3112 are both formed with a first wall 313. The first sub-wall 3111 and the second sub-wall 3112 intersect. Then, the deformation directions of the buffer portions 3132 of the first sub-wall 3111 and the second sub-wall 3112 intersect with respect to the electrode assembly 32, which is beneficial to further improving the buffering effect of the housing 311 on the expansion force of the electrode assembly 32, and further beneficial to reducing the risk of cracking at the connection between the first wall 313 and the end cap 312.

[0158] In some embodiments, as Figure 4 and Figure 5 shown, the two first sub-walls 3111 and the two second sub-walls 3112 both include a first wall 313. The buffer portions 3132 of the adjacent first sub-wall 3111 and second sub-wall 3112 are connected to each other, and the plurality of buffer portions 3132 enclose a ring shape.

[0159] Thus, the buffer portions 3132 of the two first sub-walls 3111 and the two second sub-walls 3112 are connected end to end to form a ring shape. Then, along the circumferential direction of the electrode assembly 32, there is a corresponding buffer portion 3132. During the expansion of the electrode assembly 32 towards any side, there is a corresponding buffer portion 3132 that buffers the acting force of the electrode assembly 32 on the connection between the first wall 313 and the end cap 312 by deforming. Thus, it is beneficial to further reduce the risk of cracking at the connection between the first wall 313 and the end cap 312.

[0160] Optionally, the connection manner between the housing 311 and the end cap 312 can be snap connection, riveting, welding, or bonding, etc., and can be specifically selected according to needs.

[0161] In some embodiments, as Figure 6 shown, the housing 311 and the end cap 312 are welded together.

[0162] Welding connection has a relatively high connection strength and good sealing performance. Thus, it is beneficial to improve the connection strength between the housing 311 and the end cap 312, and beneficial to improving the sealing performance of the accommodation cavity 31a, and further beneficial to improving the reliable performance of the battery cell 30.

[0163] In some embodiments, as Figure 6 shown, the housing 311 and the end cap 312 are welded together to form a weld mark 33, and the buffer portion 3132 is located on the side of the weld mark 33 facing away from the end cap 312.

[0164] The buffer portion 3132 is located on the side of the welding mark 33 facing away from the end cap 312, so that the buffer portion 3132 does not overlap with the area where the welding mark 33 is located. Thus, under the action of the expansion force of the electrode assembly 32, the expansion force of the electrode assembly 32 on the first wall 313 needs to be transmitted to the area where the welding mark 33 is located through the buffer portion 3132. After the expansion force is transmitted to the buffer portion 3132, the buffer portion 3132 will first reduce the magnitude of the expansion force of the electrode assembly 32 on the first wall 313 by means of deformation, which is beneficial to reducing the magnitude of the expansion force of the electrode assembly 32 borne by the welded joint between the first wall 313 and the end cap 312, and further reducing the risk of cracking at the welded joint between the housing 311 and the end cap 312.

[0165] In some embodiments, as Figure 4 and Figure 6 shown, the electrode assembly 32 includes an electrode body 321 and a tab 322, and the tab 322 is led out from the end of the electrode body 321 facing the end cap 312. The minimum distance between the edge of the orthographic projection of the electrode body 321 on the first wall 313 and the edge of the welding mark 33 in the thickness direction of the end cap 312 is d, and the maximum dimension of the buffer portion 3132 in the thickness direction of the end cap 312 is L, where 0.8 ≤ L / d ≤ 1.

[0166] Optionally, L / d can be 0.8, 0.85, 0.9, 0.95 or 1, etc.

[0167] Thus, the buffer portion 3132 is located between the welding mark 33 and the orthographic projection of the electrode body 321 on the first wall 313, and the dimension of the buffer portion 3132 in the thickness direction of the end cap 312 is relatively large. Thus, the expansion force of the electrode assembly 32 on the first wall 313 needs to be transmitted to the connection between the first wall 313 and the end cap 312 through the buffer portion 3132, and the deformation that the buffer portion 3132 can generate is also relatively large.

[0168] The inventors found through systematic analysis and research that setting the orthographic projection of the electrode body 321 on the first wall 313 on the side of the buffer portion 3132 facing away from the end cap 312 and setting 0.8 ≤ L / d ≤ 1 is beneficial to further improving the buffering effect of the buffer portion 3132 on the expansion force of the electrode assembly 32, and further reducing the risk of cracking at the connection between the housing 311 and the end cap 312 caused by the expansion of the electrode assembly 32.

[0169] In a second aspect, the battery device 10 provided in the embodiments of the present application includes the battery cell 30 provided in any of the above embodiments.

[0170] Since the battery device 10 provided in the embodiments of the present application adopts the battery cell 30 provided in any of the above embodiments, it has the same technical effects and will not be elaborated here.

[0171] In a third aspect, the electrical device provided by the embodiments of the present application includes the battery cell 30 or the battery device 10 provided by any of the above embodiments, and the battery device 10 is used to provide electrical energy.

[0172] Since the electrical device provided by the embodiments of the present application adopts the battery device 10 or the battery cell 30 provided by any of the above embodiments, it has the same technical effects and will not be elaborated here.

[0173] In some embodiments, such as Figures 4 to 6As shown, the battery cell 30 includes a housing 31 and an electrode assembly 32. The housing 31 includes a shell 311 and an end cap 312. The shell 311 has an opening 311a, and the end cap 312 covers the opening 311a and is welded to the shell 311. The shell 311 and the end cap 312 enclose a receiving cavity 31a, and the electrode assembly 32 is received in the receiving cavity 31a. The shell 311 includes a first wall 313, the first wall 313 is connected to the end cap 312, and includes a wall body 3131 and a buffer portion 3132. The wall body 3131 and the buffer portion 3132 are integrally formed. The buffer portion 3132 is flexibly connected between the wall body 3131 and the end cap 312 in a deformable manner. The buffer portion 3132 is strip-shaped and includes an arc-shaped sub-portion 3132a and a transition sub-portion 3132b. One end of the arc-shaped sub-portion 3132a is connected to the wall body 3131, and the other end of the arc-shaped sub-portion 3132a is connected to the end cap 312. The arc-shaped sub-portion 3132a protrudes toward the side of the receiving cavity 31a with respect to the wall body 3131. The transition sub-portion 3132b is curved and connects the wall body 3131 and the arc-shaped sub-portion 3132a. The centers of curvature of the transition sub-portion 3132b and the arc-shaped sub-portion 3132a are located on both sides of the first wall 313 respectively. Along the thickness direction of the wall body 3131, there is a first gap between the wall body 3131 and the electrode assembly 32. The projection of the surface of the arc-shaped sub-portion 3132a facing the electrode assembly 32 on the end cap 312 is located within the projection of the first gap on the end cap 312. The electrode assembly 32 includes two first surfaces 321a opposite to each other in the first direction X and two second surfaces 321b opposite to each other in the second direction Y. The first surfaces 321a connect the two second surfaces 321b. The first direction X, the second direction Y, and the thickness direction of the end cap 312 are perpendicular to each other in pairs. The area of the first surface 321a is larger than the area of the second surface 321b. At least one first surface 321a is disposed opposite to the first wall 313, and at least one second surface 321b is disposed opposite to the first wall 313. The shell 311 and the end cap 312 are welded to form a weld mark 33, and the buffer portion 3132 is located on the side of the weld mark 33 facing away from the end cap 312. The electrode assembly 32 includes an electrode body 321 and a tab 322. The tab 322 is led out from the end of the electrode body 321 facing the end cap 312. The minimum distance between the edge of the projection of the electrode body 321 on the first wall 313 and the edge of the weld mark 33 in the thickness direction of the end cap 312 is d, and the maximum dimension of the buffer portion 3132 in the thickness direction of the end cap 312 is L, and 0.8 ≤ L / d ≤ 1.

[0174] The battery cell 30 provided by the embodiment of the present application is configured such that the first wall 313 of the housing 311 has a buffer portion 3132 and a wall body 3131, and the buffer portion 3132 is deformably and flexibly connected between the wall body 3131 and the end cap 312. When the first wall 313 is subjected to the expansion force of the electrode assembly 32 or an external load, the buffer portion 3132 deforms first to buffer the expansion force of the electrode assembly 32 or the acting force of the external load, reducing the magnitude of the external force borne at the connection between the end cap 312 and the housing 311, thereby reducing the risk of cracking at the connection between the end cap 312 and the housing 311. Thus, it is beneficial to improve the reliability of the battery cell 30.

[0175] Although the present application has been described with reference to the preferred embodiments, various modifications 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 various technical features mentioned in each embodiment can be combined in any way. 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 cell, characterized in that: include: The housing comprises a shell and an end cover, wherein the shell has an opening, the end cover covers the opening and is connected to the shell, and the shell and the end cover enclose a receiving cavity; An electrode assembly, accommodated in the accommodation cavity; Wherein, the shell includes a first wall, the first wall is connected to the end cover, and includes a wall body and a buffer portion, and the buffer portion is deformably and flexibly connected between the wall body and the end cover.

2. The battery cell according to claim 1, characterized in that: The wall body and the buffer portion are integrally formed.

3. The battery cell according to claim 1, characterized in that: The buffer portion includes an arc-shaped sub-portion, one end of the arc-shaped sub-portion is connected to the wall body, and the other end of the arc-shaped sub-portion is connected to the end cover.

4. The battery cell according to claim 3, characterized in that: The arc-shaped sub-portion is arranged to protrude relative to a side of the wall body toward the accommodating cavity.

5. The battery cell according to claim 4, characterized in that: Along the thickness direction of the wall body, there is a first gap between the wall body and the electrode assembly. The orthographic projection of the surface of the arc-shaped sub-portion facing the electrode assembly on the end cover is located within the orthographic projection of the first gap on the end cover.

6. The battery cell according to claim 3, characterized in that: The buffer portion further includes a transition sub-portion, which is curved and connects the wall body and the arc-shaped sub-portion, and the curvature centers of the transition sub-portion and the arc-shaped sub-portion are respectively located on both sides of the first wall.

7. The battery cell according to claim 1, characterized in that: The electrode assembly comprises an electrode body and a pole ear, wherein the pole ear is led out from the end of the electrode body, and the orthographic projection of the electrode body on the first wall is located inside the wall body.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The buffer portion extends in a long strip shape.

9. The battery cell according to any one of claims 1 to 7, characterized in that: The electrode assembly comprises two first surfaces opposite to each other in a first direction and two second surfaces opposite to each other in a second direction, the first surface connects the two second surfaces, the first direction, the second direction and the thickness direction of the end cap are perpendicular to each other, and the area of ​​the first surface is greater than the area of ​​the second surface; At least one of the first surfaces is disposed opposite to the first wall.

10. The battery cell according to claim 9, characterized in that: At least one of the second surfaces is disposed opposite to the first wall.

11. The battery cell according to any one of claims 1 to 7, characterized in that: The shell comprises two first sub-walls opposite to each other in a first direction and two second sub-walls opposite to each other in a second direction, the first sub-wall connects the two second sub-walls, the first direction, the second direction and the thickness direction of the end cover are perpendicular to each other, and the surface area of ​​the first sub-wall is greater than the surface area of ​​the second sub-wall; At least one of the first sub-walls forms the first wall.

12. The battery cell according to claim 11, characterized in that: At least one of the second sub-walls forms the first wall.

13. The battery cell according to claim 12, characterized in that: The two first sub-walls and the two second sub-walls each include the first wall, the buffer portions of adjacent first sub-walls and second sub-walls are connected to each other, and a plurality of the buffer portions are enclosed in a ring shape.

14. The battery cell according to any one of claims 1 to 7, characterized in that: The shell is connected to the end cover by welding.

15. The battery cell according to claim 14, characterized in that: The shell body is connected to the end cover by welding to form a weld mark, and the buffer portion is located on a side of the weld mark facing away from the end cover.

16. The battery cell according to claim 15, characterized in that: The electrode assembly comprises an electrode body and a pole ear, wherein the pole ear is led out from the end of the electrode body toward the end cover; The minimum distance between the edge of the orthographic projection of the electrode body on the first wall and the edge of the weld mark along the thickness direction of the end cover is d, the maximum dimension of the buffer portion along the thickness direction of the end cover is L, and 0.8≤L / d≤1.

17. A battery device, characterized in that: Comprising the battery cell according to any one of claims 1 to 16.

18. An electrical device, characterized in that: Comprising the battery device as claimed in claim 17, the battery device is used to provide electrical energy.

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