Battery cells, batteries and power consuming devices

Abstract

The present application discloses a battery cell (100), a battery, and a power consumption device, the battery cell (100) including an outer housing (10) and an electrode assembly (20), the electrode assembly (20) being disposed within the outer housing (10), wherein a buffer member (30) is further disposed within the outer housing (10), the buffer member (30) being configured to be deformable when the electrode assembly (20) is deformed.

Description

[Technical Field]

[0001] This application relates to the field of batteries, and more particularly to battery cells, batteries, and power consuming devices. [Background technology]

[0002] Energy conservation and reduced pollutant emissions are key to the sustainable development of the automotive industry, and electric vehicles, with their energy-saving and environmentally friendly advantages, have become an important component of this industry. However, battery technology is a key factor in the development of electric vehicles.

[0003] During the charging and discharging process, the volume of the battery cells changes significantly, which causes problems of high expansion and further affects the service life of the battery. Summary of the Invention [Means for solving the problem]

[0004] In view of the above problems, the present application provides a battery cell, a battery, and a power consumption device that can alleviate the problem of high expansion during use of the battery cell and improve the service life of the battery cell.

[0005] According to a first aspect, the present application provides a battery cell, the battery cell including an outer housing and an electrode assembly, the electrode assembly being disposed within the outer housing, wherein a buffer member is further disposed within the outer housing, the buffer member being configured to be deformable when the electrode assembly is deformed.

[0006] In the technical solution of the embodiments of the present application, a buffer member is installed inside the outer housing. When the battery cell is charged or discharged, the buffer member deforms in accordance with the deformation of the electrode assembly, changing the space inside the battery cell that accommodates the electrode assembly. This reduces the stress experienced by the electrode assembly when it expands, and at the same time reduces the amount of deformation occurring in the outer housing of the battery cell, thereby alleviating the problem of high expansion during charging and discharging of the battery cell and extending the service life of the battery cell.

[0007] In some embodiments, the buffer member corresponds to at least the largest surface area of ​​the electrode assembly. In the above technical solution, the buffer member faces the large surface of the electrode assembly, thereby absorbing as much of the expansion of the large surface as possible.

[0008] In some embodiments, the buffer member is formed in a sheet-like shape, and in the above technical solution, by installing it in a sheet-like structure, it is possible to facilitate the installation of the buffer member within the battery cell and at the same time minimize the space occupied by the buffer member.

[0009] In some embodiments, the buffer member has a lightweight structure. In the above technical solution, the lightweight structure can be installed to reduce the weight of the buffer member, which can further reduce the weight of the battery cell.

[0010] In some embodiments, the lightweight structure is at least one of a groove, a hole, and a rough surface. In the above technical solution, the groove or other structure is installed to reduce the weight of the buffer member, provided that the elasticity is not affected.

[0011] In some embodiments, the lightweight structure includes a filler, which may be at least one of a reactive ion replenisher, a flame retardant / safety agent, and a complexing agent for eluted metal elements, and the filler can improve the service life of the battery cell or reduce catalytic activity through complexing, thereby ensuring the chemical stability of the battery cell.

[0012] In some embodiments, the outer surface of the buffer member is coated with a flame retardant and / or has a molding material on the outer surface of the buffer member. In the above technical solution, the flame retardant can improve safety performance and prevent thermal runaway, heat propagation, etc., and the molding material can prevent thermal shrinkage or wrinkles of the buffer member after hot pressing.

[0013] In some embodiments, the buffer member comprises one or more of rubber, foam, aerogel, silica gel, and other polymers, etc. The above technical solution can improve the elasticity of the buffer member while reducing the manufacturing cost.

[0014] In some embodiments, the buffer member is provided between the outer housing and the electrode assembly. In the above technical solution, the buffer member is installed between the outer housing and the electrode assembly, which is easy to install and can effectively reduce the probability of deformation of the outer housing.

[0015] In some embodiments, the outer housing includes a case and end caps, the case having an accommodating cavity open on one side, the end caps being fitted to the case to seal the accommodating cavity, and the buffer member being provided between the case and the electrode assembly. In the above technical solution, the buffer member is installed between the case and the electrode assembly, which reduces the space occupied by the buffer member, improves energy density, and is easy to install.

[0016] In some embodiments, the buffer member faces the two largest side surfaces of the case and the bottom wall of the case. In the above technical solution, the buffer member faces the two largest surfaces, effectively absorbing expansion stress, and at the same time, the buffer member forms a single piece, facilitating assembly of the buffer member within the case.

[0017] In some embodiments, the buffer member is formed on the inner wall of the outer housing, and the ratio of the compressibility of the buffer member to the total thickness of the outer housing is in the range of 10% to 90%. The above technical solution ensures that the buffer member is securely fixed and can effectively absorb the expansion of the electrode assembly, thereby reducing the possibility of deformation of the outer housing.

[0018] In some embodiments, the thermal conductivity of the buffer member is greater than 0.3 W / (m·°C). In the above technical solution, the heat of the electrode assembly can be quickly transferred to the outer housing through the buffer member and then discharged through the outer housing, improving the safety performance of the battery cell.

[0019] In some embodiments, the buffer member is coated with a thermally conductive coating or is made of a thermally conductive material, which can achieve effective thermal conduction and improve safety.

[0020] In some embodiments, the buffer member is glued to the outer housing and / or the electrode assembly, and the above technical solution can improve the reliability of the buffer member fixation.

[0021] In some embodiments, the electrode assembly includes a plurality of electrode assemblies, and the buffer member is provided between at least two adjacent electrode assemblies. In the above technical solution, the buffer member can effectively absorb the expansion of the electrode assemblies and reduce the stress that the electrode assemblies experience due to the expansion.

[0022] In some embodiments, the electrode assembly includes a plurality of plates, and the buffer member is provided between at least two adjacent plates. In the above technical solution, the buffer member can effectively absorb the expansion of the plates, and further reduce stress when the electrode assembly expands.

[0023] In some embodiments, the electrode assembly further includes a separator member, the electrode plates include a positive electrode plate and a negative electrode plate, and the buffer member is disposed between the separator member and the negative electrode plate. In the above technical solution, the negative electrode plate has a large deformation amount, and since the buffer member is disposed between the separator member and the negative electrode plate, it can effectively absorb the expansion of the negative electrode plate and further reduce the stress experienced when the electrode assembly expands.

[0024] In some embodiments, the thermal conductivity of the buffer material is 0.2 W / (m·°C) or less. The above technical solution can achieve effective thermal insulation, improve the overall failure temperature, and enhance safety performance.

[0025] In some embodiments, the compressibility of the buffer member is equal to or greater than the expansion of the electrode assembly. In the above technical solution, the buffer member can absorb as much of the expansion of the electrode assembly as possible, reduce the stress experienced by the electrode assembly due to the expansion, and further reduce the deformation of the entire battery cell, thereby improving the service life of the battery cell.

[0026] In some embodiments, the compressibility of the buffer member ranges from 1 mm to 100 mm. The above technical solution can reduce the stress that the electrode assembly experiences due to expansion, while simultaneously preventing the buffer member from occupying too much space and affecting the energy density of the battery cell.

[0027] In some examples, the compressibility of the buffer member is 10% to 95%. In the above technical solution, the buffer member can be compressed and deformed in accordance with the expansion of the electrode assembly, and absorbs the expansion of the electrode assembly as much as possible.

[0028] In some embodiments, the expansion of the electrode assembly ranges from 0.2 mm to 80 mm. In the above technical solution, the buffer member can absorb the expansion of the electrode assembly as much as possible and reduce the stress that the electrode assembly experiences due to the expansion; In some examples, the expansion rate of the electrode assembly ranges from 5% to 200%. In the above technical solution, deformation occurring in an electrode assembly with a high expansion rate is absorbed by the buffer member, reducing the stress experienced by the electrode assembly due to expansion, thereby improving the service life of the battery cell.

[0029] In some embodiments, the ratio of the total volume of the buffer member to the total volume inside the outer housing is 0.05 to 0.6. The above technical solution can avoid the buffer member occupying too large a space, which would affect the space of the electrode assembly and affect the energy density, and at the same time avoid the buffer member occupying too small a space, which would prevent it from effectively absorbing the expansion of the electrode assembly.

[0030] In some embodiments, the ratio of the area of ​​the buffer member to the area of ​​the largest surface of the electrode assembly is in the range of 0.1 to 1. The above technical solution can reduce the size of the elastic sheet, reduce costs, lighten the weight of the entire structure, and further lower the precision requirements for installing the elastic sheet, while ensuring effective absorption of expansion.

[0031] In some embodiments, the ratio of the compressibility of the buffer member to the thickness of the electrode assembly in a fully discharged state of the battery cell is in the range of 5% to 80%, thereby improving the buffer member's ability to absorb the expansion of the electrode assembly as much as possible and reducing the stress experienced by the electrode assembly due to the expansion.

[0032] In some embodiments, the battery cell is a metal battery, and the above technical solution can solve the problem of high expansion of the metal battery and improve the service life of the metal battery.

[0033] In some embodiments, the negative electrode plate of the electrode assembly includes a substrate and a conductive coating applied to the surface of the substrate. In the above technical solution, the negative electrode plate is composed of a substrate and a conductive coating on the substrate, and no negative active material layer is installed. Therefore, when the battery cell is charged and discharged, the negative electrode plate expands relatively greatly. Therefore, by installing a buffer member, the problem of high expansion of the negative electrode plate during battery charge and discharge can be effectively reduced, and the service life of the battery cell can be improved.

[0034] In some embodiments, the battery cell is a sodium metal battery, and in the above technical solution, the sodium metal battery has a relatively high expansion rate, which can solve the high expansion problem of the sodium metal battery and improve the service life of the metal battery.

[0035] According to a second aspect, the present application provides a battery, which includes the battery cell in the above embodiment.

[0036] According to a third aspect, the present application provides a power consuming device, the power consuming device including a battery cell according to any of the above embodiments, the battery cell being used to provide electrical energy.

[0037] The above description is merely a summary of the technical solution of the present application, which may be implemented according to the contents of the specification in order to more clearly understand the technical means of the present application. In order to make the above and other objectives, features and advantages of the present application more clearly understandable, the following particularly cites specific embodiments of the present application for description. [Brief explanation of the drawings]

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. The drawings are only used to illustrate the purpose of the preferred embodiments and are not to be considered as limitations on the present application. Note that the same drawing numbers refer to the same elements in all drawings.

[0039] [Figure 1] FIG. 1 is a schematic diagram of a vehicle in the related art. [Figure 2] FIG. 1 is a schematic diagram of a battery in the related art. [Figure 3] FIG. 1 is a schematic diagram of a battery cell according to some embodiments of the present application. [Figure 4] FIG. 2 is an exploded view of a battery cell according to some embodiments of the present application. [Figure 5] FIG. 2 is an exploded perspective view of a battery cell according to some embodiments of the present application. [Figure 6] 1A-1C are cross-sectional views of local structures of some embodiments of the present application, where the electrode assembly is in a fully discharged state. [Figure 7] 1 is a cross-sectional view of a local structure of some embodiments of the present application, where the electrode assembly is in a fully charged state. [Figure 8] 10A to 10C are cross-sectional views of local structures of battery cells according to some other embodiments of the present application. [Figure 9] FIG. 10 is a cross-sectional view of a local structure of a battery cell according to some other embodiments of the present application, in which the electrode assembly is in a fully discharged state. [Figure 10] 1 is a partial structural cross-sectional view of some other embodiments of the present application, in which the electrode assembly is in a fully charged state. [Figure 11] 10A-10C are cross-sectional views of local structures of further some embodiments of the present application, where the electrode assembly is in a fully discharged state. [Figure 12] 10A-10C are cross-sectional views of local structures of further some embodiments of the present application, where the electrode assembly is in a fully charged state. [Figure 13] FIG. 10 is a cross-sectional view of a local structure of a battery cell according to some other embodiments of the present application, in which the electrode assembly is in a fully discharged state. [Figure 14] 1 is a partial structural cross-sectional view of some other embodiments of the present application, in which the electrode assembly is in a fully charged state. DETAILED DESCRIPTION OF THE INVENTION

[0040] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the following will clearly describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without any creative efforts fall within the scope of protection of the present application.

[0041] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art of this application, and the terms used in the specification of the utility model in this application are only for describing specific embodiments and are not intended to limit this application, and the terms "comprises," "has," and any variations thereof in the specification and claims of this application and the above drawings are intended to cover a non-exclusive "comprise." The terms "first," "second," etc. in the specification and claims of this application or the above drawings are not intended to describe a specific order or a hierarchical relationship, but are intended to distinguish different objects.

[0042] An "embodiment" referred to in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments of other embodiments.

[0043] In the description of this application, it should be explained that unless otherwise clearly defined or limited, the terms "attached," "connected," "joined," and "attached" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0044] The term "and / or" in this application merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B may represent three cases: A alone, a combination of A and B, and B alone. Also, the character " / " in this application generally indicates that the related objects before and after are in an "or" relationship.

[0045] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments will be omitted. It should be understood that the dimensions such as thickness, aspect, etc. of various components in the embodiments of the present application shown in the drawings, and the dimensions such as thickness, aspect, etc. of the entire integrated device are for illustrative purposes only and do not constitute any limitations on the present application.

[0046] The term "plurality" as used herein refers to two or more (including two).

[0047] The battery referred to in the embodiments of the present application may be a single physical module including one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or series-parallel via electrical connecting members.

[0048] In some embodiments, the battery may be a battery module, and if there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0049] In some embodiments, the battery may be a battery pack, which includes a housing and battery cells, with the battery cells or modules housed within the housing.

[0050] In some embodiments, the housing may be part of a chassis structure of a vehicle, for example, a portion of the housing may be at least a portion of a floor of the vehicle, or a portion of the housing may be at least a portion of a cross member and a side member of the vehicle.

[0051] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage electrical cabinet, or the like.

[0052] In the embodiment of the present application, the battery cell may be a secondary battery, which is a battery cell that can be continuously used by activating the active material in a charging manner after discharging the battery cell.

[0053] The battery cells may be lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, lead acid batteries, etc., and the embodiments of the present application are not limited thereto.

[0054] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator member. During charging and discharging of the battery cell, active ions (e.g., lithium ions) are absorbed and released by oscillating between the positive electrode and the negative electrode. The separator member, located between the positive electrode and the negative electrode, prevents short-circuiting between the positive and negative electrodes while allowing the active ions to pass through.

[0055] In some embodiments, the positive electrode may be a positive electrode plate, which 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.

[0056] For example, a positive electrode current collector has two surfaces that face each other in the thickness direction of the positive electrode current collector, and a positive electrode active material is disposed on one or both of the two facing surfaces of the positive electrode current collector.

[0057] For example, the positive electrode current collector may be a metal foil sheet or a composite current collector. For example, the metal foil sheet may be silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, or polyethylene).

[0058] For example, the positive electrode active material may include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound thereof, but the present application is not limited to these materials and other conventional materials that can be used as positive electrode active materials in batteries may also be used.

[0059] In some examples, the negative electrode may be a negative electrode plate, and the negative electrode plate may include a negative electrode current collector.

[0060] For example, the negative electrode current collector may be a metal foil sheet or a composite current collector, such as silver-surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium.

[0061] In some embodiments, the negative electrode current collector has two surfaces facing each other in the thickness direction thereof, and the negative electrode active material is disposed on one or both of the two facing surfaces of the negative electrode current collector.

[0062] For example, the negative electrode active material may be a negative electrode active material for batteries known in the art. For example, the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material may be selected from at least one of silicon elemental, silicon oxide compounds, silicon carbon composites, silicon nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of tin elemental, stannic oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative electrode active material may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0063] In some embodiments, the separator member is a separator film. The present application does not particularly limit the type of separator, and any known porous structure separator with good chemical stability and mechanical stability may be selected.

[0064] For example, the main material of the separator may be at least one selected from glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator may be a single-layer film or a multi-layer composite film, without any particular limitation. When the separator is a multi-layer composite film, the materials of each layer may be the same or different, without any particular limitation. The separator member may be a separate member located between the positive and negative electrodes, or may be attached to the surfaces of the positive and negative electrodes.

[0065] In some embodiments, the separator member is a solid electrolyte that is disposed between the positive and negative electrodes and simultaneously functions to transport ions and separate the positive and negative electrodes.

[0066] In some embodiments, the electrode assembly is a wound structure, and the positive and negative electrode plates are wound into the wound structure.

[0067] In some embodiments, the electrode assembly is a laminate structure.

[0068] In some embodiments, the battery cell may include an outer housing. The outer housing may be used to package components such as the electrode assembly and the electrolyte. The outer housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), an aluminum-plastic film, or the like.

[0069] In some embodiments, the outer housing includes an end cap and a case, the case having an opening, and the end cap closing the opening to form a sealed space for containing the electrode assembly and materials such as an electrolyte. The case may have one or more openings. One or more end caps may be provided.

[0070] In some embodiments, at least one electrode terminal is provided on the outer housing and electrically connected to a tab of the electrode assembly. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via an interposer. The electrode terminal may be provided on an end cap or on the case.

[0071] In some embodiments, an explosion-proof valve is installed on the outer housing, which is used to release the internal pressure of the battery cell.

[0072] For example, the battery cells may be cylindrical, prismatic, pouch, or other shaped battery cells, and the prismatic battery cells include prismatic, blade-shaped, and polygonal prismatic batteries, and the polygonal prismatic batteries include, for example, hexagonal prismatic batteries, and the embodiments of the present application are not particularly limited. Referring to Figure 3, the embodiments of the present application take prismatic battery cells as an example.

[0073] For example, as shown in Figure 2, a battery includes a housing and battery cells, and the housing includes an upper case and a lower case. When battery cells are installed in a housing, the volume of the battery cells changes significantly during charging and discharging. The high expansion of the battery cells makes the battery housing more susceptible to pressure deformation, which affects the battery's service life. In conventional technology, a cushion is installed between adjacent battery cells in the battery housing to reduce the pressure of the battery cells against the housing. However, during the battery charging and discharging process, the high expansion of the battery cells can cause structural damage and even cause the battery cells to expire, shortening the battery's service life.

[0074] In order to reduce the probability of a battery having a short service life due to high expansion of the battery cell, the inventors have discovered that the structure of the battery cell can be improved. Specifically, the battery cell according to the present application includes an outer housing and an electrode assembly, the electrode assembly is installed in the outer housing, and a buffer member is further provided in the outer housing, and the buffer member is deformable when the electrode assembly is deformed.

[0075] In a battery cell having the above structure, by installing a buffer member inside the outer housing, when the battery cell is charged or discharged, the buffer member deforms in accordance with the deformation of the electrode assembly, changing the space inside the battery cell that accommodates the electrode assembly. This reduces the stress that the electrode assembly experiences when it expands, and at the same time reduces the amount of deformation that occurs in the outer housing of the battery cell, thereby alleviating the problem of high expansion during charging and discharging of the battery cell and extending the service life of the battery cell.

[0076] The battery cells disclosed in the embodiments of the present application can be used in power consumption devices such as, but not limited to, vehicles, ships, or aircraft, and the power supply system of such power consumption devices can be configured using the batteries disclosed in the present application to ensure the safety and reliability of use of the power consumption devices.

[0077] An embodiment of the present application provides a power-consuming device that uses a battery as a power source, and the power-consuming 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 steamship, a spacecraft, etc. Here, the electric toy may include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric steamship toy, and an electric plane toy, and the spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0078] For convenience of explanation, the following embodiment will be described taking an example in which the power consuming device in one embodiment of the present application is a vehicle.

[0079] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range extender vehicle, etc. A battery cell 100 is installed inside the vehicle 1000, and the battery cell 100 may be installed at the bottom, head, or tail of the vehicle 1000. The battery cell 100 may be used to power the vehicle 1000, for example, as an operating power source for the vehicle 1000, and may be used in the circuit system of the vehicle 1000, for example, for starting the vehicle 1000, navigation, and operating power consumption needs during driving.

[0080] The vehicle 1000 may further include a controller 200 and a motor 300, where the controller 200 is used to control the battery 100 to power the motor 300 for use in, for example, starting the vehicle 1000, navigation, and operating power consumption needs during driving.

[0081] In some embodiments of the present application, the battery 100 can not only be the operating power source for the vehicle 1000, but can also be the driving power source for the vehicle 1000, providing driving power to the vehicle 1000 in place of or in place of fuel oil or natural gas.

[0082] Optionally, as shown in Figure 1, when the battery cells are used in a vehicle, a battery can be formed by a plurality of battery cells, and the battery cells and the battery can be installed at the bottom, head, or tail of the vehicle. The battery cells can be used to supply power to the vehicle, for example, the battery cells can be used as an operating power source for the vehicle. The vehicle can further include a controller and a motor, and the controller can be used to control the battery cells to supply power to the motor for use in, for example, starting the vehicle, navigation, and operating power consumption needs during driving.

[0083] Referring to FIG. 2, FIG. 2 is an exploded view of a battery 2000 according to some embodiments of the present application. The battery 2000 includes a housing 400 and a battery cell 100 housed within the housing 400. Here, the housing 400 is used to provide a housing space for the battery cell 100, and the housing 400 may adopt various structures. In some embodiments, the housing 400 may include a first portion 410 and a second portion 420, the first portion 410 and the second portion 420 being placed over each other, and the first portion 410 and the second portion 420 jointly defining a housing space for housing the battery cell 100. The second part 420 has a hollow structure with one end open, and the first part 410 may have a plate-like structure, and the first part 410 is placed over the open side of the second part 420, thereby defining an accommodation space together with the second part 420. The first part 410 and the second part 420 may both have a hollow structure with one end open, and the open side of the first part 410 is placed over the open side of the second part 420. Of course, the housing 400 formed by the first part 410 and the second part 420 may have various shapes, such as a cylinder or a rectangular parallelepiped.

[0084] The battery 2000 may include a plurality of battery cells 100, and the plurality of battery cells 100 may be connected in series, parallel, or series-parallel. A series-parallel connection means that the plurality of battery cells 100 may be connected in series or in parallel. The plurality of battery cells 100 may be directly connected in series, parallel, or series-parallel, and the entire battery set made up of the plurality of battery cells 100 may be housed in the housing 400. Of course, the battery 2000 may be formed by first connecting the plurality of battery cells 100 in series, parallel, or series-parallel to form a battery module, and then connecting the plurality of battery modules in series, parallel, or series-parallel to form an integrated battery module housed in the housing 400. The battery 2000 may further include other structures; for example, the battery 2000 may further include bus bar members for electrically connecting the plurality of battery cells 100 together.

[0085] A battery cell 100 according to an embodiment of the present application will be described below in conjunction with the drawings.

[0086] As shown in Figures 3 and 4, a battery cell 100 according to an embodiment of the present application includes an outer housing 10 and an electrode assembly 20, the electrode assembly 20 is installed in the outer housing 10, and a buffer member 30 is further provided in the outer housing 10, so that the buffer member 30 can be deformed when the electrode assembly 20 is deformed.

[0087] The outer housing 10 refers to the outermost structural member of the battery cell 100, and the electrode assembly 20, electrolyte, etc. are housed within the outer housing 10, and the outer housing 10 here may be an aluminum housing.

[0088] The electrode assembly 20 is installed in the outer housing 10. The electrode assembly 20 may be a stacked type, i.e., multiple electrode plates of the electrode assembly 20 are stacked and arranged, or the electrode assembly 20 may be a wound type, i.e., the positive electrode plate and the negative electrode plate of the electrode assembly 20 are overlapped and then wound. Furthermore, one electrode assembly 20 or multiple electrode assemblies 20 may be installed in the outer housing 10.

[0089] The buffer member 30 is installed within the outer housing 10, i.e., the buffer member 30 is located inside one battery cell 100. The buffer member 30 may be located between the outer housing 10 and the electrode assembly 20, or may be located between adjacent electrode assemblies 20, or may even be located inside the electrode assembly 20, i.e., the buffer member 30 is located between the positive and negative electrode plates.

[0090] When the battery cell 100 is charged or discharged and the electrode assembly 20 expands and deforms, the expansion of the electrode assembly 20 compresses the buffer member 30, compressing and deforming the buffer member 30, reducing the space occupied by the buffer member 30 and thereby increasing the space within the outer housing 10 for accommodating the electrode assembly 20. The expanding portion of the electrode assembly 20 can occupy this space, thereby reducing the stress experienced by the electrode assembly 20 when it expands. At the same time, the deformation of the outer housing 10 is minimized, avoiding damage to the battery or power consumption devices or shortening their service life due to transient deformation of the outer housing 10.

[0091] In the battery cell 100 having the above structure, by installing the buffer member 30 inside the outer housing 10, when the battery cell 100 is charged or discharged, the buffer member 30 deforms in accordance with the deformation of the electrode assembly 20, changing the space inside the battery cell that accommodates the electrode assembly 20. This reduces the stress that the electrode assembly 20 experiences when it expands, and at the same time reduces the amount of deformation that occurs in the outer housing 10 of the battery cell 100, thereby alleviating the problem of high expansion during charging or discharging of the battery cell 100 and extending the service life of the battery cell 100.

[0092] In some embodiments, the buffer member 30 corresponds to at least the largest surface area of ​​the electrode assembly 20 .

[0093] 4 and 9, some electrode assemblies 20 have two end faces and four side faces, of which two opposing side faces have relatively large areas, i.e., the large faces of the electrode assembly 20, and the other two opposing side faces have relatively small areas, i.e., the small faces of the electrode assembly 20. The buffer members 30 correspond to the large faces, or both the large and small faces have corresponding buffer members 30, or one end face and the large face have corresponding buffer members 30, or two end faces and the large faces have corresponding buffer members 30. When the electrode assembly 20 expands, the amount of expansion of the large faces is relatively large. Therefore, by arranging the buffer members 30 facing the large faces of the electrode assembly 20, the expansion of the large faces can be absorbed as much as possible, thereby reducing the stress experienced by the electrode assembly 20 due to expansion.

[0094] In some embodiments, the cushioning member 30 is formed in a sheet shape.

[0095] Here, the buffer member 30 can be formed in the shape of a square sheet, a circular sheet, or a triangular sheet. In the above technical solution, by installing it in a sheet-like structure, it is possible to easily install the buffer member 30 within the battery cell 100 and at the same time reduce the space occupied by the buffer member 30 as much as possible.

[0096] In some embodiments, one side of the buffer member 30 that comes into contact with the electrode assembly 20 is a smooth plane, which can avoid problems such as uneven force and excessive local stress due to point contact.

[0097] As can be appreciated, the cushioning member 30 can form a single layer or a multi-layer sheet-like structure, which can form a unitary structure, improving the stability of the cushioning member 30 while also facilitating assembly of the cushioning member 30 within the battery cell 100.

[0098] In some embodiments, the buffer member 30 has a lightweight structure. In the above technical solution, the weight of the buffer member 30 can be reduced by providing a lightweight structure, which can further reduce the weight of the entire battery.

[0099] In some embodiments, the weight-reducing structure is at least one of a groove, a hole, and a roughened surface.

[0100] The lightweight structure can be designed by providing grooves or holes in the buffer member 30 or by roughening the surface of the buffer member 30, and multiple types of lightweight structures can be installed.

[0101] In the above technical solution, a structure such as a groove is provided to reduce the weight of the buffer member 30, on the premise that the elasticity is not affected.

[0102] In some embodiments, a filler is provided within the lightweight structure, and the filler is at least one of a reactive ion replenisher, a flame retardant / safety agent, and a leaching metal element complexing agent.

[0103] That is, a reactive ion replenisher, such as a lithium replenisher or a sodium replenisher, may be further installed in the lightweight structure to replenish the reactive ions and thereby improve the service life of the battery cell 100; an eluted metal complexing agent may be installed in the lightweight structure to complex with the reactive ions, reducing catalytic activity and preventing excess reactive ions from accumulating and depositing and piercing the separator member, causing a short circuit, etc.

[0104] A flame retardant or safety agent may also be incorporated into the lightweight structure. The flame retardant may be aluminum hydroxide, magnesium hydroxide, zinc borate, silicon flame retardant, phosphate, ammonium polyphosphate, silicate, etc., or a coating material such as boehmite aluminum oxide may be used to improve the chemical stability of the buffer material. The safety agent may be a carbonate-based material that decomposes non-flammable carbon dioxide at high temperatures and pre-opens the explosion-proof valve, thereby performing an active safety function. In other words, the incorporation of a flame retardant can improve safety performance. In other words, the lightweight structure can incorporate various functional agents that are beneficial to the performance of the battery cell.

[0105] In the above technical solution, the filler is installed to improve the service life of the battery cell 100, or to reduce the catalytic activity of the transition metal after it is dissolved through complexation, thereby ensuring the chemical stability of the battery cell 100.

[0106] In some embodiments, the outer surface of the cushioning member 30 is coated with a flame retardant and / or has a molded material on the outer surface of the cushioning member 30.

[0107] The flame retardant may be aluminum hydroxide, magnesium hydroxide, zinc borate, silicon flame retardant, phosphate, ammonium polyphosphate, silicate, etc., or a coating material such as boehmite aluminum oxide may be used to improve the chemical stability of the buffer material, or a carbonate-based material may be used to decompose non-flammable carbon dioxide at high temperatures and pre-open the explosion-proof valve, thereby playing an active safety role; that is, the installation of a flame retardant can improve safety performance.

[0108] The molding material may be a ceramic material, and by installing the molding material, it is possible to prevent thermal shrinkage or wrinkles of the buffer member 30 located between the electrode plate layers after the buffer member 30 is hot-pressed together with the electrode assembly 20, thereby improving the stability of the structure.

[0109] As can be understood, the structure coated or provided on the outer surface of the cushioning member 30 is part of the cushioning member 30, and when calculating the thickness of the cushioning member 30, the thickness of the entire cushioning member 30 is calculated, and there is no need to remove the additional structure such as the coating.

[0110] In the above technical solution, the addition of a flame retardant can improve safety performance and prevent thermal runaway, heat propagation, etc., and the addition of a shaped material can prevent thermal shrinkage or wrinkles of the buffer member 30 located between the electrode plate layers after the buffer member 30 is hot-pressed together with the electrode assembly 20.

[0111] In addition, the outer surface of the buffer member 30 may be further coated with a lithium replenisher or a sodium replenisher to improve the service life of the battery cell 100, or may be coated with an eluted metal complexing agent, whose complexing effect reduces catalytic activity.

[0112] In some embodiments, cushioning member 30 comprises one or more of rubber, foam, aerogel, a polymeric polymer, such as silica gel, or the like.

[0113] In some examples, the cushioning member 30 may be made of one of rubber, foam, aerogel, and silica gel, or the cushioning member 30 may be a composite member formed by combining rubber, foam, aerogel, and silica gel.

[0114] In the above technical solution, by using such a high molecular weight polymer, the elastic performance of the buffer member 30 can be improved and the manufacturing cost can be reduced.

[0115] In some embodiments, a buffer member 30 is provided between the outer housing 10 and the electrode assembly 20 .

[0116] By providing the buffer member 30 on the outer housing 10 and the electrode assembly 20, when the battery cell 100 is charged or discharged, the buffer member 30 is compressed and deformed as the electrode assembly 20 expands, thereby increasing the space inside the battery cell 100 for accommodating the electrode assembly 20 and reducing the stress experienced by the electrode assembly 20 due to expansion. At the same time, the probability of deformation of the outer housing 10 can be effectively reduced, thereby alleviating the problem of high expansion during charging or discharging of the battery cell 100 and extending the service life of the battery cell 100.

[0117] In the above technical solution, the buffer member 30 is installed between the outer housing 10 and the electrode assembly 20, which is easy to install and can effectively reduce the probability of the outer housing 10 being deformed.

[0118] In some embodiments, the outer housing 10 includes a case 11 and an end cap 12, the case 11 having a storage cavity open on one side, the end cap 12 fitting with the case 11 to seal the storage cavity, and the buffer member 30 being positioned between the case 11 and the electrode assembly 20.

[0119] The case 11 and the end cap 12 are fitted together to form the entire outer housing 10, and the buffer member 30 is installed between the case 11 and the electrode assembly 20, thereby reducing the space occupied by the buffer member 30 and improving energy density, while also making it easy to install.

[0120] In some embodiments, the buffer members 30 correspond to the two sides of the case 11 with the largest area and the bottom wall of the case 11 .

[0121] The side of the case 11 includes two large surfaces and two small surfaces. Because the large surfaces expand relatively greatly, the buffer member 30 is placed opposite the two large surfaces to effectively absorb the expansion of the electrode assembly 20 and reduce the expansion stress experienced by the electrode assembly 20. A portion of the buffer member 30 corresponds to the bottom wall of the case 11, allowing the buffer member 30 to form an integrated U-shaped structural member. This makes it easier to assemble the buffer member 30 and the case 11, and the buffer member 30 is less likely to displace.

[0122] In the above technical solution, the buffer member 30 faces two large surfaces, thereby achieving the effect of effectively absorbing the amount of expansion; at the same time, the buffer member 30 forms an integral member, which makes it easy to assemble the buffer member 30 inside the case 11.

[0123] In some embodiments, the cushioning member 30 is formed on the inner wall of the outer housing 10, and the compressibility of the cushioning member 30 is in the range of 10% to 90% of the sum of the wall thickness of the outer housing 10 and the thickness of the cushioning member 30.

[0124] Here, the compressibility of the buffer member 30 is Q, the wall thickness of the outer housing 10 is B, and the thickness of the buffer member 30 is the initial thickness D0 of the buffer member 30. That is, the range of Q / (B+D0) is 10% to 90%. If this ratio is too large, the compressibility of the buffer member 30 is too large, and generally a buffer member 30 with a relatively large thickness is required. If the buffer member 30 occupies too much space, it is likely to affect the energy density of the battery cell 100. If this ratio is too small, the compressibility of the buffer member 30 is relatively small, and it is difficult to absorb deformation of the electrode assembly 20. Therefore, Q / (B+D0) is limited to the range of 10% to 90%, that is, Q / (B+D0) may be 10%, 90%, or any value between 10% and 90%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, etc.

[0125] In the above technical solution, the buffer member 30 can effectively absorb the expansion of the electrode assembly 20, thereby reducing the probability of deformation of the outer housing 10, and at the same time, does not occupy excessive space, avoiding a decrease in the energy density of the battery cell 100.

[0126] As shown in FIG. 8 , in some examples, an inner housing 13 that encases the electrode assembly 20 is further provided within the outer housing 10, and one or more electrode assemblies 20 are provided within the inner housing 13. A buffer member 30 is positioned between the outer housing 10 and the inner housing 13. When the electrode assembly 20 deforms, the inner housing 13 can be deformed accordingly, further driving the buffer member 30 to deform. The buffer member 30 can buffer the expansion and deformation of the electrode assembly 20 and reduce the stress that the electrode assembly 20 experiences when it expands.

[0127] In some embodiments, the thermal conductivity of the buffer member 30 is greater than 0.3 W / (m·° C.).

[0128] By installing the buffer member 30 with a relatively large thermal conductivity coefficient, the heat of the electrode assembly 20 can be quickly transferred to the outer housing 10 through the buffer member 30 and then dissipated through the outer housing 10, improving the safety performance of the battery cell 100.

[0129] In some specific embodiments, the buffer member 30 is installed between the outer housing 10 and the electrode assembly 20, and the porosity of the buffer member 30 is between 20% and 30%. When the thermal conductivity coefficient α of the buffer member 30 is greater than or equal to 0.3 W / (m·°C), the safety and expiration temperature can be improved, and the service life of the battery cell 100 can be extended. Some specific embodiments are shown in the table below.

[0130] [Table 1]

[0131] Here, the test method for the capacity retention rate of the battery cell 100 is as follows: Taking a sodium-ion battery as an example, a freshly manufactured sodium-ion battery was taken, fully discharged, charged to 100% SOC, and then fully discharged to the lower limit voltage of 0% SOC. The initial discharge capacity of the battery, Cap0, was recorded. After that, 100 charge-discharge cycles were performed at 25°C and 1C, and the battery was fully discharged to the lower limit voltage of 0% SOC. The discharge capacity of the sodium-ion battery after the 100th cycle, Cap1, was recorded, and the capacity retention rate of the sodium-ion battery, K=(Cap1-Cap0) / Cap0×100%, was calculated.

[0132] Mass energy density (unit: Wh / Kg) test method: At 25°C, charge the battery to the upper limit voltage at a rate of 0.33C, then discharge to the lower limit voltage at a rate of 0.33C. Mass energy density (Wh / kg) = discharge capacity * discharge platform voltage / (total mass of battery cell).

[0133] In some embodiments, the buffer member 30 is coated with a thermally conductive coating or is made of a thermally conductive material.

[0134] To meet the thermal conductivity of the buffer member 30, a thermally conductive coating may be applied to the buffer member 30. The thermally conductive coating may be silicate, graphene, zirconium oxide, or the like. The buffer member 30 may also be directly manufactured using a thermally conductive material. For example, the buffer member 30 may be made of silica gel with a thermal conductivity of 0.8 W / (m·°C) to 2.0 W / (m·°C).

[0135] In some embodiments, the cushioning member 30 is adhered to the outer housing 10 and / or the electrode assembly 20 .

[0136] The buffer member 30 may be bonded to the outer housing 10, so that the buffer member 30 and the outer housing 10 form an integral structure, improving the stability and reliability of the buffer member 30; the buffer member 30 may be bonded to the electrode assembly 20, so that the buffer member 30 and the electrode assembly 20 form an integral structure, improving the stability and reliability of the buffer member 30; the buffer member 30 may also be bonded to the outer housing 10 and the electrode assembly 20 simultaneously, improving the fixing reliability of the buffer member 30 and the stability of the overall structure of the battery cell 100.

[0137] The above technical solution can improve the reliability of fixing the buffer member 30.

[0138] In some embodiments, the electrode assemblies 20 are plural, and a buffer member 30 is provided between at least two adjacent electrode assemblies 20 .

[0139] As shown in Figures 11 and 12, a buffer member 30 is provided between adjacent electrode assemblies 20. For example, a buffer member 30 may be installed between any two adjacent electrode assemblies 20, or a buffer member 30 may be installed between some two adjacent electrode assemblies 20. Thus, the number of buffer members 30 may be one or more, and the total compressible amount of the buffer member 30 is set to be equal to or greater than the expansion amount of the plurality of electrode assemblies 20 as much as possible.

[0140] In the above technical solution, by installing the buffer member 30 between the electrode assemblies 20, the buffer member 30 can effectively absorb the expansion of the electrode assemblies 20 and reduce the stress that the electrode assemblies 20 experience due to expansion.

[0141] In some embodiments, the electrode assembly 20 includes multiple plates, with a buffer member 30 provided between at least two adjacent plates.

[0142] As shown in Figures 13 and 14, a buffer member 30 is provided between adjacent electrode plates. For example, a buffer member 30 may be installed between any two adjacent electrode plates, or a buffer member 30 may be installed between some two adjacent electrode plates. Thus, the number of buffer members 30 may be one or more, and the total compressible amount of the buffer members 30 should be greater than or equal to the expansion amount of the electrode assembly 20 as much as possible.

[0143] In the above technical solution, the buffer member 30 is installed between the electrode plates, so that the buffer member 30 can effectively absorb the expansion of the electrode plates, and further reduce the stress when the electrode assembly 20 expands.

[0144] In some embodiments, the electrode assembly 20 further includes a separator member 23 , the plates include a positive electrode plate 21 and a negative electrode plate 22 , and the buffer member 30 is provided between the separator member 23 and the negative electrode plate 22 .

[0145] Because the deformation of the negative electrode plate 22 is relatively large, the buffer member 30 is installed between the separator member 23 and the negative electrode plate 22, which can effectively absorb the expansion of the negative electrode plate 22 and further reduce the stress that the electrode assembly 20 receives when it expands.

[0146] In some embodiments, the thermal conductivity of buffer member 30 is less than or equal to 0.2 W / (m·° C.).

[0147] If the thermal conductivity coefficient α of the buffer member 30 is too large, heat is likely to dissipate between adjacent electrode assemblies 20 or adjacent electrode plates through the buffer member 30, affecting the safety performance of the battery cell 100. Therefore, the thermal conductivity coefficient α should be ≦0.2 W / (m·°C), which will improve the overall failure temperature and enhance safety.

[0148] The above technical solution can achieve effective heat insulation and improve safety performance.

[0149] In some specific embodiments, the buffer member 30 is installed between two adjacent electrode assemblies 20 or between the plates of the electrode assemblies 20, and the porosity of the buffer member 30 is between 20% and 30%. When the thermal conductivity coefficient α of the buffer member 30 is greater than or equal to 0.3 W / (m·°C), the safety and the expiration temperature can be improved, and the service life of the battery cell 100 can be extended. Some specific embodiments are shown in the table below.

[0150] [Table 2]

[0151] When the buffer member 30 is installed between adjacent electrode plates or adjacent electrode assemblies 20, it must have a certain level of thermal insulation ability. In this case, a buffer member 30 with a low thermal conductivity can be used to distribute some of the heat to the electrode assembly 20. The thermal conductivity of the insulating layer 32 may be limited to within 0.2 W / (m·°C), achieving a thermal insulation effect and preventing heat accumulation in the electrode assembly 20 due to the buffer member 30 having an excessively high thermal conductivity. This prevents heat from being rapidly transferred between adjacent electrode plates or adjacent electrode assemblies 20, which could affect the safety performance of the battery cell 100. The method for testing the capacity retention rate of the battery cell 100 is the same as described above, and will not be described further here.

[0152] In some embodiments, at a preset pressure, the amount of compressibility of the cushioning member 30 is equal to or greater than the amount of expansion of the electrode assembly 20 .

[0153] Here, the compressibility of the buffer member 30 is Q, and the compressibility Q is the thickness D1 of the buffer member 30 after being compressed under the action of a predetermined pressure, compared to the thickness D0 of the buffer member 30 in its initial free state, i.e., Q=D0-D1. The predetermined pressure here may be the maximum surface pressure that the electrode assembly 20 receives.

[0154] It should be noted that when one buffer member 30 is installed, the thickness D0 of the buffer member 30 in its initial free state is the thickness of the buffer member 30 in its free state when the electrode assembly 20 is in a fully discharged state, and the thickness D1 of the buffer member 30 after compression is the thickness of the buffer member 30 when the electrode assembly 20 is in a fully charged state.

[0155] When multiple buffer members 30 are installed, the thickness D0 of the buffer member 30 in the initial free state is the sum of the thicknesses of the multiple buffer members 30 in the free state, and the thickness D1 of the buffer member 30 after compression is the sum of the thicknesses of the multiple buffer members 30 after compression; or when the buffer member 30 includes multiple portions corresponding to large surfaces of the electrode assembly 20, the thickness D0 of the buffer member 30 in the initial free state is the sum of the thicknesses of the multiple portions of the buffer member 30 in the free state, and the thickness D1 of the buffer member 30 after compression is the sum of the thicknesses of the multiple portions of the buffer member 30 For example, as shown in Figures 6 and 7, the buffer member 30 is located between the outer housing 10 and the electrode assembly 20, and includes two portions corresponding to the large surfaces of the electrode assembly 20. If the thicknesses of the two portions are the same, the thickness of each portion in the free state is D0 / 2, and the thickness of each portion after compression is D1 / 2. If the thicknesses of the two portions are different, the sum of the thicknesses of the two portions in the free state is D0, and the sum of the thicknesses of the two portions after compression is D1.

[0156] The expansion amount here is W, and the expansion amount W is the difference between the total thickness W1 of the electrode assembly 20 when fully charged at 100% SOC (charged state) and the thickness W2 of the electrode assembly 20 when fully discharged at 0% SOC, i.e., W=W1-W2.

[0157] It should be noted that when one electrode assembly 20 is provided within the outer housing 10, the total thicknesses W1 and W2 of the electrode assembly 20 are the thicknesses W1 and W2 of this electrode assembly 20, and when multiple electrode assemblies 20 are provided within the outer housing 10, the total thicknesses W1 and W2 of the electrode assemblies 20 are the sums W1 and W2 of the thicknesses of the multiple electrode assemblies 20. As shown in Figures 10 and 11, when two electrode assemblies 20 are provided within the outer housing 10, the thickness of each electrode assembly 20 when fully charged to 100% SOC (charged state) is W1 / 2, and the thickness of each electrode assembly 20 when fully discharged to 0% SOC (charged state) is W2 / 2.

[0158] Here, the thickness of the cushioning member 30 after compression and the thickness of the cushioning member 30 in its free state can be measured using a device such as a thickness gauge or a micrometer. Similarly, the total thickness of the electrode assembly 20 when fully charged (100% SOC) and when fully discharged (0% SOC) can be measured using a device such as a thickness gauge or a micrometer.

[0159] In the above technical solution, the buffer member 30 can absorb the expansion of the electrode assembly 20 as much as possible, reduce the stress that the electrode assembly 20 experiences due to the expansion, and further reduce the deformation of the entire battery cell 100, thereby improving the service life of the battery cell 100.

[0160] In some embodiments, the compressibility of the cushioning member 30 ranges from 1 mm to 100 mm.

[0161] The applicant has discovered that the maximum surface pressure received by the electrode assembly 20 does not exceed 0.8 MPa, and therefore, under a pressure of 0.8 MPa, the compressible amount Q of the buffer member 30 in the thickness direction of the electrode plate is in the range of 1 mm to 100 mm, i.e., Q may be 1 mm, 100 mm, or any value between 1 mm and 100 mm, for example, 2 mm, 4 mm, 6 mm, 7 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, 34 mm, 36 mm, 38 mm, 40 mm, 42 mm, 44 mm, 46 mm, 48 mm, 49 mm, 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm, 61 mm, 62 mm, 63 mm, 64 mm, 65 mm, 66 mm, 67 mm, 68 mm, 69 mm, 70 mm, 71 mm, 72 mm, 73 mm, 74 mm, 75 mm, 76 mm, 77 mm, 78 mm, 79 mm, 80 mm, 81 mm, 82 mm, 83 mm, 84 mm, 85 mm, 86 mm, 87 mm, 88 mm, 89 mm, 90 mm, 91 mm, 92 mm, 93 mm, 94 mm, 95 mm, 96 mm, 97 mm, 98 mm, 99 mm, 100 mm, 101 mm, 102 mm, 103 mm, 104 mm mm, 44 mm, 46 mm, 48 mm, 50 mm, 52 mm, 54 mm, 56 mm, 58 mm, 60 mm, 62 mm, 64 mm, 66 mm, 68 mm, 70 mm, 72 mm, 74 mm, 76 mm, 78 mm, 80 mm, 82 mm, 84 mm, 86 mm, 88 mm, 90 mm, 92 mm, 94 mm, 96 mm, 98 mm, etc., where if the compressible amount Q is too small, the buffer member 30 will not be able to effectively absorb the expansion of the electrode assembly 20, and if the compressible amount Q is too large, the space occupied by the buffer member 30 will be too large, which will likely affect the energy density of the battery cell 100. It should be noted that there may be multiple buffer members 30, and the compressible amount of the buffer members 30 here refers to the total compressible amount of the multiple buffer members 30.

[0162] In some preferred examples, the compressibility Q of the cushioning member 30 is in the range of 2 mm to 80 mm, i.e., Q may be 2 mm, 80 mm, or any value between 2 mm and 80 mm, for example, 4 mm, 6 mm, 7 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, 34 mm, 36 mm, 38 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm m, 42 mm, 44 mm, 46 mm, 48 mm, 50 mm, 52 mm, 54 mm, 56 mm, 58 mm, 60 mm, 62 mm, 64 mm, 66 mm, 68 mm, 70 mm, 72 mm, 74 mm, 76 mm, 78 mm, etc., so that the buffer member 30 can effectively absorb the amount of expansion of the electrode assembly 20, and at the same time, the buffer member 30 does not occupy excessive space, ensuring that the energy density of the battery cell 100 is relatively high.

[0163] The above technical solution not only reduces the stress that the electrode assembly 20 experiences due to expansion, but also prevents the buffer member 30 from occupying too much space and affecting the energy density of the battery cell 100.

[0164] In some embodiments, the expansion of the electrode assembly 20 ranges from 0.2 mm to 80 mm.

[0165] That is, the electrode assemblies 20 include those having a small expansion amount of 0.2 mm, those having a large expansion amount of 80 mm, and those having an expansion amount of any value between 0.2 mm and 80 mm, for example, 0.3 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, 21 mm, 23 mm, 25 mm, 27 mm, 29 mm, 31 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm, 61 mm, 62 mm, 63 mm, 64 mm, 65 mm, 66 mm, 67 mm, 68 mm, 69 mm, 70 mm, 71 mm, 72 mm, 73 mm, 74 mm, 75 mm, 76 mm, 77 mm, 78 mm, 79 mm, 80 mm, 81 mm, 82 mm, 83 mm, 84 mm, 85 mm, 86 mm, 87 mm, 88 mm, 89 mm, 90 mm, 91 mm, 92 mm, 93 mm, 94 mm, 95 mm, 96 mm, 97 mm, 98 mm, 99 mm, 100 mm, 101 mm, 10 In any case, by providing the buffer member 30, the buffer member 30 can be compressed to absorb the expansion of the electrode assembly 20 and reduce the stress experienced by the electrode assembly 20. It should be noted that there may be a plurality of electrode assemblies 20, and the expansion amount of the electrode assembly 20 here refers to the total expansion amount of the plurality of electrode assemblies 20.

[0166] In some preferred examples, the expansion amount of the electrode assembly 20 is between 0.5 mm and 70 mm, i.e., the expansion amount of the electrode assembly 20 may be 0.5 mm, 0.8 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, 21 mm, 23 mm, 25 mm, 27 mm, 29 mm, 31 mm, 33 mm, 35 mm, 37 mm, 39 mm, 1 mm, 43 mm, 45 mm, 47 mm, 49 mm, 51 mm, 53 mm, 55 mm, 57 mm, 59 mm, 61 mm, 63 mm, 65 mm, 67 mm, 69 mm, 70 mm, etc.

[0167] In the above technical solution, the buffer member 30 can absorb the expansion of the electrode assembly 20 as much as possible, thereby reducing the stress that the electrode assembly 20 experiences when it expands.

[0168] In some examples, the compressibility of the cushioning member 30 is between 10% and 95%.

[0169] The compressible ratio of the buffer member 30 is K, where K=Q / D0, where Q is the compressible amount of the buffer member 30, Q=D0-D1, D1 is the thickness of the buffer member 30 after compression, D0 is the thickness of the buffer member 30 in its initial free state, and K=(D0-D1) / D0. If the compressible ratio of the buffer member 30 is less than 10%, the compressible amount of the buffer member 30 is relatively small and it is difficult to absorb deformation of the electrode assembly 20. If the compressible ratio of the buffer member 30 is greater than 95%, a buffer member 30 with a relatively large thickness is generally required, and if the space occupied by the buffer member 30 is too large, it is likely to affect the energy density of the battery cell 100. Therefore, the compressible ratio K of the buffer member 30 may be 10% or 95%. The thickness of the cushioning member 30 after compression and in its free state can be measured using a device such as a thickness gauge or a micrometer.

[0170] In some preferred examples, the compressible ratio K of the cushioning member 30 is 10% to 90%, and the compressible ratio K of the cushioning member 30 may be 10%, 95%, or any value between 10% and 95%, for example, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94%, etc., which ensures that the buffer member 30 can buffer the expansion and deformation of the electrode assembly 20, reduce the stress that the electrode assembly 20 experiences due to expansion, and improve the service life and safety performance.

[0171] In the above technical solution, the buffer member 30 can be compressed and deformed with the expansion of the electrode assembly 20, and absorbs the expansion of the electrode assembly 20 as much as possible.

[0172] In some examples, the expansion rate range of the electrode assembly 20 is between 5% and 200%.

[0173] Here, the expansion rate k is (the ratio of the total thickness of the electrode assembly 20 at 100% SOC when fully charged / the total thickness of the electrode assembly at 0% SOC) -1, i.e., k = W1 / W2 -1. That is, the electrode assemblies 20 include those having a small expansion rate of 5%, those having a large expansion rate of 200%, and those having an expansion rate of any value between 5% and 200%, for example, those having an expansion rate of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 210%, 220%, 230%, 240%, 250%, 260%, 270%, 280%, 290%, 310%, 320%, 330%, 340%, 350%, 360%, 370%, 380%, 390%, 410%, 420%, 430%, 440%, 450%, 460%, 470%, 480%, 490%, 510%, 520%, 530%, 540%, 550%, 560%, 570%, 580%, 590%, 610%, 620%, 630%, 640%, 650%, 660%, 670%, 680%, 690%, 710%, 720%, 730%, 740%, 750%, 760%, 770%, 05%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, etc., and in any case, by installing the buffer member 30, the buffer member 30 can be compressed to absorb the expansion of the electrode assembly 20, thereby reducing the stress received by the electrode assembly 20.

[0174] Here, the total thickness of the electrode assembly 20 when fully charged (100% SOC) and the thickness of the electrode assembly 20 when fully discharged (0% SOC) can be measured using a device such as a thickness gauge or a micrometer.

[0175] In some preferred examples, the expansion rate k of the electrode assembly 20 is in the range of 8% to 180%, i.e., the expansion rate k may be 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 175%, 180%, etc. At this expansion rate, the buffer member 30 can be effectively compressed and deformed accordingly, compressing the buffer member 30 to absorb the expansion of the electrode assembly 20 and reducing the stress experienced by the electrode assembly 20 due to expansion.

[0176] In the above technical solution, deformation occurring in the electrode assembly 20, which has a high expansion rate, is absorbed by the buffer member 30, thereby reducing the stress that the electrode assembly 20 experiences due to expansion and improving the service life of the battery cell 100.

[0177] In some embodiments, the ratio of the total volume of the buffer member 30 to the total volume inside the outer housing 10 is between 0.05 and 0.6.

[0178] To prevent the buffer member 30 from occupying too much space, which would affect the space of the electrode assembly 20 and affect the energy density of the battery cell 100, and at the same time ensure that the buffer member 30 can effectively absorb the expansion of the electrode assembly 20, the ratio of the total volume of the buffer member 300 to the total volume inside the outer housing 10 can be limited. Here, the total volume inside the outer housing 10 refers to the total volume of the accommodation space inside the outer housing 10, and the buffer member 30 here refers to the total volume of all the buffer members 30 installed in the outer housing 10. Of course, if only one buffer member 30 is installed in the outer housing 10, the total volume of the buffer member 30 is the volume of this buffer member 30.

[0179] In some specific embodiments, when the ratio of the total volume of the buffer member 30 to the total volume inside the outer housing 10 is 0.05 to 0.6, the capacity retention rate of the battery cells 100 can reach 90% or more, and the weight energy density is 150 Wh / kg or more, that is, the impact of the buffer member 30 on the weight energy density of the battery cells 100 is relatively small. Some specific embodiments are shown in the table below.

[0180] [Table 3]

[0181] This limits the ratio of the total volume of the buffer member 30 to the total volume inside the outer housing 10 to between 0.05 and 0.6, where the volume ratio may be 0.05, 0.6, or any value between 0.05 and 0.6, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, etc.

[0182] The above technical solution can avoid the buffer member 30 occupying too large a space, which would affect the space of the electrode assembly 20 and affect the energy density, and at the same time, it can avoid the buffer member 30 occupying too small a space, which would prevent it from effectively absorbing the expansion of the electrode assembly 20.

[0183] In some preferred examples, the ratio of the total volume of the buffer member 30 to the total volume inside the outer housing 10 is 0.08 to 0.55, where the volume ratio may be 0.08, 0.55, or any value between 0.08 and 0.55, such as 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.54, etc.

[0184] In some embodiments, the ratio of the area of ​​the buffer member 30 to the area of ​​the largest surface of the electrode assembly 20 is in the range of 0.1 to 1.

[0185] Here, the area of ​​the buffer member 30 may be the area of ​​the surface of the buffer member 30 that corresponds to the larger surface of the electrode assembly 20, and the area of ​​the buffer member 30 may be the same as the larger surface of the electrode assembly 20, or may be smaller than the size of the larger surface; that is, the buffer member does not have to completely cover the electrode assembly 20, but may have an area that partially overlaps the larger surface of the electrode assembly; that is, the ratio of the area of ​​the buffer member 30 to the area of ​​the surface of the electrode assembly 20 that has the largest area may be 0.1, 0.3, 0.5, 0.7, 0.9, etc.

[0186] In some preferred examples, the ratio of the area of ​​the buffer member 30 to the area of ​​the surface with the largest area of ​​the electrode assembly 20 is 0.2 to 0.95, i.e., the area ratio may be 0.2, 0.95, or any value between 0.2 and 0.95, such as 0.3, 0.5, 0.7, 0.9, etc.

[0187] The above technical solution can reduce the size of the elastic sheet, reduce costs, lighten the weight of the entire structure, and further lower the precision requirements for installing the elastic sheet, while still ensuring effective absorption of expansion.

[0188] In some embodiments, the ratio of the compressible amount of the buffer member 30 to the thickness of the electrode assembly 20 in the fully discharged state of the battery cell 100 ranges from 5% to 80%.

[0189] The compressibility of the buffer member 30 is Q, and when the battery cell 100 is in a fully discharged state, the thickness of the electrode assembly 20 is W2. Here, if Q / W2 is too small, the buffer member 30 has difficulty absorbing the expansion of the electrode assembly 20. If Q / W2 is too large, the buffer member 30 occupies too much space, which affects the energy density of the battery cell 100. Therefore, Q / W2 is limited to 5% to 80%, and Q / W2 may be 5%, 80%, or any value between 5% and 80%, such as 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, etc.

[0190] In some preferred examples, the ratio Q / W2 of the compressible amount of the buffer member 30 to the thickness of the battery cell 100 of the electrode assembly 20 in a fully discharged state is 6% to 70%, i.e., Q / W2 may be 6%, 70%, or any value between 6% and 70%, such as 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, etc.

[0191] The above technical solution improves the ability of the buffer member 30 to absorb the expansion of the electrode assembly 20 as much as possible, reducing the stress that the electrode assembly 20 experiences due to expansion, while also avoiding the buffer member 30 occupying too much space, which would affect the energy density of the battery cell 100.

[0192] In some embodiments, the battery cell 100 is a metal battery, which has a relatively high expansion rate. Therefore, by installing the buffer member 30 in the metal battery, the stress experienced by the electrode assembly 20 when it expands can be effectively reduced, and the service life of the battery cell 100 can be improved.

[0193] In some embodiments, the battery cell 100 is a sodium metal battery, which has a relatively high expansion rate. By installing the buffer member 30 in the sodium metal battery, the stress experienced by the electrode assembly 20 when it expands can be effectively reduced, reducing the amount of deformation occurring in the outer housing 10 of the sodium metal battery, alleviating the problem of high expansion during charging and discharging of the sodium metal battery, and improving the service life of the battery cell 100.

[0194] In some embodiments, the negative electrode plate 22 of the electrode assembly 20 includes a substrate and a conductive coating applied to a surface of the substrate.

[0195] By way of example, the conductive coating may be conductive carbon.

[0196] That is, the negative electrode plate 22 is composed of a substrate and a conductive coating on the substrate, and does not require the installation of a negative electrode active material layer. Since the negative electrode plate 22 expands relatively greatly when the battery cell 100 is charged or discharged, the installation of the buffer member 30 can effectively reduce the problem of high expansion of the negative electrode plate 22 during battery charging and discharging, and improve the service life of the battery cell 100.

[0197] The above technical solution can solve the problem of high expansion of metal batteries and improve the service life of metal batteries.

[0198] The battery 2000 according to the embodiment of the second aspect of the present application includes the battery cell 100 according to the embodiment of the first aspect of the present application.

[0199] The power consuming device according to the embodiment of the third aspect of the present application includes the battery cell 100 according to the embodiment of the first aspect of the present application, which is used to provide electrical energy to the power consuming device. Thus, the use of the above-mentioned battery cell 100 is advantageous in improving the safety and reliability of use of the power consuming device.

[0200] A battery cell 100 according to one specific embodiment of the present application will be described below in conjunction with the drawings.

[0201] As shown in Figures 5 to 7, the battery cell 100 includes an outer housing 10 and an electrode assembly 20. The outer housing 10 includes a case 11 and an end cap 12. The electrode assembly 20 is installed within the outer housing 10, with a buffer member 30 between the electrode assembly 20 and the case 11. The buffer member 30 includes a portion corresponding to the two large-area side surfaces of the case 11 and a portion corresponding to the bottom surface of the case 11. The buffer member 30 forms a U-shaped member and is adhesively fitted to the case 11. The buffer member 30 may be made of a rubber material, and is coated with a thermally conductive coating.

[0202] In the above embodiment, by installing the buffer member 30 in the outer housing 10 and the electrode assembly 20, when the battery cell 100 is charged or discharged, the buffer member 30 is compressed and deformed as the electrode assembly 20 expands, thereby increasing the space inside the battery cell 100 for accommodating the electrode assembly 20 and reducing the stress experienced by the electrode assembly 20 due to expansion. At the same time, the probability of deformation of the outer housing 10 is effectively reduced, thereby alleviating the problem of high expansion during charging and discharging of the battery cell 100 and extending the service life of the battery cell 100. Furthermore, heat from the electrode assembly 20 is quickly transferred to the outer housing 10 via the buffer member 30 and then dissipated through the outer housing 10, improving the safety performance of the battery cell 100.

[0203] A battery cell 100 according to another specific embodiment of the present application will be described below in conjunction with the drawings.

[0204] As shown in Figures 11 and 12, a battery cell 100 includes an outer housing 10 and a plurality of electrode assemblies 20. A buffer member 30 is provided between two adjacent electrode assemblies 20. The buffer member 30 corresponds to the large surface of the electrode assemblies 20, and the area of ​​the buffer member 30 is the same as the area of ​​the large surface of the electrode assemblies 20. The buffer member 30 may be made of silica gel, and may be coated with a heat-insulating coating.

[0205] In the above embodiment, by installing the buffer member 30 between two adjacent electrode assemblies 20, when the battery cell 100 is charged or discharged, the buffer member 30 is compressed and deformed as the electrode assemblies 20 expand, thereby increasing the space inside the battery cell 100 for accommodating the electrode assemblies 20 and reducing the stress experienced by the electrode assemblies 20 due to their expansion. At the same time, the probability of deformation of the outer housing 10 is effectively reduced, thereby alleviating the problem of high expansion during charging and discharging of the battery cells 100 and extending the service life of the battery cells 100. Furthermore, the heat from the electrode assemblies 20 is prevented from being rapidly transferred to adjacent electrode assemblies 20 via the buffer member 30, preventing rapid heat transfer between the electrode assemblies 20, and ensuring the safety performance of the battery cells 100.

[0206] A battery cell 100 according to another specific embodiment of the present application will be described below in conjunction with the drawings.

[0207] As shown in Figures 13 and 14, the battery cell 100 is a stacked battery, and the electrode assembly 20 of the battery cell 100 includes a positive electrode plate 21, a negative electrode plate 22, and a separator member 23 that are stacked, and the buffer member 30 is installed between the negative electrode plate 22 and the separator member 23.

[0208] In the above embodiment, by installing the buffer member 30 inside the electrode assembly 20, when the battery cell 100 is charged or discharged, the buffer member 30 is compressed and deformed as the electrode plates expand, thereby increasing the space inside the battery cell 100 for accommodating the electrode assembly 20 and further reducing the stress experienced by the electrode assembly 20 due to expansion. At the same time, the probability of deformation of the outer housing 10 can be effectively reduced, thereby alleviating the problem of high expansion during charging and discharging of the battery cell 100 and extending the service life of the battery cell 100.

[0209] Finally, it should be noted that the above embodiments are merely for illustrating the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications may still be made to the technical solutions described in the above embodiments, or equivalent substitutions may be made for some or all of the technical features therein. Such modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and should all be included in the scope of the claims and description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in the embodiments may be combined in any manner. The present application is not limited to the specific embodiments disclosed in the description, but includes all technical solutions included within the scope of the claims. [Explanation of symbols]

[0210] Vehicle 1000, controller 200, motor 300, battery 2000, housing 400, first part 410, second part 420, battery cell 100, outer housing 10, case 11, end cap 12, inner housing 13, electrode assembly 20, positive electrode plate 21, negative electrode plate 22, separator member 23, buffer member 30.

Claims

1. A battery cell, An outer housing; an electrode assembly, the electrode assembly being disposed within the outer housing; The battery cell further includes a buffer member provided within the outer housing, the buffer member being configured to be deformable when the electrode assembly is deformed.

2. The battery cell according to claim 1 , wherein the buffer member corresponds to at least the surface of the electrode assembly with the largest area.

3. The battery cell according to claim 1 or 2, wherein the buffer member is formed in a sheet shape.

4. The battery cell according to claim 1 , wherein the buffer member has a lightweight structure.

5. The battery cell according to claim 4 , wherein the weight-reducing structure is at least one of a groove, a hole, and a rough surface.

6. 6. The battery cell according to claim 4, wherein a filler is provided in the lightweight structure, and the filler is at least one of a reactive ion replenisher, a flame retardant / safety agent, and an eluted metal element complexing agent.

7. The battery cell according to claim 1 , wherein the outer surface of the buffer member is coated with a flame retardant and / or has a molded material on the outer surface of the buffer member.

8. The battery cell according to claim 1 , wherein the buffer member includes one or more of rubber, foam, aerogel, and a polymer such as silica gel.

9. The battery cell according to claim 1 , wherein the buffer member is provided between the outer housing and the electrode assembly.

10. 10. The battery cell according to claim 9, wherein the outer housing includes a case and an end cap, the case having an accommodating cavity open on one side, the end cap fitting with the case to seal the accommodating cavity, and the buffer member being provided between the case and the electrode assembly.

11. The battery cell according to claim 10 , wherein the buffer members correspond to the two largest side surfaces of the case and the bottom wall of the case.

12. 12. The battery cell according to claim 9, wherein the compressibility of the cushioning member is in the range of 10% to 90% of the sum of the thickness of the outer housing and the thickness of the cushioning member.

13. The battery cell according to claim 9 , wherein the buffer member has a thermal conductivity coefficient greater than 0.3 W / (m·° C.).

14. The battery cell according to claim 13 , wherein the buffer member is coated with a thermally conductive coating or is made of a thermally conductive material.

15. The battery cell according to claim 1 , wherein the buffer member is adhered to the outer housing and / or the electrode assembly.

16. The battery cell according to claim 1 , wherein the electrode assemblies are plural, and the buffer member is provided between at least two adjacent electrode assemblies.

17. The battery cell according to claim 1 , wherein the electrode assembly includes a plurality of electrode plates, and the buffer member is provided between at least two adjacent electrode plates.

18. 18. The battery cell of claim 17, wherein the electrode assembly further includes a separator member, the electrode plates include a positive electrode plate and a negative electrode plate, and the buffer member is provided between the separator member and the negative electrode plate.

19. 19. The battery cell according to claim 16, wherein the buffer member has a thermal conductivity coefficient of 0.2 W / (m·°C) or less.

20. The battery cell according to claim 1 , wherein the compressible amount of the buffer member is equal to or greater than the expansion amount of the electrode assembly.

21. At a predetermined pressure, the compressibility of the cushioning member is in the range of 1 mm to 100 mm; and / or 21. The battery cell according to claim 1, wherein the compressible ratio of the cushioning member is 10% to 95%.

22. The expansion of the electrode assembly ranges from 0.2 mm to 80 mm; and / or 22. The battery cell according to claim 1, wherein the expansion rate of the electrode assembly ranges from 5% to 200%.

23. the ratio of the total volume of the buffer member to the total volume inside the outer housing is between 0.05 and 0.6; and / or The ratio of the area of ​​the buffer member facing the electrode assembly to the area of ​​the surface of the electrode assembly that has the largest area is in the range of 0.1 to 1; and / or 23. The battery cell according to claim 1, wherein a ratio of a compressible amount of the buffer member to a thickness of the electrode assembly in a fully discharged state of the battery cell is in a range of 5% to 80%.

24. 24. The battery cell of claim 1, wherein the battery cell is a metal battery.

25. 25. The battery cell according to claim 1, wherein the negative electrode plate of the electrode assembly includes a substrate and a conductive coating applied to a surface of the substrate.

26. 26. The battery cell of claim 1, wherein the battery cell is a sodium metal battery.

27. A battery comprising a battery cell according to any one of claims 1 to 26.

28. 27. A power consuming device comprising a battery cell for supplying electrical energy according to any one of claims 1 to 26.

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