Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, the battery monomer is an alkali metal battery, the battery monomer comprises a shell, an electrode assembly, an electrode terminal and a first supporting piece, the shell is internally provided with a containing cavity, the shell comprises a first wall, a second wall and a third wall, and the first wall and the second wall are oppositely arranged; the third wall is arranged between the first wall and the second wall, one end of the third wall is connected to the first wall, the other end of the third wall is connected to the second wall, the electrode assembly is contained in the containing cavity and located between the first wall and the second wall, the electrode assembly comprises a pole piece, and the electrode terminal is arranged on the third wall and electrically connected to the electrode assembly. The first supporting piece is arranged between the first wall and the electrode assembly, a first cavity is formed between the first supporting piece and the first wall and / or between the first supporting piece and the electrode assembly, and the first cavity is communicated with the space where the pole piece is located.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] To improve battery energy density, the internal space of batteries is designed with limits to ensure that the group margin of electrode components reaches over 90%. However, this structure results in limited internal space. For battery cells with high gas production, insufficient internal space can easily lead to increased internal pressure during use, affecting battery life. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can increase the space inside the battery for accommodating gas and electrolyte, thereby improving the battery's service life.

[0005] In a first aspect, this application provides a battery cell, which is an alkali metal battery. The battery cell includes a casing, an electrode assembly, electrode terminals, and a first support member. The casing has an internal cavity and includes a first wall, a second wall, and a third wall. The first wall and the second wall are disposed opposite to each other, and the third wall is disposed between the first wall and the second wall. One end of the third wall is connected to the first wall and the other end is connected to the second wall. The electrode assembly is accommodated in the cavity and is located between the first wall and the second wall. The electrode assembly includes an electrode sheet. The electrode terminal is disposed on the third wall and electrically connected to the electrode assembly. The first support member is disposed between the first wall and the electrode assembly. A first cavity is formed between the first support member and the first wall and / or between the first support member and the electrode assembly. The first cavity is connected to the space where the electrode sheet is located.

[0006] In this embodiment, a first cavity is provided between the first support member and the first wall and / or between the first support member and the electrode assembly, which can reserve sufficient space in the cavity to accommodate the gas generated by the chemical reaction of the battery cell, reduce the internal gas pressure of the battery cell during use, and improve the long-term performance and service life of the battery cell.

[0007] In some embodiments, the first support member includes a plate and a protrusion. The plate is used to support the electrode assembly. The protrusion of the first support member is disposed on the plate and protrudes toward the first wall. A first cavity is formed between the plate of the first support member and the first wall through the protrusion along a first direction, where the first direction is perpendicular to the first wall.

[0008] In some embodiments, the protrusion is a hollow structure, which can reduce the weight of the first support member, thereby reducing the weight of the battery cell and improving the performance of the battery cell.

[0009] In some embodiments, the electrode assembly includes at least two electrodes wound around a winding axis extending along a first direction, or the electrodes are stacked together. A hollow portion of the protrusion extends through the protrusion along the first direction, and a first connecting hole is provided on the plate corresponding to the protrusion. The space containing the electrode is connected to a first cavity through the first connecting hole and the hollow portion, facilitating the transfer of gas and electrolyte and improving the wetting effect on the electrode.

[0010] In some embodiments, the electrode assembly includes at least two electrodes wound around a winding axis extending in a first direction, or the electrodes are stacked together. The plate also has a second connecting hole, through which the space containing the electrodes communicates with the first cavity to facilitate the transfer of gas and electrolyte and improve the wetting effect on the electrodes.

[0011] In some embodiments, the electrode assembly includes at least two electrodes wound around a winding axis extending along a second direction, or the electrodes are stacked together. A third wall is disposed on at least one side of the housing along the second direction. The tabs of the electrode assembly are disposed facing the third wall and have a gap with the third wall along the second direction. A first cavity communicates with the space where the electrodes are located through the gap, so as to facilitate the transfer of gas and electrolyte between the first cavity and the space where the electrodes are located, thereby improving the wetting effect on the electrodes.

[0012] In some embodiments, the housing includes a shell and an end cap assembly. The shell includes a first wall and a second wall, and an opening is provided on at least one side in a second direction. The end cap assembly closes the opening and forms a third wall. The electrode terminals include a first electrode terminal and a second electrode terminal, both of which are disposed on the end cap assembly. A gap exists between the electrode tab and the end cap assembly. That is, when the third wall is the end cap assembly, a gap exists between the electrode tab and the end cap assembly, allowing the first cavity to communicate with the space where the electrode sheet is located through the gap between the electrode tab and the end cap assembly.

[0013] In some embodiments, the housing has an opening on one side in the second direction, and the first electrode terminal and the second electrode terminal are both disposed on the same end cap assembly; or, the housing has openings on both sides in the second direction, and the first electrode terminal and the second electrode terminal are respectively disposed on the end cap assemblies on both sides.

[0014] In this embodiment of the application, when the third wall is an end cap assembly, the end cap assembly can be disposed on one side of the battery cell along the second direction, or the end cap assembly can be disposed on both sides of the battery cell along the second direction, so that the first cavity is connected to the space where the electrode sheet is located through the gap between the tabs on both sides and the end cap assembly.

[0015] In some embodiments, the housing includes a shell and an end cap assembly. The shell includes a first wall, a second wall, and a third wall. An opening is provided on one side of the shell in a second direction. The end cap assembly covers the opening and is disposed opposite to the third wall. The electrode terminals include a first electrode terminal and a second electrode terminal. At least one of the first electrode terminal and the second electrode terminal is disposed on the third wall of the shell. A first support member extends at least partially between the third wall and the electrode assembly. A tab forms a gap between the first support member and the third wall.

[0016] In this embodiment, the third wall can also be a bottom wall disposed opposite to the end cap assembly. When at least one of the first electrode terminal and the second electrode terminal is disposed on the bottom wall of the housing, the first support member extends at least partially between the third wall and the electrode assembly. The electrode tab forms a gap between the first support member and the third wall, so that the first cavity is connected to the space where the electrode sheet is located through the gap between the first support member and the third wall.

[0017] In some embodiments, the end cap assembly includes a cover body and an insulating member disposed on the side of the cover body facing the receiving cavity. One of the insulating member and the first support member is partially bent onto the other and overlapped with it. The insulating member and the first support member are connected in the overlapping area, which can reduce or avoid relative movement between the first support member and the electrode assembly when the battery cell vibrates, thereby reducing the risk of the first support member deviating from its set position within the housing.

[0018] In some embodiments, the first support member has a connection hole in the overlapping area, and the insulating member extends at least partially into the connection hole and is fixedly connected to the first support member. For example, the insulating member of the end cap can be fixed by snap-fit ​​heat fusion at the overlapping position with the first support member.

[0019] In some embodiments, the number of protrusions is two or more, and the protrusions are spaced apart on the plate, which can provide multi-point support for the electrode assembly, improve the support performance of the electrode assembly, and reduce the risk of interference between the electrode assembly and the transition section.

[0020] In some embodiments, the protrusion of the first support member has a maximum protrusion distance of 4 mm or more and 50 mm or less in the first direction, so as to reserve sufficient space inside the housing to accommodate the gas generated by the chemical reaction of the battery cell, reduce the internal gas pressure of the battery cell during use, and improve the long-term performance and service life of the battery cell.

[0021] In some embodiments, the battery cell further includes a second support member disposed between the second wall and the electrode assembly. A second cavity is formed between the second support member and the second wall and / or between the second support member and the electrode assembly. The second cavity is connected to the space where the electrode sheet is located, so as to simultaneously connect with the space where the electrode sheet is located through the first cavity and the second cavity, for the purpose of accommodating the gas generated by the chemical reaction of the battery cell.

[0022] In some embodiments, the structure of the second support member is the same as that of the first support member. The protrusion of the second support member is disposed on the plate and protrudes towards the second wall. A second cavity is formed between the plate and the second wall along the first direction through the protrusion. The sum of the maximum protrusion distance of the protrusion of the first support member and the maximum protrusion distance of the protrusion of the second support member in the first direction is greater than or equal to 4 mm and less than or equal to 50 mm. That is, the structures of the first support members on both sides can be the same to simplify the structure and improve the stability of the battery cell.

[0023] In some embodiments, the maximum protrusion distance of the protrusion of the first support member in the first direction and the maximum protrusion distance of the protrusion of the second support member in the first direction are both greater than or equal to 2 mm and less than or equal to 25 mm, so as to balance the space of the first cavity and the second cavity on both sides of the battery cell and improve the stability of the battery cell.

[0024] In some embodiments, the cell capacity A of the battery cell is 10Ah≤A≤50Ah, and the maximum protrusion distance of the protrusion of at least one of the first support member and the second support member along the first direction is greater than or equal to 2mm and less than or equal to 8mm; or, the cell capacity A of the battery cell is 50Ah≤A≤100Ah, and the maximum protrusion distance of the protrusion of at least one of the first support member and the second support member along the first direction is greater than or equal to 5mm and less than or equal to 18mm; or, the cell capacity A of the battery cell is 100Ah≤A≤250Ah, and the maximum protrusion distance of the protrusion of at least one of the first support member and the second support member along the first direction is greater than or equal to 5mm and less than or equal to 25mm.

[0025] In some embodiments, the ratio 'a' of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity is greater than or equal to 2% and less than or equal to 16%. The volume of the first cavity is the difference between the product of the maximum protrusion distance of the protrusion of the first support member along the first direction and the area of ​​the plate, and the volume of the protrusion itself. The volume of the second cavity is the difference between the product of the maximum protrusion distance of the protrusion of the second support member along the first direction and the area of ​​the plate, and the volume of the protrusion itself.

[0026] In some embodiments, the cell capacity A of the battery cell is 10Ah≤A≤50Ah, and the ratio a of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity satisfies 2%≤a≤12%; or, the cell capacity A of the battery cell is 50Ah≤A≤100Ah, and the ratio a of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity satisfies 5%≤a≤14%; or, the cell capacity A of the battery cell is 100Ah≤A≤250Ah, and the ratio a of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity satisfies 5%≤a≤16%.

[0027] In some embodiments, the thickness of the plate of the first support member along the first direction is greater than or equal to 0.3 mm, which can provide sufficient support force so that the electrode assembly will not interfere with the transition section of the housing.

[0028] In some embodiments, the battery cell further includes an insulating film that covers the outer periphery of the first support and the electrode assembly, and separates the first support and the electrode assembly from the first wall. Alternatively, the insulating film covers the electrode assembly, the first support is disposed between the insulating film and the first wall, and the insulating film has a third through hole.

[0029] In this embodiment, by covering the outer periphery of the first support member and the electrode assembly with an insulating film, i.e., the first support member is disposed inside the insulating film, it is easier for electrolyte and gas to flow.

[0030] In some embodiments, the electrode includes a negative electrode, which includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, the active material layer including an elemental active metal.

[0031] In some embodiments, the active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

[0032] In some embodiments, the battery cell further includes an electrolyte disposed in a receiving cavity. The electrolyte includes a solvent, which includes at least one of ether solvents or ester solvents. This reduces hydrogen production in the metal battery, thereby extending its lifespan.

[0033] In some embodiments, the solvent includes ether solvents, which include at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxane.

[0034] Secondly, this application provides a battery device including a plurality of battery cells as described in the first aspect.

[0035] Thirdly, this application provides an electrical device, including the battery device as described in the second aspect.

[0036] According to an embodiment of this application, the battery cell is an alkali metal battery. The battery cell includes a casing, an electrode assembly, and a first support member. The casing includes a housing and an end cap, and the housing includes side walls. The first support member supports the electrode assembly to fix and protect it. By improving the structure of the first support member, a first cavity can be formed between the first support member and the first wall and / or between the first support member and the electrode assembly. This first cavity accommodates gases generated by the chemical reaction within the battery cell, thereby reducing the internal gas pressure during use and improving the long-term performance and service life of the battery cell.

[0037] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 It is a cross-sectional view of a single battery cell in the relevant technology;

[0040] Figure 2 These are schematic diagrams of the vehicle structure provided in some embodiments of this application;

[0041] Figure 3 This is an exploded schematic diagram of a battery device provided in some embodiments of this application;

[0042] Figure 4 These are schematic diagrams of the structure of a single battery cell provided in some embodiments of this application;

[0043] Figure 5 This is a schematic diagram of the structure of a battery cell without a casing, provided in some embodiments of this application;

[0044] Figure 6 This is a schematic diagram of the structure of the first support member provided in some embodiments of this application;

[0045] Figure 7This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0046] Figure 8 These are schematic diagrams of the electrode assemblies provided in other embodiments of this application;

[0047] Figure 9 This is a schematic diagram of a battery cell without a casing provided in some other embodiments of this application;

[0048] Figure 10 yes Figure 9 Enlarged view of point A in the middle;

[0049] Figure 11 This is a schematic diagram of a battery cell without a casing provided in some embodiments of this application;

[0050] Figure 12 This is a schematic diagram of the structure of the first support member provided in some embodiments of this application;

[0051] Figure 13 This is a side view of the first support provided in some embodiments of this application;

[0052] Figure 14 This is a side view of the second support provided in some embodiments of this application;

[0053] Figure 15 This is a top view of the first support member provided in some embodiments of this application;

[0054] Figure 16 This is a schematic diagram of a battery cell without a casing provided in some embodiments of this application;

[0055] Figure 17 This is a side view of a third support provided in some embodiments of this application;

[0056] Figure 18 This is a schematic diagram of a battery cell without a casing provided in some embodiments of this application.

[0057] The reference numerals in the detailed embodiments are as follows:

[0058] 100 battery packs, 200 controllers, 300 motors;

[0059] 10 individual battery cells, 20 casing cells;

[0060] 1. Outer shell; 11. Side wall; 11a. First wall; 11b. Second wall; 12. Third wall; 121. Electrode terminal; 121a. First electrode terminal; 121b. Second electrode terminal; 122. Pressure relief mechanism; 123. Insulating component; 13. Transition section; 2. Electrode assembly; 21. Electrode sheet; 21a. Positive electrode sheet; 21b. Negative electrode sheet; 22. Isolator; 3. Support component; 3a. First support component; 3b. Second support component; 3c. Third support component; 31. Plate; 32. Protrusion; 33. Second connecting hole; 34. Connection hole; 4. Insulating film;

[0061] S1 is the first cavity, S2 is the space where the electrode is located, S3 is the second cavity, and S4 is the third cavity;

[0062] X is the first direction, Y is the third direction, and Z is the second direction. Detailed Implementation

[0063] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0064] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0065] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0066] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0067] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0068] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0069] With the development of the new energy industry, batteries are gradually moving towards higher energy density and higher power density, and the requirements for battery performance and safety are increasing.

[0070] Please see Figure 1 , Figure 1 A cross-sectional schematic diagram of a battery cell 10 in the related art is shown.

[0071] The battery cell 10 includes a housing 1 and an electrode assembly 2 disposed within the housing 1. Currently, in most batteries, in order to meet the capacity requirements of the electrode assembly 2, the internal space of the battery cell 10 is designed to be extremely limited, so that the cell mass margin of the battery cell can reach more than 90%.

[0072] However, since the battery cell 10 generates gas through a chemical reaction during use, the gas will accumulate in the internal space of the battery cell 10. Because the gap L between the electrode assembly 2 and the outer casing 1 is too small in the battery cell of the related technology, the internal storage space of the battery cell 10 is limited. Therefore, for battery cells 10 with a large internal gas production, adopting the above structure will lead to a significant increase in internal pressure during use, affecting the service life of the battery cell.

[0073] Based on the above considerations, in order to increase the space inside the battery for accommodating gas and electrolyte, this application provides an embodiment of a new battery cell. By improving the structure of the support member, while the support member serves to support the electrode assembly, a cavity structure is formed between the electrode assembly and the sidewall by removing part of the support member material. This cavity structure can be used to accommodate the electrolyte and the gas generated by the chemical reaction in metal batteries or sodium-ion batteries, thereby improving the long-term performance and capacity of the battery.

[0074] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0075] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. This application does not impose any special limitations on the above-mentioned electrical devices.

[0076] It should be understood that the technical solutions described in the embodiments of this application are applicable to all electrical devices including battery devices and those using batteries, but for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0077] Please see Figure 2 , Figure 2 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0078] The vehicle has a battery device 100 installed inside, which can be located at the bottom, front, or rear of the vehicle. The battery device 100 can be used to power the vehicle; for example, it can serve as the vehicle's operating power source. The vehicle may also include a controller 200 and a motor 300. The controller 200 controls the battery device 100 to supply power to the motor 300, for example, to meet the vehicle's power needs during starting, navigation, and driving.

[0079] Please see Figure 3 , Figure 3 This is an exploded view of a battery device 100 provided in some embodiments of this application.

[0080] The battery device 100 mentioned in the embodiments of this application may include one or more battery cells 10 assemblies for providing voltage and capacity. A battery cell 10 assembly may include multiple battery cells 10, which are connected in series, parallel, or mixed connections via a busbar. A battery cell 10 assembly may be a battery module, which is formed by arranging and fixing multiple battery cells 10 into an independent module.

[0081] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 20 and one or more battery cell 10 assemblies. The battery cell 10 assemblies are housed in the housing 20 to encapsulate one or more battery cells 10 and prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells 10.

[0082] In this embodiment of the application, the battery cell 10 can be a secondary battery, which refers to the battery cell 10 that can be used again after being discharged by recharging to activate the active materials.

[0083] As an example, the battery cell 10 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0084] Please refer to the following: Figures 4 to 5 , Figure 4 This is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application. Figure 5 This is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application, omitting the casing.

[0085] This application provides a battery cell 10, which is an alkali metal battery.

[0086] Alkali metal batteries are batteries that use alkali metals (such as lithium, sodium, potassium, etc.) as negative electrode materials. They are characterized by high energy density and long cycle life, but due to the reactivity of alkali metal battery materials, a lot of gas is generated during use.

[0087] The battery cell 10 includes a housing 1, an electrode assembly 2, an electrode terminal 121, and a first support member 3a. The housing 1 has an internal cavity and includes a first wall 11a, a second wall 11b, and a third wall 12. The first wall 11a and the second wall 11b are arranged opposite to each other, and the third wall 12 is disposed between the first wall 11a and the second wall 11b. One end of the third wall 12 is connected to the first wall 11a and the other end is connected to the second wall 11b. The electrode assembly 2 is accommodated in the cavity and is located between the first wall 11a and the second wall 11b. The electrode assembly 2 includes an electrode sheet 21. The electrode terminal 121 is disposed on the third wall 12 and is electrically connected to the electrode assembly 2. The first support member 3a is disposed between the first wall 11a and the electrode assembly 2. A first cavity S1 is formed between the first support member 3a and the first wall 11a and / or between the first support member 3a and the electrode assembly 2. The first cavity S1 is connected to the space S2 where the electrode sheet is located.

[0088] The housing 1 is a component for forming the internal environment of the battery cell 10, and has a receiving cavity inside. The housing 1 includes a side wall 11, a top wall, and a bottom wall. The side wall 11 includes a first wall 11a and a second wall 11b disposed opposite to each other. The electrode assembly 2 is received in the receiving cavity and is located between the first wall 11a and the second wall 11b. The third wall 12 is one of the top wall and the bottom wall, with one end connected to the first wall 11a and the other end connected to the second wall 11b. The electrode terminal 121 is disposed on the third wall 12.

[0089] The electrode assembly 2 is disposed in a receiving cavity, which is also filled with an electrolyte, such as a liquid electrolyte, to transfer charge and maintain the charging and discharging process of the battery cell 10. The electrode assembly 2 includes electrode plates, including a positive electrode plate and a negative electrode plate. During the charging and discharging process of the battery cell, active ions (such as sodium ions) are inserted and extracted back and forth between the positive and negative electrode plates. In some embodiments, the electrode assembly 2 also includes a separator membrane disposed between the negative and positive electrode plates, which can prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0090] The electrode includes a current collector and an active material layer disposed on at least one surface of the current collector. The portion with the active material layer serves as the electrode body, and the portion without the active material layer serves as the tab. The tab is used to conduct current from the electrode assembly 2. The tab includes a positive tab and a negative tab. The electrode terminal 121 is electrically connected to the tab. The electrode terminal 121 can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector.

[0091] The first support member 3a is used to support the electrode assembly 2. Specifically, since the rounded corners where the side walls 11 of the housing intersect are rounded, a transition section 13 is formed at the junction of two adjacent side walls 11. Therefore, the gap between the rounded corners where the side walls 11 of the housing intersect and the electrode assembly 2 is smaller than the gap between the side walls 11 of the housing and the electrode assembly 2. Therefore, by providing the first support member 3a between the electrode assembly 2 and the side wall 11, the first support member 3a can support the electrode assembly 2, thereby protecting the electrode assembly 2, reducing the risk of displacement of the electrode assembly 2 under vibration and impact, and also reducing the risk of damage to the electrode assembly 2 caused by compression from the rounded corners of the housing.

[0092] In this embodiment of the application, the battery cell 10 improves the structure of the first support member 3a so that while the first support member 3a serves to support the electrode assembly 2, a portion of the material of the first support member 3a is removed to create a first cavity S1 between the first support member 3a and the first wall 11a and / or between the first support member 3a and the electrode assembly 2. This reduces the space occupied by the first support member 3a inside the battery and uses the first cavity S1 to accommodate the gas generated by the chemical reaction of the battery cell, thereby reducing the internal gas pressure of the battery and improving the battery's service life.

[0093] Furthermore, during battery manufacturing, the first cavity S1 can also accommodate electrolyte to increase the electrolyte volume of the battery. The space where the electrode is located refers to the space occupied by the electrode 21 within the battery cell 10. Since the first cavity S1 is connected to the space where the electrode is located, electrolyte can flow from the first cavity S1 to the space where the electrode is located to replenish the electrolyte consumed during the use of the electrode assembly 2. Moreover, as the electrolyte is consumed, the space freed up by the first cavity S1 can also be used to accommodate more gas. There is a linkage between the two to make full use of the first cavity S1 formed by the first support member 3a, thereby improving the long-term performance and capacity of the battery cell 10.

[0094] It is understood that a first cavity S1 exists between the first support member 3a and the first wall 11a and / or between the first support member 3a and the electrode assembly 2. This first cavity S1 can be formed by the first support member 3a itself, for example, by providing a hollow portion. Thus, when the first support member 3a is positioned between the electrode assembly 2 and the side wall 11a, a first cavity S1 can be formed between the first support member 3a and the first wall 11a, and between the first support member 3a and the electrode assembly 2. Alternatively, when the first support member 3a is positioned between the electrode assembly 2 and the first wall 11a, at least a portion of the first support member 3a is spaced apart from the first wall 11a and / or the electrode assembly 2, thereby creating a first cavity S1 between the first support member 3a and the first wall 11a and / or between the first support member 3a and the electrode assembly 2.

[0095] Optionally, taking a rectangular shell as an example, the first wall 11a and the second wall 11b can be the small facets of the side wall 11 of the shell, so that the electrode assembly 2 can be supported from the small facet side of the shell by the first support member 3a, thereby reducing the risk of interference between the electrode assembly 2 and the transition section 13.

[0096] Please see Figures 4 to 6 , Figure 6 A schematic diagram of the structure of the first support member 3a provided in some embodiments of this application is shown.

[0097] As an optional implementation, the first support member 3a includes a plate 31 and a protrusion 32. The plate 31 is supported on the electrode assembly 2, and the protrusion 32 is disposed on the plate 31 and protrudes toward the first wall 11a. A first cavity S1 is formed between the plate 31 and the first wall 11a along the first direction X through the protrusion 32. The first direction X is a direction perpendicular to the first wall 11a.

[0098] It is understandable that by including a plate 31 and a protrusion 32 in the first support member 3a, the first support member 3a can form a first cavity S1 between the plate 31 and the first wall 11a through the protrusion 32 to accommodate electrolyte and gas, thereby improving the long-term performance and service life of the battery cell 10. The structure is simple and reliable. In addition, compared with directly supporting the electrode assembly 2 through the protrusion 32, the first support member 3a in this embodiment of the application increases the contact area between the first support member 3a and the electrode assembly 2 by setting the plate 31 and supporting the first support member 3a through the plate 31. Therefore, under the condition of vibration and impact, the force will be dispersed and transmitted to the electrode assembly 2 through the plate 31, reducing damage to the electrode assembly 2.

[0099] In some alternative embodiments, the protrusion 32 is a hollow structure, which can reduce the weight of the first support 3a, thereby reducing the weight of the battery cell 10 and improving the performance of the battery cell 10.

[0100] For the first support member 3a, it needs to connect the formed first cavity S1 with the space S2 where the electrode is located to realize the replenishment of electrolyte and the transfer of generated gas during the use of the electrode assembly 2. Specifically, since the electrode assembly 2 can be a wound structure or a stacked structure, different connection paths can be designed according to the structure of the electrode assembly 2 to connect the first cavity S1 with the space S2 where the electrode is located.

[0101] Please see Figures 4 to 7 , Figure 7 A schematic diagram of the structure of the electrode assembly 2 provided in some embodiments of this application is shown.

[0102] When the electrode assembly 2 has a stacked structure, specifically, the electrode assembly 2 includes multiple electrode sheets 21, each including a positive electrode sheet 21a and a negative electrode sheet 21b. The positive electrode sheets 21a and negative electrode sheets 21b are alternately stacked, and the stacking direction of the positive electrode sheets 21a and negative electrode sheets 21b is parallel to the thickness direction of the positive electrode sheets 21a and negative electrode sheets 21b. In some examples, the positive electrode sheets 21a and negative electrode sheets 21b are both rectangular flat plates and are arranged parallel to each other.

[0103] In some embodiments, the electrode assembly 2 further includes a spacer 22, which may be configured as a continuous structure, i.e., there may be two spacers 22. Each spacer 22 is reciprocated and bent into multiple layers, including multiple isolation layers and bending layers, with each bending layer connecting two adjacent isolation layers. Each isolation layer separates adjacent positive electrode plates 21a and negative electrode plates 21b. Optionally, the radius of the bending layer is small, and the isolation layer may be approximately planar.

[0104] It is understood that when the electrode assembly 2 is a stacked structure, the space S2 where the electrode is located is at least partially open along the first direction X and the second direction Z. Therefore, the first cavity S1 only needs to be connected to the space S2 where the electrode is located in at least one of the first direction X and the second direction Z.

[0105] Please see Figures 4 to 8 , Figure 8 A schematic diagram of the structure of the electrode assembly 2 provided in some other embodiments of this application is shown.

[0106] When the electrode assembly 2 has a wound structure, specifically, the at least two electrode pieces 21 of the electrode assembly 2 include a positive electrode piece 21a and a negative electrode piece 21b, which are wound along a winding axis. The electrode assembly 2 may also include a spacer 22, which can be continuously arranged and is disposed between any adjacent positive electrode pieces 21a and negative electrode pieces 21b by winding. The positive electrode piece 21a, the negative electrode piece 21b, and the spacer 22 are wound to form the electrode assembly 2.

[0107] In this configuration, the winding axis of the electrode 21 of the electrode assembly 2 can extend along a first direction X. In this case, the tab is located on at least one side of the electrode body along the first direction X, which is perpendicular to the first wall 11a. Alternatively, the winding axis of the electrode 21 of the electrode assembly 2 can also extend along a second direction Z. In this case, the tab is located on at least one side of the electrode body along the second direction Z, which is the opening direction of the housing.

[0108] It is understandable that when the electrode assembly 2 has a stacked structure, the open position of the space S2 where the electrode is located is related to the extension direction of the winding axis. When the winding axis of the electrode 21 of the electrode assembly 2 extends along the first direction X, the first cavity S1 needs to be connected to the space S2 where the electrode is located in the first direction X. When the winding axis of the electrode 21 of the electrode assembly 2 extends along the second direction Z, the first cavity S1 needs to be connected to the space S2 where the electrode is located in the second direction Z.

[0109] Based on the above conditions, when the winding axis of the electrode 21 of the electrode assembly 2 extends along the first direction X, or when the electrode 21 of the electrode assembly 2 is stacked, in order to connect the first cavity S1 with the space S2 where the electrode is located in the first direction X, as an optional implementation, the hollow portion of the protrusion 32 is provided through the protrusion 32 along the first direction X, and the plate 31 is provided with a first connecting hole corresponding to the protrusion 32. The space S2 where the electrode is located is connected to the first cavity S1 through the first connecting hole and the hollow portion. By making the hollow portion of the protrusion 32 extend through the protrusion 32 along the first direction X, and the plate 31 is provided with a first connecting hole corresponding to the protrusion 32, the first cavity S1 can be connected to the space S2 where the electrode is located along the first direction X through the first connecting hole and the hollow portion. Therefore, the electrolyte contained in the first cavity S1 can enter the space S2 where the electrode is located along the first direction X through the first connecting hole and the hollow portion, thereby replenishing the electrolyte. Meanwhile, the gas generated by the reaction of the electrode assembly 2 can enter the first cavity S1 along the first direction X through the first connecting hole and the hollow part, so that the gas can be contained through the first cavity S1, reducing the risk of premature depressurization caused by excessive internal gas pressure during the use of the battery cell 10.

[0110] In addition, as another optional implementation, the plate 31 may also be provided with a second connecting hole 33, through which the space S2 where the electrode is located is connected to the first cavity S1.

[0111] In addition to providing a hollow portion for the protrusion 32 and connecting the space S2 where the electrode is located to the first cavity S1 through the first connecting hole and the hollow portion, a second connecting hole 33 can also be provided on the plate 31 so that the space S2 where the electrode is located can be connected to the first cavity S1 through the second connecting hole 33.

[0112] It is understandable that when the winding axis of the electrode 21 of the electrode assembly 2 extends along the first direction X, or when the electrode assembly 2 is a stacked structure, the space S2 where the electrode is located can be connected to the first cavity S1 by simply setting the first connecting hole and the hollow part, or the space S2 where the electrode is located can be connected to the first cavity S1 by simply setting the second connecting hole 33, or both the first connecting hole and the second connecting hole 33 can be set at the same time to connect the first cavity S1 to the space S2 where the electrode is located along the first direction X. In this way, the gas can be contained through the first cavity S1, reducing the risk of premature depressurization caused by excessive internal gas pressure during the use of the battery cell 10.

[0113] When the plate 31 is provided with a second connecting hole 33, the number of the second connecting holes 33 is at least three, and the at least three second connecting holes 33 are spaced apart along the second direction Z. That is, the second connecting holes 33 can be spaced apart on the plate 31 along the second direction Z. By opening holes in the plate 31 at multiple points along the second direction Z, the first cavity S1 can be connected to the space S2 where the electrode is located from multiple points, thereby improving the wetting effect on the electrode assembly 2.

[0114] Optionally, the opening area of ​​the second connecting hole 33 is greater than or equal to 6 mm². 2 This facilitates the first cavity S1 to communicate with the space S2 where the electrode is located from multiple points, thereby improving the wetting effect on the electrode assembly 2.

[0115] Based on the above conditions, in some other embodiments, when the winding axis of the electrode 21 of the electrode assembly 2 extends along the second direction Z, or when the electrode 21 of the electrode assembly 2 is stacked, in order to make the first cavity S1 communicate with the space S2 where the electrode is located in the second direction Z, as an optional implementation, the third wall 12 is disposed on at least one side of the outer shell 1 along the second direction Z, the electrode tab is disposed toward the third wall 12 and has a gap with the third wall 12 along the second direction Z, and the first cavity S1 communicates with the space S2 where the electrode is located through the gap.

[0116] By creating a gap between the tab and the third wall 12 along the second direction Z, when the electrode assembly 2 is configured as a wound structure with the winding axis along the second direction Z, or when the electrode sheets 21 of the electrode assembly 2 are stacked, the first cavity S1 can communicate with the space S2 where the electrode sheets are located through the gap. This allows the electrolyte to flow from the first cavity S1 through the gap to the space S2 where the electrode sheets are located, thus replenishing the electrolyte. Furthermore, during the use of the battery cell 10, the gas generated by the chemical reaction of the electrode assembly 2 can also enter the first cavity S1 through the gap, allowing the first cavity S1 to contain the gas, reducing the gas pressure, and thereby improving the long-term performance and service life of the battery cell 10.

[0117] The third wall 12 is determined by the location of the electrode terminal 121.

[0118] The housing 1 includes a shell and an end cap assembly. The shell includes a first wall 11a and a second wall 11b, forming a receiving cavity capable of accommodating the electrode assembly 2. The shell has an opening on at least one side in the second direction Z, i.e., this plane has no wall, allowing communication between the inside and outside of the shell. The end cap assembly covers the opening and connects to the shell, thereby closing the opening of the shell and placing the electrode assembly 2 within the closed cavity. The shell may have one or more openings, and the end cap assembly may also have one or more.

[0119] In this regard, depending on the location of the electrode terminal 121, when the electrode terminal 121 is disposed on the end cap assembly, the end cap assembly serves as the third wall 12 of the outer shell 1, and when the electrode terminal 121 is disposed on the bottom wall of the shell, the bottom wall of the shell serves as the third wall 12 of the outer shell 1.

[0120] Please see Figures 4 to 9 , Figure 9 A schematic diagram of the battery cell 10 without a casing is shown in some other embodiments of this application.

[0121] In one optional implementation, the end cap assembly closes the opening and forms a third wall 12. The electrode terminal 121 includes a first electrode terminal 121a and a second electrode terminal 121b, both of which are disposed on the end cap assembly, and the tabs have a gap with the end cap assembly.

[0122] When the end cap assembly serves as the third wall 12 of the outer shell 1, since there is a gap between the tab and the end cap assembly, the first cavity S1 can communicate with the space S2 where the electrode is located through the gap between the tab and the end cap assembly, so as to realize the transfer of gas and electrolyte between the first cavity S1 and the space S2 where the electrode is located.

[0123] When the end cap assembly serves as the third wall 12 of the housing 1, it includes at least the following two cases depending on the location of the first electrode terminal 121a and the second electrode terminal 121b.

[0124] In some embodiments, the housing has an opening on one side in the second direction Z, and the first electrode terminal 121a and the second electrode terminal 121b are both disposed on the same end cap assembly; or, the housing has openings on both sides in the second direction Z, and the first electrode terminal 121a and the second electrode terminal 121b are respectively disposed on the end cap assemblies on both sides.

[0125] That is, when the third wall is an end cap assembly, such as Figure 5As shown, the end cap assembly can be disposed on one side of the electrode assembly 2 along the second direction Z. The first electrode terminal 121a and the second electrode terminal 121b can both be disposed on the same end cap assembly. The first cavity S1 is connected to the space S2 where the electrode sheet is located on the side where the end cap assembly is located through the gap between the electrode tab and the end cap assembly. Alternatively, as Figure 9 As shown, the end cap assembly can also be disposed on both sides of the electrode assembly 2 along the second direction Z. The first electrode terminal 121a and the second electrode terminal 121b are respectively disposed on the end cap assemblies on both sides. The first cavity S1 is connected to the space S2 where the electrode sheet is located through the gap between the electrode tabs on both sides and the end cap assembly.

[0126] In another alternative embodiment, the housing includes a third wall 12, and an end cap assembly covers the opening and is disposed opposite to the third wall 12. The electrode terminal 121 includes a first electrode terminal 121a and a second electrode terminal 121b, at least one of the first electrode terminal 121a and the second electrode terminal 121b is disposed on the third wall 12 of the housing, and a first support member 3a extends at least partially between the third wall 12 and the electrode assembly 2, and an electrode tab forms a gap (not shown) between the first support member 3a and the third wall 12.

[0127] When the bottom wall of the housing serves as the third wall 12 of the outer shell 1, a gap can be formed between the first support member 3a and the third wall 12 by extending at least partially the first support member 3a between the third wall 12 and the electrode assembly 2, so that the protrusion of the first support member 3a abuts against the third wall 12. This allows the first cavity S1 to communicate with the space S2 where the electrode plate is located through the gap between the electrode tab and the bottom wall of the housing.

[0128] Please see Figure 9 and Figure 10 , Figure 10 It shows Figure 9 Enlarged view of point A in the middle.

[0129] In some alternative embodiments, the end cap assembly includes a cap body and an insulating member 124 disposed on the side of the cap body facing the receiving cavity. One of the insulating member 124 and the first support member 3a is partially bent onto and overlaps the other, and the insulating member 124 and the first support member 3a are connected in the overlapping area.

[0130] By connecting the insulating member 124 to the first support member 3a, the position of the first support member 3a is fixed, which can reduce or avoid the relative movement of the first support member 3a and the electrode assembly 2 when the battery cell 10 vibrates, and reduce the risk of the first support member 3a deviating from the set position in the housing.

[0131] In some examples, the first support member 3a has a connection hole 34 in the overlapping area, and the insulating member 124 extends at least partially into the connection hole 34 and is fixedly connected to the first support member 3a.

[0132] Optionally, the insulating member 124 of the end cap assembly can be snapped and heat-fused at the overlapping position with the first support member 3a. That is, the insulating member 124 can be provided with a heat-fused column, and the first support member 3a is provided with a connecting hole 34. The heat-fused column passes through the connecting hole, and the heat-fused column can be melted and reshaped by heating to achieve the heat-fused fastening of the first support member 3a and the end cap assembly.

[0133] In some alternative embodiments, the first support member 3a may be made of a plastic polymer material, such as polypropylene.

[0134] By making the first support member 3a a plastic polymer material, that is, the first support member 3a has good insulation properties, it is possible to reliably support the electrode assembly 2 through the first support member 3a while insulating and separating the first wall 11a from the electrode assembly 2, thereby reducing the risk of the electrode assembly 2 becoming conductive with the housing.

[0135] In summary, based on the location of the electrode terminal 121, the third wall 12 of the outer casing 1 can be an end cap assembly, or the third wall 12 of the outer casing 1 can be the bottom wall of the casing. However, for ease of description, the following will use the case where the third wall 12 of the outer casing 1 is an end cap assembly, and the first electrode terminal 121a and the second electrode terminal 121b are both located in the same end cap assembly as an example.

[0136] Please see Figures 5 to 12 , Figure 11 This paper shows a schematic diagram of the structure of a battery cell 10 according to another embodiment of the present application, omitting the casing. Figure 12 A schematic diagram of the structure of the first support member 3a according to another embodiment of this application is shown. In some optional embodiments, the number of protrusions 32 is two or more, and the protrusions 32 are spaced apart on the plate 31 along the second direction Z.

[0137] By providing multiple protrusions 32 along the second direction Z, the electrode assembly 2 can be supported at multiple points along the second direction Z, thereby improving the support performance of the electrode assembly 2 and reducing the risk of interference between the electrode assembly 2 and the transition section 13.

[0138] Optionally, the protrusions 32 are provided at least at both ends of the plate 31 along the second direction Z to improve the support effect on the electrode assembly 2. The protrusions 32 are provided at both ends of the plate 31 along the second direction Z, and they can extend to the outer edge of the plate 31 in the second direction Z, or they can be spaced apart from the outer edge of the plate 31 in the second direction Z. The specific position can be adjusted according to the shape of the plate 31.

[0139] In some alternative embodiments, each protrusion 32 may extend along a third direction Y, or the protrusions 32 may be disposed opposite to each other at both ends of the plate 31 along a third direction Y.

[0140] It is understandable that when multiple protrusions 32 are provided, each protrusion 32 can be arranged as follows: Figure 6 As shown, it can be set to extend along the third direction Y, or as... Figure 12 As shown, the protrusions 32 are arranged opposite each other at both ends of the plate 31 along the third direction Y. The specific location and size of the protrusions 32 can be adjusted according to the actual support requirements. While supporting and fixing the electrode assembly 2, the first cavity S1 can accommodate the electrolyte and gas.

[0141] Since the battery cell 10 is an alkali metal battery with a large gas production, in order to further improve the reliability of the battery cell 10, the type of the battery cell 10 and the volume of the first cavity can be limited to better meet the actual use requirements of the battery cell 10.

[0142] For the battery cell 10, in some optional embodiments, the electrode 21 includes a negative electrode, which includes a negative current collector and an active material layer disposed on at least one side of the negative current collector. The active material layer includes an elemental active metal, that is, the battery cell 10 is a metal battery.

[0143] Optionally, the active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

[0144] When the battery cell 10 is configured as a metal battery, it can be configured as a sodium metal battery. Sodium metal batteries have high energy density and long cycle life. Since sodium metal batteries generate a lot of gas during use, by setting a first cavity S1 to contain the gas, the energy density and cycle life of the battery cell 10 can be improved, while reducing the risk of excessive internal gas pressure during use, thereby improving the reliability and service life of the battery cell 10.

[0145] In some optional embodiments, the battery cell further includes an electrolyte disposed in a receiving cavity, the electrolyte comprising a solvent, the solvent comprising at least one of an ether solvent or an ester solvent.

[0146] For metal batteries, such as sodium metal batteries or lithium metal batteries, elemental metals will be deposited on the negative electrode current collector. The elemental metals will react with some organic solvents in the electrolyte to generate gas, the main component of which is hydrogen.

[0147] Specifically, the organic solvents in the electrolyte used in conventional lithium batteries include ester solvents. However, since sodium metal is more reactive, replacing ester solvents with ether solvents can reduce the generation of hydrogen in alkali metal batteries, thereby extending the battery's lifespan.

[0148] Optionally, the solvent includes ether solvents, including at least one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxane. This reduces hydrogen production in alkali metal batteries, thereby extending their lifespan.

[0149] It is understandable that sodium metal batteries and ether solvents will still react to produce hydrogen gas. In order to reduce the internal gas generation problem during the use of metal batteries, the volume of the first cavity S1 needs to be able to meet the gas containment requirements.

[0150] Please see Figure 15 and Figure 13 , Figure 13 A side view of a first support 3a provided in some embodiments of this application is shown.

[0151] Based on the above-mentioned battery cell 10 being an alkali metal battery, in some optional embodiments, the maximum protrusion distance L1 of the protrusion of the first support member 3a is greater than or equal to 4 mm and less than or equal to 50 mm in the first direction X.

[0152] It is understandable that when the first support member 3a is provided with multiple protrusions 32, the protrusion distance L1 of each protrusion 32 in the first direction X may be the same or different, and the volume of the first cavity S1 is mainly determined by the maximum protrusion distance L1 of the protrusions 32 of the first support member 3a in the first direction X.

[0153] By ensuring that the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a in the first direction X is greater than or equal to 4 mm, the maximum size of the first cavity S1 in the first direction X can be greater than or equal to 4 mm. This allows sufficient space to be reserved inside the casing to accommodate the gas generated by the chemical reaction of the battery cell 10, increasing the volume of the first cavity S1 between the electrode assembly 2 and the casing, reducing the internal gas pressure of the battery cell 10 during use, and improving the long-term performance and service life of the battery cell 10. Furthermore, by ensuring that the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a in the first direction X is less than or equal to 50 mm, the maximum size of the first cavity S1 in the first direction X can be less than or equal to 50 mm. This prevents the maximum size of the first cavity S1 along the first direction X from becoming excessive, thereby reducing the volume of the battery cell 10 with the same cell capacity. The maximum protrusion distance L1 of the protrusion 32 of the first support member 3a in the first direction X can be adjusted according to actual needs, for example, it can be set to the minimum value required to meet the gas pressure and electrolyte capacity requirements.

[0154] It is understood that, in addition to the first support member 3a being provided between the first wall 11a and the electrode assembly 2, a second support member 3b may also be provided between the second wall 11b and the electrode assembly 2.

[0155] Please see Figure 5 , Figure 13 and Figure 14 , Figure 14 A side view of the second support 3b provided in some embodiments of this application is shown.

[0156] In some optional embodiments, the battery cell 10 further includes a second support member 3b, which is disposed between the second wall 11b and the electrode assembly 2. A second cavity S3 is formed between the second support member 3b and the second wall 11b and / or between the second support member 3b and the electrode assembly 2. The second cavity S3 is connected to the space S2 where the electrode sheet is located.

[0157] The battery cell 10 may include a support member 3, which includes a first support member 3a and a second support member 3b. The first support member 3a and the second support member 3b are respectively disposed on both sides of the electrode assembly 2 along the first direction X, so as to support the electrode assembly 2 on both sides of the first direction X, thereby improving the support effect of the electrode assembly 2 and improving the reliability of the battery cell 10. Furthermore, it is also possible to form a first cavity S1 and a second cavity S3 with the housing on both sides of the electrode assembly 2 along the first direction X, so as to simultaneously connect with the space S2 where the electrode sheet is located through the first cavity S1 and the second cavity S3, which is more suitable for the high gas production of the battery cell 10, improving the long-term performance and service life of the battery cell 10.

[0158] In one optional implementation, the structure of the second support member 3b is the same as that of the first support member 3a. The protrusion 32 of the second support member 3b is disposed on the plate 31 and protrudes toward the second wall 11b. A second cavity S3 is formed between the plate 31 and the second wall 11b along the first direction X through the protrusion 32. That is, the structures of the first support member 3a and the second support member 3b can be the same to simplify the structure and improve the stability of the battery cell 10.

[0159] Furthermore, the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b in the first direction X is greater than or equal to 4 mm and less than or equal to 50 mm.

[0160] By ensuring that the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b in the first direction X is greater than or equal to 4 mm and less than or equal to 50 mm, it is possible to achieve reliable support for the electrode assembly 2 while forming a sufficient cavity volume to accommodate the electrolyte and gas, thereby improving the long-term performance and service life of the battery cell 10. The structure is simple and reliable.

[0161] The following uses sodium metal battery and lithium metal battery as examples. By taking the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a in the first direction X and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b in the first direction X as variables, the battery cell is tested for cracking after 500 cycles.

[0162] Table 1

[0163] L1+L2(mm) Battery cell type Electrolyte composition Test Results Comparative Example 1 0 Sodium metal battery ether solvents shell crack Comparative Example 2 0 Lithium metal batteries Ester solvents shell crack Example 1 4 Sodium metal battery ether solvents intact shell Example 2 10 Sodium metal battery ether solvents intact shell Example 3 25 Sodium metal battery ether solvents intact shell Example 4 40 Sodium metal battery ether solvents intact shell Example 5 50 Sodium metal battery ether solvents intact shell Example 6 4 Lithium metal batteries Ester solvents intact shell Example 7 10 Lithium metal batteries Ester solvents intact shell Example 8 25 Lithium metal batteries Ester solvents intact shell Example 9 40 Lithium metal batteries Ester solvents intact shell Example 10 50 Lithium metal batteries Ester solvents intact shell

[0164] Comparing the two comparative examples in Table 1 with the ten embodiments reveals that, in the comparative examples, when the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b is 0 mm (i.e., no cavity is formed), due to the limited internal space of the battery, there is a risk of casing cracking during use, especially in the case of sodium metal batteries with ether-based electrolytes or lithium metal batteries with ester-based electrolytes. In the embodiments, by ensuring that the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b is greater than or equal to 4 mm, the design requirements of the battery cell 10 can be met when the battery cell 10 is a sodium metal battery with an ether-based electrolyte or a lithium metal battery with an ester-based electrolyte.

[0165] It is understandable that when the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b is large, for example, when the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b is set to 100mm, the cell group margin will be reduced, affecting the battery energy density. Therefore, in this embodiment, by setting the sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b to 4mm to 50mm, both battery life and energy density can be balanced, resulting in better performance.

[0166] In some alternative embodiments, the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a in the first direction X and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b are both greater than or equal to 2 mm and less than or equal to 25 mm.

[0167] That is, the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a in the first direction X satisfies 2mm≤L1≤25mm, and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b satisfies 2mm≤L2≤25mm, so as to form sufficient volume of the first cavity S1 and the second cavity S3 to accommodate electrolyte and gas, thereby improving the long-term performance and service life of the battery cell 10.

[0168] Optionally, the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a in the first direction X and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b are equal to simplify the structure of the battery cell 10. While achieving reliable support for the electrode assembly 2, the first support member 3a and the second support member 3b are further simplified, thereby improving the long-term performance and service life of the battery cell 10.

[0169] As an optional implementation, the cell capacity A of the battery cell 10 is 10Ah≤A≤50Ah, and the maximum protrusion distance of the protrusion 32 of at least one of the first support member 3a and the second support member 3b along the first direction X is greater than or equal to 2mm and less than or equal to 8mm.

[0170] Alternatively, the cell capacity A of the battery cell 10 is 50Ah≤A≤100Ah, and the maximum protrusion distance of the protrusion 32 of at least one of the first support member 3a and the second support member 3b along the first direction X is greater than or equal to 5mm and less than or equal to 18mm.

[0171] Alternatively, the cell capacity A of the battery cell 10 is 100Ah≤A≤250Ah, and the maximum protrusion distance of the protrusion 32 of at least one of the first support member 3a and the second support member 3b along the first direction X is greater than or equal to 5mm and less than or equal to 25mm.

[0172] The cell capacity A can be determined using current testing methods in relevant technologies. Specifically, it can be achieved by discharging electrode assembly 2 at a constant current to 2.0V under a test condition of 0.33C, letting it rest for 30 minutes, then charging it at a constant current and constant voltage to 3.65V under the same test condition of 0.33C, letting it rest for 30 minutes, and then discharging it at a constant current to 2.0V under the same test condition of 0.33C (the capacity measured in this step is the cell capacity A). Alternatively, it can be achieved by discharging electrode assembly 2 at a constant current to 2.5V or 2.8V under a test condition of 0.33C, letting it rest for 30 minutes, then charging it at a constant current and constant voltage to 3.65V under the same test condition of 0.33C, letting it rest for 30 minutes, and then discharging it at a constant current to 2.5V or 2.8V under the same test condition of 0.33C (the capacity measured in this step is the cell capacity A).

[0173] Since the larger the cell capacity A, the greater the amount of gas produced by the chemical reaction of the battery cell 10, by adjusting the maximum protrusion distance of the protrusion 32 of the first support member 3a and / or the second support member 3b along the first direction X according to the cell capacity A of the battery cell 10, it is possible to reduce the internal space of the battery cell 10 while meeting the gas pressure requirements, thereby improving the energy density and performance of the battery cell 10.

[0174] It is understandable that, in addition to adjusting the maximum protrusion distance of the protrusion 32 of the first support member 3a and / or the second support member 3b along the first direction X according to the cell capacity A of the battery cell 10, the battery cell 10 can also meet the usage requirements of high-yield gas cells by adjusting the volume of the first cavity S1 and / or the second cavity S3.

[0175] Please see Figure 5 , Figures 13 to 15 , Figure 15 A top view of a first support 3a provided in some embodiments of this application is shown.

[0176] In some optional embodiments, the ratio a of the volume of at least one of the first cavity S1 and the second cavity S3 to the volume of the receiving cavity is greater than or equal to 2% and less than or equal to 16%. The volume of the first cavity S1 is the difference between the product of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a along the first direction X and the area of ​​the plate 31, and the volume of the protrusion 32 itself. The volume of the second cavity S3 is the difference between the product of the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b along the first direction X and the area of ​​the plate 31, and the volume of the protrusion 32 itself.

[0177] Taking a rectangular plate 31 as an example, the dimension of the plate along the third direction Y is D1, and the dimension of the plate 31 along the second direction Z is D2. The second direction Z is the opening direction of the shell. Therefore, the area of ​​the plate 31 is the product of D1 and D2. Thus, the volume of the first cavity S1, which is the product of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a along the first direction X and the area of ​​the plate 31, is the product of the maximum protrusion distance L1 of the protrusion 32 along the first direction X, the dimension D1 of the plate along the third direction Y, and the dimension D2 of the plate 31 along the second direction Z. Similarly, the volume of the second cavity S3 can be calculated.

[0178] The volume of the protrusion 32 refers to the actual volume occupied by the protrusion 32 inside the battery. The protrusion 32 can be a hollow column structure or a solid structure. When the protrusion 32 is a hollow column structure, its volume is the same as the volume of its solid portion. The protrusion 32 can be a regular shape, which can be calculated using formulas for regular shapes. The protrusion 32 can also be an irregular shape, and its volume can be calculated using methods such as the displacement method or 3D scanning technology.

[0179] By ensuring that the ratio 'a' of the volume of at least one of the first cavity S1 and the second cavity S3 to the volume of the accommodating cavity is greater than or equal to 2% and less than or equal to 16%, sufficient space can be formed inside the battery cell 10 to accommodate the gas generated by the chemical reaction within the battery cell 10, and the volume of the sub-cavity structure can meet the requirements for high-gas-producing battery cells. Simultaneously, the battery cell 10 can also form sufficient space to accommodate the electrolyte, thereby enabling timely replenishment of the electrolyte consumed during use, improving the long-term performance and service life of the battery cell 10.

[0180] In some optional embodiments, the cell capacity A of the battery cell 10 is 10Ah≤A≤50Ah, and the ratio a of the volume of at least one of the first cavity S1 and the second cavity S3 to the volume of the accommodating cavity satisfies 2%≤a≤12%.

[0181] Alternatively, the cell capacity A of the battery cell 10 is 50Ah≤A≤100Ah, and the ratio a of the volume of at least one of the first cavity S1 and the second cavity S3 to the volume of the accommodating cavity satisfies 5%≤a≤14%.

[0182] Alternatively, the cell capacity A of the battery cell 10 is 100Ah≤A≤250Ah, and the ratio a of the volume of at least one of the first cavity S1 and the second cavity S3 to the volume of the accommodating cavity satisfies 5%≤a≤16%.

[0183] Since the larger the cell capacity A, the greater the amount of gas produced by the chemical reaction of the battery cell 10, by adjusting the ratio a of the volume of at least one of the first cavity S1 and the second cavity S3 to the volume of the casing according to the cell capacity A of the battery cell 10, it is possible to reduce the internal space of the battery cell 10 while meeting the gas pressure requirements, thereby increasing the energy density of the battery cell 10 and improving its performance.

[0184] In some alternative embodiments, the thickness of the plate 31 along the first direction X is greater than or equal to 0.3 mm. By making the dimension of the plate 31 along the first direction X greater than or equal to 0.3 mm, sufficient support force can be provided by the first support member 3a and the second support member 3b so that the electrode assembly 2 does not interfere with the transition section 13 of the housing.

[0185] Please see Figure 5 , Figures 16 to 17 , Figure 16 This application shows a schematic diagram of a battery cell structure without a casing, provided in some embodiments of this application. Figure 1 , Figure 17 This is a side view of a third support provided in other embodiments of this application.

[0186] As an optional implementation, when the third wall 12 is an end cap assembly and the first electrode terminal 121a and the second electrode terminal 121b are both disposed on the same end cap assembly, the battery cell may further include a third support member 3c. The third support member 3c is disposed between the bottom wall of the housing and the electrode assembly 2. A third cavity S4 is provided between the third support member 3c and the bottom wall and / or between the third support member 3c and the electrode assembly 2. The third cavity S4 is connected to the space S2 where the electrode is located to accommodate the gas generated by the chemical reaction of the battery cell.

[0187] When the battery cell 10 is inverted, i.e., the bottom wall of the casing faces upward and the end cap faces downward, and is placed inside the housing 20, since there is a third cavity S4 between the third support member 3c and the bottom wall and / or between the third support member 3c and the electrode assembly 2, the gas generated by the chemical reaction of the battery cell 10 can enter the first cavity S1 and the second cavity S3 through the space S2 where the electrode is located, and can also enter the third cavity S4. This can further increase the space inside the battery cell 10 that can be used to contain gas, reduce the internal gas pressure of the battery cell 10 during use, and improve the long-term performance and service life of the battery cell 10.

[0188] In addition, when a third cavity S4 is provided, the volume of the first cavity S1 and the volume of the second cavity S3 can also be adaptively reduced, that is, the sum of the volumes of the first cavity S1, the second cavity S3 and the third cavity S4 can meet the gas containment requirements of the high-yield gas battery cell 10 during use.

[0189] Optionally, the structure of the third support member 3c is the same as that of the first support member 3a. The protrusion 32 of the third support member 3c is disposed on the plate 31 and protrudes toward the bottom wall of the shell. The plate 31 of the third support member 3c and the bottom wall of the shell form a third cavity S4 along the second direction Z through the protrusion 32.

[0190] In some alternative embodiments, the cell capacity A of the battery cell 10 is 10Ah≤A≤50Ah, and the maximum protrusion distance L3 of the protrusion 32 of the third support member 3c along the second direction Z satisfies 0mm<L3≤3mm.

[0191] Alternatively, the cell capacity A of the battery cell is 50Ah≤A≤100Ah, and the maximum protrusion distance L3 of the protrusion 32 of the third support member 3c along the second direction Z satisfies 0mm<L3≤5mm.

[0192] Alternatively, the cell capacity A of the battery cell is 100Ah≤A≤250Ah, and the maximum protrusion distance L3 of the protrusion 32 of the third support member 3c along the second direction Z satisfies 0mm<L3≤7mm.

[0193] Since the larger the cell capacity A, the greater the amount of gas produced by the chemical reaction of the battery cell 10, by adjusting the volume of the first cavity S1 and the volume of the second cavity S3, the maximum protrusion distance L3 of the protrusion 32 of the third support 3c along the second direction Z can also be adjusted to better meet the gas pressure requirements of the battery cell 10 during use and improve the long-term performance and service life of the battery cell 10.

[0194] Please see Figures 5 to 18 , Figure 18 This paper shows a schematic diagram of the structure of a battery cell 10 without a casing, provided in some embodiments of this application.

[0195] In some embodiments, the battery cell 10 further includes an insulating film 4, which covers the outer periphery of the first support 3a and the electrode assembly 2 and separates the first support 3a and the electrode assembly 2 from the sidewall 11.

[0196] The battery cell 10 also includes an insulating film 4 for separating the electrode assembly 2 from the casing. The insulating film 4 is disposed between the first support member 3a and the side wall 11. Since the first support member 3a is disposed within the insulating film 4, it facilitates the flow of electrolyte and gas. Furthermore, the insulating film not only insulates the side wall 11 from the electrode assembly 2 but also cooperates with the first support member 3a to support the electrode assembly 2. The insulating film reduces the risk of electrical conductivity between the electrode assembly 2 and the casing. The insulating film can also be made of polypropylene.

[0197] In some other embodiments, the battery cell 10 further includes an insulating film 4, which covers the electrode assembly 2. A first support member 3a is disposed between the insulating film 4 and the side wall 11. The insulating film 4 is provided with a third through hole.

[0198] The first support member 3a can also be set outside the insulating film 4. When the first support member 3a is set between the insulating film 4 and the side wall 11, a third connecting hole needs to be opened on the insulating film 4 to facilitate the flow of electrolyte and gas.

[0199] In some alternative embodiments, the battery cell 10 further includes a pressure relief mechanism 122 disposed on the housing 1.

[0200] The pressure relief mechanism 122 is used to release the internal gas of the battery cell 10. As an example, it can be braked to release internal pressure or temperature when the internal pressure or temperature of the battery cell 10 reaches a predetermined threshold. When the internal pressure or temperature of the battery cell 10 reaches the predetermined threshold, the pressure relief mechanism 122 actuates or a weak structure within the pressure relief mechanism 122 is broken, thereby forming an opening or channel for internal pressure or temperature release. This threshold design varies depending on design requirements and may depend on one or more materials used in the positive electrode, negative electrode, electrolyte, and separator within the battery cell 10.

[0201] Please see Figures 1 to 18 The specific structure of the battery cell 10 will be described in detail below with reference to an embodiment of this application.

[0202] The battery cell 10 includes a housing 1, an electrode assembly 2, a first support 3a and a second support 3b. The housing 1 includes a shell and an end cap assembly. The shell includes a bottom wall, a first wall 11a and a second wall 11b. The first wall 11a and the second wall 11b are arranged opposite to each other along a first direction X. The shell has an opening. The end cap assembly covers the opening and serves as a third wall 12. The third wall 12 is provided with electrode terminals 121.

[0203] The first support member 3a and the second support member 3b have the same structure and both include a plate 31 and a protrusion 32. The protrusion 32 is a hollow structure. The first support member 3a and the second support member 3b are disposed on both sides of the electrode assembly 2 along the first direction X. The plate 31 of the first support member 3a is supported on the electrode assembly 2, and the protrusion 32 is disposed on the plate 31 and protrudes towards the first wall 11a along the first direction X. The first support member 3a and the first wall 11a have a first cavity S1. The plate 31 of the second support member 3b is supported on the electrode assembly 2, and the protrusion 32 is disposed on the plate 31 and protrudes towards the second wall 11b along the first direction X. The second support member 3b and the second wall 11b have a second cavity S3. The first cavity S1 and the second cavity S3 are connected to the space S2 where the electrode sheet is located.

[0204] The maximum dimension of the plate 31 of at least one of the first support member 3a and the second support member 3b along the first direction X is greater than or equal to 0.3 mm. The sum of the maximum protrusion distance L1 of the protrusion 32 of the first support member 3a and the maximum protrusion distance L2 of the protrusion 32 of the second support member 3b is greater than or equal to 4 mm and less than or equal to 50 mm, so as to form sufficient space to accommodate the gas generated by the chemical reaction of the alkali metal battery, reduce the internal gas pressure of the battery, and improve the service life of the battery.

[0205] The battery device and power-consuming device in the embodiments of this application, since they include the battery cells in the above embodiments, also have the beneficial effects of the battery cell 10 in the above embodiments, which will not be elaborated here.

[0206] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, said battery cell being an alkali metal battery, characterized in that, The battery cell includes: The outer shell has an internal cavity. The outer shell includes a first wall, a second wall, and a third wall. The first wall and the second wall are disposed opposite to each other. The third wall is disposed between the first wall and the second wall. One end of the third wall is connected to the first wall and the other end is connected to the second wall. An electrode assembly is housed in the receiving cavity and located between the first wall and the second wall, the electrode assembly comprising an electrode sheet; Electrode terminals are disposed on the third wall and are electrically connected to the electrode assembly; A first support member is disposed between the first wall and the electrode assembly, and a first cavity is formed between the first support member and the first wall and / or between the first support member and the electrode assembly, and the first cavity is connected to the space where the electrode sheet is located.

2. The battery cell according to claim 1, characterized in that, The first support member includes a plate and a protrusion. The plate is used to support the electrode assembly. The protrusion of the first support member is disposed on the plate and protrudes toward the first wall. The plate of the first support member and the first wall form the first cavity through the protrusion along a first direction, where the first direction is perpendicular to the first wall.

3. The battery cell according to claim 2, characterized in that, The protrusion is a hollow structure.

4. The battery cell according to claim 3, characterized in that, The electrode assembly includes at least two electrodes, which are wound around a winding axis that extends along the first direction; or, the electrodes are stacked together. The hollow portion of the protrusion extends through the protrusion along the first direction. The plate body is provided with a first connecting hole corresponding to the protrusion. The space where the electrode is located is connected to the first cavity through the first connecting hole and the hollow portion.

5. The battery cell according to claim 2, characterized in that, The electrode assembly includes at least two electrodes, which are wound around a winding axis that extends along the first direction; or, the electrodes are stacked together. The plate is also provided with a second connecting hole, and the space where the electrode is located is connected to the first cavity through the second connecting hole.

6. The battery cell according to claim 2, characterized in that, The electrode assembly includes at least two electrodes wound around a winding axis extending along a second direction; or, the electrodes are stacked together, with the second direction intersecting the first direction. The third wall is disposed on at least one side of the outer casing along the second direction, the electrode tabs of the electrode assembly are disposed facing the third wall and have a gap with the third wall along the second direction, and the first cavity is connected to the space where the electrode is located through the gap.

7. The battery cell according to claim 6, characterized in that, The housing includes a shell and an end cap assembly. The shell includes a first wall and a second wall. The shell has an opening on at least one side in a second direction. The end cap assembly covers the opening and forms the third wall. The electrode terminal includes a first electrode terminal and a second electrode terminal, both of which are disposed on the end cap assembly, and the electrode tab has a gap with the end cap assembly.

8. The battery cell according to claim 7, characterized in that, The housing has an opening on one side in the second direction, and the first electrode terminal and the second electrode terminal are both disposed on the same end cap assembly; Alternatively, the housing may have openings on both sides in the second direction, with the first electrode terminal and the second electrode terminal respectively disposed on the end cap assemblies on both sides.

9. The battery cell according to claim 6, characterized in that, The outer casing includes a housing and an end cap assembly. The housing includes a first wall, a second wall, and a third wall. The housing has an opening on one side in a second direction. The end cap assembly covers the opening and is disposed opposite to the third wall. The electrode terminals include a first electrode terminal and a second electrode terminal, at least one of the first electrode terminal and the second electrode terminal is disposed on the third wall of the housing, the first support extends at least partially between the third wall and the electrode assembly, and the tab forms the gap between the first support and the third wall.

10. The battery cell according to any one of claims 7 to 9, characterized in that, The end cap assembly includes a cap body and an insulating member disposed on the side of the cap body facing the receiving cavity; One portion of the insulating member and the first support member is bent onto the other and overlaps with it, and the insulating member and the first support member are connected in the overlapping area.

11. The battery cell according to claim 10, characterized in that, The first support member has a connection hole in the overlapping area, and the insulating member extends at least partially into the connection hole and is fixedly connected to the first support member.

12. The battery cell according to any one of claims 2 to 9, characterized in that, The number of protrusions is two or more, and the two or more protrusions are spaced apart on the plate.

13. The battery cell according to any one of claims 2 to 9, characterized in that, The maximum protrusion distance of the protrusion of the first support member in the first direction is greater than or equal to 4 mm and less than or equal to 50 mm.

14. The battery cell according to any one of claims 2 to 9, characterized in that, The battery cell further includes a second support member, which is disposed between the second wall and the electrode assembly. A second cavity is formed between the second support member and the second wall and / or between the second support member and the electrode assembly. The second cavity is connected to the space where the electrode sheet is located.

15. The battery cell according to claim 14, characterized in that, The structure of the second support member is the same as that of the first support member. The protrusion of the second support member is disposed on the plate and protrudes toward the second wall. The plate of the second support member and the second wall form the second cavity through the protrusion along the first direction. The sum of the maximum protrusion distance of the protrusion of the first support member in the first direction and the maximum protrusion distance of the protrusion of the second support member in the first direction is greater than or equal to 4 mm and less than or equal to 50 mm.

16. The battery cell according to claim 15, characterized in that, The maximum protrusion distance of the protrusion of the first support member in the first direction and the maximum protrusion distance of the protrusion of the second support member in the first direction are both greater than or equal to 2 mm and less than or equal to 25 mm.

17. The battery cell according to claim 15, characterized in that, The cell capacity A of the battery cell is 10Ah≤A≤50Ah, and the maximum protrusion distance of the protrusion of at least one of the first support member and the second support member along the first direction is greater than or equal to 2mm and less than or equal to 8mm. Alternatively, the cell capacity A of the battery cell is 50Ah≤A≤100Ah, and the maximum protrusion distance of the protrusion of at least one of the first support member and the second support member along the first direction is greater than or equal to 5mm and less than or equal to 18mm. Alternatively, the cell capacity A of the battery cell is 100Ah≤A≤250Ah, and the maximum protrusion distance of the protrusion of at least one of the first support member and the second support member along the first direction is greater than or equal to 5mm and less than or equal to 25mm.

18. The battery cell according to claim 15, characterized in that, The ratio 'a' of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity is greater than or equal to 2% and less than or equal to 16%. The volume of the first cavity is the difference between the product of the protrusion distance of the protrusion of the first support member along the first direction and the area of ​​the plate, and the volume of the protrusion itself. The volume of the second cavity is the difference between the product of the protrusion distance of the protrusion of the second support member along the first direction and the area of ​​the plate, and the volume of the protrusion itself.

19. The battery cell according to claim 18, characterized in that, The cell capacity A of the battery cell is 10Ah≤A≤50Ah, and the ratio a of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity satisfies 2%≤a≤12%. Alternatively, the cell capacity A of the battery cell is 50Ah≤A≤100Ah, and the ratio a of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity satisfies 5%≤a≤14%; Alternatively, the cell capacity A of the battery cell is 100Ah≤A≤250Ah, and the ratio a of the volume of at least one of the first cavity and the second cavity to the volume of the receiving cavity satisfies 5%≤a≤16%.

20. The battery cell according to any one of claims 2 to 9, characterized in that, The maximum dimension of the plate of the first support member along the first direction is greater than or equal to 0.3 mm.

21. The battery cell according to any one of claims 1 to 9, characterized in that, The battery cell also includes an insulating film, which covers the outer periphery of the first support and the electrode assembly and separates the first support and the electrode assembly from the first wall; Alternatively, the insulating film covers the electrode assembly, the first support is disposed between the insulating film and the first wall, and the insulating film is provided with a third through hole.

22. The battery cell according to any one of claims 1 to 9, characterized in that, The electrode includes a negative electrode, which includes a negative current collector and an active material layer disposed on at least one side of the negative current collector, the active material layer including an elemental active metal.

23. The battery cell according to claim 22, characterized in that, The active metal element includes one of lithium, sodium, potassium, zinc, or aluminum.

24. The battery cell according to claim 22, characterized in that, The battery cell also includes an electrolyte, which is disposed in the receiving cavity. The electrolyte includes a solvent, which includes one of an ether solvent or an ester solvent.

25. The battery cell according to claim 24, characterized in that, The solvent includes ether solvents, which include one of 1,2-dimethoxypropane, dimethoxymethane, ethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, pentaethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, or 1,3-dioxopentane.

26. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 25.

27. An electrical appliance, characterized in that, Includes the battery device as described in claim 26.

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