Battery cell, battery device, and electric apparatus

Abstract

The present application provides a battery cell, a battery device, and an electric apparatus. The battery cell comprises a casing and an electrode assembly; the casing comprises a casing body and an end cover; the casing body is provided with an opening; the end cover covers the opening and is connected to the casing body; the casing body and the end cover define an accommodating cavity; the electrode assembly is accommodated in the accommodating cavity. The casing body comprises a first wall, and the first wall intersects with the end cover and comprises a wall body and a cushioning portion that are connected to each other. The cushioning portion is flexibly connected between the wall body and the end cover in a deformable mode. The battery cell provided by the present application is conducive to reducing the expansion force of the electrode assembly or the action force of an external load borne at the connecting position of the end cover and the casing body, thereby reducing the risk of cracking at the connecting position of the end cover and the casing body. In this way, the reliability of the battery cell is improved.

Description

Battery cell, battery device and electric device Cross-reference to Related Applications

[0001] This application claims priority to Chinese Patent Application CN202421755942.6, filed on July 23, 2024, entitled “Battery cell, battery device and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a battery cell, a battery device and an electric device. BACKGROUND

[0003] Batteries are widely used in electronic devices, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools, etc.

[0004] In the development of battery cell technology, in addition to improving the performance of battery cells, the reliability of battery cells is also a problem that needs to be considered. Therefore, how to improve the reliability of battery cells is a continuous improvement problem in battery technology. SUMMARY

[0005] The present application provides a battery cell, a battery device and an electric device to improve the reliability of the battery cell.

[0006] The present application is achieved by the following technical solutions:

[0007] In a first aspect, the battery cell provided by the present application includes a shell and an electrode assembly. The shell includes a shell body and an end cover. The shell body has an opening, and the end cover covers the opening and is connected to the shell body. The shell body and the end cover form a containing cavity. The electrode assembly is contained in the containing cavity. The shell body includes a first wall that intersects the end cover and includes a wall body and a buffer portion that are connected to each other. The buffer portion is flexibly connected between the wall body and the end cover.

[0008] The battery cell provided by the present application has a first wall of the shell body with a buffer portion and a wall body, and the buffer portion is flexibly connected between the wall body and the end cover. When the first wall is subjected to the expansion force of the electrode assembly or external load, the buffer portion deforms first to buffer the external force, reducing the expansion force of the electrode assembly or the force of the external load on the connection between the end cover and the shell body, thereby reducing the risk of the connection between the end cover and the shell body cracking. This helps to improve the reliability of the battery cell.

[0009] According to some embodiments of the present application, the wall body and the buffer portion are integrally formed.

[0010] In the above scheme, the connection strength between the wall body and the buffer portion is improved, and the manufacturing process of the shell is simplified.

[0011] According to some embodiments of the present application, the buffer portion comprises an arc-shaped sub-portion, which is connected to the wall body and is arranged in a curved manner.

[0012] In the above scheme, the arc-shaped sub-portion is arranged, and the arc-shaped sub-portion is arranged in a curved manner, which reduces the structural and process difficulty of the buffer portion, improves the buffering effect of the buffer portion on the expansion force of the electrode assembly, further reduces the force borne by the connection between the first wall and the end cover, and reduces the risk of connection failure of the first wall and the end cover.

[0013] According to some embodiments of the present application, the arc-shaped sub-portion is arranged protruding towards the side of the wall body facing the accommodating cavity.

[0014] In the above scheme, during the grouping of the battery monomers, the buffer portion does not occupy additional space outside the battery monomers, and the first walls of the battery monomers can be attached to each other, facilitating the grouping of the battery monomers and improving the energy density of the battery device.

[0015] According to some embodiments of the present application, along the thickness direction of the wall body, the wall body and the electrode assembly have a first gap, and the surface of the arc-shaped sub-portion on the side facing the electrode assembly is located within the projection of the first gap on the end cover.

[0016] In the above scheme, the surface of the arc-shaped sub-portion on the side facing the electrode assembly is located within the projection of the first gap on the end cover, which reduces the risk of scratching the electrode assembly by the buffer portion during the process of loading the electrode assembly into the shell, and improves the smoothness of the electrode assembly into the shell.

[0017] According to some embodiments of the present application, the buffer portion further comprises a transition sub-portion, which is arranged in an arc shape and connects the wall body and the arc-shaped sub-portion, and the centers of curvature of the transition sub-portion and the arc-shaped sub-portion are located on the two sides of the first wall, respectively.

[0018] In the above scheme, the buffer portion further comprises a transition sub-portion, which further improves the buffering effect of the buffer portion on the expansion force of the electrode assembly, improves the smoothness of the connection between the buffer portion and the wall body, reduces the stress concentration phenomenon at the connection between the buffer portion and the wall body, and further improves the structural strength of the first wall.

[0019] According to some embodiments of the present application, the electrode assembly comprises an electrode body and a tab, the tab is led out from the end of the electrode body, and the projection of the electrode body on the first wall is located inside the wall body.

[0020] In the above scheme, the buffer part can more fully buffer the expansion force of the battery monomer, further reduce the destructive force borne by the connection between the first wall and the end cover, and reduce the risk of cracking of the first wall and the end cover.

[0021] According to some embodiments of the present application, the buffer part is in the shape of a long strip.

[0022] In the above scheme, the buffer part can produce greater deformation under the action of the expansion force of the electrode assembly, which is beneficial to further improve the buffering effect of the buffer part on the expansion force of the electrode assembly, further reduce the force borne by the connection between the first wall and the end cover, and reduce the risk of cracking of the connection between the first wall and the end cover.

[0023] According to some embodiments of the present application, the electrode assembly includes two first surfaces opposite in a first direction and two second surfaces opposite in a second direction, the first surfaces connecting the two second surfaces, the first direction, the second direction, and the thickness direction of the end cover being perpendicular to each other, the area of the first surface being greater than the area of the second surface, and at least one first surface being arranged opposite to the first wall.

[0024] In the above scheme, the expansion force of the electrode assembly can be more conveniently buffered by the deformation of the buffer part of the first wall, thereby reducing the size of the expansion force of the electrode assembly borne by the connection between the shell and the end cover, and reducing the risk of cracking of the connection between the shell and the end cover.

[0025] According to some embodiments of the present application, at least one second surface is arranged opposite to the first wall.

[0026] In the above scheme, the amount of deformation that the buffer part of the first wall can produce is improved, and the directions of deformation of different first walls can also intersect. In the case of expansion of the electrode assembly, the deformation amount that the buffer parts of the plurality of first walls can produce is greater, and the deformation directions that the buffer parts can produce are more diverse, which is further beneficial to the buffer part to reduce the expansion force of the electrode assembly on the first wall by producing deformation, and further reduce the risk of cracking of the connection between the shell and the end cover.

[0027] According to some embodiments of the present application, the shell includes two first sub-walls opposite in a first direction and two second sub-walls opposite in a second direction, the first sub-walls connecting the two second sub-walls, the first direction, the second direction, and the thickness direction of the end cover being perpendicular to each other, and the surface area of the first sub-wall being greater than the surface area of the second sub-wall. At least one first sub-wall forms a first wall. In the above scheme, the buffer part of the first wall can produce greater deformation during deformation, which is beneficial to improve the buffering effect of the buffer part on the expansion force of the electrode assembly or external load, and further reduce the risk of cracking of the connection between the first wall and the end cover.

[0028] According to some embodiments of the present application, the at least one second sub-wall forms the first wall.

[0029] In the above scheme, the directions in which the buffer portions of the first sub-wall and the second sub-wall buffer the deformation of the electrode assembly intersect, and the buffering effect of the shell on the expansion force of the electrode assembly is further improved, and the risk of cracking at the connection between the first wall and the end cover is further reduced.

[0030] According to some embodiments of the present application, the two first sub-walls and the two second sub-walls each include the first wall, and the buffer portions of adjacent first sub-walls and second sub-walls are connected to each other, and the plurality of buffer portions are enclosed in a ring shape.

[0031] In the above scheme, during the expansion of the electrode assembly towards any side, the corresponding buffer portion buffers the force of the electrode assembly on the connection between the first wall and the end cover by deforming, and thus the risk of cracking at the connection between the first wall and the end cover is reduced to a greater extent.

[0032] According to some embodiments of the present application, the shell and the end cover are welded and connected.

[0033] In the above scheme, the welded connection has high connection strength and good sealing performance, and thus the connection strength of the shell and the end cover is improved, the sealing performance of the accommodation cavity is improved, and the reliability of the battery monomer is further improved.

[0034] According to some embodiments of the present application, the shell and the end cover are welded and connected to form a weld mark, and the buffer portion is located on the side of the weld mark away from the end cover.

[0035] In the above scheme, the size of the expansion force of the electrode assembly borne by the welded connection between the first wall and the end cover is reduced, and thus the risk of cracking at the welded connection between the shell and the end cover is reduced.

[0036] 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 towards the end cover. The minimum distance between the edge of the first wall in the projection and the edge of the weld mark along the thickness direction of the end cover is d, the maximum size of the buffer portion along the thickness direction of the end cover is L, and 0.8≤L / d≤1.

[0037] In the above scheme, the projection of the electrode body on the first wall is located on the side of the buffer portion away from the end cover, and 0.8≤L / d≤1 is set, which 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 shell and the end cover due to the expansion of the electrode assembly.

[0038] In a second aspect, the battery device provided by the embodiments of the present application includes the battery monomer provided by any of the above embodiments.

[0039] The battery device provided by the embodiments of the present application has the same technical effects as the battery monomer provided by any of the above embodiments, and thus will not be described here again.

[0040] In a third aspect, the battery monomer or the battery device provided by the embodiments of the present application is used in the power utilization device.

[0041] The power utilization device provided by the embodiments of the present application has the same technical effects as the battery monomer or the battery device provided by any of the above embodiments, and thus will not be described here again.

[0042] Additional aspects and advantages of the present application will be described in the description that follows, will become apparent to those skilled in the art, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0044] FIG. 1 is a structural schematic diagram of a vehicle provided by the embodiments of the present application;

[0045] FIG. 2 is a structural schematic diagram of a battery device provided by the embodiments of the present application;

[0046] FIG. 3 is a structural schematic diagram of a battery module in the battery device provided by the embodiments of the present application;

[0047] FIG. 4 is an exploded structural schematic diagram of a battery monomer provided by the embodiments of the present application;

[0048] FIG. 5 is a structural schematic diagram of a battery monomer provided by the embodiments of the present application;

[0049] FIG. 6 is a sectional structural schematic diagram of a battery monomer provided by the embodiments of the present application.

[0050] In the drawings, the drawings are not necessarily drawn to scale.

[0051] Explanation of reference signs:

[0052] 1-vehicle;

[0053] 10-battery device; 111-first sub-box body; 112-second sub-box body; 11-box body; 1a-motor; 1b-controller;

[0054] 20-battery module;

[0055] 30 - battery cell; 31 - outer shell; 31a - accommodating cavity; 311 - shell body; 3111 - first sub-wall; 3112 - second sub-wall; 311a - opening; 312 - end cover; 313 - first wall; 3131 - wall body; 3132 - buffer portion; 3132a - arc-shaped sub-portion; 3132b - transition sub-portion; 32 - electrode assembly; 321 - electrode body; 321a - first surface; 321b - second surface; 322 - tab; 33 - welding mark; 34 - electrode terminal;

[0056] X - first direction; Y - second direction. DETAILED DESCRIPTION

[0057] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0058] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, and are not intended to describe a particular order or primary and secondary relationship.

[0059] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0060] In the description of the present application, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0061] The term "and / or" in the present application is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0062] The "multiple" appearing in the present application refers to two or more (including two), and similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0063] The battery apparatus mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, parallel or mixed connection through a busbar component.

[0064] 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, which is formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0065] In some embodiments, the battery apparatus can be a battery pack, which includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body.

[0066] 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.

[0067] As an example, the battery cell assembly can also be accommodated in the box body by directly fixing a plurality of battery cells in the box body.

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

[0069] In some embodiments, the battery device can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, and the like.

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

[0071] The battery cell can be, but is not limited to, a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, and the like.

[0072] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode and can prevent the positive and negative electrodes from shorting while allowing the active ions to pass through.

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

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

[0075] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, stainless steel, stainless steel, copper, aluminum, carbon, nickel, or titanium, etc. with silver plating on the surface can be used. The composite current collector can include a high molecular material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a high molecular material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

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

[0077] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0078] As an example, the negative electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver plating surface treatment, stainless steel with a silver plating surface treatment, stainless steel, copper, aluminum, a carbon electrode, carbon, nickel, titanium, or the like can be employed.

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

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

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

[0082] As an example, the main material of the separation film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic. The separation film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separation film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separation film can be a separate member located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

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

[0084] In some embodiments, the electrode assembly is a roll structure. The positive electrode sheet and the negative electrode sheet are rolled to form the roll structure.

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

[0086] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and 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.

[0087] In some embodiments, the housing includes a cover and a shell, the shell is provided with an opening, and the cover closes the opening to form a sealed space for accommodating substances such as the electrode assembly and electrolyte. The shell can be provided with one or more openings. The cover can also be provided with one or more openings.

[0088] In some embodiments, at least one electrode terminal is provided on the housing, 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 cover or on the shell.

[0089] In some embodiments, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cell.

[0090] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or other shaped battery cells, the prismatic battery cell includes a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, etc., and the embodiments of the present application are not particularly limited.

[0091] The housing of the battery cell generally includes a shell and a cover. During the manufacturing process of the battery cell, the electrode assembly is generally loaded into the shell, and then the cover is closed and connected to the shell. The cover is generally connected to the shell by welding or other processes. The connection between the cover and the shell is generally the weaker structure of the housing. However, during the cyclic operation of the battery cell, the electrode assembly inevitably expands to a certain extent. The expansion force generated during the expansion of the electrode assembly acts on the shell, and then acts on the connection between the shell and the cover. As the expansion force of the electrode assembly increases, the expansion force of the electrode assembly reaches the level of destroying the connecting force between the shell and the cover, which causes the connection between the shell and the cover of the battery cell to crack. Thus, the reliability of the battery cell is seriously affected.

[0092] Therefore, the battery cell provided by the present application includes a housing and an electrode assembly. The housing includes a shell and a cover. The shell has an opening, and the cover is closed on the opening and connected to the shell. The shell and the cover enclose a receiving cavity, and the electrode assembly is accommodated in the receiving cavity. The shell includes a first wall connected to the cover and including a wall body and a buffer portion. The buffer portion is flexibly connected between the wall body and the cover.

[0093] The battery monomer provided by the embodiment of the application has the first wall of the shell body provided with the buffer part and the wall body, and the buffer part is flexibly connected between the wall body and the end cover, so that the buffer part is first deformed under the action of the expansion force of the electrode assembly or the action of the external load such as the vibration or impact force of the external load, the buffer part is first deformed under the action of the expansion force of the electrode assembly or the action of the external load, the force borne by the connection part of the end cover and the first wall is reduced, and the risk of the connection part of the end cover and the first wall being cracked is reduced, so that the reliability of the battery monomer is improved.

[0094] The technical solution described in the embodiment of the application is suitable for a battery monomer, a battery device including the battery monomer, and a power consumption device using the battery device.

[0095] The battery device disclosed in the embodiment of the application can be used in a power consumption device such as a vehicle, a ship or an aircraft, but is not limited to this. The power supply system of the power consumption device can be composed of the battery device disclosed in the application.

[0096] The embodiment of the application provides a power consumption device using the battery device as a power supply. The power consumption device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric vehicle, a ship, a spacecraft and the like. The electric toy can include a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy and an electric aircraft toy, and the spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft.

[0097] The following embodiments take a vehicle as an example for convenience of description.

[0098] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1 provided by an embodiment of the application. The vehicle 1 can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric vehicle, a hybrid electric vehicle or a range extended vehicle. The vehicle 1 is internally provided with a battery device 10, which can be arranged at the bottom, the head or the tail of the vehicle 1. The battery device 10 can be used for power supply of the vehicle 1, for example, the battery device 10 can be used as an operating power supply of the vehicle 1, which is used for the working power demand of the circuit system of the vehicle 1, for example, the starting, navigation and running of the vehicle 1.

[0099] The vehicle 1 can further include a controller 1b and a motor 1a, and the controller 1b is used to control the battery device 10 to supply power to the motor 1a, for example, the working power demand of the vehicle 1 during starting, navigation and driving.

[0100] In some embodiments of this application, the battery device 10 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0101] Please refer to Figures 2 and 3. Figure 2 is a structural schematic diagram of the battery device 10 provided in an embodiment of this application, and Figure 3 is a structural schematic diagram of the battery module 20 in the battery device 10 provided in an embodiment of this application. The battery device 10 includes a housing 11 and a battery cell 30, with the battery cell 30 housed within the housing 11. The housing 11 provides a space for accommodating the battery cell 30, and the housing 11 can adopt various structures. In some embodiments, the housing 11 may include a first sub-housing 111 and a second sub-housing 112, which overlap each other, and together define a space for accommodating the battery cell 30. The second sub-box 112 can be a hollow structure with one end open, and the first sub-box 111 can be a plate-like structure. The first sub-box 111 covers the opening side of the second sub-box 112 so that the first sub-box 111 and the second sub-box 112 together define the accommodating space. Alternatively, the first sub-box 111 and the second sub-box 112 can both be hollow structures with one side open, and the opening side of the first sub-box 111 covers the opening side of the second sub-box 112.

[0102] In the battery device 10, there can be multiple battery cells 30, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 30 are connected in both series and parallel configurations. Multiple battery cells 30 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 30 is housed within the housing 11. Alternatively, the battery device 10 can also consist of multiple battery cells 30 first connected in series, parallel, or in a mixed manner to form a battery module 20, and then multiple battery modules 20 connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 11. The battery device 10 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 30.

[0103] 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 to these.

[0104] Please refer to Figure 4, which is an exploded structural diagram of the battery cell 30 provided in this embodiment. As shown in Figure 4, 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.

[0105] The housing 311 is a component used to cooperate with the end cap 312 to form the internal environment of the battery cell 30, wherein the formed internal environment can accommodate the electrode assembly 32, electrolyte, and other components. The housing 311 and the end cap 312 can be independent components. The housing 311 can have 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 housing 311 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0106] End cap 312 refers to a component that covers the opening 311a of housing 311 to isolate the internal environment of battery cell 30 from the external environment. The shape of end cap 312 can be adapted to the shape of housing 311 to fit it. Optionally, end cap 312 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 312 is not easily deformed under pressure and impact, giving battery cell 30 higher structural strength and improved reliability. Functional components such as electrode terminals 34 can be provided on end cap 312. Electrode terminals 34 can be used for electrical connection with electrode assembly 32 to output or input electrical energy to battery cell 30. The material of end cap 312 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating structure may be provided on the inner side of the end cap 312. The insulating structure can be used to isolate the electrical connection components within the housing 311 from the end cap 312 to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, etc.

[0107] Electrode assembly 32 is the component in the battery cell 30 where electrochemical reactions occur. The housing 311 may contain one or more electrode assemblies 32. The electrode assembly 32 is mainly formed by winding or stacking positive and negative electrode plates, and typically a separator is provided between the positive and negative electrode plates to separate them and prevent internal short circuits. The portions of the positive and negative electrode plates containing active material constitute the electrode body 321 of the electrode assembly 32, while the portions of the positive and negative electrode plates without active material each constitute a tab 322. The positive and negative tabs can be located together at one end of the electrode body 321 or separately at both ends of the electrode body 321. During the charging and discharging process of the battery cell 30, the positive and negative active materials react with the electrolyte, and the tabs 322 connect to the electrode terminals 34 to form a current loop.

[0108] In a first aspect, as shown in Figures 4 and 5, the battery cell 30 provided in this 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 closes to 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 within the receiving cavity 31a. The shell 311 includes a first wall 313, which is connected to the end cap 312, and includes a wall body 3131 and a buffer portion 3132. The buffer portion 3132 is deformably and flexibly connected between the wall body 3131 and the end cap 312.

[0109] The outer casing 31 includes a housing 311 and end caps 312. The housing 311 has an opening 311a. Optionally, the housing 311 may have one opening 311a, or the housing 311 may have two openings 311a, which may be arranged opposite to or adjacent to each other. Correspondingly, the outer casing 31 may have one or two end caps 312, which are arranged in a one-to-one correspondence with the openings 311a of the housing 311.

[0110] End cap 312 is connected to housing 311. Optionally, the ends of end cap 312 and housing 311 can be connected together by welding or adhesive bonding to form a sealed receiving cavity 31a.

[0111] The housing 311 includes a first wall 313. Optionally, the housing 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 cover 312, so the first wall 313 can be arranged adjacent to the end cover 312.

[0112] The electrode assembly 32 is housed within the receiving cavity 31a. During cyclic operation, the electrode assembly 32 will inevitably expand, and this expansion will act on the first wall 313, generating an expansion force on the first wall 313. In addition, the battery cell 30 will inevitably be subjected to external loads such as impacts or vibrations during operation, and these external loads will also reach the connection between the first wall 313 and the end cap 312.

[0113] The first wall 313 includes a wall body 3131 and a buffer portion 3132. Optionally, the wall body 3131 and the buffer portion 3132 can be integrally formed, with the buffer portion 3132 being processed into corresponding structures and shapes at corresponding positions. Of course, the wall body 3131 and the buffer portion 3132 can also be formed separately and then connected together, depending on actual needs.

[0114] When the electrode assembly 32 expands or is subjected to an external load, it exerts 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 is transmitted to the wall body 3131 and the buffer portion 3132. Because the buffer portion 3132 is deformably and flexibly connected between the wall body 3131 and the end cap 312, the buffer portion 3132 can undergo flexible deformation under the expansion force of the electrode assembly 32. Thus, the buffer portion 3132 can buffer the expansion force of the electrode assembly 32 or the external load through its own deformation, reducing the risk of connection failure between the housing 311 and the end cap 312 caused by the expansion force of the electrode assembly 32 or the external load acting on the connection between the housing 311 and the end cap 312.

[0115] Optionally, the buffer portion 3132 may be disposed opposite to the electrode body 321 of the electrode assembly 32, or the buffer portion 3132 may be disposed offset from the electrode body 321 of the electrode assembly 32, and the buffer portion 3132 may be disposed on the side of the first wall 313 near the end cap 312.

[0116] Under the influence of the expansion force of the electrode assembly 32 or the action of an external load, the deformation generated by the buffer part 3132 can be elastic deformation or plastic deformation. The form of deformation generated by the buffer part 3132 can be bending deformation or tensile deformation, etc.

[0117] The structure of the buffer part 3132 can be any form that can deform under the action of external force. The buffer part 3132 can be curved, concave or convex, etc.

[0118] Optionally, during the expansion of the electrode assembly 32, the wall body 3131 may deform under the expansion force of the electrode assembly 32 to further alleviate the expansion force of the electrode assembly 32. Alternatively, the wall body 3131 may not deform, and the expansion force of the electrode assembly 32 may be buffered only by the deformation of the buffer portion 3132.

[0119] Optionally, a first wall 313 may have one, two or more buffer sections 3132, and the specific positions of different buffer sections 3132 may be set as needed.

[0120] The battery cell 30 provided in this application embodiment has a buffer portion 3132 and a wall body 3131 on the first wall 313 of the housing 311. The buffer portion 3132 is flexibly connected between the wall body 3131 and the end cap 312 in a deformable manner. When the first wall 313 is subjected to the expansion force of the electrode assembly 32 or the external load, the buffer portion 3132 deforms first to buffer the external force, reduce the magnitude of the expansion force of the electrode assembly 32 or the force of the external load on the connection between the end cap 312 and the housing 311, and thus reduce the risk of cracking at the connection between the end cap 312 and the housing 311. This is beneficial to improving the reliability of the battery cell 30.

[0121] In some embodiments, as shown in Figures 4 and 5, the wall body 3131 and the buffer portion 3132 are integrally formed.

[0122] If the wall body 3131 and the buffer part 3132 are integrally formed, the buffer part 3132 can be formed by processes such as stamping. This is beneficial to improving the connection strength between the wall body 3131 and the buffer part 3132, and also to simplifying the manufacturing process of the shell 311.

[0123] In some embodiments, as shown in FIG5, the buffer portion 3132 includes an arc-shaped sub-portion 3132a, one end of which is connected to the wall body 3131, and the other end of which is connected to the end cap 312.

[0124] The buffer portion 3132 includes an arc-shaped sub-portion 3132a, which 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 shape through processes such as stamping. The arc-shaped sub-portion 3132a can be bent toward one side of the receiving cavity 31a, or it can be bent away from the receiving cavity 31a. Alternatively, a portion of the arc-shaped sub-portion 3132a can be bent toward the receiving cavity 31a, while another portion is bent away from it. The buffer portion 3132 can include one or more arc-shaped sub-portions 3132a. The bending direction, radius of curvature, etc., of different arc-shaped sub-portions 3132a can be the same or different, and can be set according to actual needs.

[0125] Optionally, the surface of the arc-shaped sub-part 3132a may be a portion of a cylinder, or the surface of the arc-shaped sub-part 3132a may be a portion of an ellipsoid or a sphere.

[0126] The arc-shaped sub-part 3132a is curved. When the arc-shaped sub-part 3132a is subjected to the expansion force of the electrode assembly 32, the arc-shaped sub-part 3132a can provide more space for the expansion of the electrode assembly 32 through deformation, such as increasing the radius of curvature at various points of the arc-shaped sub-part 3132a. This allows the electrode assembly 32 to have more expansion space, reducing the expansion force of the electrode assembly 32 on the first wall 313, and thus reducing the expansion force of the electrode assembly 32 at the connection between the first wall 313 and the end cap 312.

[0127] After the electrode assembly 32 expands and recovers, the force exerted by 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 elasticity. When the electrode assembly 32 expands again in subsequent cycles, the arc-shaped sub-part 3132a can deform again.

[0128] Therefore, the buffer portion 3132 includes an arc-shaped sub-portion 3132a, and the arc-shaped sub-portion 3132a is bent. This helps to reduce the structural and manufacturing difficulty of the buffer portion 3132, and also helps to improve the buffering effect of the buffer portion 3132 on the expansion force of the electrode assembly 32. This further reduces the force borne at the connection between the first wall 313 and the end cap 312, and reduces the risk of connection failure between the first wall 313 and the end cap 312.

[0129] In some embodiments, as shown in Figures 4 and 6, the arcuate sub-part 3132a protrudes from the side of the wall body 3131 toward the receiving cavity 31a.

[0130] During the molding process, the arc-shaped sub-part 3132a can be bent toward one side of the receiving cavity 31a.

[0131] In this way, during the assembly process of the battery cells 30, the buffer portion 3132 will not occupy additional space outside the battery cells 30, and the first walls 313 of the battery cells 30 can fit together, which facilitates the assembly of the battery cells 30 and helps to improve the energy density of the battery device 10.

[0132] In some embodiments, along the thickness direction of the wall body 3131, the wall body 3131 and the electrode assembly 32 have a first gap, and the surface of the arc-shaped sub-part 3132a facing the electrode assembly 32 is located within the first gap in the orthogonal projection of the end cap 312 in the end cap 312.

[0133] If the surface of the arc-shaped sub-part 3132a facing the electrode assembly 32 is projected onto the end cap 312 and the first gap is within the projection of the end cap 312, then the projection of the surface of the arc-shaped sub-part 3132a facing the electrode assembly 32 along the thickness direction of the end cap falls into the first gap. This helps to reduce the risk of the buffer part 3132 scratching the electrode assembly 32 during the process of inserting the electrode assembly 32 into the housing 311, and helps to improve the smoothness of inserting the electrode assembly 32 into the housing.

[0134] In some embodiments, as shown in FIG6, the buffer portion 3132 further includes a transition portion 3132b, which is arc-shaped and connects the wall body 3131 and the arc-shaped portion 3132a. The curvature centers of the transition portion 3132b and the arc-shaped portion 3132a are located on both sides of the first wall 313.

[0135] The transition sub-part 3132b can be 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, it can also provide a certain buffering effect for the expansion of the electrode assembly 32 by deformation during the expansion process of the electrode assembly 32.

[0136] Furthermore, since the curvature center of the transition sub-part 3132b and the curvature center of the arc-shaped sub-part 3132a are located on both sides of the first wall 313 respectively, the transition sub-part 3132b connects more smoothly with the arc-shaped sub-part 3132a and the wall body 3131, which helps to reduce the stress concentration phenomenon at the connection between the buffer part 3132 and the wall body 3131.

[0137] Therefore, the buffer section 3132 also includes a transition section 3132b, which is beneficial to further improve the buffering effect of the buffer section 3132 on the expansion force of the electrode assembly 32, and to improve the smoothness of the connection between the buffer section 3132 and the wall body 3131. It is also beneficial to reduce the stress concentration phenomenon at the connection between the buffer section 3132 and the wall body 3131, and thus to improve the structural strength of the first wall 313.

[0138] In some embodiments, as shown in Figures 4 and 6, the electrode assembly 32 includes an electrode body 321 and a tab 322. The tab 322 extends from the end of the electrode body 321, and the electrode body 321 is located inside the wall body 3131 in the orthographic projection of the first wall 313.

[0139] Since the orthographic projection of the electrode body 321 onto the first wall 313 is located inside the wall body 3131, the orthographic projection of the electrode body 321 onto the first wall 313 does not overlap with the buffer portion 3132. In other words, the buffer portion 3132 is not positioned opposite to the electrode body 321. Furthermore, since the orthographic projection of the electrode body 321 onto 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 must pass through the buffer portion 3132 during its transmission to the connection between the first wall 313 and the end cap 312. Specifically, the expansion force of the electrode assembly 32 is first 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 through deformation before it is transmitted to the connection between the first wall 313 and the end cap 312.

[0140] Therefore, this design helps to more fully utilize the buffering effect of the buffer section 3132 on the expansion force of the battery cell 30, further reducing the destructive force borne by the connection between the first wall 313 and the end cover 312, and reducing the risk of cracking of the first wall 313 and the end cover 312.

[0141] In some embodiments, as shown in Figures 4 and 5, the buffer portion 3132 is elongated.

[0142] If the buffer portion 3132 is elongated, it can extend a predetermined 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 the buffer portion 3132 extends can be the same as the dimension of the first wall 313 along the extending direction. If the buffer portion 3132 includes an arc-shaped sub-portion 3132a, the arc-shaped sub-portion 3132a can be semi-cylindrical.

[0143] It is understandable that when the housing 311 includes multiple first walls 313, the extension directions of the buffer portions 3132 of different first walls 313 are not the same. Therefore, the extension directions of the buffer portions 3132 of different first walls 313 are not the same.

[0144] Since the buffer portion 3132 is elongated, it can deform more under the expansion force of the electrode assembly 32. This is beneficial to further improve the buffering effect of the buffer portion 3132 on the expansion force of the electrode assembly 32, further reduce the force borne at the connection between the first wall 313 and the end cap 312, and further reduce the risk of cracking at the connection between the first wall 313 and the end cap 312.

[0145] In some embodiments, as shown in FIG4, the electrode assembly 32 includes two first surfaces 321a opposite each other along a first direction X and two second surfaces 321b opposite each other along a 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. 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.

[0146] Optionally, either the first surface 321a can be set to be opposite to the first wall 313, or both the first surfaces 321a can be set to be opposite to the first wall 313.

[0147] Since the area of ​​the first surface 321a of the electrode assembly 32 is larger than the area of ​​the second surface 321b, the electrode assembly 32 is more likely to generate an expansion force in the direction perpendicular to the first surface 321a during the expansion process. By setting at least one first surface 321a opposite to the first wall 313, the expansion force of the electrode assembly 32 can be buffered more easily by 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 at 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.

[0148] In some embodiments, as shown in FIG4, at least one second surface 321b is disposed opposite to the first wall 313.

[0149] Optionally, either of the second surfaces 321b can be configured to be opposite to the first wall 313, or both of the second surfaces 321b can be configured to be opposite to the first wall 313.

[0150] 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 also 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. This increases the amount of deformation that the buffer portions 3132 of the first wall 313 can generate, 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. This further helps the buffer portions 3132 reduce the expansion force of the electrode assembly 32 on the first wall 313 by deforming, further reducing the risk of cracking at the connection between the housing 311 and the end cap 312.

[0151] In some embodiments, as shown in Figures 4 and 5, the housing 311 includes two first sub-walls 3111 opposite each other along a first direction X and two second sub-walls 3112 opposite each other along a 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. The surface area of ​​the first sub-wall 3111 is larger than the surface area of ​​the second sub-wall 3112. At least one first sub-wall 3111 forms a first wall 313.

[0152] If the surface area of ​​the first sub-wall 3111 is greater than the surface area of ​​the second sub-wall 3112, then the dimension of the first sub-wall 3111 along the second direction Y is greater than the dimension of the second sub-wall 3112 along the first direction X.

[0153] If the first sub-wall 3111 forms the first wall 313, then at least a portion of the first sub-wall 3111 is the first wall 313. The first sub-wall 3111 includes a buffer portion 3132 and a wall body 3131. Optionally, one first sub-wall 3111 may be provided to form the first wall 313, or two first sub-walls 3111 may both form the first wall 313.

[0154] Since the surface area of ​​the first sub-wall 3111 is larger than that of the second sub-wall 3112, and at least one first sub-wall 3111 forms the first wall 313, the buffer portion 3132 of the first wall 313 can generate greater deformation during the deformation process, which is beneficial to improve the buffering effect of the buffer portion 3132 on the expansion force or external load of the electrode assembly 32, and further reduce the risk of cracking at the connection between the first wall 313 and the end cap 312.

[0155] In some embodiments, as shown in Figures 4 and 5, at least one second sub-wall 3112 forms the first wall 313.

[0156] If the second sub-wall 3112 forms the first wall 313, then at least a portion of the second sub-wall 3112 is the first wall 313. In other words, the buffer portion 3132 and the wall body 3131 are part of the second sub-wall 3112.

[0157] Optionally, a second sub-wall 3112 can be set to form the first wall 313, or two second sub-walls 3112 can both form the first wall 313.

[0158] Thus, at least one first sub-wall 3111 and at least one second sub-wall 3112 are each formed with a first wall 313. The first sub-wall 3111 and the second sub-wall 3112 intersect, so the buffer portion 3132 of the first sub-wall 3111 and the buffer portion 3132 of the second sub-wall 3112 buffer the direction of deformation of the electrode assembly 32, which is beneficial to further improve the buffering effect of the housing 311 on the expansion force of the electrode assembly 32, and further beneficial to reduce the risk of cracking at the connection between the first wall 313 and the end cap 312.

[0159] In some embodiments, as shown in Figures 4 and 5, both first sub-walls 3111 and two second sub-walls 3112 include a first wall 313, and the buffer portions 3132 of adjacent first sub-walls 3111 and second sub-walls 3112 are connected to each other, and the plurality of buffer portions 3132 are arranged in a ring shape.

[0160] Thus, the buffer portions 3132 of the two first sub-walls 3111 and the two second sub-walls 3112 are connected end to end in a ring shape. Therefore, there is a corresponding buffer portion 3132 along the circumference of the electrode assembly 32. During the expansion of the electrode assembly 32 toward any side, the corresponding buffer portion 3132 buffers the force exerted by the electrode assembly 32 on the connection between the first wall 313 and the end cap 312 by generating deformation. This helps to reduce the risk of cracking at the connection between the first wall 313 and the end cap 312 to a greater extent.

[0161] Optionally, the connection method between the housing 311 and the end cap 312 can be snap-fit, riveting, welding or bonding, etc., which can be selected according to the needs.

[0162] In some embodiments, as shown in FIG6, the housing 311 is welded to the end cap 312.

[0163] Welded connections have high connection strength and good sealing performance, which helps to improve the connection strength between the housing 311 and the end cap 312, and also helps to improve the sealing performance of the receiving cavity 31a, further improving the reliability of the battery cell 30.

[0164] In some embodiments, as shown in FIG6, 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.

[0165] The buffer portion 3132 is located on the side of the solder mark 33 facing away from the end cap 312. Therefore, the area where the buffer portion 3132 and the solder mark 33 are located do not overlap. Thus, under 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 solder 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 deformation. This helps to reduce the magnitude of the expansion force of the electrode assembly 32 borne by the welded connection between the first wall 313 and the end cap 312, thereby reducing the risk of cracking at the welded connection between the housing 311 and the end cap 312.

[0166] In some embodiments, as shown in Figures 4 and 6, the electrode assembly 32 includes an electrode body 321 and a tab 322, the tab 322 being led out from the end of the electrode body 321 toward the end cap 312. The minimum distance d between the edge of the electrode body 321 in the orthographic projection of the first wall 313 and the edge of the solder mark 33 along the thickness direction of the end cap 312 is d, and the maximum dimension L of the buffer portion 3132 along the thickness direction of the end cap 312 is 0.8 ≤ L / d ≤ 1.

[0167] Optionally, L / d can be 0.8, 0.85, 0.9, 0.95, or 1, etc.

[0168] Thus, the buffer portion 3132 is located between the solder mark 33 and the electrode body 321 in the orthographic projection of the first wall 313, and the buffer portion 3132 has a large dimension along the thickness direction of the end cap 312. Thus, the expansion force of the electrode assembly 32 on the first wall 313 needs to be transmitted through the buffer portion 3132 to the connection between the first wall 313 and the end cap 312, and the deformation that the buffer portion 3132 can generate is also large.

[0169] Through systematic analysis and research, the inventors discovered that setting the electrode body 321 so that its orthogonal projection on the first wall 313 is located on the side of the buffer portion 3132 facing away from the end cover 312, and setting 0.8≤L / d≤1, is beneficial to further improve the buffering effect of the buffer portion 3132 on the expansion force of the electrode assembly 32, and further reduce the risk of cracking at the connection between the housing 311 and the end cover 312 caused by the expansion of the electrode assembly 32.

[0170] Secondly, the battery device 10 provided in the embodiments of this application includes the battery cell 30 provided in any of the above embodiments.

[0171] The battery device 10 provided in this application embodiment has the same technical effect as the battery cell 30 provided in any of the above embodiments, and will not be described again here.

[0172] Thirdly, the power-consuming device provided in the embodiments of this application includes the battery cell 30 or the battery device 10 provided in any of the above embodiments, and the battery device 10 is used to provide electrical energy.

[0173] The electrical device provided in this application embodiment has the same technical effect as the battery device 10 or battery cell 30 provided in any of the above embodiments, and will not be described again here.

[0174] In some embodiments, as shown in Figures 4 to 6, 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. 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, in which the electrode assembly 32 is received. The shell 311 includes a first wall 313 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 deformably and flexibly connected between the wall body 3131 and the end cap 312. 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 is connected to the end cap 312. The arc-shaped sub-portion 3132a protrudes from the side of the wall body 3131 facing the receiving cavity 31a. The transition sub-portion 3132b is curved and connects the wall body 3131 and the arc-shaped sub-portion 3132a. The curvature centers of the transition sub-portion 3132b and the arc-shaped sub-portion 3132a are located on opposite sides of the first wall 313. Along the thickness direction of the wall body 3131, the wall body 3131 and the electrode assembly 32 have a first gap. The surface of the arc-shaped sub-portion 3132a facing the electrode assembly 32 is projected onto the end cap 312 within the projection of the first gap onto the end cap 312. The electrode assembly 32 includes two first surfaces 321a opposite each other along a first direction X and two second surfaces 321b opposite each other along a 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. 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 housing 311 and the end cap 312 are welded together to form a solder mark 33. The buffer portion 3132 is located on the side of the solder 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 extends from the end of the electrode body 321 toward the end cap 312. The minimum distance between the edge of the electrode body 321 and the edge of the solder mark 33 along the thickness direction of the end cap 312 is d, and the maximum dimension of the buffer part 3132 along the thickness direction of the end cap 312 is L, 0.8≤L / d≤1.

[0175] The battery cell 30 provided in this application embodiment has a buffer portion 3132 and a wall body 3131 on the first wall 313 of the housing 311. The buffer portion 3132 is flexibly connected between the wall body 3131 and the end cap 312 in a deformable manner. When the first wall 313 is subjected to the expansion force of the electrode assembly 32 or the external load, the buffer portion 3132 deforms first to buffer the expansion force of the electrode assembly 32 or the force of the external load, thereby reducing the magnitude of the external force borne by the connection between the end cap 312 and the housing 311, and thus reducing the risk of cracking at the connection between the end cap 312 and the housing 311. This is beneficial to improving the reliability of the battery cell 30.

[0176] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, wherein, The application relates to a battery shell. The shell comprises a shell body and an end cover, the shell body has an opening, the end cover covers the opening and is connected with the shell body, and the shell body and the end cover form a containing cavity. The shell body comprises a first wall connected with the end cover and comprising a wall body and a buffer part, and the buffer part is flexibly connected between the wall body and the end cover. The wall body and the buffer part are integrally formed.

2. The battery cell of claim 1, wherein, The buffer part comprises an arc-shaped subpart, one end of the arc-shaped subpart is connected with the wall body, and the other end of the arc-shaped subpart is connected with the end cover.

3. The battery cell of claim 1, wherein, The arc-shaped subpart is convexly arranged on the side of the wall body facing the containing cavity.

4. The battery cell of claim 3, wherein, The wall body and the electrode assembly have a first gap in the thickness direction of the wall body.

5. The battery cell of claim 4, wherein, The surface of the arc-shaped subpart on the side facing the electrode assembly is located in the first gap. The buffer part further comprises a transition subpart, the transition subpart is curved and connects the wall body and the arc-shaped subpart, and the centers of curvature of the transition subpart and the arc-shaped subpart are located on the two sides of the first wall respectively.

6. The battery cell of claim 3, wherein, The electrode assembly comprises an electrode body and a tab, the tab is led out from the end of the electrode body, and the electrode body is located inside the wall body in the projection of the first wall.

7. The battery cell of claim 1, wherein, The buffer part is in the shape of a long strip.

8. The battery cell of any one of claims 1 to 7, wherein, The electrode assembly comprises two first surfaces opposite in a first direction and two second surfaces opposite 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, and the area of the first surface is larger than that of the second surface.

9. The battery cell of any one of claims 1 to 7, wherein, At least one of the first surfaces is arranged opposite to the first wall. At least one of the second surfaces is arranged opposite to the first wall.

10. The battery cell of claim 9, wherein, The shell comprises two first subwalls opposite in a first direction and two second subwalls opposite in a second direction, the first subwalls connect the two second subwalls, 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 subwall is larger than that of the second subwall.

11. The battery cell of any one of claims 1 to 7, wherein, At least one of the first subwalls forms the first wall. At least one of the second subwalls forms the first wall.

12. The battery cell of claim 11, wherein, The first subwalls and the second subwalls are connected with each other through the buffer parts, and the buffer parts are arranged in a ring shape.

13. The battery cell of claim 12, wherein, The shell and the end cover are welded.

14. The battery cell of any one of claims 1 to 7, wherein, The shell and the end cover are welded to form a welding mark, and the buffer part is located on the side of the welding mark away from the end cover.

15. The battery cell of claim 14, wherein, The electrode assembly comprises an electrode body and a tab, the tab is led out from the end of the electrode body facing the end cover.

16. The battery cell of claim 15, wherein, The minimum distance between the edge of the projection of the electrode body on the first wall and the edge of the welding mark in the thickness direction of the end cover is d, the maximum size of the buffer part in the thickness direction of the end cover is L, and 0.8<=L / d<=1. ​ 17. A battery device, wherein, A battery cell as claimed in any one of claims 1 to 16.

18. An electrical device, comprising: A battery device as claimed in claim 17, for providing electrical energy.

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