Battery cell, battery device, and electric device

Abstract

The application provides a battery cell, a battery device and a power utilization device. The battery cell is a metal battery or a sodium ion battery. The battery cell comprises a shell, an electrode assembly and a support. The shell comprises a shell body and a cover plate. The shell body comprises a side wall. The side wall encloses a receiving cavity with an opening in a first direction. The cover plate covers the opening and seals the receiving cavity. The electrode assembly is arranged in the receiving cavity. The support is used for supporting the electrode assembly. The support is arranged between the electrode assembly and the side wall and forms a cavity structure therebetween. The cavity structure is in communication with a space where the electrode assembly is located. The battery cell, the battery device and the power utilization device in the embodiments of the application can reliably support the electrode assembly, increase the available space inside the battery, and improve the long-term performance and capacity of the battery.

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 prevent interference and damage to the electrode assembly, existing batteries use support components between the electrode assembly and the casing. However, these support components significantly reduce the internal space of the casing, impacting the battery's long-term performance and capacity. Therefore, improving the long-term performance and capacity of batteries has become a pressing issue. 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 reliably support the electrode assembly while increasing the usable space inside the battery and improving the long-term performance and capacity of the battery.

[0005] In a first aspect, this application provides a battery cell, which is a metal battery or a sodium-ion battery. The battery cell includes a casing, an electrode assembly, and a support member. The casing includes a housing and a cover plate. The housing includes a side wall. The side wall surrounds a receiving cavity with an opening in a first direction. The cover plate covers the opening and seals the receiving cavity. The electrode assembly is disposed in the receiving cavity. The support member is used to support the electrode assembly. The support member is disposed between the electrode assembly and the side wall and forms a cavity structure between them. The cavity structure is in communication with the space where the electrode assembly is located.

[0006] In this embodiment, the structure of the support member is improved. While the support member reliably supports the electrode assembly, part of the material of the support member is removed to form a cavity structure between the electrode assembly and the sidewall. This cavity structure can accommodate the electrolyte and the gas generated by the chemical reaction of the metal battery or sodium-ion battery, increasing the usable space inside the battery and improving the long-term performance and service life of the battery cell.

[0007] 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.

[0008] In this embodiment, the metal battery has a high energy density and a long cycle life. However, the elemental metal reacts with some organic solvents in the electrolyte to generate gas. Therefore, by setting a cavity structure to contain the gas, the energy density and cycle life of the battery cell can be improved, while reducing the risk of excessive internal gas pressure during the use of the battery cell, thereby improving the reliability and service life of the battery cell.

[0009] In some embodiments, the active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

[0010] 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.

[0011] 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.

[0012] In some embodiments, a support member is disposed on at least one side of the electrode assembly along a second direction. The support member includes a plate and a protrusion. The plate supports the electrode assembly, and the protrusion is disposed on the plate and protrudes toward the sidewall along the second direction. The support member forms a cavity structure between the plate and the sidewall through the protrusion. The second direction intersects with the first direction, thereby enabling reliable support of the electrode assembly while forming a cavity structure to accommodate electrolyte and gas, improving the long-term performance and service life of the battery cell. The structure is simple and reliable.

[0013] In some embodiments, the electrode assembly includes at least two electrodes, which are wound around a winding axis to form a main body and an electrode tab, the winding axis extending along a first direction. The electrode tab is located on at least one side of the main body along the first direction, and on the side where the electrode tab is located, the electrode tab and the end cap have a first gap, and the cavity structure communicates with the space where the electrodes are located through the first gap.

[0014] In this embodiment of the application, when the electrode assembly is a wound structure and the winding axis extends along the first direction, the cavity structure can communicate with the space where the electrode is located through the first gap formed by the tab and the end cap, so as to realize the transfer of electrolyte and gas from the cavity structure to the space where the electrode is located.

[0015] In some embodiments, the cavity has openings on both sides, and tabs are disposed on both sides of the main body along the first direction. The tabs on both sides and the end caps have a first gap, so the cavity structure can be connected to the space where the electrode is located through the first gaps on both sides, thereby realizing the transfer of electrolyte and gas.

[0016] In some embodiments, the housing further includes a bottom wall disposed opposite to the end cap along a first direction, and an electrode tab disposed on the side of the main body facing the end cap. A support extends at least partially between the electrode assembly and the bottom wall, and the electrode assembly and the bottom wall form a second gap through the support, the second gap communicating with the cavity structure.

[0017] In some embodiments, the electrode assembly includes at least two electrodes, which are wound around a winding axis to form a main body and an electrode tab. The winding axis extends along a second direction. Alternatively, the electrodes are stacked together. At least one of the plate and the protrusion is provided with a through hole, and the cavity structure communicates with the space where the electrodes are located through the through hole.

[0018] In this embodiment of the application, when the electrode assembly is a wound structure and the winding axis extends along the second direction, or when the electrode assembly is a stacked structure, the cavity structure can be connected to the space where the electrode is located through the connecting hole to realize the transfer of electrolyte and gas.

[0019] In some embodiments, the number of connecting holes is at least three, and the at least three connecting holes are spaced apart along the first direction. By making openings in the support member at multiple points along the first direction, the cavity structure S1 can be made to flow smoothly with the space where the electrode sheet is located from multiple points, thereby improving the wetting effect on the electrode assembly.

[0020] In some embodiments, the opening area of ​​the connecting hole is greater than or equal to 6 mm. 2 This improves the wetting effect on the electrode assembly.

[0021] In some embodiments, the support includes a central region and an edge region surrounding the central region, with a protrusion at least in the edge region, so as to provide good support for the electrode assembly under vibration and impact conditions or during the use of the battery cell, thereby reducing the risk of interference between the electrode assembly and the housing.

[0022] In some embodiments, the protrusion extends along the edge region and is arranged in a ring shape, or the number of protrusions is at least two, and the at least two protrusions are spaced apart along a first direction in the edge region.

[0023] In some embodiments, the protrusions are provided at least at both ends of the plate along the first direction to improve the support effect on the electrode assembly.

[0024] In some embodiments, the number of protrusions is at least two, and the minimum dimension of each protrusion along the first direction is greater than or equal to 2 mm. And / or, the protrusions are respectively disposed on both sides of the central region along a third direction, the minimum dimension of the protrusions along the third direction is greater than or equal to 2 mm, and the third direction intersects with the first and second directions.

[0025] In some embodiments, the battery cell further includes an adhesive member for connecting the support to the electrode assembly, which can reduce or avoid relative movement between the support and the electrode assembly when the battery cell vibrates, thereby reducing the risk of the support deviating from its set position within the housing.

[0026] In some embodiments, the adhesive member includes a first adhesive portion and a second adhesive portion, the first adhesive portion being bonded to the surface of the support member facing the sidewall, and the second adhesive portion being connected to both ends of the first adhesive portion and bonded to the electrode assembly.

[0027] In some embodiments, the number of protrusions is at least two, and the first adhesive portion is bonded to the plate between two adjacent protrusions along a first direction.

[0028] In some embodiments, in the first direction, the dimension of the support member away from one end of the end cap along the second direction is smaller than the dimension of the support member toward one end of the end cap along the second direction.

[0029] In some embodiments, supports are disposed on both sides of the electrode assembly along a second direction. On either side of the electrode assembly, the dimension of the plate body along the second direction is greater than or equal to 0.3 mm, and the maximum dimension of the support member along the second direction is less than or equal to 2.5 mm, wherein the second direction intersects the first direction.

[0030] In some embodiments, a single battery cell includes multiple electrode assemblies stacked on top of each other, and each electrode assembly is provided with a support member to support each electrode assembly and improve the support performance of the electrode assembly.

[0031] In some embodiments, the support member comprises a plastic polymer material, i.e., the support member has good insulation properties, so that while the support member can reliably support the support member, the sidewalls can be insulated from the electrode assembly, thereby reducing the risk of the electrode assembly becoming conductive with the housing.

[0032] In some embodiments, the battery cell further includes an insulating film that covers the periphery of the support and electrode assembly and separates the support and electrode assembly from the sidewall. The insulating film can also cooperate with the support to support the electrode assembly and reduce the risk of the electrode assembly becoming conductive with the housing.

[0033] In some embodiments, the battery cell further includes a pressure relief mechanism for venting internal gas from the battery cell, and the pressure relief mechanism is disposed on at least one of the end cap and the housing.

[0034] In some embodiments, a battery cell includes multiple electrode assemblies, which are stacked along a first direction. Each electrode assembly is provided with a support member on at least one side along a second direction, i.e., the support member is provided separately. Its specific position and the position of its recessed portion can be adjusted according to the actual needs of the electrode assembly to support and fix each electrode assembly separately, thereby improving the support effect.

[0035] Secondly, embodiments of this application provide a battery device including a plurality of battery cells according to the first aspect.

[0036] Thirdly, embodiments of this application provide an electrical device, including the battery device of the second aspect.

[0037] According to embodiments of this application, a battery cell includes a casing, an electrode assembly, and a support member. By improving the structure of the support member, while it supports the electrode assembly, a portion of the support member's material is removed to form a cavity structure between the electrode assembly and the sidewall. This reduces the space occupied by the support member within the battery and allows the cavity structure to accommodate gases generated during chemical reactions in metal or sodium-ion batteries, lowering the internal gas pressure and improving battery lifespan. Furthermore, during battery manufacturing, the cavity structure can also accommodate electrolyte, increasing the amount of electrolyte injected into the battery. The space occupied by the electrode plates refers to the space within the battery cell occupied by the electrode plates. Since the cavity structure is connected to the electrode plate space, electrolyte can flow from the cavity structure to the electrode plate space to replenish the electrolyte consumed during electrode assembly use. Moreover, as electrolyte is consumed, the space freed up by the cavity structure can also be used to accommodate more gas. This interconnectedness fully utilizes the cavity structure formed by the support member, improving the long-term performance and capacity of the battery cell.

[0038] 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

[0039] 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:

[0040] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application;

[0041] Figure 2 This is an exploded schematic diagram of a battery device provided in some embodiments of this application;

[0042] Figure 3 These are schematic diagrams of the structure of a single battery cell provided in some embodiments of this application;

[0043] Figure 4 These are exploded views of a single battery cell provided in some embodiments of this application;

[0044] Figure 5 These are schematic diagrams of the support structure provided in some embodiments of this application;

[0045] Figure 6 This is a structural schematic diagram of the support member provided in some other embodiments of this application;

[0046] Figure 7 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0047] Figure 8 These are exploded views of a battery cell provided in other embodiments of this application;

[0048] Figure 9 This is a schematic diagram of the structure of an electrode assembly provided in other embodiments of this application;

[0049] Figure 10 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0050] Figure 11 This is a structural schematic diagram of the support member provided in some embodiments of this application;

[0051] Figure 12 This is a structural schematic diagram of the support member provided in some embodiments of this application;

[0052] Figure 13 These are exploded views of a single battery cell provided in some embodiments of this application;

[0053] Figure 14 This is a structural schematic diagram of a support member provided in some embodiments of this application.

[0054] The reference numerals in the detailed embodiments are as follows:

[0055] 100 battery packs, 200 controllers, 300 motors;

[0056] 10 individual battery cells, 20 casing cells;

[0057] 1. Outer shell; 11. Housing; 111. Side wall; 111a. First side wall; 111b. Second side wall; 112. Transition section; 12. End cap; 121. Electrode terminal; 122. Pressure relief mechanism; 2. Electrode assembly; 21. Electrode sheet; 21a. Positive electrode sheet; 21b. Negative electrode sheet; 211. Main body; 212. Electrode tab; 22. Isolator; 3. Support member; 31. Plate; 32. Protrusion; 33. Connecting hole; 4. Adhesive member; 41. First adhesive part; 42. Second adhesive part; 5. Insulating film;

[0058] S1 - Cavity structure; S2 - Space where the electrode is located; A1 - First end; A2 - Second end;

[0059] X is the second direction, Y is the third direction, and Z is the first direction. Detailed Implementation

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] Currently, in most batteries, the corners where the casing sidewalls meet are rounded, while the corners of the electrode assembly are right angles and are not rounded. Therefore, the gap between the rounded corners where the casing sidewalls meet and the electrode assembly is smaller than the gap between the casing sidewalls and the electrode assembly. To reduce interference between the electrode assembly and the rounded corners of the casing cavity, batteries in related technologies incorporate support members between the casing sidewalls and the electrode assembly. This protects the electrode assembly and reduces the risk of damage caused by pressure from the rounded corners of the casing.

[0068] The supporting structure in related technologies is a plate structure with a certain thickness. One surface of the plate supports the electrode assembly, while the other surface faces the sidewall to reduce interference between the electrode assembly and the casing. However, this structure occupies a significant amount of internal space in the casing, reducing the internal electrolyte filling space and affecting the battery's long-term performance and capacity. Especially when the battery cell is a metal or sodium-ion battery, the high chemical properties of these batteries easily lead to the violent and continuous decomposition of electrolyte solvents and trace amounts of water impurities on the electrode surface, generating gas. For battery cells with such high gas production, the small internal space of the casing can also lead to excessive internal gas pressure, affecting the battery cell's lifespan.

[0069] Based on the above considerations, in order to reduce the impact of the support component on battery performance, this application provides an embodiment of a new battery cell. By improving the structure of the support component, while the support component serves to support the electrode assembly, a cavity structure is formed between the electrode assembly and the sidewall by removing part of the support component. The 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.

[0070] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices using battery devices.

[0071] 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.

[0072] 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.

[0073] Please see Figure 1 , Figure 1 The diagram shows the structure of a vehicle provided in some embodiments of this application.

[0074] 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.

[0075] Please see Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application.

[0076] The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells 10, which are connected in series, parallel, or mixed connections via a busbar. A battery cell assembly may be a battery module, which is formed by arranging and fixing multiple battery cells 10 into an independent module.

[0077] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 20 and one or more battery cell assemblies. The battery cell 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.

[0078] 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 material.

[0079] 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.

[0080] Please refer to the following: Figures 3 to 4 , Figure 3 This is a schematic diagram of the structure of a battery cell 10 provided in some embodiments of this application. Figure 4 An exploded view of a battery cell 10 provided in some embodiments of this application.

[0081] This application provides a battery cell 10, which is a metal battery or a sodium-ion battery. The metal battery can be a lithium metal battery, a sodium metal battery, etc.

[0082] The battery cell 10 includes a casing 1, an electrode assembly 2, and a support member 3. The casing 1 includes a housing 11 and an end cap 12. The housing 11 includes a side wall 111, which encloses a receiving cavity with an opening in a first direction. The end cap 12 covers the opening and seals the receiving cavity. The electrode assembly 2 is disposed in the receiving cavity and includes an electrode sheet 21. The support member 3 supports the electrode assembly 2 and is disposed between the electrode assembly 2 and the side wall 111, forming a cavity structure between them. The cavity structure S1 communicates with the space S2 where the electrode sheet is located.

[0083] The outer casing 1 includes a housing 11 and an end cap 12. The housing 11 is a component used to form the internal environment of the battery cell 10. When the housing 11 is a hollow cuboid or cube, one of its planes is an open surface, meaning that this plane has no wall, allowing communication between the inside and outside of the housing 11. The end cap 12 covers the opening and connects to the housing 11, thereby sealing the opening of the housing 11 and placing the electrode assembly 2 within the closed cavity. The housing 11 is filled with an electrolyte, such as an electrolyte solution. The housing 11 may have one or more openings. The end cap 12 may also have one or more.

[0084] 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 an electrode 21, which includes a positive electrode and a negative electrode. 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. In some embodiments, the electrode assembly 2 also includes a separator membrane disposed between the negative and positive electrode, which can prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0085] The support member 3 is disposed between the electrode assembly 2 and the side wall 111. The support member 3 can support the electrode assembly 2, so that a sufficient gap is formed between the electrode assembly 2 and the housing 11, thereby reducing the risk of interference between the electrode assembly 2 and the housing 11.

[0086] In this embodiment, the battery cell 10 improves the structure of the support member 3 so that while the support member 3 serves to support the electrode assembly 2, some material of the support member 3 is removed to form a cavity structure S1 between the electrode assembly 2 and the side wall 111. This reduces the space occupied by the support member 3 inside the battery and uses the cavity structure S1 to accommodate the gas generated by the chemical reaction of the metal battery or sodium-ion battery, thereby reducing the internal gas pressure of the battery and improving the battery's service life.

[0087] Furthermore, during battery manufacturing, the cavity structure 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 cavity structure S1 is connected to the space where the electrode is located, the electrolyte can flow from the cavity structure 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 cavity structure S1 can also be used to accommodate more gas. There is a linkage between the two to make full use of the cavity structure S1 formed by the support member 3, thereby improving the long-term performance and capacity of the battery cell 10.

[0088] In some alternative 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, i.e., the battery cell 10 is a metal battery.

[0089] Optionally, the active metal element includes at least one of lithium, sodium, potassium, zinc, or aluminum.

[0090] As an alternative implementation, when the battery cell 10 is configured as a metal battery, the battery cell 10 can be configured as a sodium metal battery, which has a high energy density and a long cycle life.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] It is understandable that sodium metal batteries and ether solvents will still react to produce hydrogen gas. Therefore, by setting a cavity structure 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 the use of the battery cell 10, thereby improving the reliability and service life of the battery cell 10.

[0096] It is understood that the support member 3 forms a cavity structure S1 between the electrode assembly 2 and the side wall 111. This cavity structure S1 can be formed by the support member 3 itself, for example, by the support member 3 having a hollow portion. Thus, when the support member 3 is positioned between the electrode assembly 2 and the side wall 111, a cavity structure can be formed between them. Alternatively, when the support member 3 is positioned between the electrode assembly 2 and the side wall 111, at least a portion of the support member 3 is spaced apart from the electrode assembly 2 and / or the side wall 111, thereby forming a cavity structure between them.

[0097] Please see Figure 5 and Figure 6 , Figure 5 The following is a schematic diagram of the structure of the support member 3 provided in some embodiments of this application. Figure 6 A structural schematic diagram of the support member 3 provided in some other embodiments of this application is shown.

[0098] As an optional implementation, the support member 3 is disposed on at least one side of the electrode assembly 2 along the second direction X. The support member 3 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 side wall 111 along the second direction X. The support member 3 forms a cavity structure between the plate 31 and the side wall 111 through the protrusion 32. The second direction X intersects with the first direction Z.

[0099] Taking a square housing 11 as an example, the sidewall 111 includes a first sidewall 111a and a second sidewall 111b. The housing 11 also includes a transition section 112 disposed between the first sidewall 111a and the second sidewall 111b. The support member 3 is disposed on at least one side of the electrode assembly 2 along a second direction X. The second direction X can be a direction perpendicular to the first sidewall 111a, that is, the support member 3 can be disposed between the electrode assembly 2 and the first sidewall 111a, thereby supporting the electrode assembly 2 from the first sidewall 111a side to reduce the risk of interference between the electrode assembly 2 and the transition section 112.

[0100] Optionally, the area of ​​the first sidewall 111a can be equal to the area of ​​the second sidewall 111b, or the area of ​​the first sidewall 111a can be smaller than the area of ​​the second sidewall 111b.

[0101] For ease of description, the following description will use the example of a square shell 11, a side wall 111 including a first side wall 111a and a second side wall 111b, and a support member 3 disposed at least along the second direction X between the first side wall 111a and the electrode assembly 2.

[0102] Understandably, compared to setting the support member 3 as a plate structure with a certain thickness, by removing part of the material facing the first sidewall 111a from the support member 3, which includes the plate 31 and the protrusion 32, the protrusion 32 is formed while keeping the total thickness of the support member 3 unchanged. The support member 3 forms a cavity structure S1 between the plate 31 and the first sidewall 111a through the protrusion 32. This allows for reliable support of the electrode assembly 2 while forming a cavity structure S1 to accommodate electrolyte and gas, improving the long-term performance and service life of the battery cell 10. The structure is simple and reliable.

[0103] In addition, compared to directly supporting the electrode assembly 2 through the protrusion 32, the support member 3 in this embodiment of the application is provided with a plate 31, and the support member 3 is supported on the electrode assembly 2 through the plate 31. This increases the contact area between the support member 3 and the electrode assembly 2. 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 the damage to the electrode assembly 2.

[0104] In some alternative embodiments, the support 3 includes a central region and an edge region surrounding the central region, with the protrusion 32 at least disposed in the edge region.

[0105] By providing the protrusion 32 at least in the edge region, the electrode assembly 2 can be well supported under vibration and impact conditions or during the use of the battery cell 10, reducing the risk of interference between the electrode assembly 2 and the transition section 112. As for the central region of the support member 3, since its impact on the support performance is small, it is equivalent to removing the material in the central region and forming the protrusion 32 in the edge region. When the support member 3 is placed between the electrode assembly 2 and the first sidewall 111a, a cavity structure S1 can be formed between the first sidewall 111a and the central region of the support member 3 to accommodate the electrolyte and the gas generated by the chemical reaction of the battery cell 10, thereby improving the long-term performance and service life of the battery cell 10.

[0106] It is understandable that the central area and the edge area are relative terms. The range of the central area and the edge area, as well as the specific position of the protrusion 32, can be adjusted according to the support requirements, as long as they can meet the support requirements of the electrode assembly 2.

[0107] In some alternative embodiments, the protrusion 32 extends along the edge region and is arranged in a ring shape, or the number of protrusions 32 is at least two, and at least two protrusions 32 are arranged at intervals along the first direction Z in the edge region.

[0108] That is, the support member 3 can remove only the material in the central region, while forming a ring structure around the entire perimeter in the edge region. A cavity structure S1 is formed between the first sidewall 111a and the central region of the support member 3. The support performance and overall structural strength of the support member 3 are better with the above structure. Alternatively, the support member 3 can also remove the material in the central region and part of the edge region, while forming multiple spaced protrusions 32 in the edge region. A cavity structure S1 is formed between the first sidewall 111a and the central region and part of the edge region of the support member 3. The above structure can increase the volume of the cavity structure S1, thereby increasing the space available to accommodate electrolyte and gas, reducing the internal gas pressure of the battery cell 10 during use, and improving its service life.

[0109] It is understandable that when at least two protrusions 32 are provided, by distributing at least two protrusions 32 at intervals along the first direction Z in the edge region, the electrode assembly 2 can be supported at multiple points along the first direction Z, thereby increasing the volume of the cavity structure, improving the support performance of the electrode assembly 2, and reducing the risk of interference between the electrode assembly 2 and the transition section 112.

[0110] In some optional embodiments, the protrusions 32 are provided at least at both ends of the plate 31 along the first 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 first direction Z, and may extend to the outer edge of the plate 31 along the first direction Z, or may be spaced apart from the outer edge of the plate 31 along the first direction Z. Their specific positions can be adjusted according to the shape of the plate 31.

[0111] As an alternative implementation, the protrusions 32 are disposed at the top, middle and bottom of the plate 31 along the first direction Z, so as to reduce the number of protrusions 32 and increase the volume of the cavity structure S1 while achieving reliable support for the electrode assembly 2, so as to make fuller use of the internal space of the battery cell 10.

[0112] In some alternative embodiments, the number of protrusions 32 is at least two, and the minimum dimension of each protrusion 32 along the first direction Z is greater than or equal to 2 mm. And / or, the protrusions 32 are respectively disposed on both sides of the central region along the third direction Y, the minimum dimension of the protrusions 32 along the third direction Y is greater than or equal to 2 mm, and the third direction Y intersects the first direction Z and the second direction X.

[0113] Wherein, the third direction Y can be a direction perpendicular to the second sidewall 111b. When multiple protrusions 32 are provided, by making the minimum size of each protrusion 32 along the first direction Z greater than or equal to 2mm, and the minimum size of each protrusion 32 along the third direction Y greater than or equal to 2mm, the area of ​​each protrusion 32 is increased, thereby improving the support effect of the support member 3.

[0114] It is understandable that when multiple protrusions 32 are provided, the specific location and size of the protrusions 32 can be adjusted according to the actual support requirements, so as to increase the volume of the cavity structure S1 while supporting and fixing the electrode assembly 2.

[0115] For the support member 3, it needs to connect the formed cavity structure 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 cavity structure S1 with the space S2 where the electrode is located.

[0116] Please see Figures 3 to 7 , Figure 7 A schematic diagram of the structure of the electrode assembly 2 provided in some embodiments is shown.

[0117] In some alternative embodiments, the electrode assembly 2 includes at least two electrode pieces 21, which are wound around a winding axis to form a main body portion 211 and an electrode tab 212. The winding axis extends along a first direction Z. The electrode tab 212 is located on at least one side of the main body portion 211 along the first direction Z. On the side where the electrode tab 212 is located, the electrode tab 212 and the end cap 12 have a first gap. The cavity structure S1 communicates with the space S2 where the electrode pieces are located through the first gap.

[0118] When the electrode assembly 2 has a wound structure, at least two electrodes 21 of the electrode assembly 2 include a positive electrode 21a and a negative electrode 21b, which are wound along a winding axis. The electrode assembly 2 may also include a separator 22, which can be continuously arranged and wound between any adjacent positive electrode 21a and negative electrode 21b. The positive electrode 21a, negative electrode 21b, and separator 22 are wound to form an electrode assembly 2 having a main body 211 and a tab 212. The tab 212 is used to conduct current from the electrode assembly 2. The tab 212 includes a positive tab and a negative tab. An electrode terminal 121 is provided on the end cap 12. The electrode terminal 121 is electrically connected to the tab 212. The electrode terminal 121 can be directly connected to the tab 212, or it can be indirectly connected to the tab 212 through a current collector.

[0119] When the electrode assembly 2 has a wound structure, the space S2 where the electrode sheet is located needs to be connected to the cavity structure S1 at least at one end of the extension direction of its winding axis. Specifically, when the winding axis of the electrode assembly 2 extends along the first direction Z, the positive and negative electrodes can be located on one side of the main body 211 along the first direction Z, or on both sides of the main body 211 along the first direction Z.

[0120] Since there is a first gap between the tab 212 and the end cap 12 on the side where the tab 212 is located, when the electrode assembly 2 is configured as a wound structure and the winding axis is arranged along the first direction Z, the cavity structure S1 can communicate with the space S2 where the electrode is located through the first gap. This allows the electrolyte to flow from the cavity structure S1 through the first gap to the space S2 where the electrode is located, thereby 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 cavity structure S1 through the first gap, so that the cavity structure S1 can contain the gas, reduce the gas pressure, and thus improve the long-term performance and service life of the battery cell 10.

[0121] In some alternative embodiments, the receiving cavity has openings on both sides, and the tabs 212 are disposed on both sides of the main body 211 along the first direction Z, with the tabs 212 on both sides having a first gap with the end cap 12.

[0122] For the electrode assembly 2, where the positive and negative tabs are respectively disposed on both sides of the main body 211 along the first direction Z, both sides of the receiving cavity have openings, and the end caps 12 are disposed opposite to the openings on both sides to seal the openings on both sides. At this time, since the tabs 212 and the end caps 12 have a first gap on both sides of the electrode assembly 2, the cavity structure S1 can be connected to the space S2 where the electrode is located through the first gap on both sides, so as to realize the transfer of electrolyte and gas.

[0123] In other embodiments, the housing 11 further includes a bottom wall disposed opposite to the end cap 12 along a first direction, and an electrode tab 212 is disposed on the side of the main body 211 facing the end cap 12. The support member 3 extends between the electrode assembly 2 and the bottom wall, and the electrode assembly 2 and the bottom wall form a second gap through the support member 3, the second gap communicating with the cavity structure S1.

[0124] For the electrode assembly 2, where both the positive and negative tabs are located on the side of the main body 211 along the first direction Z, the receiving cavity has an opening on only one side. The housing 11 also includes a bottom wall that is disposed opposite to the end cap 12. In this case, the support member 3 can be extended between the electrode assembly 2 and the bottom wall so that the electrode assembly 2 and the bottom wall form a second gap through the support member 3.

[0125] When the battery cell 10 is inverted, i.e., the bottom wall of the casing 11 faces upward and the end cap 12 faces downward, and it is placed inside the housing 20, since the support member 3 extends between the electrode assembly 2 and the bottom wall, the gas generated by the chemical reaction of the battery cell 10 can enter the cavity structure S1 from the space S2 where the electrode is located, and then enter the second gap from the cavity structure S1. This increases the space inside the battery cell 10 that can be used to contain gas, reduces the internal gas pressure of the battery cell 10 during use, and improves the long-term performance and service life of the battery cell 10.

[0126] It is understood that the support member 3 may include a first support portion and a second support portion. The first support portion is disposed between the first sidewall 111a and the electrode assembly 2 along the second direction X, and the second support portion is disposed between the bottom wall and the electrode assembly 2 along the first direction Z. The structures of the first support portion and the second support portion may be the same or different. The first support portion and the second support portion may be integrally disposed or separately disposed, and their specific dimensions may be adjusted according to actual needs.

[0127] Please see Figure 8 and Figure 9 , Figure 8 Exploded views of the battery cell 10 provided in other embodiments of this application are shown. Figure 9 A schematic diagram of the structure of the electrode assembly 2 provided in some other embodiments of this application is shown.

[0128] When the electrode assembly 2 is a wound structure, its winding axis can be extended in the first direction Z or the second direction X.

[0129] When the winding axis extends along the second direction X, in order to connect the space S2 where the electrode is located with the cavity structure S1 along the second direction X, in some optional embodiments, the winding axis extends along the second direction X, and at least one of the plate 31 and the protrusion 32 is provided with a through hole 33. The cavity structure S1 is connected to the space S2 where the electrode is located through the through hole 33, so the electrolyte contained in the cavity structure S1 can enter the space S2 where the electrode is located through the through hole 33 to replenish the electrolyte. At the same time, the gas generated by the reaction of the electrode assembly 2 can enter the cavity structure S1 through the through hole 33, so that the cavity structure S1 can contain the gas, reducing the risk of premature depressurization caused by excessive internal gas pressure during the use of the battery cell 10.

[0130] Please see Figures 8 to 10 , Figure 10 A schematic diagram of the structure of the electrode assembly 2 provided in some embodiments of this application is shown.

[0131] When the electrode assembly 2 has a stacked structure, it 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 their thickness direction, i.e., the third direction Y. In some examples, the positive electrode sheet 21a and the negative electrode sheet 21b are both rectangular flat plates and are arranged parallel to each other.

[0132] 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.

[0133] In order to connect the space S2 where the electrode is located with the cavity structure S1, in some optional embodiments, the electrode 21 is stacked between each other, and at least one of the plate 31 and the protrusion 32 is provided with a through hole 33, through which the cavity structure S1 is connected to the space S2 where the electrode is located.

[0134] Since the electrode assembly 2 has a stacked structure, the space S2 where the electrode is located can be connected to the cavity structure S1 in all directions. Therefore, as an optional implementation, at least one of the plate 31 and the protrusion 32 can be provided with a through hole 33 so that the space S2 where the electrode is located can be connected to the cavity structure S1 in the second direction X. Thus, the electrolyte contained in the cavity structure S1 can enter the space S2 where the electrode is located through the through hole 33 to replenish the electrolyte. At the same time, the gas generated by the reaction of the electrode assembly 2 can enter the cavity structure S1 through the through hole 33, so that the cavity structure S1 can contain the gas and reduce the risk of premature depressurization caused by excessive internal gas pressure during the use of the battery cell 10.

[0135] Please see Figures 8 to 11 , Figure 11 The diagram shows a structural schematic of the support member 3 provided in some embodiments of this application. When the support member 3 is provided with connecting holes 33, in some optional embodiments, the number of connecting holes 33 is at least three, and the at least three connecting holes 33 are spaced apart along the first direction Z.

[0136] That is, the connecting holes 33 can be arranged at intervals along the first direction Z on the support member 3. By making holes in the support member 3 at multiple points along the first direction Z, the cavity structure 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.

[0137] As an optional implementation, the connecting holes 33 are respectively provided on the upper, middle and lower parts of the support member 3. Depending on the position of the connecting holes 33, the connecting holes 33 can be provided on the plate 31 or on the protrusion 32, as long as they can satisfy the passage between the cavity structure S1 and the space S2 where the electrode is located.

[0138] Optionally, the opening area of ​​the connecting hole 33 is greater than or equal to 6 mm. 2 This facilitates the cavity structure 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.

[0139] Please see Figures 8 to 12 , Figure 12 A schematic diagram of the support member 3 provided in some embodiments of this application is shown. In some optional embodiments, in the first direction Z, the dimension of the support member 3 away from the end cap 12 along the second direction X is smaller than the dimension of the support member 3 towards the end cap 12 along the second direction X.

[0140] The thickness of the support member 3 refers to its dimension along the second direction X. For ease of description, the end of the support member 3 facing the end cap 12 is defined as the first end A1, and the end of the support member 3 away from the end cap 12 is defined as the second end A2. Since the second end A2 of the support member 3 enters the receiving cavity first when the support member 3 is placed into the housing 11, by making the dimension of the second end A2 of the support member 3 along the second direction X smaller than the dimension of the first end A1 of the support member 3 along the second direction X, it is easier to install the electrode assembly 2 into the housing 11. At the same time, the first end A1 of the support member 3 can reliably support the electrode assembly 2, improving the long-term performance and capacity of the battery cell 10.

[0141] Optionally, the dimensions of the support member 3 can be gradually varied along the second direction X in the direction away from the end cap 12 to simplify the structure of the support member 3.

[0142] In some alternative embodiments, the support members 3 are disposed on both sides of the electrode assembly 2 along the second direction X. The support members 3 may be disposed in pairs on both sides of the electrode assembly 2 along the second direction X, that is, a support member 3 is disposed between the electrode assembly 2 and each of the first sidewalls 111a.

[0143] Specifically, in some examples, there are two support members 3, one support member 3 is located between the electrode assembly 2 and a first sidewall 111a, and the other support member 3 is located between the electrode assembly 2 and another first sidewall 111a, so as to support and fix the electrode assembly 2 from both sides, thereby improving the performance and life of the battery cell 10.

[0144] On either side of the electrode assembly 2, the size of the plate 31 along the second direction X is greater than or equal to 0.3 mm, and the maximum size of the support 3 along the second direction X is less than or equal to 2.5 mm.

[0145] When the electrode assembly 2 is provided with support members 3 on both sides along the second direction X, by making the dimension of the plate 31 along the second direction X greater than or equal to 0.3 mm, the support members 3 can provide sufficient support force so that the electrode assembly 2 will not interfere with the transition section 112 of the housing 11. In addition, the maximum dimension of the support member 3 along the second direction X refers to the position where the sum of the dimensions of the plate 31 and the protrusion 32 is the largest. By making the maximum dimension of the support member 3 along the second direction X less than or equal to 2.5 mm, it can play a certain role in fixing the electrode assembly 2, while reducing the space occupied by the support member 3 in the internal space of the housing 11.

[0146] As an alternative implementation, the dimension of the plate 31 along the second direction X can be set to 0.5 mm, and the maximum dimension of the protrusion 32 along the second direction X can be set to 2 mm.

[0147] In some alternative embodiments, the battery cell 10 includes a plurality of electrode assemblies 2, which are stacked together, and each electrode assembly 2 is provided with a corresponding support member 3.

[0148] That is, multiple electrode components 2 are stacked along the third direction Y, and each electrode component 2 is provided with a support member 3 on at least one side along the second direction X, so as to support each electrode component 2 through the support member 3 and improve the support performance of the electrode component 2.

[0149] Optionally, when multiple electrode assemblies 2 are provided, the number of support members 3 can be less than the number of electrode assemblies 2, and multiple electrode assemblies 2 can be supported by the same support member 3. Alternatively, the number of support members 3 can be equal to the number of electrode assemblies 2, and each electrode assembly 2 can be supported by the support member 3 to achieve separate support and fixation of each electrode assembly 2.

[0150] Please see Figures 3 to 14 , Figure 13 An exploded view of the battery cell 10 provided in some other embodiments of this application is shown. Figure 14 A schematic diagram of the structure of the support member 3 provided in some embodiments of this application is shown.

[0151] In some alternative embodiments, the battery cell 10 further includes an adhesive member 4 for connecting the support member 3 to the electrode assembly 2.

[0152] The adhesive component 4 is used to fix the support 3 to the electrode assembly 2. This reduces or prevents relative movement between the support 3 and the electrode assembly 2 when the battery cell 10 vibrates, lowering the risk of the support 3 deviating from its intended position within the housing 11. Furthermore, during the process of placing the electrode assembly 2 into the housing 11, the support 3 can enter the housing 11 along with the electrode assembly 2, thereby simplifying the assembly process of the battery cell 10. In some examples, the adhesive component 4 is adhesive tape. In other examples, an adhesive can be applied to the surface of the support 3, and then the support 3 can be adhered to the electrode assembly 2; the adhesive cures to form the adhesive component 4.

[0153] In some alternative embodiments, the adhesive member 4 includes a first adhesive portion 41 and a second adhesive portion 42. The first adhesive portion 41 is bonded to the surface of the support member 3 facing the side wall 111, and the second adhesive portion 42 is connected to both ends of the first adhesive portion 41 and bonded to the electrode assembly 2.

[0154] The first adhesive portion 41 is used to adhere to the surface of the support member 3 facing the first sidewall 111a, and the first adhesive portion 41 also serves to support the electrode assembly 2. Since the area on the electrode assembly 2 corresponding to the transition section 112 of the housing 11 is also easily subjected to the force of the transition section 112, the electrode 21 near the transition section 112 is more prone to active material detachment. The adhesive member 4 can cover at least a portion of the transition section 112 from the outside and space the connection point from the transition section 112, thereby reducing the force on the electrode 21 and reducing the risk of active material detachment.

[0155] The second adhesive part 42 is used to adhere to the electrode assembly 2, that is, the adhesive member 4 is bent into a U-shape.

[0156] In some embodiments, the adhesive members 4 are a plurality of non-continuous members, and the plurality of adhesive members 4 are spaced apart along the first direction Z. Since the support member 3 has a large dimension in the first direction Z, the plurality of adhesive members 4 can improve the connection strength between the support member 3 and the electrode assembly 2.

[0157] In some alternative embodiments, the number of protrusions 32 is at least two, and the first adhesive portion 41 is adhered to the plate 31 between two adjacent protrusions 32 along the first direction Z.

[0158] By bonding the first adhesive portion 41 along the first direction Z between two adjacent protrusions 32, that is, by allowing the first adhesive portion 41 to avoid the position of the protrusions 32, reliable bonding of the support member 3 can be achieved.

[0159] When the support member 3 is provided with a connecting hole 33, the adhesive member 4 should be positioned to avoid the connecting hole 33 so that the cavity structure S1 can communicate with the space S2 where the electrode is located through the connecting hole 33. As an optional embodiment, in the first direction Z, the position of the connecting hole 33 can correspond to the position of the protrusion 32. Therefore, when the first adhesive part 41 is bonded to the plate 31 between two adjacent protrusions 32 along the first direction Z, it is also easier for the adhesive member 4 to avoid the protrusion 32 and reduce the viscosity of the adhesive member 4.

[0160] In some alternative embodiments, the support member 3 may be made of a plastic polymer material, such as polypropylene.

[0161] By making the support member 3 a plastic polymer material, that is, the support member 3 has good insulation properties, it is possible to reliably support the support member 3 while insulating and separating the side wall 111 from the electrode assembly 2, thereby reducing the risk of the electrode assembly 2 and the housing 11 becoming conductive.

[0162] Optionally, the battery cell 10 also includes an insulating film 5, which covers the outer periphery of the support 3 and the electrode assembly 2 and separates the support 3 and the electrode assembly 2 from the sidewall 111.

[0163] The battery cell 10 also includes an insulating film 5 for separating the electrode assembly 2 and the housing 11. The insulating film 5 is disposed between the support member 3 and the side wall 111. The insulating film 5 not only insulates the side wall 111 from the electrode assembly 2, but also cooperates with the support member 3 to support the electrode assembly 2. The insulating film 5 can reduce the risk of electrical conductivity between the electrode assembly 2 and the housing 11. The insulating film 5 can also be made of polypropylene.

[0164] The position of the insulating film 5 can be set according to requirements. For example, when assembling the battery cell 10, the support 3 can be fixed to the electrode assembly 2 first by the adhesive component 4, and then the insulating film 5 can be wrapped around the outside of the electrode assembly 2 and the adhesive component 4. In the process of putting the electrode assembly 2 into the housing 11, the insulating film 5 can protect the support 3 and guide the support 3 into the housing, preventing the support 3 from being scratched by the housing 11.

[0165] In some alternative embodiments, the battery cell 10 further includes a pressure relief mechanism 122 disposed on at least one of the end cap 12 and the housing 11.

[0166] 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.

[0167] Please see Figures 1 to 14 The specific structure of the battery cell 10 will be described in detail below with reference to an embodiment of this application.

[0168] The battery cell 10 includes a housing 1, an electrode assembly 2, and a support 3. The housing 1 includes a shell 11 and an end cap 12. The shell 11 includes a bottom wall and a side wall 111. The bottom wall and the side wall 111 enclose a receiving cavity with an opening in the first direction Z. The end cap 12 covers the opening and seals the receiving cavity.

[0169] In this configuration, support members 3 are arranged in pairs along the second direction X on both sides of the electrode assembly 2. Each support member 3 includes a plate 31 and a protrusion 32. The plate 31 supports the electrode assembly 2, and the protrusion 32 is disposed on the plate 31 and protrudes towards the side wall 111 along the second direction X. When the support member 3 is disposed between the electrode assembly 2 and the side wall 111, the support member 3 can form a cavity structure S1 between the plate 31 and the side wall 111 through the protrusion 32. The support member 3 has a connecting hole 33, and the cavity structure S1 is connected to the space S2 where the electrode is located through the connecting hole 33. This cavity structure S1 is used to accommodate the gas generated by the chemical reaction of the metal battery or sodium-ion battery, thereby reducing the internal gas pressure of the battery and improving the battery's service life.

[0170] Furthermore, during battery manufacturing, the cavity structure S1 can also accommodate electrolyte to increase the electrolyte injection volume. The electrolyte can flow from the cavity structure S1 to the space where the electrode plates are 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 cavity structure S1 can also be used to accommodate more gas. There is a linkage between the two to make full use of the cavity structure S1 formed by the support member 3, thereby improving the long-term performance and capacity of the battery cell 10.

[0171] 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, characterized in that, The battery cell is a metal battery or a sodium-ion battery, and the battery cell includes: The housing includes a shell and an end cap, the shell including a sidewall that encloses a receiving cavity having an opening in a first direction, and the end cap covering the opening and sealing the receiving cavity; An electrode assembly, disposed in the receiving cavity, includes electrode plates; A support member is provided for supporting the electrode assembly. The support member is disposed between the electrode assembly and the sidewall and forms a cavity structure between them. The cavity structure is in communication with the space where the electrode sheet is located.

2. The battery cell according to claim 1, 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.

3. The battery cell according to claim 2, characterized in that, The active metal element includes one of lithium, sodium, potassium, zinc, or aluminum.

4. The battery cell according to claim 2, characterized in that, The battery cell also includes an electrolyte, which is disposed in a receiving cavity. The electrolyte includes a solvent, which includes one of an ether solvent or an ester solvent.

5. The battery cell according to claim 4, 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.

6. The battery cell according to claim 1, characterized in that, The support member is disposed on at least one side of the electrode assembly along the second direction; The support member includes a plate and a protrusion. The plate supports the electrode assembly. The protrusion is disposed on the plate and protrudes toward the side wall along the second direction. The support member forms the cavity structure between the plate and the side wall through the protrusion. The second direction intersects with the first direction.

7. The battery cell according to claim 6, characterized in that, The electrode assembly includes at least two electrode pieces, which are wound around a winding axis to form a main body and an electrode tab, and the winding axis extends along the first direction. The electrode tab is located on at least one side of the main body along the first direction. On the side where the electrode tab is located, the electrode tab and the end cap have a first gap. The cavity structure communicates with the space where the electrode sheet is located through the first gap.

8. The battery cell according to claim 7, characterized in that, The receiving cavity has openings on both sides, and the electrode tabs are disposed on both sides of the main body along the first direction. The electrode tabs on both sides and the end caps have a first gap.

9. The battery cell according to claim 7, characterized in that, The housing also includes a bottom wall disposed opposite to the end cap along a first direction, and the electrode tab is disposed on the side of the main body facing the end cap; The support extends at least partially between the electrode assembly and the bottom wall, and the electrode assembly and the bottom wall form a second gap through the support, the second gap communicating with the cavity structure.

10. The battery cell according to claim 6, characterized in that, The electrode assembly includes at least two electrodes, which are wound around a winding axis to form a main body and an electrode tab. The winding axis extends along the second direction, or the electrodes are stacked together. At least one of the plate and the protrusion is provided with a through hole, and the cavity structure is connected to the space where the electrode is located through the through hole.

11. The battery cell according to claim 10, characterized in that, The number of the connecting holes is at least three, and the at least three connecting holes are spaced apart along the first direction.

12. The battery cell according to claim 10, characterized in that, The opening area of ​​the connecting hole is greater than or equal to 6mm. 2 .

13. The battery cell according to any one of claims 6 to 12, characterized in that, The support member includes a central region and an edge region surrounding the central region, and the protrusion is provided at least in the edge region.

14. The battery cell according to claim 13, characterized in that, The protrusion extends along the edge region and is arranged in a ring shape, or the number of the protrusions is at least two, and at least two of the protrusions are spaced apart along the first direction in the edge region.

15. The battery cell according to claim 14, characterized in that, The protrusions are provided at least at both ends of the plate along the first direction.

16. The battery cell according to claim 14, characterized in that, The number of protrusions is at least two, and the minimum dimension of each protrusion along the first direction is greater than or equal to 2 mm; And / or, the protrusions are respectively disposed on both sides of the central region along a third direction, the minimum size of the protrusions along the third direction is greater than or equal to 2mm, and the third direction intersects with the first direction and the second direction.

17. The battery cell according to claim 14, characterized in that, The battery cell also includes an adhesive component for connecting the support to the electrode assembly.

18. The battery cell according to claim 17, characterized in that, The adhesive component includes a first adhesive portion and a second adhesive portion. The first adhesive portion is bonded to the surface of the support member facing the side wall, and the second adhesive portion is connected to both ends of the first adhesive portion and bonded to the electrode assembly.

19. The battery cell according to claim 18, characterized in that, The number of protrusions is at least two, and the first adhesive part is bonded to the plate between two adjacent protrusions along the first direction.

20. The battery cell according to any one of claims 6 to 12, characterized in that, In the first direction, the dimension of the support member away from the end cap along the second direction is smaller than the dimension of the support member toward the end cap along the second direction.

21. The battery cell according to any one of claims 6 to 12, characterized in that, The support members are disposed on both sides of the electrode assembly along the second direction; On either side of the electrode assembly, the dimension of the plate along the second direction is greater than or equal to 0.3 mm, and the maximum dimension of the support along the second direction is less than or equal to 2.5 mm, wherein the second direction intersects the first direction.

22. The battery cell according to any one of claims 1 to 12, characterized in that, The battery cell includes multiple electrode assemblies, which are stacked together, and each electrode assembly is provided with a corresponding support member.

23. The battery cell according to any one of claims 1 to 12, characterized in that, The support component comprises a plastic polymer material.

24. The battery cell according to any one of claims 1 to 12, characterized in that, The battery cell also includes an insulating film that covers the outer periphery of the support and the electrode assembly and separates the support and the electrode assembly from the sidewall.

25. The battery cell according to any one of claims 1 to 12, characterized in that, The battery cell also includes a pressure relief mechanism, which is disposed on at least one of the end cap and the housing.

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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