Battery cell, battery device, and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, the battery monomer comprises a shell and an electrode assembly, the electrode assembly is accommodated in the shell, the electrode assembly comprises an electrode body and a tab, the tab is led out from the end part of the electrode body, the electrode body comprises an elastic piece and at least two winding structures, the pole pieces of the winding structures are wound to be in a hollow column shape, the at least two winding structures are arranged in a sleeved mode, the different winding structures are insulated from each other, and the elastic pieces are arranged between the two adjacent winding structures. The elastic piece comprises a hollow cavity, and the hollow cavity is configured to provide an avoiding space for deformation of the elastic piece. According to the battery monomer provided by the invention, the elastic piece can relieve the expansive force of the pole piece in a manner of generating deformation towards the hollow cavity, so that the risk of breakage of the pole piece or collapse of the central hole of the electrode body is reduced, and the reliability of the battery monomer is further improved.

Description

Technical Field

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

[0002] Battery monomers are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, 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 energy density of battery cells is also an issue that needs to be considered. Therefore, how to improve the energy density of battery cells is an issue of continuous improvement in battery cell technology. Utility Model Content

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

[0005] This application is achieved through the following technical solutions:

[0006] In the first aspect, the battery cell provided by the embodiment of the present application includes a housing and an electrode assembly, the electrode assembly is contained in the housing, the electrode assembly includes an electrode body and a pole ear, the pole ear is led out from the end of the electrode body, the electrode body includes an elastic member and at least two winding structures, the pole piece of the winding structure is wound in a hollow column, at least two winding structures are mutually nested, different winding structures are mutually insulated, and the elastic member is arranged between two adjacent winding structures. The elastic member includes a hollow cavity, and the hollow cavity is configured to provide an escape space for the deformation of the elastic member.

[0007] The battery cell provided in the embodiment of the present application is configured such that the electrode body of the electrode assembly includes an elastic member and at least two winding structures, and the winding structures are nested with each other, and the elastic member is disposed between two adjacent winding structures, and the elastic member has a hollow cavity. In the process of expansion, the pole piece of the winding structure generates an expansion force on the elastic member. Under the action of the expansion force of the winding structure, the elastic member can be deformed into the hollow cavity, so that the hollow cavity provides an avoidance space for the deformation of the elastic member. In this way, the elastic member can buffer the expansion force of the winding structure to a greater extent, which is beneficial to reducing the expansion force inside the pole piece, thereby reducing the risk of fracture of the pole piece and collapse of the center hole of the electrode body, and is beneficial to improving the reliability performance of the battery cell.

[0008] According to some embodiments of the present application, the electrode body is cylindrical.

[0009] In the above scheme, the pole piece of the winding structure is wound more densely during the winding process, and the gap between two adjacent turns of the pole piece is smaller. During the cycle of the battery cell, the expansion force of the pole piece is also larger. By arranging the elastic member between two adjacent winding structures, the deformation of the elastic member has a more obvious effect on alleviating the expansion force of the pole piece during the expansion of the winding structure, and has a more significant effect on reducing the fracture of the pole piece and the collapse of the center hole of the electrode body.

[0010] According to some embodiments of the present application, the electrode tab is led out from the end of the electrode body along the first direction, the elastic member is in a hollow columnar shape, and both ends of the elastic member along the first direction are flush with the winding structure.

[0011] In the above scheme, by setting the elastic member to be a hollow columnar shape and setting the two ends of the elastic member along the first direction to be flush with the winding structure, the expansion of the winding structure at any position along the first direction can be buffered by the elastic member, which is beneficial to further improve the buffering effect of the elastic member on the expansion force of the pole piece of the winding structure, further reduce the risk of pole piece breakage or collapse of the center hole of the electrode body, and help to further improve the reliability performance of the battery cell.

[0012] According to some embodiments of the present application, the elastic member includes a hollow cavity, and the hollow cavity is configured to provide an escape space for deformation of the elastic member.

[0013] In the above scheme, by setting the elastic part to include a hollow cavity, the elastic part can be deformed into the hollow cavity under the action of the expansion force of the winding structure, so that the hollow cavity provides an escape space for the deformation of the elastic part. In this way, the elastic part can buffer the expansion force of the winding structure to a greater extent, which is beneficial to further reduce the expansion force of the pole piece of the winding structure, and further reduce the risk of pole piece breakage or collapse of the center hole of the electrode assembly.

[0014] According to some embodiments of the present application, the hollow cavity has a through hole, which is communicated with the hollow cavity and penetrates at least one side of the elastic member toward the winding structure.

[0015] In the above scheme, by arranging the elastic member to have a through hole, and arranging the through hole to be connected with the hollow cavity, while providing an escape space for the winding structure through the hollow cavity to reduce the expansion force of the pole piece of the winding structure, the hollow cavity can also be used to store electrolyte, which is beneficial to improve the injection coefficient of the battery cell and further beneficial to improve the cycle performance of the battery cell.

[0016] According to some embodiments of the present application, the through hole penetrates the elastic member and faces two sides of two adjacent elastic members.

[0017] In the above scheme, by setting a through hole penetrating the elastic member toward both sides of the two adjacent elastic members, the hollow cavity can provide electrolyte to the two adjacent winding structures through the through hole, which is beneficial to improving the cycle performance of the electrode assembly and further beneficial to improving the cycle life of the battery cell.

[0018] According to some embodiments of the present application, the electrode tab is led out from the end of the electrode body along the first direction, and the elastic member includes a plurality of through holes, and the plurality of through holes are arranged at intervals along the first direction.

[0019] In the above solution, the hollow cavity provides electrolyte to multiple locations of the winding structure along the first direction through multiple through holes, which is beneficial to further improve the cycle performance of the electrode assembly and thus improve the cycle life of the battery cell.

[0020] According to some embodiments of the present application, the housing has a first wall, the battery cell further includes a pressure relief mechanism, the pressure relief mechanism is disposed on the first wall, and the hollow cavity penetrates one end of the elastic member toward the first wall.

[0021] In the above scheme, by setting a hollow cavity passing through one end of the elastic member toward the first wall, in the event of thermal runaway of the battery cell, it is beneficial to improve the timeliness of the actuation of the pressure relief mechanism and to improve the smoothness of the discharge of emissions inside the battery cell, which is beneficial to reduce the risk of explosion in the event of thermal runaway of the battery cell.

[0022] According to some embodiments of the present application, the elastic member includes a plurality of hollow cavities, and the plurality of hollow cavities are arranged at least along the circumference of the elastic member.

[0023] In the above scheme, when the pole pieces of the winding structure at multiple positions along the circumference of the elastic member expand, multiple hollow cavities can provide space for the expansion of the pole pieces, which is conducive to further reducing the risk of the pole pieces of the winding structure breaking or the risk of the central hole of the electrode assembly collapsing. In addition, multiple hollow cavities can provide electrolyte to multiple positions along the circumference of the winding structure through through holes, which is conducive to further improving the cycle performance of the electrolyte, thereby improving the cycle life of the battery cell.

[0024] According to some embodiments of the present application, the electrode body includes at least three winding structures and at least two elastic members, the at least three winding structures are nested with each other, and an elastic member is provided between any two adjacent winding structures.

[0025] In the above scheme, when the pole piece of the wound structure expands, the elastic member has a greater buffering effect on the deformation of the pole piece, which is beneficial to reduce the risk of fracture of the pole piece or collapse of the center hole to a greater extent.

[0026] According to some embodiments of the present application, the absolute value of the difference in capacity between different winding structures is C, 0≤C≤2Ah.

[0027] In the above scheme, by setting 0≤C≤2Ah, it is helpful to reduce the risk of wasting the capacity of some winding structures due to the fact that some winding structures are fully charged while others are not fully charged during the charging process.

[0028] According to some embodiments of the present application, the material of the negative electrode sheet of the electrode assembly includes silicon, and / or the material of the positive electrode sheet of the electrode assembly includes a ternary material.

[0029] In the above solution, the pole piece has a larger volume when expanded, and the expansion force between the pole pieces is also greater. Therefore, the elastic member has a more obvious buffering effect on the deformation of the pole piece, which can reduce the problem of pole piece breakage or the collapse of the center hole of the electrode assembly to a greater extent.

[0030] In a second aspect, the battery device provided in the embodiments of the present application includes the battery cell provided in any of the above embodiments.

[0031] The battery device provided in the embodiment of the present application has the same technical effect as the battery cell provided in any of the above embodiments, and thus will not be described in detail here.

[0032] In a third aspect, the electrical device provided in the embodiments of the present application includes the battery device provided in any of the above embodiments.

[0033] The electric device provided in the embodiment of the present application has the same technical effect as the battery device provided in the above embodiment, and thus will not be described in detail here.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of a battery device provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the structure of a battery module in a battery device provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of the explosion structure of a battery cell provided in an embodiment of the present application;

[0040] Figure 5 A schematic cross-sectional view of an elastic member in a battery cell provided in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of the structure of the elastic member provided in an embodiment of the present application.

[0042] In the drawings, the figures are not necessarily drawn to scale.

[0043] Description of reference numerals:

[0044] 1-Vehicle; 1a-Motor; 1b-Controller;

[0045] 10-battery device; 11-box; 111-first sub-box; 112-second sub-box;

[0046] 20-battery module;

[0047] 30-battery cell; 31-housing; 311-housing; 312-end cover; 32-electrode assembly; 321-electrode body; 3211-winding structure; 322-ear; 33-electrode terminal;

[0048] 40-elastic member; 40a-hollow cavity; 40b-through hole;

[0049] X - first direction. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0052] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0053] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", 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 a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0055] The term "multiple" as used in the present application refers to more than two (including two). Similarly, the term "multiple groups" refers to more than two groups (including two groups), and the term "multiple sheets" refers to more than two sheets (including two sheets).

[0056] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, in parallel or in mixed connection through a busbar component.

[0057] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, a battery cell assembly may be a battery module, and a battery module is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, a battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0058] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0059] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0060] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0061] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0062] In some embodiments, the battery device may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0063] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0064] The battery cells may be, but are not limited to, lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel hydrogen batteries, nickel cadmium batteries, lead storage batteries, etc.

[0065] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0066] 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.

[0067] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0068] 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, stainless steel, copper, aluminum, carbon electrode, carbon, nickel or titanium with surface silver plating 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 (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.).

[0069] As an example, the positive electrode active material may 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 may also be used.

[0070] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0071] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, copper, aluminum, carbon electrode, carbon, nickel or titanium.

[0072] In some embodiments, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode active material is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0073] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0074] In some embodiments, the diaphragm is an isolation membrane. The present application has no particular limitation on the type of isolation membrane, and any known isolation membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0075] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.

[0076] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0077] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0078] In some embodiments, the electrode assembly is a laminate structure.

[0079] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0080] In some embodiments, the housing includes an end cap and a shell, the shell is provided with an opening, and the end cap closes the opening to form a closed space for accommodating substances such as the electrode assembly and the electrolyte. The shell may be provided with one or more openings. One or more end caps may also be provided.

[0081] In some embodiments, at least one electrode terminal is disposed on the housing, and the electrode terminal is electrically connected to the electrode tab of the electrode assembly. The electrode terminal may be directly connected to the electrode tab, or may be indirectly connected to the electrode tab through a current collector. The electrode terminal may be disposed on an end cap, or may be disposed on the housing.

[0082] In some embodiments, an explosion-proof valve is provided on the housing, and the explosion-proof valve is used to release the internal pressure of the battery cell.

[0083] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal prismatic battery, such as a hexagonal prismatic battery, etc. There is no particular limitation in the embodiments of the present application.

[0084] During the cycle of battery cells, the pole pieces inside them will inevitably expand. However, the space inside the battery cells is limited. The expansion of the pole pieces will generate expansion forces between adjacent pole pieces. As the expansion force of the pole pieces increases, it is easy to cause problems such as pole piece breakage. For wound electrode assemblies, it is also easy to cause the center hole of the electrode assembly to collapse, which seriously affects the reliability of the battery cells.

[0085] In view of this, the battery cell provided in the embodiment of the present application includes a shell and an electrode assembly, the electrode assembly is accommodated in the shell, the electrode assembly includes an electrode body and a pole ear, the pole ear is led out from the end of the electrode body, the electrode body includes an elastic member and at least two winding structures, the pole piece of the winding structure is wound into a hollow columnar shape, at least two winding structures are mutually nested, different winding structures are insulated from each other, and the elastic member is arranged between two adjacent winding structures.

[0086] The battery cell provided in the embodiment of the present application is configured such that the electrode body of the electrode assembly includes an elastic member and at least two winding structures, and the winding structures are nested with each other, and the elastic member is disposed between two adjacent winding structures. In the process of expansion, the pole piece of the winding structure generates an expansion force on the elastic member, and the elastic member can alleviate the expansion force of the pole piece by deforming itself to reduce the expansion force inside the pole piece, thereby reducing the risk of fracture of the pole piece and collapse of the center hole of the electrode body, which is beneficial to improving the reliability performance of the battery cell.

[0087] 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 the battery devices.

[0088] The battery device disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships, or aircraft. The battery device disclosed in the present application can be used to form a power supply system of the electrical device.

[0089] The embodiment of the present application provides an electric device using a battery device as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0090] For the convenience of description, the following embodiments are described by taking a vehicle 1 as an example of an electrical device in an embodiment of the present application.

[0091] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1 provided in an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 10 is provided inside the vehicle 1, and the battery device 10 may be provided at the bottom, head or tail of the vehicle 1. The battery device 10 may be used to power the vehicle 1, for example, the battery device 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the startup, navigation and operation of the vehicle 1.

[0092] The vehicle 1 may further include a controller 1b and a motor 1a, wherein the controller 1b is used to control the battery device 10 to supply power to the motor 1a, for example, to meet the power requirements of starting, navigating, and driving the vehicle 1.

[0093] In some embodiments of the present application, the battery device 10 can not only serve as an operating power source for the vehicle 1 , but also serve as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0094] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of the battery device 10 provided in an embodiment of the present application. Figure 3 A schematic diagram of the structure of a battery cell 30 provided in an embodiment of the present application. The battery device 10 includes a housing 11 and a battery cell 30, and the battery cell 30 is accommodated in the housing 11. The housing 11 is used to provide a storage space for the battery cell 30, and the housing 11 can adopt a variety of structures. In some embodiments, the housing 11 may include a first sub-housing 111 and a second sub-housing 112, and the first sub-housing 111 and the second sub-housing 112 cover each other, and the first sub-housing 111 and the second sub-housing 112 jointly define a storage space for accommodating the battery cell 30. The second sub-box 112 may be a hollow structure with one end open, and the first sub-box 111 may be a plate-like structure, and the first sub-box 111 covers the open side of the second sub-box 112, so that the first sub-box 111 and the second sub-box 112 jointly define a storage space; the first sub-box 111 and the second sub-box 112 may also be hollow structures both with one side open, and the open side of the first sub-box 111 covers the open side of the second sub-box 112.

[0095] In the battery device 10, there may be multiple battery cells 30, and the multiple battery cells 30 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 30 are both connected in series and in parallel. The multiple battery cells 30 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 30 is accommodated in the box 11; of course, the battery device 10 may also be a battery module 20 in the form of multiple battery cells 30 connected in series, in parallel, or in a mixed connection, and then the multiple battery modules 20 are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 11. The battery device 10 may also include other structures, for example, the battery device 10 may also include a busbar component for realizing electrical connection between the multiple battery cells 30.

[0096] The battery cell 30 may be a secondary battery or a primary battery; the battery cell 30 may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.

[0097] Please refer to Figure 4 , Figure 4 Schematic diagram of the exploded structure of the battery cell 30 in the battery device 10 provided in the embodiment of the present application. Figure 4As shown, the battery cell 30 includes a housing 31, an electrode assembly 32 and an electrode terminal 33. The housing 31 includes a shell 311 and an end cap 312. The shell 311 has an opening, and the end cap 312 closes the opening to isolate the internal environment of the battery cell 30 from the external environment.

[0098] The shell 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 be used to accommodate the electrode assembly 32, the electrolyte and other components. The shell 311 and the end cap 312 can be independent components. The shell 311 can be of various shapes and sizes. Specifically, the shape of the shell 311 can be determined according to the specific shape and size of the electrode assembly 32. The material of the shell 311 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0099] The end cap 312 refers to a component that covers the opening of the shell 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 shell 311 to match the shell 311. Optionally, the end cap 312 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 312 is not easily deformed when squeezed and collided, so that the battery cell 30 can have a higher structural strength and reliability can also be improved. Functional components such as electrode terminals 33 can be provided on the end cap 312. The electrode terminal 33 can be used to electrically connect to the electrode assembly 32 for outputting or inputting electrical energy of the battery cell 30. The material of the end cap 312 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating structure may be provided inside the end cap 312, and the insulating structure may be used to isolate the electrical connection components in the housing 311 from the end cap 312 to reduce the risk of short circuit. For example, the insulating structure may be plastic, rubber, or the like.

[0100] The electrode assembly 32 is a component in the battery cell 30 where an electrochemical reaction occurs. One or more electrode assemblies 32 may be included in the housing 311. The electrode assembly 32 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet, and the separator is used to separate the positive electrode sheet and the negative electrode sheet to avoid short circuits between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the electrode body 321 of the electrode assembly 32, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute the tabs 322. The positive tab and the negative tab may be located together at one end of the electrode body 321 or at both ends of the electrode body 321, respectively. During the charge and discharge process of the battery cell 30, the positive active material and the negative active material react with the electrolyte, and the tabs 322 are connected to the electrode terminals 33 to form a current loop.

[0101] First, as Figure 4 and Figure 5 As shown, the battery cell 30 provided in the embodiment of the present application includes a housing 31 and an electrode assembly 32, the electrode assembly 32 is accommodated in the housing 31, the electrode assembly 32 includes an electrode body 321 and a pole ear 322, the pole ear 322 is led out from the end of the electrode body 321, the electrode body 321 includes an elastic member 40 and at least two winding structures 3211, the pole pieces of the winding structure 3211 are wound in a hollow column, at least two winding structures 3211 are mutually nested, different winding structures 3211 are insulated from each other, and the elastic member 40 is arranged between two adjacent winding structures 3211. The elastic member 40 includes a hollow cavity 40a, and the hollow cavity 40a is configured to provide an escape space for the deformation of the elastic member 40.

[0102] The electrode assembly 32 includes an electrode body 321 and a pole ear 322 . The pole ear 322 is led out from the end of the electrode body 321 . Optionally, the pole ear 322 can be led out from one end of the electrode body 321 , or two pole ears 322 with opposite polarities can be led out from both ends of the electrode body 321 .

[0103] The electrode body 321 includes at least two winding structures 3211. Since the pole pieces of the winding structures 3211 are wound, and the winding structures 3211 are in the shape of a hollow column. Optionally, the electrode body 321 may include one, two or more winding structures 3211, and different winding structures 3211 are mutually nested. Therefore, the cross-sections of different winding structures 3211 may be annular, and the sizes of different winding structures 3211 are different, so that different winding structures 3211 can be mutually nested.

[0104] The winding structure 3211 may be cylindrical, or the winding structure 3211 may be prismatic, and the corresponding shell 31 may be cylindrical, or the shell 31 may be hollow columnar.

[0105] Different winding structures 3211 are nested with each other, so that one winding structure 3211 is nested on the outer peripheral side of another winding structure 3211, or is nested in the hollow structure of another winding structure 3211, and the winding centers of multiple winding structures 3211 can overlap with each other.

[0106] Different winding structures 3211 are insulated from each other, and the pole ears 322 led out from different winding structures 3211 are electrically connected to each other at the pole ears 322, so the electrical connection relationship of different winding structures 3211 is parallel. The insulation of the two adjacent winding structures 3211 can be achieved by providing a relevant insulating member between two adjacent winding structures 3211 along the radial direction of the electrode body 321, or the elastic member 40 is provided with an insulating function to achieve the insulation of the two adjacent winding structures 3211 through the elastic member 40.

[0107] The elastic member 40 is disposed between two adjacent winding structures 3211 , that is, the elastic member 40 is disposed between the winding structures 3211 that are adjacent and mutually nested along the radial direction of the electrode body 321 .

[0108] Optionally, the elastic member 40 may be in the shape of a hollow column, or the elastic member 40 may be in the shape of a curved plate, that is, the cross section of the elastic member 40 along the direction perpendicular to the winding direction may be in the shape of a ring or a fan ring.

[0109] Optionally, one or more elastic members 40 may be disposed between two adjacent winding structures 3211 , and the multiple elastic members 40 may be arranged along the winding center of the winding structure 3211 .

[0110] The electrode body 321 may include two, three or more winding structures 3211 . Different winding structures 3211 may be coaxially nested with each other, and an elastic member 40 may be provided between two adjacent winding structures 3211 .

[0111] The elastic member 40 has a hollow cavity 40a. Optionally, the hollow cavity 40a may be closed, or the hollow cavity 40a may be semi-closed, that is, the hollow cavity 40a may have a gap connected to the outside, or the hollow cavity 40a may be connected to the outside. An elastic member 40 may have one or more hollow cavities 40a, and the multiple hollow cavities 40a may be distributed in different areas.

[0112] In this way, the two winding structures 3211 adjacent to the elastic member 40 can transmit the expansion force to the elastic member 40 during the expansion process, so that the elastic member 40 absorbs the expansion force of the pole piece of the winding structure 3211 by deformation. Under the action of the expansion force of the winding structure 3211, the elastic member 40 can be deformed into the hollow cavity 40a, so that the hollow cavity 40a provides an avoidance space for the deformation of the elastic member 40. This is conducive to reducing the expansion force of the pole piece, thereby reducing the risk of the pole piece breaking, and is conducive to reducing the risk of collapse of the center hole of the electrode body 321.

[0113] It is understandable that the elastic modulus of the elastic member 40 can be reasonably set according to the expansion force of the pole piece, so that the elastic member 40 can provide a certain support for the winding structure 3211, and it is also convenient for the elastic member 40 to deform in time under the action of the expansion force of the pole piece. The elastic member 40 can be set as a solid, or a part of the elastic member 40 can be set as a hollow, which can be selected according to actual needs.

[0114] The battery cell 30 provided in the embodiment of the present application is configured such that the electrode body 321 of the electrode assembly 32 includes an elastic member 40 and at least two winding structures 3211, and the winding structures 3211 are nested with each other, and the elastic member 40 is disposed between two adjacent winding structures 3211, and the elastic member 40 has a hollow cavity. In the process of expansion, the pole piece of the winding structure 3211 generates an expansion force on the elastic member 40. Under the action of the expansion force of the winding structure 3211, the elastic member 40 can be deformed into the hollow cavity 40a, so that the hollow cavity 40a provides an avoidance space for the deformation of the elastic member 40. This is beneficial to reduce the expansion force inside the pole piece, thereby reducing the risk of pole piece breakage and collapse of the center hole of the electrode body 321, and is beneficial to improving the reliability of the battery cell 30.

[0115] The central hole of the electrode body 321 may be the winding center of the innermost winding structure 3211 , which is generally cylindrical.

[0116] In some embodiments, Figure 4 and Figure 5 As shown, the electrode body 321 is cylindrical.

[0117] The electrode body 321 is cylindrical, and the winding structure 3211 can be a hollow cylindrical shape. In this way, the pole pieces of the winding structure 3211 are wound more densely during the winding process, and the gap between two adjacent turns of pole pieces is smaller. In this way, during the cycle of the battery cell 30, the expansion force of the pole pieces is also greater.

[0118] In the present application, the elastic member 40 is arranged between two adjacent winding structures 3211. During the expansion of the winding structure 3211, the deformation of the elastic member 40 is more effective in alleviating the expansion force of the pole piece, and is more effective in reducing the fracture of the pole piece and the collapse of the center hole of the electrode body 321, which is beneficial to further improve the reliability performance of the battery cell 30.

[0119] In some embodiments, the tab 322 is led out from the end of the electrode body 321 along the first direction X, the elastic member 40 is in a hollow columnar shape, and both ends of the elastic member 40 along the first direction X are flush with the winding structure 3211 .

[0120] The first direction X is the direction in which the electrode tab 322 is led out from the end of the electrode body 321 . The first direction X may be parallel to the winding center of the winding structure 3211 .

[0121] The elastic member 40 is in a hollow columnar shape, and both ends of the elastic member 40 along the first direction X are flush with the winding structure 3211. Therefore, the winding structure 3211 at any position along the first direction X has an elastic member 40 opposite to it in a direction perpendicular to the first direction X. Therefore, expansion of the winding structure 3211 at any position along the first direction X can be buffered by the deformation of the elastic member 40 opposite to it in a direction perpendicular to the first direction X.

[0122] It should be noted that the two ends of the elastic member 40 along the first direction X are flush with the winding structure 3211, which is only macroscopically flush, and does not mean that the same end of the elastic member 40 and the winding structure 3211 along the first direction X are in the same plane, but within the allowable error range, a certain distance is allowed between the end face of the elastic member 40 and the end face of the winding structure 3211, therefore, from a microscopic point of view, the end of the elastic member 40 along the first direction X can be arranged beyond the winding structure 3211, or the end of the winding structure 3211 along the first direction X can be arranged beyond the elastic member 40. Exemplarily, if the distance between the end face of the elastic member 40 and the end face of the winding structure 3211 is within 5 mm, it can be considered that the end of the elastic member 40 is flush with the end of the winding structure 3211.

[0123] Therefore, by setting the elastic member 40 to be a hollow columnar shape and setting the two ends of the elastic member 40 along the first direction X to be flush with the winding structure 3211, the expansion of the winding structure 3211 at any position along the first direction X can be buffered by the elastic member 40, which is beneficial to further improve the buffering effect of the elastic member 40 on the expansion force of the pole piece of the winding structure 3211, further reduce the risk of pole piece breakage or collapse of the center hole of the electrode body 321, and help to further improve the reliability performance of the battery cell 30.

[0124] In some embodiments, Figure 5 and Figure 6 As shown, the hollow cavity 40 a has a through hole 40 b , which is communicated with the hollow cavity 40 a and passes through at least one side of the elastic member 40 toward the winding structure 3211 .

[0125] The through hole 40b penetrates at least one side of the elastic member 40 toward the winding structure 3211. Optionally, the through hole 40b may penetrate one side of the winding structure 3211 of the elastic member 40 toward any one side, or the through hole 40b may penetrate both sides of the elastic member 40 toward two winding structures 3211. In other words, the through hole 40b may penetrate any side of the elastic member 40 in the radial direction, or the through hole 40b is arranged to penetrate the elastic member 40 in the radial direction. Exemplarily, the diameter of the through hole 40b may be set in the range of 1 mm to 2 mm.

[0126] Since the through hole 40b is connected to the hollow cavity 40a, the electrolyte of the battery cell 30 can enter the hollow cavity 40a through the through hole 40b, and the electrolyte of the hollow cavity 40a can also flow out of the hollow cavity 40a through the through hole 40b. Therefore, the hollow cavity 40a can be used to store the electrolyte and release the electrolyte to the electrode assembly 32 when needed. This is beneficial to improve the filling coefficient of the battery cell 30 and to improve the cycle life of the battery cell 30.

[0127] Therefore, by setting the elastic member 40 with a through hole 40b, and setting the through hole 40b to be connected with the hollow cavity 40a, while providing an escape space for the winding structure 3211 through the hollow cavity 40a to reduce the expansion force of the pole piece of the winding structure 3211, the hollow cavity 40a can also be used to store electrolyte, which is beneficial to improve the filling coefficient of the battery cell 30, and further beneficial to improve the cycle performance of the battery cell 30.

[0128] In some embodiments, Figure 6 As shown, the through hole 40 b penetrates through the elastic member 40 and faces two sides of two adjacent elastic members 40 .

[0129] Optionally, the through hole 40b may be in a circular hole shape or a square hole shape, etc., the through hole 40b may be larger, or the through hole 40b may be smaller. For example, the through hole 40b may be large enough so that the elastic member 40 has a mesh structure as a whole.

[0130] In this way, the electrolyte on both sides of the elastic member 40 along the radial direction of the electrode body 321 can flow into the hollow cavity 40a through the through hole 40b, and the electrolyte in the hollow cavity 40a can also flow to the winding structures 3211 on both sides through the through hole 40b to provide electrolyte for the winding structures 3211 on both sides.

[0131] Therefore, by setting a through hole 40b that passes through the elastic member 40 toward both sides of the two adjacent elastic members 40, the hollow cavity 40a can provide electrolyte to the two adjacent winding structures 3211 through the through hole 40b, which is beneficial to improving the cycle performance of the electrode assembly 32, and further beneficial to improving the cycle life of the battery cell 30.

[0132] In some embodiments, Figure 4 and Figure 6 As shown, the electrode tab 322 is led out from the end of the electrode body 321 along the first direction X, and the elastic member 40 includes a plurality of through holes 40 b , which are arranged along the first direction X at intervals.

[0133] The plurality of through holes 40b are arranged at intervals along the first direction X, and the plurality of through holes 40b are arranged along the first direction X, so that the hollow cavity 40a provides electrolyte to the plurality of parts of the winding structure 3211 along the first direction X through the plurality of through holes 40b. In this way, the cycle performance of the electrode assembly 32 is further improved, and the cycle life of the battery cell 30 is further improved.

[0134] In some embodiments, the housing 31 has a first wall, the battery cell 30 further includes a pressure relief mechanism, the pressure relief mechanism is disposed on the first wall, and the hollow cavity 40 a penetrates one end of the elastic member 40 toward the first wall.

[0135] In the case of thermal runaway of the battery cell 30, the electrode assembly 32 generates gas, which increases the pressure in the housing 31 and acts on the pressure relief mechanism. When the pressure in the housing 31 reaches the actuation pressure of the pressure relief mechanism, the pressure relief mechanism is actuated and begins to discharge emissions. By setting a hollow cavity 40a that passes through the elastic member 40 toward the first end, in the case of thermal runaway of the battery cell 30, the gas can act on the pressure relief mechanism through the hollow cavity 40a, which is conducive to improving the timeliness of the actuation of the pressure relief mechanism. After the pressure relief mechanism is opened, the emissions can flow to the pressure relief mechanism through the hollow cavity 40a, so that the hollow cavity 40a can be used as a channel for the flow of emissions.

[0136] Therefore, by setting a hollow cavity 40a that passes through one end of the elastic member 40 toward the first wall, in the event of thermal runaway of the battery cell 30, it is beneficial to improve the timeliness of the actuation of the pressure relief mechanism, and to improve the smoothness of the discharge of emissions inside the battery cell 30, which is beneficial to reducing the risk of explosion of the battery cell 30 in the event of thermal runaway.

[0137] In some embodiments, Figure 5 As shown, the elastic member 40 includes a plurality of hollow cavities 40 a , and the plurality of hollow cavities 40 a are arranged at least along the circumferential direction of the elastic member 40 .

[0138] In this way, along the circumference of the elastic member 40, when the pole pieces of the winding structure 3211 at multiple positions expand, multiple hollow cavities 40a can provide escape space for the expansion of the pole pieces. This is helpful to further reduce the risk of breakage of the pole pieces of the winding structure 3211 or the risk of collapse of the center hole of the electrode assembly 32.

[0139] In the embodiment where the elastic member 40 has a through hole 40b, the plurality of hollow cavities 40a can provide electrolyte to a plurality of locations along the circumferential direction of the winding structure 3211 through the through hole 40b, which is beneficial to further improve the cycle performance of the electrolyte and thereby improve the cycle life of the battery cell 30.

[0140] In some embodiments, the electrode body 321 includes at least three winding structures 3211 and at least two elastic members 40 . The at least three winding structures 3211 are nested with each other, and an elastic member 40 is disposed between any two adjacent winding structures 3211 .

[0141] It can be understood that, for an electrode assembly 32 of the same external size, the more winding structures 3211 it includes and the more elastic parts 40 it includes, the smaller the radial thickness of the winding structure 3211, that is, the smaller the number of winding turns of the pole piece in the winding structure 3211, the greater the buffering effect of the elastic part 40 on the deformation of the pole piece when the pole piece of the winding structure 3211 expands, and the more conducive it is to reducing the risk of breakage of the pole piece or collapse of the center hole.

[0142] In some embodiments, the absolute value of the difference in capacity between different winding structures 3211 is C, 0≤C≤2Ah.

[0143] Optionally, C can be 0, 0.5Ah, 1Ah, 1.5Ah or 2Ah, etc.

[0144] 0≤C≤2Ah is set, that is, the absolute value of the difference in capacity of different winding structures 3211 is set as small as possible. This is because different winding structures 3211 are electrically connected at the pole ear 322, so different winding structures 3211 are electrically connected in parallel. In this way, during the charging process of the battery cell 30, multiple winding structures 3211 are charged synchronously. The smaller the difference in capacity of different winding structures 3211, the more conducive it is to reduce the risk that one winding structure 3211 is already full while another winding structure 3211 is not yet full. In this way, the smaller the difference in capacity of different winding structures 3211, the more conducive it is to reduce the waste of capacity of the winding structure 3211.

[0145] Specifically, when different winding structures 3211 are formed by winding the same pole piece, in order to achieve a smaller absolute value of the difference in capacity of different winding structures 3211, the lengths of the pole pieces of different winding structures 3211 along the winding direction can be set to be as consistent as possible.

[0146] Therefore, by setting 0≤C≤2Ah, it is helpful to reduce the risk of wasting the capacity of some winding structures 3211 due to the fact that some winding structures 3211 are fully charged while others are not fully charged during the charging process.

[0147] In some embodiments, the material of the negative electrode sheet of the electrode assembly 32 includes silicon, and / or the material of the positive electrode sheet of the electrode assembly 32 includes a ternary material.

[0148] For a battery cell 30 whose negative electrode sheet material includes silicon, or whose positive electrode sheet material includes ternary material, during the cycle operation, the volume of the electrode sheet expanded is larger, and the expansion force between the electrode sheets is also greater. Therefore, the buffering effect of the elastic member 40 on the deformation of the electrode sheet is more obvious, which can reduce the problem of electrode sheet breakage or the collapse of the center hole of the electrode assembly 32 to a greater extent.

[0149] In a second aspect, the battery device 10 provided in the embodiment of the present application includes the battery cell 30 provided in any one of the above embodiments.

[0150] The battery device 10 provided in the embodiment of the present application has the same technical effect as the battery cell 30 provided in any of the above embodiments, and thus will not be described in detail here.

[0151] In a third aspect, the electrical device provided in the embodiment of the present application includes the battery device 10 provided in the above embodiment, and the battery device 10 is used to provide electrical energy.

[0152] The electric device provided in the embodiment of the present application has the same technical effect as the battery device 10 provided in the above embodiment, and thus will not be described in detail here.

[0153] In some embodiments, Figures 4 to 6As shown, the battery cell 30 includes a housing 31 and an electrode assembly 32, the electrode assembly 32 is accommodated in the housing 31, the electrode assembly 32 includes an electrode body 321 and a pole ear 322, the pole ear 322 is led out from the end of the electrode body 321 along the first direction X, the electrode body 321 is cylindrical, and includes an elastic member 40 and at least two winding structures 3211, the pole pieces of the winding structure 3211 are wound in a hollow columnar shape, at least two winding structures 3211 are mutually nested, different winding structures 3211 are insulated from each other, and the elastic member 40 is arranged between two adjacent winding structures 3211. The elastic member 40 is in a hollow columnar shape, and both ends of the elastic member 40 along the first direction X are flush with the winding structure 3211. The elastic member 40 includes a plurality of hollow cavities 40a and a plurality of through holes 40b, and the hollow cavity 40a is configured to provide an escape space for the deformation of the elastic member 40. The through hole 40b is connected to the hollow cavity 40a and passes through at least one side of the elastic member 40 facing the winding structure 3211. A plurality of through holes 40b are arranged at intervals along the first direction X. The housing 31 has a first wall, and the battery cell 30 also includes a pressure relief mechanism, which is arranged on the first wall. The hollow cavity 40a passes through one end of the elastic member 40 facing the first wall, and the plurality of hollow cavities 40a are arranged at least along the circumference of the elastic member 40. The absolute value of the difference in capacity of different winding structures 3211 is C, 0≤C≤2Ah. The material of the negative electrode sheet of the electrode assembly 32 includes silicon, and / or the material of the positive electrode sheet of the electrode assembly 32 includes a ternary material.

[0154] The battery cell 30 provided in the embodiment of the present application is configured such that the electrode body 321 of the electrode assembly 32 includes an elastic member 40 and at least two winding structures 3211, and the winding structures 3211 are nested with each other, and the elastic member 40 is disposed between two adjacent winding structures 3211, and the elastic member 40 has a hollow cavity. In the process of expansion, the pole piece of the winding structure 3211 generates an expansion force on the elastic member 40. Under the action of the expansion force of the winding structure 3211, the elastic member 40 can be deformed into the hollow cavity 40a, so that the hollow cavity 40a provides an avoidance space for the deformation of the elastic member 40. This is beneficial to reduce the expansion force inside the pole piece, thereby reducing the risk of pole piece breakage and collapse of the center hole of the electrode body 321, and is beneficial to improving the reliability of the battery cell 30.

[0155] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. 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: shell; An electrode assembly, contained in the housing, comprising an electrode body and a pole ear, wherein the pole ear is led out from the end of the electrode body, the electrode body comprising an elastic member and at least two winding structures, wherein the pole pieces of the winding structure are wound in a hollow columnar shape, at least two winding structures are mutually nested, different winding structures are mutually insulated, and the elastic member is arranged between two adjacent winding structures; The elastic member includes a hollow cavity, and the hollow cavity is configured to provide an escape space for deformation of the elastic member.

2. The battery cell according to claim 1, characterized in that: The electrode body is cylindrical.

3. The battery cell according to claim 1, characterized in that: The electrode tab is led out from the end of the electrode body along the first direction, the elastic member is in a hollow column shape, and both ends of the elastic member along the first direction are flush with the winding structure.

4. The battery cell according to claim 1, characterized in that: The elastic member has a through hole, which is communicated with the hollow cavity and penetrates at least one side of the elastic member toward the winding structure.

5. The battery cell according to claim 4, characterized in that: The through hole penetrates through the elastic member and faces two sides of two adjacent elastic members.

6. The battery cell according to claim 4, characterized in that: The electrode tab is led out from the end of the electrode body along the first direction, and the elastic member includes a plurality of through holes, which are arranged at intervals along the first direction.

7. The battery cell according to claim 4, characterized in that: The housing has a first wall, the battery cell further includes a pressure relief mechanism, the pressure relief mechanism is arranged on the first wall, and the hollow cavity penetrates through one end of the elastic member toward the first wall.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The elastic member includes a plurality of hollow cavities, and the plurality of hollow cavities are arranged at least along the circumferential direction of the elastic member.

9. The battery cell according to any one of claims 1 to 7, characterized in that: The electrode body comprises at least three winding structures and at least two elastic members. The at least three winding structures are mutually nested, and the elastic member is arranged between any two adjacent winding structures.

10. The battery cell according to any one of claims 1 to 7, characterized in that: The absolute value of the difference in capacity between the different winding structures is C, 0≤C≤2Ah.

11. The battery cell according to any one of claims 1 to 7, characterized in that: The material of the negative electrode sheet of the electrode assembly includes silicon, and / or the material of the positive electrode sheet of the electrode assembly includes a ternary material.

12. A battery device, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 11.

13. An electrical device, characterized in that: Comprising the battery device as claimed in claim 12, the battery device is used to provide electrical energy.

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