Battery cell, battery and electrical device

Abstract

Disclosed in the present application are a battery cell, a battery and an electrical device. The battery cell comprises a casing and an exhaust component, the casing being provided with a wall part and an accommodation chamber, the exhaust component being arranged on the wall part, and the exhaust component being used for discharging gas in the casing. The battery cell further comprises an electrolyte, and the electrolyte is filled in the accommodation chamber. The conductivity of the electrolyte is 2 ms / cm≤conductivity≤16 ms / cm, and the exhaust rate of the exhaust component is 0.6 mL / day≤exhaust rate≤10.0 mL / day. By matching battery cells having electrolytes of different conductivities with exhaust components of different exhaust rates, the solution of the present application can balance the contradiction between high conductivity requirements and high gas production amounts, and reduces the impact of external water vapor intrusion on batteries in the exhaust process.

Description

Battery cells, batteries and electrical equipment Technical Field

[0001] This application claims priority to Chinese patent application No. 202323354804.5, filed on December 8, 2023, entitled “Battery Cell, Battery and Electrical Equipment,” the entire contents of which are incorporated herein by reference.

[0002] Technical Field

[0003] The present application relates to the field of new energy technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] As global energy and environmental issues continue to intensify, new energy sources are rapidly developing as a sustainable development area. Batteries are becoming increasingly widely used as a new energy source, and high standards are being placed on their safety and service life. During the charge and discharge process, the generation of internal gas within the battery can cause an increase in internal pressure, reducing the safety of the battery cells and shortening their service life. The above statements are intended only to provide background information related to this application and do not necessarily constitute prior art. Summary of the Invention

[0005] The main technical problem solved by this application is to provide a battery cell, a battery and an electrical device, which can discharge the internal gas of the battery cell to the outside of the outer shell in time, so that the air pressure inside the battery cell is maintained at a normal level, which can improve the safety performance of the battery and greatly increase the battery life.

[0006] To address the aforementioned issues, this application employs a technical solution: providing a battery cell comprising a housing and a vent assembly. The housing comprises a wall portion and a receiving cavity, and the vent assembly is disposed within the wall portion and is used to exhaust gas from within the housing. The vent assembly can promptly exhaust gas from the battery cell to the exterior of the housing, maintaining the air pressure within the battery cell within a normal level, thereby improving battery safety and significantly extending battery life.

[0007] Furthermore, the battery cell also includes an electrolyte, which is filled in the accommodating cavity. The conductivity of the electrolyte is: 2ms / cm≤conductivity≤16ms / cm, and the exhaust rate of the exhaust component is: 0.6mL / day≤exhaust rate≤10.0mL / day. Exhaust components with different exhaust rates are matched for battery cells with electrolytes of different conductivities, which can balance the contradiction between high conductivity requirements and high gas production, while reducing the impact of external water vapor intrusion on the battery during the exhaust process.

[0008] In one embodiment, the electrolyte conductivity is 8 ms / cm ≤ 16 ms / cm, and the exhaust rate of the exhaust assembly is 3.3 mL / day ≤ 10.0 mL / day. Battery cells with higher electrolyte conductivity generate greater gas production, and a faster exhaust rate exhaust assembly is used to promptly exhaust the gas.

[0009] In one embodiment, the electrolyte conductivity is 11 ms / cm ≤ conductivity ≤ 14 ms / cm, and the exhaust rate of the exhaust assembly is 4.5 mL / day ≤ exhaust rate ≤ 9.0 mL / day. This allows for a more precise matching of the exhaust rate and electrolyte conductivity, improving the battery cell's charging capacity and energy density while also ensuring safety and service life.

[0010] In one embodiment, the electrolyte conductivity is: 2ms / cm ≤ conductivity ≤ 8ms / cm; and the exhaust rate of the exhaust assembly is: 0.6mL / day ≤ exhaust rate ≤ 5.0mL / day. Due to the low electrolyte conductivity and low gas production in the battery cells, a low exhaust rate exhaust assembly is used to promptly exhaust gas from the battery while reducing the probability of external impurities (air, moisture, dust, etc.) entering the battery cells.

[0011] In one embodiment, the conductivity of the electrolyte is: 4ms / cm≤conductivity≤6ms / cm; the exhaust rate of the exhaust assembly is 1.3mL / day≤second exhaust rate≤3.9mL / day; the exhaust rate and electrolyte conductivity can be matched more accurately, taking into account the safety performance and service life of the battery cell.

[0012] In one embodiment, the exhaust assembly includes a breathable membrane assembly, which includes a breathable membrane having a permeability rate of 3-10 mL / day, thereby enabling timely exhaust of gas from the battery cell while preventing external impurities (air, moisture, dust, etc.) from entering the battery cell.

[0013] In one embodiment, the breathable membrane includes a first breathable membrane, and the first breathable membrane has a permeability rate of 3-4 mL / day, which can be compatible with battery cells corresponding to electrolytes with relatively low conductivity.

[0014] In one embodiment, the breathable membrane includes a second breathable membrane, and the second breathable membrane has a breathability rate of 9-10 mL / day, which can be compatible with battery cells corresponding to electrolytes with relatively high conductivity.

[0015] In one embodiment, the exhaust assembly includes a one-way valve having an opening pressure greater than or equal to 0.2 MPa; alternatively, greater than or equal to 0.4 MPa; and alternatively, greater than or equal to 0.8 MPa. By adjusting the opening pressure, the valve can be adapted to different application scenarios and different exhaust requirements.

[0016] In one embodiment, the vent assembly includes a breathable membrane assembly and a one-way valve. The wall portion has a first vent hole, which connects the interior and exterior of the housing. The battery cells are configured so that gas exhausted through the first vent hole flows through the one-way valve and the breathable membrane assembly. In this case, the breathable membrane assembly and the one-way valve are arranged in series. The one-way valve protects the sealing of the battery cell system and reduces the probability of external moisture entering the battery cell system. Furthermore, the breathable membrane prevents electrolyte leakage and seals the battery system when the one-way valve is open.

[0017] In one embodiment, the opening pressure of the one-way valve is greater than or equal to 0.4 MPa, and the breathable membrane assembly includes a second breathable membrane having a permeability rate of 9-10 mL / day. When arranged in series, the breathable membrane with a higher permeability rate enables faster exhaust when the one-way valve is opened.

[0018] In one embodiment, the exhaust assembly includes a breathable membrane assembly and a one-way valve. The wall portion has first and third exhaust holes spaced apart, connecting the interior and exterior of the housing, respectively. The battery cell is configured such that gas exhausted through the first exhaust hole flows through the one-way valve, while gas exhausted through the third exhaust hole flows through the breathable membrane assembly. In this case, the breathable membrane assembly and the one-way valve are arranged in parallel, allowing them to exhaust gas simultaneously, achieving a relatively high exhaust rate.

[0019] In one embodiment, the opening pressure of the one-way valve is greater than or equal to 0.8 MPa, and the breathable membrane assembly includes a first breathable membrane having a permeability rate of 3-4 mL / day. When arranged in parallel, using a breathable membrane with a lower permeability rate can reduce the risk of external moisture entering the battery cell through the breathable membrane when the breathable membrane is more permeable.

[0020] In one embodiment, the gas production rate of the battery cell is: 0.006 mL / Ah / D≤gas production rate≤0.066 mL / Ah / D. A suitable exhaust assembly can be matched according to the gas production rate of the battery.

[0021] Optionally, the gas production rate of the battery cell is: 0.006 mL / Ah / D ≤ gas production rate ≤ 0.033 mL / Ah / D. A suitable exhaust component can be matched according to the gas production rate of the battery.

[0022] Furthermore, the gas production rate of the battery cell is: 0.013mL / Ah / D ≤ gas production rate ≤ 0.026mL / Ah / D. The appropriate exhaust component can be matched according to the gas production rate of the battery.

[0023] Optionally, the gas production rate of the battery cell is: 0.033 mL / Ah / D ≤ gas production rate ≤ 0.066 mL / Ah / D. A suitable exhaust assembly can be matched according to the gas production rate of the battery.

[0024] Furthermore, the gas production rate of the battery cell is: 0.045 mL / Ah / D ≤ gas production rate ≤ 0.060 mL / Ah / D. The appropriate exhaust component can be matched according to the gas production rate of the battery.

[0025] In one embodiment, the electrolyte includes one or more of chain ethers, ethylene glycol dimethyl ether and its derivatives, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclic ethers, which can reduce the risk of gas generation caused by the electrolyte.

[0026] In one embodiment, the battery cell further includes an electrode assembly housed within the housing cavity. The electrode assembly includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active layer disposed on the positive electrode current collector. The positive electrode active layer includes a positive electrode active material. The positive electrode active material includes one or more of a polyanion positive electrode material, a phosphate positive electrode material, a sulfate positive electrode material, a silicate positive electrode material, and a borate positive electrode material. Furthermore, the negative electrode sheet includes a negative electrode current collector and a carbonaceous coating disposed on the negative electrode current collector. The carbonaceous coating includes a carbonaceous material. The carbonaceous material includes one or more of conductive carbon, graphite, hard carbon, and carbon nanotubes. This can reduce the risk of gassing caused by the electrode materials.

[0027] In one embodiment, a one-way valve includes a valve body and a valve core. The valve body defines a valve cavity. The valve body is provided with an air inlet and an air outlet. The air inlet connects the valve cavity with the interior of a housing, while the air outlet connects the valve cavity with the exterior of the housing. The valve core is disposed within the valve cavity and blocks the air inlet passage of the valve cavity. The valve core is configured to open the air inlet passage in response to gas within the housing. This facilitates the discharge of gas.

[0028] In one embodiment, a breathable membrane assembly includes a breathable membrane and a connector. The connector is provided with a first breathable hole. The breathable membrane is disposed on the connector and covers the first breathable hole. The breathable membrane is configured to allow gas within the battery cell to pass through the breathable membrane and escape. This can improve the connection strength of the breathable membrane assembly and reduce the risk of deformation of the breathable membrane.

[0029] In one embodiment, the wall portion has an outer surface and an inner surface disposed in opposite directions, the outer surface facing the exterior of the housing, and the inner surface facing the interior of the housing. The wall portion is provided with a first vent hole, the first vent hole comprising a through hole segment and a first hole segment, the through hole segment and the first hole segment being arranged along the thickness direction of the wall portion, the through hole segment communicating the interior of the housing with the exterior of the housing, the first hole segment being located on a side of the through hole segment facing away from the interior of the housing, the aperture of the first hole segment being larger than the aperture of the through hole segment, and the one-way valve being at least partially accommodated in the first hole segment, thereby facilitating assembly of the one-way valve.

[0030] In one embodiment, at least a portion of the valve body of the one-way valve protrudes from the outer surface; the wall portion has a first recessed portion that is recessed relative to the inner surface. The first recessed portion is disposed around the first exhaust hole, and the breathable membrane assembly is at least partially accommodated within the first recessed portion. This can reduce the installation height of the exhaust assembly.

[0031] In one embodiment, at least a portion of the valve body of the one-way valve protrudes from the outer surface of the wall portion. The first vent further includes a second hole segment, which is located between the through-hole segment and the first hole segment along the thickness direction of the wall portion. The second hole segment has a smaller aperture than the first hole segment and a larger aperture than the through-hole segment. The breathable membrane assembly is at least partially accommodated in the second hole segment and is located on the side of the one-way valve facing the wall portion. This facilitates assembly of the vent assembly.

[0032] In one embodiment, the one-way valve includes a valve body, at least a portion of which protrudes from the inner surface of the wall portion. The valve body includes a valve seat and a valve cover. The valve seat includes a seat bottom wall and a seat sidewall connected to the seat bottom wall. The valve cover is disposed at an end of the valve seat away from the seat bottom wall. The valve cover, the seat sidewall, and the seat bottom wall enclose a valve cavity. The valve seat is provided with an air inlet for the valve cavity. The breathable membrane assembly is disposed on a side of the seat bottom wall away from the valve cavity, or on a side of the seat bottom wall facing the valve cavity. This can reduce the installation height of the exhaust assembly.

[0033] To solve the above technical problems, another technical solution adopted by the present application is to provide a battery comprising the above battery cells, which has at least the same advantages as the battery cells.

[0034] To solve the above technical problems, another technical solution adopted by the present application is to provide an electrical device comprising the above battery, which has at least the same advantages as the battery.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0037] FIG1 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0038] FIG2 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0039] FIG3 is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0040] FIG4 is a schematic diagram of a partially exploded structure of a battery cell according to one or more embodiments;

[0041] FIG5 is a front schematic view of a one-way valve according to one or more embodiments;

[0042] FIG6 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0043] FIG7 is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0044] FIG8 is a schematic front view of a one-way valve according to one or more embodiments;

[0045] FIG9 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0046] FIG10 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0047] FIG11 is a schematic cross-sectional view of a breathable membrane assembly according to one or more embodiments;

[0048] FIG12 is a schematic diagram of a partial cross-sectional structure of an end cap according to one or more embodiments;

[0049] FIG13 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0050] FIG14 is a partial front view of a battery cell according to one or more embodiments;

[0051] FIG15 is a schematic diagram of a partial cross-sectional structure of an end cap according to one or more embodiments;

[0052] FIG16 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0053] FIG17 is a partial front view of a battery cell according to one or more embodiments;

[0054] FIG18 is an exploded view of an exhaust assembly according to one or more embodiments;

[0055] FIG19 is a schematic cross-sectional view of an exhaust assembly according to one or more embodiments.

[0056] FIG20 is an exploded structural diagram of an exhaust assembly according to one or more embodiments;

[0057] FIG21 is a schematic cross-sectional view of an exhaust assembly according to one or more embodiments;

[0058] FIG22 is an exploded view of an exhaust assembly according to one or more embodiments;

[0059] FIG23 is a schematic cross-sectional view of an exhaust assembly according to one or more embodiments.

[0060] FIG24 is a schematic diagram of an exploded structure of a battery according to one or more embodiments;

[0061] FIG25 is a schematic structural diagram of a vehicle according to one or more embodiments.

[0062] In the attached figure:

[0063] 1000, vehicle; 300, motor; 200, controller; 100, battery; 10, housing; 11, first portion; 12, second portion; 20, battery cell; 21, end cap; 21a, outer surface; 21b, inner surface; 291, first vent hole; 22, housing; 221, accommodating chamber; 23, electrode assembly; 24, insulating member; 293, third vent hole; 25, electrode terminal; 90, vent assembly; 30, one-way valve; 31, valve body; 311, valve seat; 3111, first through hole; 3112, first sink; 3113, protrusion; 3114, fourth through hole; 3115, seat bottom wall; 3116, Seat side wall; 312, valve cover; 312a, convex part; 3121, cover top wall; 3122, cover side wall; 31221, second through hole; 3123, fifth through hole; 313, valve cavity; 313a, air inlet; 313b, air outlet; 313c, first exhaust gap; 32, valve core; 321, blocking member; 3211, sealing part; 3212, pressing part; 322, elastic member; 40, breathable membrane assembly; 41, breathable membrane; 42, metal member; 491, first air hole; 43, backing member; 70, pressure relief mechanism; T1, first annular table; T2, second annular table; T3, transition surface; S1, first sinking platform. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solution and effect of this application clearer and more specific, the following embodiments of the technical solution of this application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application and are therefore only examples and are not intended to limit the scope of protection of this application.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0066] In the description of the embodiments of the present application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two (including two), and "multiple pieces" refers to more than two (including two), unless otherwise clearly and specifically defined.

[0067] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0068] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0069] Amounts, ratios, and other numerical values ​​are presented herein in a range format. It should be understood that such range format is used for convenience and brevity and should be interpreted flexibly to include not only the values ​​explicitly specified as range limits, but also all individual values ​​or sub-ranges encompassed within the range, as if each value and sub-range were explicitly specified.

[0070] In the description of the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and do not constitute any limitation on this application.

[0071] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0072] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0073] Batteries have a wide range of applications in the new energy sector, primarily in electric vehicles, energy storage systems, and renewable energy. In the electric vehicle sector, higher performance features such as longer driving range and faster charging are gradually being achieved. In energy storage systems, batteries are widely used for large-scale and distributed energy storage. They can balance grid loads, store renewable energy such as solar and wind power, and release the stored energy during peak periods. Furthermore, small rechargeable batteries are widely used in applications such as wearable devices, drones, and smart homes.

[0074] Please refer to Figure 1, which is a schematic diagram of the exploded structure of a battery cell according to one or more embodiments. A battery cell 20 is provided, which is the smallest unit of a battery. As shown in Figure 1, battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0075] The end cap 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 22 to match the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). In this way, the end cap 21 is less likely to deform when squeezed or collided, so that the battery cell 20 can have a higher structural strength and improved safety performance. Functional components such as electrode terminals 25 can be provided on the end cap 21. The electrode terminals 25 can be used to electrically connect to the electrode assembly 23 to output or input electrical energy from the battery cell 20. Exemplarily, the battery cell 20 is provided with two electrode terminals 25, and both electrode terminals 25 are mounted on the end cap 21. The two electrode terminals 25 are respectively used to electrically connect to the two tabs of opposite polarity of the electrode assembly 23 to respectively output or input the positive and negative electrodes of the battery cell 20. In some embodiments, the end cap 21 may also be provided with a pressure relief mechanism 70 for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating member 24 may also be provided on the inner side of the end cap 21. The insulating member 24 may be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber, etc.

[0076] The housing 22 is a component that cooperates with the end cap 21 to form a housing cavity 221 for the battery cell 20. The resulting interior space can accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 can be placed over the opening to create the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be enclosed, the end cap 21 can be placed over the housing 22. The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylinder, or a hexagonal prism. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic, and this embodiment of the present application does not impose any particular limitations on this.

[0077] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 22. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive and negative electrode tabs may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0078] In one embodiment, the positive electrode sheet includes a positive electrode current collector and a positive electrode active layer disposed on at least one side of the positive electrode current collector, wherein the positive electrode active layer includes a positive electrode active material.

[0079] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active layer may be provided on either or both of the two facing surfaces of the positive electrode current collector.

[0080] In one embodiment, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0081] In one embodiment, the positive electrode material includes one or more of a polyanion positive electrode material, a phosphate positive electrode material, a sulfate positive electrode material, a silicate positive electrode material, and a borate positive electrode material. For example, in the positive electrode active material of a sodium battery, the polyanion compound includes a compound based on phosphoric acid and fluorophosphate. The compound based on phosphoric acid includes Na x1 Fe y1 P m1 O n1 For example, sodium iron phosphate with a higher capacity and sodium iron pyrophosphate with a higher voltage platform. Polyanionic compounds include sodium vanadium trifluorophosphate Na3V2(PO4)2F3, sodium vanadium fluorophosphate NaVPO4F, sodium vanadium phosphate Na3V2(PO4)3, Na4Fe3(PO4)2P2O7, NaFePO4, Na3V2(PO4)3. Prussian blue compounds are Na xMM(CN)6, where M and M are one or more of Fe, Mn, Co, Ni, Cu, Zn, Cr, Ti, V, Zr, and Ce, and 0 < x ≤ 2. The positive electrode active material in the lithium metal battery may include at least one of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, or lithium iron manganese phosphate.

[0082] In one embodiment, the negative electrode sheet includes a negative electrode current collector and a negative electrode active layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode active layer includes a negative electrode active material. In this embodiment, the battery cell is an ion battery. During the charge and discharge process of the battery, active ions (such as Li + 、Na + ) is embedded / deintercalated in the negative electrode active material.

[0083] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active layer may be disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0084] In one embodiment, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base material. The composite current collector may be obtained by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer base material (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0085] In one embodiment, the negative electrode active material may include one or more of a silicon-based material, a silicon-carbon material, a carbon material, and a selenium-based material. Specifically, it includes one or more of artificial graphite, natural graphite, hard carbon, soft carbon, a silicon-based material, and a selenium-based material. The silicon-based material may be selected from one or more of elemental silicon, a silicon oxide (e.g., silicon 2 oxide), a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The selenium-based material may be selected from one or more of elemental selenium, a selenium oxide, and a selenium alloy.

[0086] In one embodiment, the negative electrode plate includes a negative electrode current collector and a carbonaceous coating provided on at least one surface of the negative electrode current collector. In this embodiment, the battery cell is a metal battery, and during the charge and discharge process of the battery, active ions are deposited / stripped at the negative electrode plate. The metal battery can be an alkali metal battery, such as a lithium metal battery, a sodium metal battery, a potassium metal battery, a zinc metal battery, or an aluminum metal battery. This type of battery can also be called a "negative electrode-free battery". During the charging process, the active ions (such as Na +) is deposited onto the negative electrode current collector to form sodium metal. The provision of a carbon-containing coating facilitates more uniform metal deposition. The carbon-containing material includes one or more of conductive carbon, graphite, hard carbon, and carbon nanotubes.

[0087] In other embodiments, a conductive film layer may be deposited on the negative electrode current collector. Examples include alloy materials, titanium-based materials, active metals (e.g., sodium metal), carbon-based materials deposited with metals, composite materials containing metals, and alloy materials containing metals. Such alloy materials include, but are not limited to, sodium-tin alloys, sodium-germanium alloys, and sodium-antimony alloys. Such titanium-based materials include, but are not limited to, titanium dioxide, titanates, and titanium phosphates.

[0088] In one embodiment, the positive electrode active layer and the negative electrode active layer may further include a binder and a conductive agent. As an example, the binder may include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and at least one of a fluorine-containing acrylate resin. As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

[0089] In one embodiment, the isolation membrane can be any known porous structure isolation membrane with good chemical stability and mechanical stability.

[0090] In one embodiment, the material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0091] The electrolyte conducts ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid.

[0092] In some embodiments, the electrolyte is an electrolyte solution. The electrolyte solution includes an electrolyte salt and a solvent. The electrolyte salt dissolves to form electrolyte ions, and conduction is achieved through the movement of the electrolyte ions in the electrolyte salt.

[0093] In one embodiment, in a sodium battery, the electrolyte salt includes sodium hexafluorophosphate (NaPF6), sodium bis(fluorosulfonyl)imide (NaFSI), sodium trifluoromethanesulfonate (CF3NaO3S), sodium sulfide (Na2S), and the like. A lithium battery includes at least one lithium salt selected from the group consisting of lithium perchlorate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium difluorooxalatoborate, lithium tetrafluoroborate, and lithium trifluoromethanesulfonate.

[0094] In one embodiment, the solvent includes one or more solvents selected from the group consisting of chain ethers, ethylene glycol dimethyl ether and its derivatives, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclic ethers, specifically including dimethyl ether (DME), diethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, 2,2,2,2-trifluoroethyl ether, ethylene glycol diethyl ether, triethylene glycol dimethyl ether, ethylene glycol dimethyl ether derivatives, trifluoroethyl methyl carbonate (FEMC), dioxolane (DOL), acetonitrile (AN), fluorobenzene, triethyl phosphate (TEP), sulfolane, 2-methyltetrahydrofuran, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylacetamide, and the like.

[0095] In one embodiment, the electrolyte may further include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives capable of improving certain battery properties, such as additives that improve battery overcharge performance, and additives that improve battery high or low temperature performance.

[0096] As the battery charges and discharges, some side reactions generate gases. If these gases are not promptly discharged, the internal pressure of the battery will increase. Excessive internal pressure can negatively impact the battery's performance and appearance. For example, in severe cases, this can have devastating effects on the battery's performance and appearance, such as leakage, bulging, increased internal resistance, and shortened discharge time and cycle life. Furthermore, batteries can be subject to abnormal operation during use, including overcharging, over-discharging, and internal failures. In these cases, the chemical reactions within the battery may become uncontrolled, accompanied by a violent release of gas, and even trigger thermal runaway. Battery thermal runaway refers to a chain reaction phenomenon triggered by various factors. The large amount of heat and harmful gases emitted by thermal runaway can cause the battery to catch fire and explode.

[0097] Research has found that the electrolyte is one of the key factors affecting gas production. On the one hand, the electrolyte contains some highly active organic matter, which is prone to oxidation reactions on the positive electrode side or reduction reactions on the negative electrode side, thereby producing gas. On the other hand, the electrolyte plays the role of conducting ions between the positive and negative electrodes. In order to achieve rapid ion migration, the electrolyte generally needs to have a high ionic conductivity. However, higher ionic conductivity will make the electrolyte components more active and more prone to gas production. Therefore, it is necessary to balance the relationship between battery gas production and ionic conductivity.

[0098] Please refer to Figure 2, which is a schematic diagram of the exploded structure of a battery cell according to one or more embodiments. According to some embodiments of the present application, the present application discloses a battery cell 20, which includes a housing and a vent assembly 90. The housing has a wall portion and a receiving cavity 221. The vent assembly 90 is disposed in the wall portion and is used to exhaust gas from the interior of the housing. The provision of the vent assembly 90 can promptly exhaust the gas inside the battery cell outside the housing, maintaining the air pressure inside the battery cell within a normal level, thereby improving the safety performance of the battery and significantly increasing the battery life.

[0099] In this embodiment, the battery cell 20 further includes an electrolyte, which fills the receiving cavity 221. The conductivity of the electrolyte is: 2ms / cm≤conductivity≤16ms / cm, and the exhaust rate of the exhaust assembly 90 is: 0.6mL / day≤exhaust rate≤10.0mL / day.

[0100] Conductivity is a numerical measure of a solution's ability to conduct an electric current. The conductivity of an electrolyte depends on the concentration of mobile ions and the rate at which they migrate under a given electric field. High conductivity enables rapid ion migration, improving the overall battery's charge capacity and energy density. However, high-conductivity electrolyte components are more susceptible to oxidation / reduction reactions during charge and discharge, increasing gassing in the battery cells and leading to increased internal battery pressure, resulting in a range of adverse consequences. Choosing a low-conductivity electrolyte to balance gassing can compromise charge capacity and energy density.

[0101] The conductivity of the electrolyte generally refers to the reciprocal of the resistance of one cubic centimeter of liquid at 25°C, expressed in Ω. -1 cm -1 Or expressed in S / cm.

[0102] Conductivity test principle: The conductivity of a solution is related to its resistance. A large resistance indicates poor conductivity, while a small resistance indicates good conductivity. According to Ohm's law, at a constant temperature, the resistance of a solution is inversely proportional to the vertical cross-sectional area of ​​the electrodes and directly proportional to the distance between the electrodes. The unit of resistance is ohm (Ω); the unit of resistivity is ohm (Ω.M).

[0103] National standards for parameter testing:

[0104] The conductivity of the electrolyte can be measured using instruments and methods known in the art, for example, according to the HG / T4067-2015 standard.

[0105] Test method:

[0106] (1) Density meter method, also known as arbitration method.

[0107] The instrument measurement temperature was set to 20°C, the sample was injected into the measurement cell of the instrument, the measurement was performed and the data was read.

[0108] (2) Density meter method

[0109] Use a dry, clean, corrosion-resistant sample bottle to take about 100 mL of sample, seal it and place it in a constant temperature water bath at 25℃±0.5℃, shake it from time to time. When the sample temperature is constant, replace the sample bottle cap with a rubber stopper with an electrode. When the temperature is within the range of 25℃±0.5℃, read the data in the conductivity meter, which is the conductivity of the tested sample.

[0110] The exhaust rate of the exhaust assembly is defined as the volume of gas discharged from a battery cell in one day. A higher exhaust rate facilitates the discharge of gas from the battery cell. However, the presence of the exhaust assembly 90 somewhat reduces the sealing of the battery system, allowing external moisture to easily enter the battery housing through the exhaust assembly 90, resulting in reduced battery performance. Therefore, it is not advisable to design the exhaust assembly 90 with a relatively high exhaust rate simply to meet exhaust requirements.

[0111] Exhaust rate test principle: Based on GB / T1038-2000 standard, the exhaust assembly separates the low-pressure chamber and the high-pressure chamber. The high-pressure chamber is filled with about 10 5 The test gas is at a pressure of 0.1 MPa (i.e., 0.1 MPa). The volume of the low-pressure chamber is known. After the sample is sealed, the air in the low-pressure chamber is evacuated to near zero (i.e., evacuated) using a vacuum pump. The pressure increment ΔP in the low-pressure chamber is measured with a manometer to determine the amount of test gas that permeates the membrane (or sheet) from the high-pressure chamber to the low-pressure chamber as a function of time. However, the initial period, during which the gas permeation rate varies with time, must be excluded. The gas permeation rate and gas permeation coefficient can be calculated by the instrument's computer according to the specified program and output to a floppy disk or printed on a recording paper. Alternatively, the values ​​can be calculated using the test values.

[0112] In this application, the gas production behavior of electrolytes with different conductivities is fully studied, and exhaust components with different exhaust rates are matched for battery cells with electrolytes with different conductivities; it is possible to balance the contradiction between high conductivity requirements and high gas production; at the same time, for some battery systems that do not require high conductivity, there is no need to match them with exhaust components with large exhaust capacity, so as to reduce the impact of external water vapor intrusion on the battery during the exhaust process.

[0113] In one embodiment, when the conductivity of the electrolyte system within the battery cell is within the range of 2ms / cm-16ms / cm, the exhaust rate of the exhaust assembly on the battery cell can be controlled to 0.6mL / day-10.0mL / day, which can meet the most basic ventilation requirements while reducing the intrusion of external moisture.

[0114] In one embodiment, the conductivity of the electrolyte is: 8 ms / cm≤conductivity≤16 ms / cm; and the exhaust rate of the exhaust component is: 3.3 mL / day≤exhaust rate≤10.0 mL / day.

[0115] At this time, the electrolyte has a high conductivity, the ion migration speed is fast, and the battery cell produces a large amount of gas. Therefore, matching the exhaust component with a high exhaust rate can discharge the gas in time.

[0116] Furthermore, the exhaust rate of the exhaust assembly can be 4.5 mL / day to 8.0 mL / day, which can more accurately match the exhaust rate and electrolyte conductivity, thereby improving the battery cell's charging capacity and energy density while also taking into account the safety performance and service life of the battery cell.

[0117] In other embodiments, the combination scheme of electrolytes with different conductivities and exhaust components can also be: the electrolyte conductivity is 8ms / cm-10ms / cm, and the exhaust rate of the exhaust component is 3.3mL / day-5.0mL / day; the electrolyte conductivity is 10ms / cm-12ms / cm, and the exhaust rate of the exhaust component is 5.0mL / day-6.7mL / day; the electrolyte conductivity is 11ms / cm-14ms / cm, and the exhaust rate of the exhaust component is 4.5mL / day-9.0mL / day; the electrolyte conductivity is 14ms / cm-16ms / cm, and the exhaust rate of the exhaust component is 8.4mL / day-10.0mL / day.

[0118] In one embodiment, the conductivity of the electrolyte is: 2 ms / cm≤conductivity≤8 ms / cm; and the exhaust rate of the exhaust component is: 0.6 mL / day≤exhaust rate≤5.0 mL / day.

[0119] At this time, the electrolyte's conductivity is low, ion migration is slow, and the battery cell's gas production is low. Therefore, matching the exhaust component with a slow exhaust rate can not only promptly exhaust the gas inside the battery, but also reduce the probability of external impurities (air, moisture, dust, etc.) entering the battery cell.

[0120] Furthermore, the exhaust rate of the exhaust assembly can be 1.3 mL / day to 3.9 mL / day, which can more accurately match the exhaust rate and electrolyte conductivity, while taking into account the safety performance and service life of the battery cell.

[0121] In other embodiments, the combination scheme of electrolytes with different conductivities and exhaust components can also be: the electrolyte conductivity is 2ms / cm-4ms / cm and the exhaust rate of the exhaust component is 0.6mL / day-2.1mL / day; the electrolyte conductivity is 4ms / cm-6ms / cm and the exhaust rate of the exhaust component is 1.3mL / day-3.9mL / day; the electrolyte conductivity is 6ms / cm-8ms / cm and the exhaust rate of the exhaust component is 3.6mL / day-5.0mL / day.

[0122] According to some embodiments of the present application, the exhaust assembly 90 includes a breathable membrane assembly 40 , which includes a breathable membrane 41 . The breathable membrane 41 is configured to allow gas inside the battery cell 20 to be discharged through the breathable membrane 41 .

[0123] According to some embodiments of the present application, the breathable membrane assembly 40 includes a breathable membrane 41. The breathable membrane 41 is made of a breathable material with excellent air permeability, allowing gas molecules to pass through. By selecting the breathable membrane assembly 40 as the exhaust assembly 90, the battery cell 20 can discharge internal gas through the breathable membrane 41 while in a sealed state, promptly discharging the internal gas of the battery cell outside the housing, preventing the air pressure inside the battery cell from becoming excessively high and the pressure relief mechanism from prematurely opening the valve, thereby significantly improving battery life.

[0124] Furthermore, the breathable membrane also has liquid-isolating properties, preventing liquid from passing through, so it can prevent the electrolyte from overflowing while discharging gas. In addition, the breathable membrane can also block external water vapor, dust and impurities from entering the battery cell, protecting the internal environment of the battery cell and effectively improving the reliability of the battery cell. The breathable membrane also has good weather resistance, chemical corrosion resistance, and structural stability. If it is an automotive power battery, it also needs to have oleophobicity. Therefore, the material of the breathable membrane can be selected from polymer materials, such as polytetrafluoroethylene, polypropylene, etc. In addition, since the generation of gas inside the battery will cause the internal pressure to rise rapidly, the breathable membrane needs to have certain mechanical strength and elasticity.

[0125] The air permeability rate of the breathable membrane assembly 40 depends on the properties of the breathable membrane 41. A polymer membrane with a certain porosity can be selected as the breathable membrane 41. Using materials with different porosities can produce breathable membranes 41 with different air permeability rates. For example, the air permeability rate of the breathable membrane 41 can be 0.5 mL / day, 1.0 mL / day, 1.5 mL / day, 2.5 mL / day, 3.0 mL / day, 3.5 mL / day, 4.0 mL / day, 5.0 mL / day, 6.5 mL / day, 8.5 mL / day, 9.0 mL / day, 9.5 mL / day, or 10.0 mL / day. The air permeability test conditions for the breathable membrane are 23°C, 0% RH (0% humidity), and 0.1 MPa air pressure.

[0126] According to some embodiments of the present application, the breathable membrane includes a first breathable membrane, and the breathability of the first breathable membrane is 3-4 mL / day.

[0127] According to some embodiments of the present application, the breathable membrane includes a second breathable membrane, and the breathability of the second breathable membrane is 9-10 mL / day.

[0128] According to some embodiments of the present application, the vent assembly 90 includes a one-way valve 30, which is configured to actuate and release gas from the battery cell 20 when the internal gas pressure of the battery cell 20 reaches a threshold value. In other words, the one-way valve 30 is used to exhaust gas from the interior of the housing. That is, the one-way valve 30 can be opened in one direction to exhaust gas, so that the gas inside the housing can be discharged to the outside of the housing through the one-way valve 30.

[0129] Please refer to Figure 3, which is a schematic cross-sectional view of a one-way valve according to one or more embodiments. According to some embodiments of the present application, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 has a valve cavity 313 therein. The valve body 31 is provided with an air inlet 313a and an air outlet 313b. The air inlet 313a is used to connect the valve cavity 313 with the interior of the housing, and the air outlet 313b is used to connect the valve cavity 313 with the exterior of the housing. The valve core 32 is disposed in the valve cavity 313 and is used to block the air inlet passage of the valve cavity 313. The valve core 32 is configured to open the air inlet passage under the action of the gas inside the housing and release the gas inside the battery cell.

[0130] As shown in Figure 3, Figure 3 (a) is a schematic diagram of the one-way valve in the closed state; Figure 3 (b) is a schematic diagram of the one-way valve in the open state. The valve core 32 includes an elastic member 322 and a blocking member 321. The elastic member 322 provides an elastic force F1 to the blocking member 321, which is pressed to block the air inlet 313a. When the force F2 exerted by the gas inside the housing on the blocking member 321 is greater than the elastic force F1 of the elastic member, the gas inside the housing can overcome the elastic force of the elastic member and push the blocking member 321 to open the air inlet 313a, allowing the gas inside the housing to enter the valve chamber 313 and then be discharged to the outside of the housing through the air outlet 313b. Conversely, after the gas inside the housing is discharged and the force F2 exerted by the gas inside the housing on the blocking member 321 is less than the elastic force F1 of the elastic member, the elastic member 322 can drive the blocking member 321 to reset, thereby blocking the air inlet 313a.

[0131] Specifically, when the air pressure inside the shell increases to a certain value P1, the air pressure applies a force F2 to the lower surface of the sealing member 321. When F2 is greater than the spring compression force F1, the sealing interface fails, and the gas inside the shell is discharged to the outside of the shell through the channel inside the valve body 31. As the gas inside the shell is discharged, the internal air pressure drops. When the air pressure reaches a certain value P2, the valve body 31 closes to achieve sealing. The valve body 31 can be opened and closed repeatedly to exhaust and vent air, so that the air pressure inside the shell is maintained between P1-P2, thereby preventing the pressure relief mechanism from opening the valve prematurely due to excessive air pressure inside the shell. In other words, a one-way valve requires a certain pressure threshold to open.

[0132] According to some embodiments of the present application, the opening pressure of the valve core is greater than or equal to 0.2 MPa; further, greater than or equal to 0.4 MPa; and further, greater than or equal to 0.8 MPa. For example, the opening pressure can be 0.20 MPa, 0.25 MPa, 0.30 MPa, 0.35 MPa, 0.40 MPa, 0.45 MPa, 0.50 MPa, 0.55 MPa, 0.60 MPa, 0.65 MPa, 0.70 MPa, 0.75 MPa, 0.80 MPa, etc.

[0133] The one-way valve opening pressure test method and principle can be tested based on the helium leakage standard. The helium leakage standard is defined as follows: if the leakage rate is less than 10^-6Pa.m^3 / s, the system is considered to be sealed; if the leakage rate is greater than 10^-6Pa.m^3 / s, it indicates that there is a gas leak in the system.

[0134] During testing, the test chamber is sealed with a one-way valve and filled with helium. The amount of helium in the test chamber environment is monitored using a helium detector. If helium is detected and the leakage rate is greater than 10^-6Pa.m^3 / s, it means that the test chamber is no longer sealed and helium is leaking out. The helium leakage rate is continuously monitored. When the leakage rate is greater than 10^-5Pa.m^3 / s, the one-way valve is determined to be open for release. The pressure in the test chamber at this time is recorded as the opening pressure of the one-way valve.

[0135] According to some embodiments of the present application, the structure of the exhaust assembly can be selected based on the required exhaust rate of the exhaust assembly. The exhaust assembly can include a breathable membrane assembly, i.e., the breathable membrane assembly is selected as the exhaust assembly. The exhaust assembly can include a one-way valve, i.e., the one-way valve is selected as the exhaust assembly. In other embodiments, the exhaust assembly can include both a one-way valve and a breathable membrane assembly.

[0136] According to some embodiments of the present application, the exhaust assembly may be a breathable membrane assembly or a one-way valve. For example, the exhaust assembly may be a breathable membrane assembly comprising a first breathable membrane, a breathable membrane assembly comprising a second breathable membrane, or a one-way valve with a cracking pressure greater than 0.4 MPa; or a breathable membrane assembly comprising a second breathable membrane, or a one-way valve with a cracking pressure greater than 0.2 MPa.

[0137] According to some embodiments of the present application, the exhaust assembly 90 includes a breathable membrane assembly 40 and a one-way valve 30, and the wall has a first exhaust hole 291, which connects the inside of the shell with the outside of the shell, and the battery cell 20 is configured so that the gas discharged through the first exhaust hole 291 flows through the one-way valve 30 and the breathable membrane assembly 40.

[0138] As shown in Figure 2, the first vent 291 connects the interior of the housing with the exterior of the housing. That is, the first vent 291 is a through hole, allowing gas inside the battery cell 20 housing to be discharged through the first vent 291, thereby regulating the pressure inside the battery cell 20 housing. The battery cell 20 is configured so that the gas discharged through the first vent 291 flows through the one-way valve 30 and the breathable membrane assembly 40. This means that when the gas flows through the first vent 291, it also flows through the one-way valve 30 and the breathable membrane assembly 40, which belong to the same vent assembly 90; in other words, the gas exhaust path needs to flow through both the one-way valve 30 and the breathable membrane assembly 40 simultaneously. Alternatively, the one-way valve 30 and the breathable membrane assembly 40, which belong to the same vent assembly 90, are connected in series. When the gas flows through the vent assembly 90, it flows sequentially through the one-way valve 30 and the breathable membrane assembly 40 in the vent assembly 90. The gas may first flow through the breathable membrane assembly 40 and then through the one-way valve 30, or it may first flow through the one-way valve 30 and then through the breathable membrane assembly 40. The order of flow can be set as needed, but both structures need to flow through, rather than having some gas only flow through the one-way valve 30 and be discharged, while another part of the gas only flows through the breathable membrane assembly. The end cap 21 may be provided with a single first exhaust hole 291, or it may be provided with multiple first exhaust holes 291. When there are multiple first exhaust holes 291, each first exhaust hole 291 is equipped with a set of exhaust assemblies 90, and when the gas is discharged through the first exhaust hole 291, it will flow through the one-way valve 30 and breathable membrane assembly 40 in the exhaust assembly 90 provided at the first exhaust hole 291.

[0139] In this embodiment, by arranging the breathable membrane assembly 40 and the one-way valve 30 in series, the presence of the one-way valve 30 can control the system to not be in a breathable state all the time, but only activate the one-way valve 30 to exhaust when the gas accumulates to a certain threshold, which can protect the sealing of the battery cell 20 system and reduce the probability of external water vapor entering the battery cell 20 system; at the same time, the presence of the breathable membrane 41 can, on the one hand, prevent the overflow of the electrolyte, and on the other hand, when the one-way valve 30 is open, the breathable membrane 41 can realize the closure of the battery system, so that the battery cell 20 can discharge the internal gas through the breathable membrane 41 and the one-way valve 30 in a sealed state, thereby improving the disadvantage that when the one-way valve 30 is exhausting, the battery cell 20 system is in an open state and is easily invaded by external water vapor.

[0140] According to some embodiments of the present application, when the exhaust assembly 90 includes a breathable membrane assembly 40 and a one-way valve 30, and the breathable membrane assembly 40 and the one-way valve 30 are connected in series, breathable membranes 41 with different permeability rates and one-way valves 30 with different opening pressures can be used.

[0141] According to some embodiments of the present application, the opening pressure of the one-way valve 30 is greater than or equal to 0.4 MPa, the breathable membrane assembly 40 includes a second breathable membrane, and the breathability rate of the second breathable membrane is 9-10 mL / day.

[0142] Please refer to Figure 4, which is a schematic diagram of the exploded structure of a battery cell according to one or more embodiments. According to some embodiments of the present application, the exhaust assembly 90 includes a breathable membrane assembly 40 and a one-way valve 30. The wall portion has a first exhaust hole 291 and a third exhaust hole 293 spaced apart. The first exhaust hole 291 and the third exhaust hole 293 respectively connect the interior of the housing to the exterior of the housing. The battery cell 20 is configured such that gas exhausted through the first exhaust hole 291 flows through the one-way valve 30, and gas exhausted through the third exhaust hole 293 flows through the breathable membrane assembly 40.

[0143] The first vent hole 291 connects the inside and outside of the housing, and the third vent hole 293 also connects the inside and outside of the housing. In other words, the two are independent holes that can simultaneously exhaust gas to regulate the pressure inside the housing of the battery cell 20. The end cap 21 may be provided with one first vent hole 291 and one third vent hole 293, or may be provided with multiple first vent holes 291 and multiple third vent holes 293. The battery cell 20 is configured so that gas discharged through the first vent 291 flows through the one-way valve 30, and gas discharged through the third vent 293 flows through the breathable membrane assembly 40. This means that gas can be discharged from the battery cell 20 through both the first vent 291 and the third vent 293 simultaneously. When discharged through the first vent 291, gas flows through the one-way valve 30, and when discharged through the third vent 293, gas flows through the breathable membrane assembly 40. In other words, the one-way valve 30 and the breathable membrane assembly 40 are connected in parallel. When gas flows through the vent assembly 90, gas can simultaneously flow through the one-way valve 30 and the breathable membrane assembly 40 in the vent assembly 90. That is, some gas flows only through the one-way valve 30 for discharge, and some gas flows only through the breathable membrane assembly 40 for discharge. When there are multiple first vents 291, each first vent 291 is equipped with a one-way valve 30; when there are multiple third vents 293, each third vent 293 is equipped with a breathable membrane assembly 40.

[0144] In this embodiment, by providing a breathable membrane assembly 40 in parallel with the one-way valve 30, exhaust is primarily discharged through the breathable membrane assembly 40 when the internal pressure of the battery cell 20 is low, and primarily through the one-way valve 30 when the internal pressure of the battery cell 20 is high. This reduces the problem of frequent opening of the one-way valve 30 caused by unstable internal pressure in the battery cell 20, reduces the intrusion of external water vapor, and improves the sealing of the battery cell 20 system. At the same time, when the air pressure is low, gas can be promptly discharged through the breathable membrane assembly 40, which helps the exhaust assembly 90 adapt to different air pressure environments and improves its flexibility.

[0145] According to some embodiments of the present application, when the exhaust assembly 90 includes a breathable membrane assembly 40 and a one-way valve 30, and the breathable membrane assembly 40 and the one-way valve 30 are connected in parallel, breathable membranes 41 with different permeability rates and one-way valves 30 with different opening pressures can be used.

[0146] According to some embodiments of the present application, the opening pressure of the one-way valve 30 is greater than or equal to 0.4 MPa, the breathable membrane assembly 40 includes a second breathable membrane, and the breathability rate of the second breathable membrane is 3-4 mL / day.

[0147] According to some embodiments of the present application, the exhaust assembly may be configured with a breathable membrane assembly and a one-way valve in series, or in parallel. For example, the exhaust assembly may be configured with a breathable membrane assembly having a second breathable membrane and a one-way valve having a cracking pressure greater than 0.4 MPa in series.

[0148] According to some embodiments of the present application, the exhaust assembly may be configured with a breathable membrane assembly and a one-way valve in series, or in parallel. For example, the exhaust assembly may be configured with a breathable membrane assembly having a first breathable membrane in parallel with a one-way valve having an opening pressure greater than 0.8 MPa.

[0149] In other embodiments, the one-way valve 30 and the breathable membrane assembly 40 in the exhaust assembly may be mixed, that is, the exhaust assembly may include both the one-way valve 30 and the breathable membrane assembly 40 in series and the one-way valve 30 and the breathable membrane assembly 40 in parallel.

[0150] According to some embodiments of the present application, the electrolyte conductivity and exhaust assembly combination scheme provided herein can be applied to alkali metal batteries, such as lithium metal batteries, sodium metal batteries, potassium metal batteries, zinc metal batteries, and aluminum metal batteries. Of course, it is also applicable to other types of batteries, such as lithium-ion batteries and sodium-ion batteries.

[0151] According to some embodiments of the present application, the gas production rate of the battery used in the combination scheme of electrolyte conductivity and exhaust components provided in the present application is: the gas production rate of the battery cell is: 0.006mL / Ah / D≤gas production rate≤0.066mL / Ah / D.

[0152] Optionally, the gas production rate of the battery cell is: 0.013 mL / Ah / D ≤ gas production rate ≤ 0.026 mL / Ah / D. In this case, the gas production rate of the battery cell is relatively low, and the electrolyte and exhaust components are matched. The electrolyte conductivity is 2 ms / cm-8 ms / cm, and the exhaust rate of the exhaust component is 0.6 mL / day-5.0 mL / day.

[0153] Optionally, the gas production rate of the battery cell is: 0.045 mL / Ah / D ≤ Gas production rate ≤ 0.060 mL / Ah / D. In this case, the gas production rate of the battery cell is relatively high, and the electrolyte and exhaust components are matched. The electrolyte conductivity is 8ms / cm-16ms / cm; the exhaust rate of the exhaust component is 3.3mL / day-10.0mL / day.

[0154] According to some embodiments of the present application, the battery's residual volume V used in the electrolyte conductivity and vent assembly matching scheme provided herein is 0.5 mL / Ah ≤ V ≤ 3.5 mL / Ah, and may be 0.5 mL / Ah ≤ V ≤ 2 mL / Ah, 0.8 mL / Ah ≤ V ≤ 1.5 mL / Ah, 2.0 mL / Ah ≤ V ≤ 3.5 mL / Ah, 2.5 mL / Ah ≤ V ≤ 3.0 mL / Ah, etc. An appropriate vent assembly can be selected based on the battery capacity and residual volume.

[0155] The residual space is defined as the volume space remaining inside the shell of the battery cell after the shell is filled with liquid.

[0156] Test conditions: Baked battery cells, electrolyte of known density, vacuum chamber, injector, and two aluminum plate fixtures.

[0157] Steps:

[0158] 1. Weigh the mass of the battery cell after baking and record it;

[0159] 2. Use a clamp to clamp the battery cell to prevent swelling and deformation;

[0160] 3. Align the nozzle of the injector with the filling port of the battery cell, pour in a certain amount of electrolyte, place it in a vacuum box to evacuate, and let it stand at room temperature for more than 24 hours until the battery cell is fully filled;

[0161] 4. After fully filling, remove the fixture and weigh it, and record the mass of the fully filled battery cell;

[0162] Data processing: The residual space volume of the battery cell after filling is obtained by subtracting the electrolyte retention amount from the mass difference before and after the full filling experiment and converting it through the electrolyte density.

[0163] According to some embodiments of the present application, the electrolyte of the battery used in the combination scheme of electrolyte conductivity and exhaust components provided in the present application includes one or more of chain ethers, ethylene glycol dimethyl ether and its derivatives, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclic ethers.

[0164] According to some embodiments of the present application, the positive electrode plate of the battery used in the combination scheme of electrolyte conductivity and exhaust component provided in the present application includes a positive electrode collector and a positive electrode active layer arranged on the positive electrode collector, the positive electrode active layer includes a positive electrode active material, and the positive electrode active material includes one or more of a polyanion positive electrode material, a phosphate positive electrode material, a sulfate positive electrode material, a silicate positive electrode material, and a borate positive electrode material.

[0165] According to some embodiments of the present application, the negative electrode plate of the battery used in the combination scheme of electrolyte conductivity and exhaust component provided in the present application includes a negative electrode current collector and a carbon-containing coating arranged on the negative electrode current collector, the carbon-containing coating includes a carbon-containing material, and the carbon-containing material includes one or more of conductive carbon, graphite, hard carbon, and carbon nanotubes.

[0166] In one embodiment, the exhaust assembly 90 is arranged on the wall portion of the outer shell of the battery cell 20. The outer shell includes an end cover 21 and a shell 22. The wall portion can be the wall of the end cover 21 or the wall of the shell 22. That is, the exhaust assembly 90 can be arranged on the end cover 21 or on the shell 22. In other words, the wall portion for mounting the exhaust assembly 90 can be the end cover 21 of the outer shell or a wall of the shell 22 of the outer shell. Exemplarily, the wall portion is the end cover 21. Of course, the structure of the battery cell is not limited to this. In other embodiments, the wall portion can also be the bottom wall of the shell and the end cover, which are arranged opposite to each other. The wall portion can also be the side wall of the shell and the end cover that are adjacent to and connected to each other. In one embodiment, the exhaust assembly is preferably located on the wall with the top facing up when the battery cell is in a placed state. The following will illustrate the present application scheme by taking the wall portion as the wall of the end cover 21 as an example, but this should not limit the present application.

[0167] Please refer to Figures 5, 6, and 7. Figure 5 is a front view of a one-way valve according to one or more embodiments, Figure 6 is an exploded structural diagram of a one-way valve according to one or more embodiments, and Figure 7 is a partial cross-sectional structural diagram of a battery cell according to one or more embodiments. According to some embodiments of the present application, the end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite each other, with the outer surface 21a facing the exterior of the housing and the inner surface 21b facing the interior of the housing. The one-way valve 30 is disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the exterior of the housing and at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21.

[0168] In this embodiment, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve seat 311 and a valve cover 312. The valve cover 312 includes a cover top wall 3121 and a cover side wall 3122 connected to the cover top wall 3121. The cover top wall 3121, the cover side wall 3122, and the valve seat 311 enclose a valve cavity 313. The valve seat 311 is provided with an air inlet for the valve cavity 313, connecting the valve cavity 313 with the interior of the housing. The valve cover 312 is provided with an air outlet for the valve cavity 313, connecting the valve cavity 313 with the exterior of the housing. The valve core 32 is used to block the air inlet channel of the valve cavity 313. The valve core 32 is configured to open the air inlet channel in response to gas inside the housing, thereby releasing gas from the battery cells.

[0169] Continuing with Figures 5 and 6 , according to some embodiments of the present application, the valve seat 311 has a first through-hole 3111 extending through the valve seat 311. The first through-hole 3111 serves as the air inlet for the valve cavity 313. The cover sidewall 3122 has a second through-hole 31221 extending through the cover sidewall 3122. The second through-hole 31221 serves as the air outlet for the valve cavity 313. This arrangement facilitates the outward transmission of gas from within the battery.

[0170] According to some embodiments of the present application, the second through hole 31221 extends to the end of the cover side wall 3122 in a direction away from the cover top wall 3121. As shown in Figure 6, the direction away from the cover top wall 3121 is the direction from the cover top wall 3121 to the valve seat 311 (the X direction in the figure). The second through hole 31221 is formed by removing part of the structure of the cover side wall 3122. Along the X direction, the cover side wall 3122 is directly hollowed out to the bottom end of the cover side wall 3122. In a further embodiment, along the X direction, the lower opening surface of the second through hole 31221 can be flush with the sealing surface of the blocking member 321. Through this arrangement, when the one-way valve 30 is opened to exhaust, that is, when the blocking member 321 opens the sealing interface, the electrolyte liquid carried out with the gas can be discharged outward in a timely manner, so that the electrolyte is not easily accumulated on the outer edge of the blocking member 321, thereby effectively ensuring the sealing and repeated opening function of the one-way valve 30.

[0171] According to some embodiments of the present application, there are multiple second through holes 31221, and the multiple second through holes 31221 are spaced apart in the circumferential direction of the cover side wall 3122. This arrangement allows for faster exhaust of gas when the one-way valve 30 is opened for exhaust, shortening the exhaust time, that is, shortening the time the battery cell is in the open state, thereby reducing the intrusion of external moisture into the battery system during the valve opening period.

[0172] Please refer to Figures 8, 9 and 10. Figure 8 is a front view of a one-way valve according to one or more embodiments, and Figure 9 is a schematic diagram of the exploded structure of a one-way valve according to one or more embodiments. Figure 10 is a schematic diagram of the partial cross-sectional structure of a battery cell according to one or more embodiments. According to some embodiments of the present application, the end cover 21 includes an outer surface 21a and an inner surface 21b arranged in opposite directions, the outer surface 21a is arranged toward the outside of the shell, and the inner surface 21b is arranged toward the inside of the shell; the one-way valve 30 is arranged on the end cover 21, and the valve body 31 of the one-way valve 30 faces the inside of the shell and at least a portion of the valve body 31 protrudes from the inner surface 21b of the end cover 21. That is, the valve body 31 extends into the shell along the thickness direction of the end cover 21.

[0173] In this embodiment, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve seat 311 and a valve cover 312. The valve seat 311 includes a seat bottom wall 3115 and a seat sidewall 3116 connected to the seat bottom wall 3115. The valve cover 312 is disposed at one end of the valve seat 311 away from the seat bottom wall 3115. The valve cover 312, the seat sidewall 3116, and the seat bottom wall 3115 enclose the valve cavity 313. The valve seat 311 is provided with an air inlet for the valve cavity 313, connecting the valve cavity 313 with the interior of the housing. The valve core 32 is used to block the air inlet passage of the valve cavity 313. The valve core 32 is configured to open the air inlet passage in response to gas within the housing, thereby releasing gas from the battery cells.

[0174] Continuing with reference to Figures 8, 9, and 10, according to some embodiments of the present application, the valve seat 311 has a fourth through hole 3114 extending through the bottom wall 3115 of the seat, and the air inlet is the fourth through hole 3114, that is, the fourth through hole 3114 serves as the air inlet of the valve cavity 313. Of course, in other embodiments, the air inlet can also be provided on the outer circumferential surface of the portion of the valve body 311 extending into the housing. When the air inlet is provided on the outer circumferential surface of the portion of the valve body 311 extending into the housing, the setting direction of the valve core 32 will be changed accordingly, and the blocking member 321 is movably provided in the valve cavity 313 along the radial direction of the valve seat 311, so that the valve core blocks the air inlet.

[0175] Continuing with Figures 8, 9, and 10, according to some embodiments of the present application, the gas outlet can be directly provided on the valve cover, i.e., the gas outlet is a channel provided on the valve cover. Specifically, the valve cover 312 has a fifth through hole 3123 extending therethrough, and the gas outlet is the fifth through hole 3123, i.e., the fifth through hole 3123 serves as the gas outlet of the valve cavity 313. This arrangement facilitates the outward transmission of gas from within the battery.

[0176] The fifth through hole 3123 provided on the valve cover 312 can be one or more. For example, in Figures 8 and 9, the valve cover 312 is provided with three fifth through holes 3123. Of course, in other embodiments, the valve cover 312 can also be provided with two, four, five, or six fifth through holes 3123. By way of example, the valve cover 312 is provided with multiple fifth through holes 3123, and the multiple fifth through holes 3123 are arranged at equal intervals. By way of example, the multiple fifth through holes 3123 are arranged at equal intervals around the center of the valve cover 312, which allows for smoother gas flow.

[0177] Please refer to Figure 11, which is a schematic cross-sectional view of a breathable membrane assembly according to one or more embodiments. According to some embodiments of the present application, the breathable membrane assembly 40 further includes a metal member 42. Specifically, the breathable membrane assembly 40 includes a breathable membrane 41 and a metal member 42, which is used to support the breathable membrane 41. Specifically, the metal member 42 is provided with a first vent 491, and the breathable membrane 41 is disposed on the metal member 42, covering the first vent 491.

[0178] The metal part 42 can support the breathable membrane 41 to protect the breathable membrane 41 from excessive deformation. At the same time, the metal part 42 can also serve as a medium for connecting other components of the breathable membrane assembly 40. The breathable membrane 41 is connected to other components through the metal part 42 to improve the stability of the connection. The metal part 42 is provided with at least one first air hole 491 as a release channel for the gas inside the battery so that the gas can pass through the metal part 42. The shape of the first air hole 491 includes geometric shapes such as circle, square, and ellipse. The metal part 42 can also be provided with multiple first air holes 491. The aperture, shape, and arrangement of the first air hole 491 are not specifically limited here. Optionally, the aperture of the first air hole 491 can be less than or equal to the aperture of the exhaust hole on the battery cell.

[0179] Please continue to refer to Figure 11. According to some embodiments of the present application, the breathable membrane assembly 40 also includes a backing member 43, that is, the breathable membrane assembly 40 includes a breathable membrane 41, a metal member 42 and a backing member 43, the breathable membrane 41 is arranged on the metal member 42, and the backing member 43 is arranged between the breathable membrane 41 and the metal member 42, and the backing member 43 is used to support the breathable membrane 41 and allow gas to pass through the breathable membrane 41.

[0180] Backing member 43 supports breathable membrane 41, preventing it from deforming. Backing member 43 is made of a material with better air permeability than membrane 41 to ensure it does not interfere with the ventilation process of membrane 41. Backing member 43 is also corrosion-resistant and heat-resistant. A wide variety of materials are available for backing member 43, including porous polymers such as polypropylene, polyamide, polytetrafluoroethylene, and polyperfluoroethylene propylene. Metal-organic framework porous materials, carbon membranes, and ceramic porous materials are also possible, but are not limited here.

[0181] Please continue to refer to Figure 11. According to some embodiments of the present application, the metal part 42 has a first annular table T1 and a second annular table T2 that are recessed relative to the surface of the metal part 42, and a transition surface T3. The first annular table T1 is arranged around the second annular table T2, and the transition surface T3 connects the first annular table T1 and the second annular table T2. The first annular table T1 is closer to the surface of the metal part 42 than the second annular table T2. The second annular table T2 is arranged around the first air hole 491. The backing member 43 is arranged on the second annular table T2, and the breathable membrane 41 is arranged on the first annular table T1.

[0182] The first annular table surface T1 and the second annular table surface T2 are formed by inward depressions on the surface of the metal member 42. This can be achieved by stamping the metal member 42 to form the inward depressions, or by etching the metal member 42 to remove a portion of the structure. The depth of the depressions of the first annular table surface T1 and the second annular table surface T2 relative to the surface of the metal member 42 can be set based on the thickness of the breathable membrane 41 and the backing member 43. Preferably, the depth of the depression of the second annular table surface T2 relative to the first annular table surface T1 (i.e., the height of the transition surface T3) is equal to the thickness of the backing member 43, so that the second annular table can accommodate the backing member 43, and the surface of the backing member 43 facing the breathable membrane 41 is flush with the first annular table surface T1. Furthermore, the depression depth of the first annular platform T1 relative to the surface of the metal component 42 is equal to the thickness of the breathable membrane 41 , so that the first annular platform can accommodate the breathable membrane 41 , and the side surface of the breathable membrane 41 away from the metal component 42 is flush with the surface of the metal component 42 .

[0183] By providing a recessed platform on the metal part 42, the surface of the breathable membrane 41 can be flush with the surface of the metal part 42, thereby reducing the overall height of the breathable membrane assembly 40 and further reducing the installation height of the breathable membrane assembly 40. In other embodiments, if the breathable membrane assembly 40 does not include a backing member 43, only the first annular table T1 can be provided to support the breathable membrane 41. As shown in FIG11(b), in another embodiment, when the breathable membrane assembly 40 includes a backing member 43, only the first annular table T1 can be provided to support the backing member 43, and the breathable membrane 41 can be directly attached to the surface of the metal part 42. In this way, because the thickness of the breathable membrane 41 is relatively small, the impact on the overall height of the breathable membrane assembly 40 is relatively small. By reducing the provision of the recessed surface on the metal part 42, on the one hand, the manufacturing process can be simplified, and on the other hand, the strength of the metal part 42 can be improved.

[0184] Please refer to Figures 12, 13, and 14. Figure 12 is a partial cross-sectional view of an end cap according to one or more embodiments; Figure 13 is a cross-sectional view of a battery cell according to one or more embodiments; and Figure 14 is a front view of an end cap of a battery cell according to one or more embodiments.

[0185] According to some embodiments of the present application, the one-way valve 30 is arranged on the end cover 21, the valve body 31 of the one-way valve 30 faces the outside of the shell and at least part of the valve body 31 protrudes from the outer surface 21a of the end cover 21, and the breathable membrane assembly 40 is arranged on the side of the end cover 21 facing the inside of the shell; the one-way valve 30 and the breathable membrane assembly 40 are respectively and independently connected to the end cover 21.

[0186] According to some embodiments of the present application, the end cap 21 is provided with a first vent 291. The first vent 291 includes a through-hole section 280 and a first hole section 281. The through-hole section 280 and the first hole section 281 are arranged along the thickness direction of the end cap 21. The through-hole section 280 connects the interior of the housing with the exterior of the housing. The first hole section 281 is located on the side of the through-hole section 280 facing away from the interior of the housing. The aperture of the first hole section 281 is larger than the aperture of the through-hole section 280. The one-way valve 30 is at least partially accommodated in the first hole section 281. The valve body 31 of the one-way valve 30 faces the exterior of the housing, and at least a portion of the valve body 31 protrudes from the outer surface 21a of the end cap 21. As shown in FIG. 19 , the first vent 291 is a countersunk hole that is recessed relative to the outer surface 21a of the end cap 21. When the one-way valve 30 is connected to the end cap 21, a portion of the one-way valve 30 can be embedded in the first vent 291 to reduce the installation height.

[0187] According to some embodiments of the present application, the one-way valve 30 is welded to the end cap 21. As shown in FIG13 , the valve seat 311 of the one-way valve 30 can be welded to the end cap 21; specifically, the valve cap 312 of the one-way valve 30 is connected to the valve seat 311, and the valve seat 311 is welded to the end cap 21.

[0188] According to some embodiments of the present application, the breathable membrane assembly 40 includes a breathable membrane 41 and a metal member 42. The breathable membrane 41 is disposed on the metal member 42. The breathable membrane assembly 40 is disposed on the end cap 21, and the metal member 42 is connected to the end cap 21. Specifically, the breathable membrane 41 is connected to the end cap 21 via the metal member 42. The metal member 42 can be connected to the end cap 21 by welding, interference fit, or other methods. This method can enhance the connection strength between the breathable membrane assembly 40 and the end cap 21.

[0189] Please continue to refer to Figures 13 and 14. According to some embodiments of the present application, the end cover 21 has an outer surface 21a and an inner surface 21b arranged in opposite directions, the outer surface 21a is arranged toward the outside of the shell, and the inner surface 21b is arranged toward the inside of the shell. The end cover 21 has a first sink S1 that is recessed relative to the inner surface 21b. The first sink S1 is arranged around the first exhaust hole 291, and the breathable membrane assembly 40 is at least partially accommodated in the first sink S1.

[0190] Among them, the first depression S1 is formed by the inner surface 21b of the end cover 21 being recessed in the direction of the outer surface 21a of the end cover 21. The end cover 21 can be stamped to form the recessed first depression S1, or the end cover 21 can be etched to remove part of the structure to form the recessed first depression S1. The recessed depth of the first depression S1 relative to the inner surface 21b of the end cover 21 can be set according to the thickness of the breathable membrane assembly 40. The thickness of the breathable membrane assembly 40 is the overall thickness including the breathable membrane 41, the metal part 42 and the backing part 43. As mentioned above, the breathable membrane 41 and the backing part 43 can be accommodated in the annular platform on the metal part 42 that is recessed relative to the surface of the metal part 42, that is, the overall thickness of the breathable membrane assembly 40 can be equal to the thickness of the metal part 42. Preferably, the depth of the first recessed portion S1 relative to the inner surface 21b of the end cap 21 is equal to the thickness of the breathable membrane assembly 40, so that the breathable membrane assembly 40 is accommodated within the first recessed portion S1, and the surface of the breathable membrane assembly 40 facing the interior of the housing is flush with the inner surface 21b of the end cap 21. In this way, the installation height of the breathable membrane assembly 40 can be reduced, thereby reducing the space occupied by the battery cell 20 interior housing and improving the space utilization inside the housing.

[0191] As shown in Figure 14 , the breathable membrane 41 can be positioned on the side of the metal member 42 facing the interior of the housing; that is, the breathable membrane 41 is positioned below the metal member 42. This arrangement reduces the impact of the operating environment of the battery cell 20 on the breathable membrane 41. In other embodiments, the breathable membrane 41 can also be positioned on the side of the metal member 42 facing the exterior of the housing, that is, between the metal member 42 and the end cap 21. This arrangement reduces erosion of the breathable membrane 41 by the electrolyte system.

[0192] Please refer to Figures 15, 16 and 17. Figure 15 is a schematic diagram of the partial cross-sectional structure of the end cover according to one or more embodiments; Figure 16 is a schematic diagram of the cross-sectional structure of the battery cell according to one or more embodiments; Figure 17 is a front view of the end cover of the battery cell according to one or more embodiments.

[0193] According to some embodiments of the present application, the one-way valve 30 is arranged on the end cover 21, the valve body 31 of the one-way valve 30 faces the outside of the shell and at least part of the valve body 31 protrudes from the outer surface 21a of the end cover 21, and the breathable membrane assembly 40 is arranged on the side of the end cover 21 facing the outside of the shell; the one-way valve 30 and the breathable membrane assembly 40 are respectively and independently connected to the end cover 21.

[0194] As previously described, the end cap 21 is provided with a first vent 291, which includes a first hole section 281. The one-way valve 30 is at least partially accommodated in the first hole section 281. The valve body 31 of the one-way valve 30 faces the exterior of the housing, and at least a portion of the valve body 31 protrudes from the outer surface 21a of the end cap 21. In this embodiment, the breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the exterior of the housing. The breathable membrane assembly 40 is at least partially accommodated within the first vent 291, and the breathable membrane assembly 40 is located on the side of the one-way valve 30 facing the end cap 21.

[0195] Specifically, the first exhaust hole 291 also includes a second hole section 282. Along the thickness direction of the end cover 21, the second hole section 282 is located between the through hole section 280 and the first hole section 281. The aperture of the second hole section 282 is smaller than the aperture of the first hole section 281, and the aperture of the second hole section 282 is larger than the aperture of the through hole section 280. The breathable membrane assembly 40 is at least partially accommodated in the second hole section 282.

[0196] According to some embodiments of the present application, a breathable membrane assembly includes a breathable membrane and a connector, wherein the connector is provided with a first breathable hole, and the breathable membrane is disposed on the connector and covers the first breathable hole; the breathable membrane is configured to allow gas inside the battery cell to pass through the breathable membrane and be discharged. The connector can be a sheet-like member or a metal member.

[0197] In one embodiment, the breathable membrane assembly 40 includes a breathable membrane 41 and a metal part 42 . The metal part 42 is provided with a first breathable hole 491 . The breathable membrane 41 is provided on the metal part 42 and covers the first breathable hole 491 . The metal part 42 is welded to the end cover 21 .

[0198] According to some embodiments of the present application, the one-way valve 30 may be disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the interior of the housing and at least a portion of the valve body 31 protruding from the inner surface 21b of the end cap 21. The breathable membrane assembly 40 is connected to the one-way valve 30, and the one-way valve 30 is connected to the end cap 21. In other words, the one-way valve 30 and the breathable membrane assembly 40 are first assembled and then connected to the end cap 21.

[0199] Please refer to Figures 18 and 19. Figure 18 is a schematic diagram of the decomposed structure of the exhaust assembly according to one or more embodiments; Figure 19 is a schematic diagram of the cross-sectional structure of the exhaust assembly according to one or more embodiments. According to some embodiments of the present application, the breathable membrane 41 membrane assembly is arranged on the side of the seat bottom wall 3115 of the one-way valve 30 away from the valve cavity 313. The breathable membrane assembly 40 includes a breathable membrane 41, which is connected to the seat bottom wall 3115 and covers the fourth through hole 3114. In this embodiment, the breathable membrane assembly 40 is compounded with the one-way valve 30, and the breathable membrane 41 is attached to the seat bottom wall 3115 of the one-way valve 30, which can reduce the installation height; at the same time, only the one-way valve 30 needs to be connected to the end cover 21, which can simplify the assembly process.

[0200] Please refer to Figures 20 and 21 . Figure 20 is a schematic diagram of the exploded structure of an exhaust assembly according to one or more embodiments; Figure 21 is a schematic diagram of the cross-sectional structure of an exhaust assembly according to one or more embodiments. According to some embodiments of the present application, a breathable membrane assembly 40 is disposed on a side of the seat bottom wall 3115 of the one-way valve 30 away from the valve cavity 313. The breathable membrane assembly 40 includes a breathable membrane 41 and a metal member 42. The metal member 42 is provided with a first breathable hole 491. The breathable membrane 41 is disposed on the metal member 42 and covers the first breathable hole 491. The metal member 42 is connected to the seat bottom wall 3115. In this embodiment, by utilizing the metal member 42 to connect to the seat bottom wall 3115, the connection strength can be improved.

[0201] Referring to Figures 22 and 23 , Figure 22 is an exploded view of an exhaust assembly according to one or more embodiments; Figure 23 is a cross-sectional view of an exhaust assembly according to one or more embodiments. According to some embodiments of the present application, the breathable membrane assembly 40 is disposed on the side of the seat bottom wall 3115 facing the valve cavity 313.

[0202] The valve chamber 313 includes a first chamber 3131 and a second chamber 3132 that are interconnected. The second chamber 3132 is closer to the seat bottom wall 3115. Along a direction parallel to the seat bottom wall 3115, the cross-sectional area of ​​the first chamber 3131 is larger than that of the second chamber 3132. The valve core 32 is located in the first chamber 3131, and the breathable membrane assembly 40 is located in the second chamber 3132. This arrangement allows gas to enter the valve chamber and first pass through the breathable membrane assembly before reaching the valve core, thereby preventing electrolyte from overflowing.

[0203] Furthermore, the seat sidewall 3116 includes a first sidewall portion 3116a, a second sidewall portion 3116b, and a third sidewall portion 3116c. The first sidewall portion 3116a and the second sidewall portion 3116b enclose a first cavity 3131. The third sidewall portion 3116c and the seat bottom wall 3115 enclose the first cavity 3131. The blocking member 321 of the valve core 32 abuts the second sidewall portion 3116b. In this embodiment, the second cavity 3132 is open to communicate with the first cavity 3131. The blocking member 321 of the valve core 32 located in the first cavity 3131 abuts the second sidewall portion 3116b, allowing the blocking member 321 to block the second cavity 3132. When the internal air pressure of the battery cell is low, the gas cannot enter the first cavity 3131 from the second cavity 3132 . When the internal air pressure of the battery cell is high, the gas enters the second cavity 3132 , pushes open the sealing member 321 , enters the first cavity 3131 , and is then discharged from the gas outlet of the valve cavity 313 .

[0204] 23 , according to some embodiments of the present application, the breathable membrane assembly 40 is located in the second cavity 3132 , so that gas passes through the breathable membrane assembly 40 before being discharged from the first cavity 3131 through the second cavity 3132 .

[0205] In which, the breathable membrane assembly 40 can only include a breathable membrane 41, which is attached to the side of the seat bottom wall 3115 facing the valve cavity 313 and covers the fourth through hole 3114. In this case, the gas entering from the fourth through hole 3114 passes through the breathable membrane 41, blocking the electrolyte from entering the second cavity 3132.

[0206] In another embodiment, the breathable membrane assembly 40 may include a breathable membrane 41 and a metal part 42, and the breathable membrane 41 is arranged on the metal part 42. The metal part 42 is connected to the wall of the second cavity 3132 (the third side wall portion 3116c), which can improve the stability of the connection and prevent the breathable membrane 41 from being displaced by the gas top.

[0207] The breathable membrane 41 can be disposed on the side of the metal member 42 facing the seat bottom wall 3115, so that the metal member 42 provides support for the breathable membrane 41 and prevents the breathable membrane 41 from being displaced by the gas. In other embodiments, the breathable membrane 41 can also be disposed on the side of the metal member 42 away from the seat bottom wall 3115.

[0208] Please continue to refer to Figure 23. According to some embodiments of the present application, when the breathable membrane 41 is arranged on the side of the metal part 42 facing the seat bottom wall 3115, the surface of the side of the metal part 42 away from the breathable membrane 41 is lower than the surface of the second side wall portion 3116b. Through this arrangement, a certain cavity can be created between the metal part 42 and the sealing part 321, which is conducive to the discharge of gas.

[0209] 23 , according to some embodiments of the present application, the battery cell 20 further includes a sealing ring 80 disposed between the breathable membrane assembly 40 and the seat bottom wall 3115. This arrangement can improve the sealing between the breathable membrane assembly 40 and the seat bottom wall 3115.

[0210] Furthermore, a sealing ring 80 is disposed between the breathable membrane 41 and the seat bottom wall 3115. The sealing ring 80 is disposed around the fourth through hole 3114 and is provided with a second breathable hole 801. The aperture of the second breathable hole 801 is larger than the aperture of the fourth through hole 3114. The breathable membrane 41 covers the second breathable hole 801. This arrangement improves the sealing between the breathable membrane 41 and the seat bottom wall 3115, and the sealing ring 80 does not block the flow of gas.

[0211] According to some embodiments of the present application, the metal member 42 is welded to the third side wall portion 3116 c ; or the metal member 42 is interference fit to the third side wall portion 3116 c .

[0212] According to some embodiments of the present application, a battery 100 is provided, comprising a battery cell 20 according to any of the above-described embodiments. Please refer to FIG. 24 , which is a schematic diagram of an exploded structure of a battery according to one or more embodiments. The battery 100 comprises a housing 10 and a battery cell 20, with the battery cell 20 contained within the housing 10. The housing 10 is configured to provide a storage space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap with each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open, and the first portion 11 can be a plate-like structure, overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0213] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0214] Each battery cell 20 may be a secondary battery or a primary battery; specific examples include all types of primary or secondary batteries. For example, it may be a lithium battery, a sodium battery, a potassium battery, or other different types of secondary batteries. Lithium secondary batteries may include lithium metal secondary batteries, lithium ion secondary batteries, lithium polymer secondary batteries, or lithium ion polymer secondary batteries. Other types may include, but are not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. Battery cells 20 may be cylindrical, flat, rectangular, or other shapes.

[0215] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0216] According to some embodiments of the present application, the present application further provides an electric device, which includes a battery cell according to any of the above solutions, and the battery cell is used to provide power to the electric device. The electric device can be any of the above devices or systems using the battery cell.

[0217] In some embodiments, the purposes of the electric equipment of the present application are not particularly limited, and it can be used for any electronic device known in the prior art. The battery disclosed in the embodiment of the present application can be used for electric equipment using a battery as a power source or various energy storage systems using a battery as an energy storage element. That is, a kind of electric equipment is provided. In some embodiments, the electric equipment of the present application can be used for, but not limited to, a laptop computer, a pen-input type computer, a mobile computer, an e-book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a head-mounted stereo headset, a video recorder, an LCD TV, a portable cleaner, a portable CD player, a mini disc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, a car, a motorcycle, a power-assisted bicycle, a bicycle, a ship, a spacecraft, a lighting fixture, a toy, a game console, a clock, an electric tool, a flashlight, a camera, a large-scale battery for household use and a lithium-ion capacitor etc.

[0218] Electrical equipment can choose battery cells, battery modules or battery packs according to its usage requirements.

[0219] Please refer to Figure 25, which is a schematic structural diagram of a vehicle according to one or more embodiments. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0220] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0221] In the above embodiments, the provision of a breathable membrane assembly enables the battery cell to release internal gas through the breathable membrane while in a sealed state, promptly discharging the gas inside the battery cell outside the housing. This prevents excessive pressure inside the battery cell and prevents the pressure relief mechanism from prematurely opening the valve, significantly improving battery life. A battery cell can be equipped with one or more breathable membrane assemblies, each of which can be positioned and arranged differently. For example, one breathable membrane assembly can be positioned on the side of the end cap facing the interior of the battery cell, while another can be positioned on the side of the end cap facing the exterior of the battery cell. Alternatively, one breathable membrane assembly can be positioned on the end cap, while another can be positioned on the housing.

[0222] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery cell, wherein: include: A housing having a wall portion and a receiving cavity; An exhaust component, disposed on the wall portion, and used to exhaust gas inside the housing; An electrolyte is filled in the containing cavity; Wherein, the conductivity of the electrolyte is: 2ms / cm≤conductivity≤16ms / cm; the exhaust rate of the exhaust component is: 0.6mL / day≤exhaust rate≤10.0mL / day.

2. The battery cell according to claim 1, wherein: The conductivity of the electrolyte is: 8ms / cm≤conductivity≤16ms / cm; the exhaust rate of the exhaust component is: 3.3mL / day≤exhaust rate≤10.0mL / day; Optionally, the conductivity of the electrolyte is: 11 ms / cm≤conductivity≤14 ms / cm, and the exhaust rate of the exhaust component is 4.5 mL / day≤exhaust rate≤9.0 mL / day.

3. The battery cell according to claim 1, wherein: The conductivity of the electrolyte is: 2ms / cm≤conductivity≤8ms / cm; the exhaust rate of the exhaust component is: 0.6mL / day≤exhaust rate≤5.0mL / day; Optionally, the conductivity of the electrolyte is: 4 ms / cm≤conductivity≤6 ms / cm; the exhaust rate of the exhaust component is 1.3 mL / day≤second exhaust rate≤3.9 mL / day.

4. The battery cell according to any one of claims 1 to 3, wherein: The exhaust component comprises a breathable membrane component, the breathable membrane component comprises a breathable membrane, and the breathable membrane has a breathability rate of 3-10 mL / day.

5. The battery cell according to claim 4, wherein: The breathable membrane comprises a first breathable membrane, and the breathability of the first breathable membrane is 3-4 mL / day; or The breathable membrane comprises a second breathable membrane, and the breathability of the second breathable membrane is 9-10 mL / day.

6. The battery cell according to any one of claims 1 to 3, wherein: The exhaust component includes a one-way valve, and the opening pressure of the one-way valve is greater than or equal to 0.2 MPa; optionally, greater than or equal to 0.4 MPa; and further optionally, greater than or equal to 0.8 MPa.

7. The battery cell according to any one of claims 1 to 3, wherein: The exhaust assembly includes a breathable membrane assembly and a one-way valve, the wall portion has a first exhaust hole, the first exhaust hole connects the inside of the shell with the outside of the shell, and the battery cell is configured so that the gas exhausted through the first exhaust hole flows through the one-way valve and the breathable membrane assembly.

8. The battery cell according to claim 7, wherein: The opening pressure of the one-way valve is greater than or equal to 0.4 MPa, and the breathable membrane assembly includes a second breathable membrane, and the breathability rate of the second breathable membrane is 9-10 mL / day.

9. The battery cell according to any one of claims 1 to 3, wherein: The exhaust assembly includes a breathable membrane assembly and a one-way valve, the wall portion has a first exhaust hole and a third exhaust hole arranged at intervals, the first exhaust hole and the third exhaust hole respectively connect the inside of the shell and the outside of the shell, and the battery cell is configured so that the gas exhausted through the first exhaust hole flows through the one-way valve, and the gas exhausted through the third exhaust hole passes through the breathable membrane assembly.

10. The battery cell according to claim 9, wherein: The opening pressure of the one-way valve is greater than or equal to 0.8 MPa. The breathable membrane assembly includes a first breathable membrane. The breathability rate of the first breathable membrane is 3-4 mL / day.

11. The battery cell according to any one of claims 1 to 10, wherein: The gas production rate of the battery cell is: 0.006 mL / Ah / D≤gas production rate≤0.066 mL / Ah / D; Optionally, the gas production rate of the battery cell is: 0.006 mL / Ah / D≤gas production rate≤0.033 mL / Ah / D; Optionally, the gas production rate of the battery cell is: 0.013 mL / Ah / D≤gas production rate≤0.026 mL / Ah / D; Optionally, the gas production rate of the battery cell is: 0.033 mL / Ah / D≤gas production rate≤0.066 mL / Ah / D; Optionally, the gas production rate of the battery cell is: 0.045 mL / Ah / D≤gas production rate≤0.060 mL / Ah / D.

12. The battery cell according to any one of claims 1 to 11, wherein: The electrolyte includes one or more of chain ethers, ethylene glycol dimethyl ether and its derivatives, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclic ethers.

13. The battery cell according to any one of claims 1 to 12, wherein: The battery cell further includes an electrode assembly, which is accommodated in the accommodation cavity. The electrode assembly includes a positive electrode sheet and a negative electrode sheet, wherein: The positive electrode sheet comprises a positive electrode current collector and a positive electrode active layer disposed on the positive electrode current collector, the positive electrode active layer comprises a positive electrode active material, and the positive electrode active material comprises one or more of a polyanion positive electrode material, a phosphate positive electrode material, a sulfate positive electrode material, a silicate positive electrode material, and a borate positive electrode material; and / or The negative electrode plate includes a negative electrode current collector and a carbonaceous coating disposed on the negative electrode current collector, wherein the carbonaceous coating includes a carbonaceous material, and the carbonaceous material includes one or more of conductive carbon, graphite, hard carbon, and carbon nanotubes.

14. The battery cell according to any one of claims 6 to 10, wherein: The one-way valve includes a valve body and a valve core, the valve body has a valve cavity inside, the valve body is provided with an air inlet and an air outlet, the air inlet is used to connect the valve cavity with the inside of the shell, and the air outlet is used to connect the valve cavity with the outside of the shell; the valve core is arranged in the valve cavity, the valve core is used to block the air inlet channel of the valve cavity, and the valve core is configured to open the air inlet channel under the action of the gas inside the shell.

15. The battery cell according to any one of claims 4, 5, 7 to 10, wherein: The breathable membrane assembly includes a breathable membrane and a connector, wherein the connector is provided with a first breathable hole, and the breathable membrane is provided on the connector and covers the first breathable hole; the breathable membrane is configured to allow gas inside the battery cell to pass through the breathable membrane and be discharged.

16. The battery cell according to claim 7 or 8, wherein: The wall portion has an outer surface and an inner surface that are arranged opposite to each other, the outer surface is arranged toward the outside of the shell, and the inner surface is arranged toward the inside of the shell, the wall portion is provided with a first exhaust hole, the first exhaust hole includes a through hole section and a first hole section, the through hole section and the first hole section are arranged along the thickness direction of the wall portion, the through hole section connects the inside of the shell with the outside of the shell, the first hole section is located on the side of the through hole section away from the inside of the shell, the aperture of the first hole section is larger than the aperture of the through hole section, and the one-way valve is at least partially accommodated in the first hole section.

17. The battery cell according to claim 16, wherein: At least part of the valve body of the one-way valve protrudes from the outer surface; the wall portion has a first sinker that is recessed relative to the inner surface, the first sinker is arranged around the first exhaust hole, and the breathable membrane assembly is at least partly accommodated in the first sinker.

18. The battery cell according to claim 16, wherein: At least part of the valve body of the one-way valve protrudes from the outer surface of the wall portion; the first exhaust hole also includes a second hole segment, along the thickness direction of the wall portion, the second hole segment is located between the through hole segment and the first hole segment, the aperture of the second hole segment is smaller than the aperture of the first hole segment, the aperture of the second hole segment is larger than the aperture of the through hole segment, the breathable membrane assembly is at least partially accommodated in the second hole segment, and the breathable membrane assembly is located on the side of the one-way valve facing the wall portion.

19. The battery cell according to claim 16, wherein: The one-way valve comprises a valve body, at least part of which protrudes from the inner surface of the wall portion, the valve body comprises a valve seat and a valve cover, the valve seat comprises a seat bottom wall and a seat side wall connected to the seat bottom wall; the valve cover is arranged at one end of the valve seat away from the seat bottom wall, the valve cover, the seat side wall and the seat bottom wall are enclosed to form the valve cavity, and the valve seat is provided with an air inlet of the valve cavity; wherein, The breathable membrane assembly is arranged on a side of the seat bottom wall away from the valve cavity; or The air-permeable membrane assembly is arranged on a side of the seat bottom wall facing the valve cavity.

20. A battery, wherein: Comprising a battery cell as claimed in any one of claims 1 to 19.

21. An electrical device, wherein: The invention comprises a battery cell as claimed in any one of claims 1 to 19, wherein the battery cell is used to provide electrical energy.

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