Battery cells, batteries and electrical equipment

Abstract

The present application discloses a battery cell, a battery and an electrical device. The battery cell includes a shell and a breathable membrane assembly, the shell has a wall portion, the wall portion has a first exhaust hole, the first exhaust hole connects the inside of the shell with the outside of the shell; the breathable membrane assembly is arranged on the wall portion, the breathable membrane assembly includes a breathable membrane, and the breathable membrane assembly covers the first exhaust hole. Through this arrangement, the present application can discharge the internal gas of the battery cell through the breathable membrane in a sealed state, and timely discharge the internal gas of the battery shell to the outside of the shell, so that the air pressure inside the battery shell is not too high, reducing the risk of premature valve opening of the pressure relief mechanism, and can greatly improve the battery life.

Description

Technical Field

[0001] 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

[0002] As global energy and environmental problems continue to intensify, new energy is developing rapidly as one of the areas of sustainable development. Batteries are increasingly widely used as a new energy source, and they have high requirements for reliability and service life. During the use of batteries in the process of charging and discharging, the internal pressure of the battery will increase due to the generation of gas inside the battery. In order to ensure the safety of the battery cell, a pressure relief mechanism for releasing the internal pressure of the battery cell is generally provided on the outer shell of the battery cell, so that when the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief mechanism can be actuated and release the pressure inside the battery cell. However, the pressure relief mechanism of the existing battery cell may actuate the pressure relief in advance during use, resulting in poor stability in the use of the battery cell, which is not conducive to improving the service life and reliability of the battery cell. The above statements are only used to provide background technical information related to the present application, and do not necessarily constitute prior art. Utility Model Content

[0003] The main technical problem solved by the present application is to provide a battery cell, a battery and an electrical device, which can enable the battery cell to discharge internal gas through a breathable membrane in a sealed state, and promptly discharge the internal gas of the battery shell to the outside of the shell, so that the air pressure inside the battery shell will not be too high, reduce the risk of premature valve opening of the pressure relief mechanism, and greatly increase the life of the battery cell.

[0004] In order to solve the above technical problems, a technical solution adopted by the present application is: provide a battery cell, the battery cell includes a shell and a breathable membrane assembly, the shell has a wall portion, the wall portion has a first exhaust hole, the first exhaust hole connects the inside of the shell with the outside of the shell; the breathable membrane assembly is arranged on the wall portion, the breathable membrane assembly includes a breathable membrane, and the breathable membrane assembly covers the first exhaust hole. Through this arrangement, the battery cell is in a sealed state. The internal gas is discharged through the breathable membrane, and the internal gas of the battery shell is discharged to the outside of the shell in time, so that the gas pressure inside the battery shell is not too high, reducing the risk of the pressure relief mechanism opening the valve in advance, which can greatly improve the life of the battery cell.

[0005] In one embodiment, the battery cell further comprises a sealant, which is arranged between the breathable membrane assembly and the wall portion. This arrangement can enhance the sealing between the breathable membrane assembly and the wall portion to prevent external water vapor, oxygen, etc. from entering the battery cell.

[0006] In one embodiment, the seal is disposed between the breathable membrane and the wall portion. This arrangement can achieve sealing between the breathable membrane and the wall portion, allowing gas to be discharged through the breathable membrane, while also preventing external water vapor, oxygen, etc. from entering the battery cell.

[0007] In one embodiment, the seal is arranged around the first exhaust hole, the seal is provided with a second air hole, the aperture of the second air hole is larger than the aperture of the first exhaust hole, and the air permeable membrane covers the second air hole. Through this arrangement, the seal can be used to limit the gas passing through the first exhaust hole to the space enclosed by the seal between the wall and the air permeable membrane, so that the gas continues to be discharged through the air permeable membrane. It is also possible to achieve sealing around the first exhaust hole, preventing external water vapor from entering the battery cell through the first exhaust hole.

[0008] In one embodiment, the breathable membrane assembly further comprises a connector, the connector is provided with a first breathable hole, the breathable membrane is provided on the connector, the breathable membrane covers the first breathable hole, and the breathable membrane is provided between the connector and the sealing member. With this arrangement, the sealing member can be fixed by the connector.

[0009] In one embodiment, the wall portion has a first sunken platform and a second sunken platform that are recessed relative to the surface of the wall portion, the first sunken platform is arranged around the second sunken platform, the first sunken platform is closer to the surface of the wall portion than the second sunken platform, the second sunken platform is arranged around the first exhaust hole, at least part of the seal is located on the second sunken platform, and at least part of the breathable membrane assembly is located on the first sunken platform. Through this arrangement, the installation height of the breathable membrane assembly can be reduced and the space utilization rate can be improved.

[0010] In one embodiment, the second sinking platform includes a platform surface, and a first boss protruding from the platform surface is further arranged on the second sinking platform, and the first boss is spaced apart from the breathable membrane. This arrangement can reduce the risk of the breathable membrane being damaged.

[0011] In one embodiment, the first boss is an annular boss surrounding the first exhaust hole. This arrangement can effectively position the seal and reduce the difficulty of installation.

[0012] In one embodiment, there are a plurality of first bosses, and the plurality of first bosses are arranged at intervals in the circumferential direction of the first exhaust hole. This arrangement can simplify the manufacturing process while achieving positioning.

[0013] In one embodiment, the connecting piece is connected to the wall by welding. This arrangement can enhance the connection stability between the breathable membrane assembly and the wall.

[0014] In one embodiment, the connecting member and the wall portion are interference-fitted, and the manufacturing process is simplified by this arrangement.

[0015] In one embodiment, the wall portion has a first sunken platform that is recessed relative to the surface of the wall portion, the first sunken platform is arranged around the first exhaust hole, and at least part of the breathable membrane assembly is located on the first sunken platform. This arrangement can reduce the installation depth of the breathable membrane assembly and improve space utilization.

[0016] In one embodiment, the wall portion includes an outer surface and an inner surface disposed opposite to each other, the outer surface is disposed toward the outside of the shell, and the inner surface is disposed toward the inside of the shell, and the wall portion has a first sinking platform that is recessed relative to the inner surface of the wall portion. This arrangement can reduce the installation height of the breathable membrane assembly and improve space utilization.

[0017] In one embodiment, the wall portion further has a third sunken platform that is recessed relative to the inner surface of the wall portion, the first sunken platform is arranged around the third sunken platform, the first sunken platform is closer to the inner surface of the wall portion than the third sunken platform, and the third sunken platform is arranged around the first exhaust hole. Through this arrangement, the area where the third sunken platform is located is a cavity, which can facilitate gas discharge.

[0018] In one embodiment, the breathable membrane assembly further comprises a connecting member, the connecting member is arranged on the first sink, the connecting member is provided with a first breathable hole; the breathable membrane is arranged on the side of the connecting member facing the inside of the shell, the breathable membrane covers the first breathable hole; or the breathable membrane is arranged on the side of the connecting member facing the wall, the breathable membrane covers the first breathable hole. This arrangement facilitates the discharge of gas.

[0019] In one embodiment, the orthographic projection of the first vent hole on the wall does not overlap with the area where the first exhaust hole is located. This arrangement can prevent foreign impurities from entering the breathable membrane assembly through the first exhaust hole.

[0020] In one embodiment, the breathable membrane assembly is arranged on the side of the wall portion facing the inside of the housing. This arrangement is conducive to improving the sealing performance of the battery cell.

[0021] In one embodiment, the breathable membrane assembly is arranged on the side of the wall portion facing the outside of the housing. This arrangement facilitates the assembly of the breathable membrane assembly.

[0022] In one embodiment, the wall portion has an outer surface and an inner surface disposed opposite to each other, the outer surface is disposed toward the outside of the shell, and the inner surface is disposed toward the inside of the shell, the wall portion has a first sinking platform that is recessed relative to the outer surface, and the breathable membrane assembly is at least partially located in the first sinking platform. This arrangement can reduce the installation height of the breathable membrane assembly.

[0023] In one embodiment, the breathable membrane assembly further comprises a connecting member, which is arranged on the first sinking platform and has a first breathable hole; the breathable membrane is arranged on a side of the connecting member facing the wall, and the breathable membrane covers the first breathable hole. This arrangement facilitates the discharge of gas.

[0024] In one embodiment, the wall portion includes a wall portion body, the wall portion body has an outer surface and an inner surface disposed opposite to each other, the outer surface is disposed toward the outside of the shell, and the inner surface is disposed toward the inside of the shell, and the wall portion has a wall portion boss protruding relative to the inner surface; the orthographic projection of the wall portion boss on the wall portion body at least partially overlaps with the orthographic projection of the breathable membrane assembly on the wall portion body. Through this arrangement, the strength of the wall portion in the area where the breathable membrane assembly is located can be enhanced.

[0025] In one embodiment, the battery cell further includes an insulating member, which is disposed on a side of the wall portion facing the interior of the housing; a second exhaust hole penetrating the insulating member is disposed on the insulating member, and the second exhaust hole is connected to the first exhaust hole. This arrangement can prevent the wall portion from contacting the electrode assembly, etc., and reduce the risk of short circuit.

[0026] In one embodiment, the insulating member is provided with a second boss protruding from the insulating member, the second boss is arranged around the second exhaust hole, and the second boss extends toward the wall portion into the first exhaust hole. Through this arrangement, the wall portion at the through hole can be protected from contacting the electrode assembly, etc., reducing the risk of short circuit.

[0027] In one embodiment, the second boss is spaced apart from the breathable membrane. This arrangement can reduce the risk of damage to the breathable membrane assembly.

[0028] In one embodiment, the insulating member has an upper surface, the upper surface is arranged toward the wall, the insulating member has a sixth sinking platform that is recessed relative to the upper surface, the wall has a wall boss that protrudes relative to the inner surface of the wall, and the wall boss is at least partially located on the sixth sinking platform. This arrangement can improve space utilization.

[0029] In one embodiment, the battery cell further comprises an adapter plate, the adapter plate has a first surface, the first surface is arranged toward the insulating member, the adapter plate has a seventh depression recessed relative to the first surface, the insulating member has a body boss protruding relative to the lower surface of the insulating member, and the body boss is at least partially located on the seventh depression. This arrangement can improve space utilization.

[0030] In one embodiment, the battery cell further includes a shielding member, which is mounted on the wall portion, is located on the side of the wall portion facing the outside of the housing, and shields the breathable membrane assembly, wherein a first discharge channel is formed between the shielding member and the wall portion, and the first discharge channel connects the air outlet of the breathable membrane assembly with the outside of the battery cell. This arrangement can protect the breathable membrane assembly and prevent dust, particles, etc. in the external environment from entering the breathable membrane assembly.

[0031] In one embodiment, the wall portion has an outer surface and an inner surface disposed opposite to each other, the outer surface is disposed toward the outside of the shell, and the inner surface is disposed toward the inside of the shell, the wall portion has a fourth sunken platform that is recessed relative to the outer surface of the wall portion, the fourth sunken platform is disposed around the first sunken platform, the fourth sunken platform is closer to the outer surface of the wall portion than the first sunken platform, the breathable membrane assembly is at least partially disposed on the first sunken platform, and the shielding member is at least partially disposed on the fourth sunken platform. With this arrangement, the installation height of the shielding member and the breathable membrane assembly can be reduced.

[0032] In one embodiment, the wall portion further has a fifth sunken platform that is recessed relative to the outer surface of the wall portion, the fourth sunken platform is arranged around the fifth sunken platform, and the fifth sunken platform is located between the fourth sunken platform and the first sunken platform. Through this arrangement, a cavity can be formed between the breathable membrane assembly and the shielding member, which is conducive to regulating the discharge of gas.

[0033] In one embodiment, the first exhaust channel includes a first exhaust gap formed between the shielding member and the side surface of the fourth sinker, and the first exhaust gap is used to connect the gas outlet and the outside of the shell. This arrangement is conducive to the exhaust of gas.

[0034] In one embodiment, the first exhaust channel further includes a second exhaust gap formed between the shielding member and the bottom surface of the fourth sinker, and the second exhaust gap communicates with the first exhaust gap and the gas outlet. This arrangement facilitates the exhaust of gas.

[0035] In one embodiment, the battery cell further includes a protective patch, which is disposed on a side of the wall portion facing the outside of the housing, and covers the shielding member. This arrangement can protect the shielding member and maintain the appearance of the battery cell unchanged.

[0036] In one embodiment, the protective patch is provided with an information collection hole that penetrates the protective patch, and the orthographic projection of the information collection hole on the wall is located inside the shielding member, so that the exposed area of ​​the information collection hole is the surface of the shielding member, so that the information code can be set on the shielding member or a detection element for sampling can be connected.

[0037] In one embodiment, the battery cell further includes a protective patch, which is disposed on a side of the wall portion facing the outside of the housing, and covers the first exhaust hole. This arrangement can prevent dust, particles, etc. in the external environment from entering the first exhaust hole, reducing the risk of poor exhaust due to blockage of the exhaust channel.

[0038] In one embodiment, an adhesive layer is provided on the side of the protective patch facing the wall, and the adhesive layer bonds the protective patch and the wall; wherein the adhesive layer is provided with an escape groove, and a second exhaust channel is formed between the escape groove and the wall. This arrangement can enhance the connection strength between the protective patch and the wall, while leaving an exhaust space.

[0039] In one embodiment, the breathable membrane assembly further comprises a connecting piece, the connecting piece is provided with a first breathable hole, the breathable membrane is provided on the connecting piece, and the breathable membrane covers the first breathable hole, so as to enhance the connection strength between the breathable membrane assembly and the wall portion and reduce the probability of deformation of the breathable membrane.

[0040] In one embodiment, the connector has a first annular table surface that is recessed relative to the surface of the connector, the first annular table surface is arranged around the first vent hole, and the vent membrane is arranged on the first annular table surface. Through this arrangement, the overall height of the vent membrane assembly can be reduced.

[0041] In one embodiment, the breathable membrane assembly further comprises a backing member, which is disposed between the breathable membrane and the connecting member, and the air permeability rate of the backing member is greater than the air permeability rate of the breathable membrane. This arrangement can provide support for the breathable membrane and protect the breathable membrane from being easily deformed.

[0042] In one embodiment, the connector further has a second annular table surface that is recessed relative to the surface of the connector, the second annular table surface is disposed around the first vent hole, and the backing member is at least partially disposed on the second annular table surface, thereby reducing the overall height of the breathable membrane assembly.

[0043] In one embodiment, the area of ​​the groove where the second annular table is located is 30mm 2 -250mm 2 Optionally, the area of ​​the groove where the second annular table is located is 60mm 2 -200mm 2 This can improve the air permeability of the controlled breathable membrane assembly and reduce the amount of external water vapor entering the battery cell.

[0044] In one embodiment, the first air holes include a plurality of circular through holes, and the diameter of the circular through holes is less than 3.0 mm, so as to provide support for the air-permeable membrane and protect the air-permeable membrane from being easily deformed.

[0045] In one embodiment, the thickness of the breathable membrane is 0.1-3.0 mm, and optionally, the thickness is 0.2-0.8 mm, so as to balance the breathability and strength of the breathable membrane.

[0046] In one embodiment, the connecting piece is a metal piece, which can enhance the connection strength between the breathable membrane assembly and the wall.

[0047] In one embodiment, the permeability rate of the breathable membrane is 3-10 mL / day, and optionally, the permeability rate is 4-6 mL / day, so that the gas of the battery cell can be discharged in time to maintain the internal pressure balance of the battery.

[0048] In one embodiment, the housing includes a shell and an end cap: a receiving cavity with an opening is formed inside the shell, and the receiving cavity is used to receive the electrode assembly; the end cap closes the opening; wherein the end cap is a wall; or the shell includes a wall; or the wall is a wall located at the top of the housing when the battery cell is in a placed state. This can facilitate the timely discharge of gas.

[0049] In one embodiment, the battery cell further includes a pressure relief mechanism, the pressure relief structure is disposed on the housing, and the pressure relief mechanism is configured to be activated and release the internal pressure of the battery cell when the battery cell thermally runs away.

[0050] In order to solve the above technical problems, another technical solution adopted by the present application is to provide a battery, the battery comprising the above battery monomer. The battery has at least the same advantages as the battery monomer.

[0051] In order to solve the above technical problems, another technical solution adopted by the present application is to provide an electric device, which includes the above battery. The electric device has at least the same advantages as the battery.

[0052] 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

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. 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 paying any creative work.

[0054] Figure 1 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0055] Figure 2 is a schematic diagram of a partial exploded structure of a battery cell according to one or more embodiments;

[0056] Figure 3 is a schematic cross-sectional structure diagram of a breathable membrane assembly according to one or more embodiments;

[0057] Figure 4 is a schematic cross-sectional structure diagram of a breathable membrane assembly according to one or more embodiments;

[0058] Figure 5 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0059] Figure 6 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0060] Figure 7 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0061] Figure 8 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0062] Fig. 9 is a schematic diagram of a partial exploded structure of a battery cell according to one or more embodiments;

[0063] Fig.10 for Fig. 9 A magnified schematic diagram of the middle A area;

[0064] Fig.11 is a schematic diagram of a partial cross-sectional structure of an end cap according to one or more embodiments;

[0065] Fig.12 is a schematic diagram of a partial exploded structure of a battery cell according to one or more embodiments;

[0066] Fig.13 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0067] Fig.14 is a schematic diagram of a partial exploded structure of a battery cell according to one or more embodiments;

[0068] Fig.15 is a schematic diagram of a partial cross-sectional structure of an insulating member according to one or more embodiments;

[0069] Fig.16a is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0070] Fig.16b A schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments

[0071] Fig.17a is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0072] Fig.17b is a bottom view of an adhesive layer of a protective patch according to one or more embodiments;

[0073] Fig.18 is a schematic diagram of an exploded structure of a battery according to one or more embodiments;

[0074] Fig.19is a schematic diagram of the structure of a vehicle according to one or more embodiments.

[0075] In the attached figure:

[0076] 1000, vehicle; 300, motor; 200, controller; 100, battery; 10, housing; 11, first part; 12, second part; 20, battery cell; 21, end cap; 21a, outer surface; 21b, inner surface; 211, first boss; 212, wall boss; 291, first vent; 22, housing; 23, electrode assembly; 24, insulating member; 241, second boss; 242, body; 242a, upper surface; 2421, body boss; 29 2. second vent hole; 25. electrode terminal; 26. adapter; 26a. first surface; 40. breathable membrane assembly; 41. breathable membrane; 42. metal part; 491. first vent hole; 43. backing member; 44. sealing member; 492. second vent hole; 50. shielding member; 501. first vent gap; 60. protective patch; 601. information collection hole; 602. first avoidance hole; 603. second avoidance hole; 610. adhesive layer; 611. avoidance groove; 70. pressure relief mechanism;

[0077] T1, first annular table surface; T2, second annular table surface; T3, transition surface;

[0078] S1, first sinker; S11, bearing surface; S12, connection surface; S2, second sinker; S22, platform surface; C1, first transition connection surface; S3, third sinker; C2, second transition connection surface; S4, fourth sinker; S42, connection surface; S5, fifth sinker; C3, third transition connection surface; C4, fourth transition connection surface; S6, sixth sinker; S7, seventh sinker; W1, weld. DETAILED DESCRIPTION

[0079] In order to make the purpose, technical solution and effect of the present application clearer and more specific, the following will describe the embodiments of the technical solution of the present application in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0080] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0081] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, 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), and similarly, "multiple groups" refers to more than two (including two groups), and "multiple pieces" refers to more than two (including two pieces), unless otherwise clearly and specifically defined.

[0082] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0083] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0084] Amounts, ratios and other numerical values ​​are presented herein in a range format. It should be understood that such a range format is for convenience and brevity and should be flexibly understood 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.

[0085] In the description of the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0086] 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. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0087] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0088] Batteries are widely used in the field of new energy, mainly including electric vehicles, energy storage systems and renewable energy. In the field of electric vehicles, higher performance such as longer driving range and fast charging are gradually achieved. In terms of energy storage systems, batteries are widely used in large-scale and distributed energy storage. They can balance the load of the grid, store renewable energy such as solar and wind power, and release the stored energy during peak hours. In addition, small rechargeable batteries are also widely used in applications such as wearable devices, drones and smart homes.

[0089] As the battery is charged and discharged, some side reactions will produce gas. If the gas produced by the battery is not discharged in time, the internal pressure of the battery will increase. Excessive internal pressure will have a negative impact on the performance and appearance of the battery. For example, in severe cases, it will have a destructive effect on the performance and appearance of the battery, such as leakage, bulging, increased internal resistance of the battery, and shortened discharge time and cycle life. In addition, there are some abnormal operations of the battery during use, including overcharging, over-discharging, internal failure, etc. In this case, the chemical reaction inside the battery may be uncontrolled, accompanied by violent release of gas, and even cause thermal runaway of the battery. Battery thermal runaway refers to a chain reaction phenomenon caused by various inducements. The large amount of heat and harmful gases emitted by thermal runaway can cause the battery to catch fire and explode.

[0090] In order to ensure the safety of battery cells, a pressure relief mechanism is usually provided on the outer shell of the battery cell to release the internal pressure of the battery cell through the pressure relief mechanism, thereby effectively improving the safety of the battery cell. However, the instability of the internal pressure during the use of the battery cell may cause the pressure relief mechanism of the battery cell to actuate and release pressure in advance, resulting in poor stability in the use of the battery cell, which is not conducive to improving the service life and reliability of the battery cell.

[0091] Based on the above considerations, an embodiment of the present application provides a battery cell, on which a breathable membrane assembly is arranged, and the gas inside the battery cell is discharged in time by utilizing the permeability of the breathable membrane in the breathable membrane assembly to maintain a stable internal pressure of the battery cell.

[0092] Please refer to Figure 1 , Figure 1 FIG. 2 is a schematic diagram of an exploded structure of a battery cell 20 according to one or more embodiments. The battery cell 20 is the smallest unit constituting the battery 100. Figure 1 The battery cell 20 includes an end cover 21, a shell 22, an electrode assembly 23 and other functional components.

[0093] The end cap 21 refers to a component that covers the opening of the shell 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 shell 22 to match the shell 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 21 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals 25 can be provided on the end cap 21. The electrode terminal 25 can be used to electrically connect with the electrode assembly 23 for outputting or inputting the electrical energy of the battery cell 20. Exemplarily, the battery cell 20 is provided with two electrode terminals 25, and the two electrode terminals 25 are both installed on the end cap 21, and the two electrode terminals 25 are respectively used to electrically connect with the two pole ears of opposite polarity of the electrode assembly 23 to realize the output or input of the positive and negative electrodes of the battery cell 20 respectively. 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, and 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 24 may be plastic, rubber, etc.

[0094] The shell 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, the electrolyte and other components. The shell 22 and the end cap 21 can be independent components, and an opening can be set on the shell 22, and the internal environment of the battery cell 20 is formed by covering the opening with the end cap 21 at the opening. Without limitation, the end cap 21 and the shell 22 can also be integrated. Specifically, the end cap 21 and the shell 22 can form a common connection surface before other components are put into the shell, and when the interior of the shell 22 needs to be encapsulated, the end cap 21 covers the shell 22. The shell 22 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the shell 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0095] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be included 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 23, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab 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 100, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals 25 to form a current loop.

[0096] According to some embodiments of the present application, the present application discloses a battery cell 20, which includes an outer shell and a breathable membrane assembly 40, wherein the outer shell has a wall portion, the wall portion has a first exhaust hole, and the first exhaust hole connects the inside of the outer shell with the outside of the outer shell; the breathable membrane assembly 40 is arranged on the wall portion, the breathable membrane assembly 40 includes a breathable membrane 41, and the breathable membrane assembly 40 covers the first exhaust hole.

[0097] The housing includes an end cap 21 and a shell 22, and the wall portion can be the end cap 21 or the wall of the shell 22. That is, the breathable membrane assembly 40 can be arranged on the end cap 21 or the shell 22. The following will take the wall portion as the wall of the end cap 21 as an example to illustrate the present application, but this should not limit the present application.

[0098] Please refer to Figure 2 , Figure 2 Schematic diagram of a partial decomposition structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the battery cell 20 includes an end cap 21 and a breathable membrane assembly 40, and a first exhaust hole 291 is provided on the end cap 21. The breathable membrane assembly 40 is provided on the end cap 21 and covers the first exhaust hole 291. The first exhaust hole 291 connects the inside of the shell with the outside of the shell, and the gas inside the shell of the battery cell 20 can be discharged through the first exhaust hole 291 to regulate the pressure inside the shell of the battery cell 20. The first exhaust hole can be set at any position of the end cap 21, and can be one or more. The aperture of the first exhaust hole can be set as needed; the size and number of the exhaust holes can be designed according to the capacity of the battery cell 20, the type of battery 100, the volume, etc., the amount of gas produced, the gas production speed, etc. As before, the first exhaust hole can also be set on any wall of the shell 22.

[0099] The breathable membrane assembly 40 includes a breathable membrane 41, which is made of a breathable material and has good breathability, allowing gas molecules to pass through. By arranging the breathable membrane assembly 40 on the end cap 21 and covering the first exhaust hole 291 with the breathable membrane 41, the battery cell 20 can discharge internal gas through the breathable membrane 41 in a sealed state, and the internal gas of the battery 100 shell is discharged outside the shell in time, so that the gas pressure inside the battery 100 shell is not too high, reducing the risk of premature valve opening of the pressure relief mechanism 70, and greatly improving the life of the battery 100.

[0100] In some embodiments, the breathable membrane 41 also has a liquid barrier property, blocking the passage of liquid, so that it can block the overflow of electrolyte while discharging gas. In addition, the breathable membrane 41 can also block external water vapor, dust and impurities from entering the battery cell 20 through the first exhaust hole 291, protect the internal environment of the battery cell 20, and effectively improve the reliability of the battery cell 20. The breathable membrane 41 also has good weather resistance, chemical corrosion resistance, and structural stability. If it is an automotive power battery 100, it is also necessary to have oleophobicity. Therefore, the material of the breathable membrane 41 can be selected from polymer materials, such as polytetrafluoroethylene, polypropylene, polyethylene, polyurethane, etc. In addition, since the generation of gas inside the battery 100 will cause the internal pressure to rise rapidly, the breathable membrane 41 needs to have certain mechanical strength and elasticity.

[0101] Please refer to Figure 3 , Figure 3 Schematic diagram of the cross-sectional structure of the breathable membrane assembly 40 according to one or more embodiments. According to some embodiments of the present application, the breathable membrane assembly 40 further includes a connector 42, that is, the breathable membrane assembly 40 includes a breathable membrane 41 and a connector 42, and the connector 42 is used to support the breathable membrane 41. Specifically, the connector 42 is provided with a first air hole 491, the breathable membrane 41 is provided on the connector 42, and the breathable membrane 41 covers the first air hole 491. The breathable membrane 41 is configured to allow the gas inside the battery cell 20 to pass through the breathable membrane 41 and be discharged.

[0102] The connector 42 can support the breathable membrane 41 and reduce the risk of excessive deformation of the breathable membrane 41. At the same time, the connector 42 can also serve as a medium for connecting the breathable membrane assembly 40 with the end cap 21. The breathable membrane 41 is connected to the end cap 21 through the connector 42 to improve the stability of the connection. The connector 42 is provided with at least one first air hole 491 as a release channel for the gas inside the battery 100 so that the gas can pass through the connector 42. The shape of the first air hole 491 includes geometric shapes such as circle, square, and ellipse. The connector 42 can also be provided with multiple first air holes 491. The aperture, shape, and arrangement of the first air holes 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 first exhaust hole 291.

[0103] In one embodiment, the first air permeability hole 491 includes one hole.

[0104] In one embodiment, the first air holes 491 include a plurality of circular through holes, and the diameter of each circular through hole is less than 3.0 mm.

[0105] In one embodiment, the connector 42 may be a metal part 42, a resin part, etc. The material of the metal part 42 may be copper, iron, aluminum, steel, or aluminum alloy, etc. The connector 42 may be a sheet structure. By selecting the connector as a metal part 42, it is convenient to weld the connector to the wall. The following will take the example that the connector 42 may be a metal part 42 to illustrate the present application scheme, but it should not be limited to this, and should not bring limitations to the present application scheme, and it is still applicable to connectors made of non-metallic materials.

[0106] like Figure 3 As shown in (a), the air permeable membrane 41 can be directly disposed on the surface of the metal member 42. In other embodiments, a sink can also be disposed on the metal member 42.

[0107] Please continue reading Figure 3 As shown in (b), according to some embodiments of the present application, the metal member 42 has a first annular table surface T1 that is recessed relative to the surface of the metal member 42, the first annular table surface T1 is arranged around the first vent hole 491, and the vent membrane 41 is arranged on the first annular table surface T1. Through this arrangement, the installation height of the vent membrane assembly 40 can be reduced.

[0108] See also Figure 4 , Figure 4 Schematic diagram of the cross-sectional structure of the breathable membrane assembly 40 according to one or more embodiments. According to some embodiments of the present application, the breathable membrane assembly 40 further includes a backing member 43, which is disposed between the breathable membrane 41 and the connecting member, and the air permeability of the backing member 43 is greater than the air permeability of the breathable membrane 41.

[0109] The breathable membrane assembly 40 includes a breathable membrane 41, a metal component 42 and a backing component 43. The breathable membrane 41 is arranged on the metal component 42, and the backing component 43 is arranged between the breathable membrane 41 and the metal component 42. The backing component 43 is used to support the breathable membrane 41 and allow gas to pass through the breathable membrane 41.

[0110] The backing member 43 can support the breathable membrane 41, so that the breathable membrane 41 is not easily deformed. The backing member 43 is made of a material with better air permeability than the breathable membrane 41, that is, the air permeability rate of the backing member 43 is greater than the air permeability rate of the breathable membrane 41. It does not affect the air permeability process of the breathable membrane 41; the backing member 43 also has the characteristics of corrosion resistance and high temperature resistance. The material selection of the backing member 43 is rich, including porous polymers such as polypropylene, polyamide, polytetrafluoroethylene, polyperfluoroethylene propylene, etc., and can also be metal organic framework porous materials, as well as carbon membranes and ceramic porous materials, etc., which are not limited here.

[0111] like Figure 4 As shown in (a), the metal part 42 also has a second annular table T2 that is recessed relative to the surface of the metal part 42. The second annular table T2 is arranged around the first air hole 491, and the backing member 43 is arranged on the second annular table T2. The second annular table T2 carries 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 overall height of the breathable membrane assembly 40 is relatively small. By reducing the setting 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.

[0112] In some embodiments, the area of ​​the groove where the second annular table T2 is located is 30mm2-250mm2. Optionally, the area of ​​the groove where the second annular table T2 is located is 60mm2-200mm2. For example, it can be 30mm2, 50mm2, 80mm2, 100mm2, 120mm2, 150mm2, 180mm2, 200mm2, 230mm2, 250mm2, etc. On the one hand, it can accommodate backing members 43 of different sizes. On the other hand, controlling the area of ​​the groove where the second annular table T2 is located within the above range can improve the air permeability of the breathable membrane assembly 40 and reduce the amount of external water vapor entering the battery cell 20.

[0113] like Figure 4 As shown in (b), the metal part 42 has a first annular table T1 and a second annular table T2 which 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 air permeable membrane 41 is arranged on the first annular table T1.

[0114] The first annular table surface T1 and the second annular table surface T2 are formed by the surface of the metal member 42 being recessed inwardly, and the first annular table surface T1 and the second annular table surface T2 may be formed by stamping the metal member 42, or the first annular table surface T1 and the second annular table surface T2 may be formed by etching the metal member 42 and removing part of the structure. The recess depth of the first annular table surface T1 and the second annular table surface T2 relative to the surface of the metal member 42 may be set according to the thickness of the breathable membrane 41 and the backing member 43. Preferably, the recess depth 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 surface T2 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.

[0115] In some embodiments, the depression depth of the first annular platform T1 relative to the surface of the metal member 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 member 42 is flush with the surface of the metal member 42 .

[0116] By providing a recessed platform on the metal member 42 , the surface of the breathable membrane 41 can be flush with the surface of the metal member 42 , thereby reducing the overall height of the breathable membrane assembly 40 , thereby reducing the installation height of the breathable membrane assembly 40 on the end cover 21 .

[0117] In one embodiment, the breathable membrane 41 and the metal part 42 are compositely connected, for example, the breathable membrane 41 and the metal part 42 can be connected by using a nano injection molding process. Nano injection molding refers to nano molding technology (NMT, i.e., Nano Molding Technology), which is a process of combining metal and plastic using nano technology. That is, the metal surface is first nano-treated, and then the plastic is directly injection-molded on the metal surface, so that the metal and plastic can be integrally formed and finally combined into a product. The "nano" referred to here refers to a microporation process, that is, the metal surface is subjected to nano-scale microporation treatment through a specific solution, and the main purpose is to make the metal surface and the plastic better combined and improve the connection strength.

[0118] According to some embodiments of the present application, the breathable membrane assembly 40 may include only the breathable membrane 41, and the breathable membrane 41 is directly compounded with the end cap 21, that is, the breathable membrane assembly 40 is disposed on the end cap 21, the breathable membrane 41 is connected to the end cap 21, and covers the first exhaust hole 291. As mentioned above, the end cap 21 may be nano-processed, and then the breathable membrane 41 is compounded and connected to the end cap 21. In this embodiment, by providing the breathable membrane 41, the gas inside the battery 100 can be discharged in a sealed state in a timely manner, and the electrolyte can be prevented from overflowing, and the entry of external water vapor can be blocked, thereby protecting the internal environment of the battery cell 20 and effectively improving the reliability of the battery 100. At the same time, the breathable membrane assembly 40 has only one layer of breathable membrane 41, and its thickness is relatively small, which has little effect on the installation height of the battery cell 20.

[0119] According to some embodiments of the present application, the breathable membrane 41 may be attached to the side of the end cap 21 facing the inside of the housing, or to the side of the end cap 21 facing the outside of the housing. The breathable membrane 41 may be directly attached to the surface of the end cap 21, or a sink recessed relative to the surface of the end cap 21 may be provided on the end cap 21 to accommodate the breathable membrane 41, so that the surface of the breathable membrane 41 is flush with the surface of the end cap 21.

[0120] 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. That is, the breathable membrane 41 is connected to the end cap 21 through the metal member 42.

[0121] In some embodiments, the metal member 42 may be connected to the end cap 21 by welding, interference fit, etc. In this way, the connection strength between the breathable membrane assembly 40 and the end cap 21 can be enhanced.

[0122] Please refer to Figure 5 and Figure 6 , Figure 5 is a schematic diagram of a partial cross-sectional structure of a battery cell 20 according to one or more embodiments. Figure 6 Schematic diagram of a partial cross-sectional structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the end cap 21 has a first sinking platform S1 that is recessed relative to the surface of the end cap 21, the first sinking platform S1 is arranged around the first exhaust hole 291, and at least a portion of the breathable membrane assembly 40 is arranged on the first sinking platform S1.

[0123] The end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite to each other, the outer surface 21a is disposed toward the outside of the shell, and the inner surface 21b is disposed toward the inside of the shell. The breathable membrane assembly 40 can be disposed on the side of the end cap 21 facing the inside of the shell, or on the side of the end cap 21 facing the outside of the shell.

[0124] like Figure 5 As shown in (a) and (b), the breathable membrane assembly 40 is arranged on the side of the end cap 21 facing the inside of the shell. The wall portion has an outer surface 21a and an inner surface 21b arranged opposite to each other, 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, and the wall portion has a first sinking platform that is recessed relative to the inner surface 21b of the wall portion.

[0125] Specifically, the first sinking platform S1 is recessed relative to the inner surface 21 b of the end cover 21 , and the breathable membrane assembly 40 is disposed on the first sinking platform S1 . Optionally, the breathable membrane assembly 40 may be connected to the end cover 21 via a metal member 42 .

[0126] 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 may be stamped to form the recessed first depression S1, or the end cover 21 may be etched to remove part of the structure to form the recessed first depression S1. The recess 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 depression depth of the first depression S1 relative to the inner surface 21b of the end cover 21 is equal to the thickness of the breathable membrane assembly 40, so that the breathable membrane assembly 40 is accommodated in the first depression S1, and the surface of the breathable membrane assembly 40 facing the inside of the shell is flush with the inner surface 21b of the end cover 21. In this way, the installation height of the breathable membrane assembly 40 can be reduced, thereby reducing the occupation of the internal space of the battery cell 20 shell and improving the space utilization rate inside the shell.

[0127] like Figure 5 As shown in (a), the air permeable membrane 41 may be arranged on the side of the metal member 42 facing the inside of the housing; this arrangement can reduce the influence of the working environment of the battery cell 20 on the air permeable membrane 41. Figure 5 As shown in (b), the breathable membrane 41 may also be disposed on the side of the metal member 42 facing the end cap 21, that is, the breathable membrane 41 is disposed between the metal member 42 and the end cap 21; this arrangement can reduce the erosion of the electrolyte system on the breathable membrane 41.

[0128] like Figure 6As shown, the breathable membrane assembly 40 is arranged on the side of the end cover 21 facing the outside of the housing. Specifically, the first sinking platform S1 is recessed relative to the outer surface 21a of the end cover 21, and the breathable membrane assembly 40 is arranged on the first sinking platform S1 and connected to the end cover 21 through the metal member 42. In this embodiment, the first sinking platform S1 is formed by the outer surface 21a of the end cover 21 being recessed toward the inner surface 21b of the end cover 21. Similarly, the recessed depth of the first sinking platform S1 relative to the outer surface 21a of the end cover 21 can be equal to the thickness of the breathable membrane assembly 40.

[0129] like Figure 6 As shown, the breathable membrane 41 is arranged on the side of the metal part 42 facing the inside of the housing, that is, the breathable membrane 41 is arranged between the end cover 21 and the metal part 42. Through this arrangement, the breathable membrane 41 can be less affected by the working environment of the battery cell 20. In other embodiments, the breathable membrane 41 can also be arranged on the side of the metal part 42 facing the outside of the housing.

[0130] Please refer to Figure 7 , Figure 7 The partial cross-sectional structure diagram of the battery cell 20 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 end cap 21 facing the inside of the housing, and the breathable membrane 41 is disposed on the side of the metal part 42 facing the inside of the housing.

[0131] In some embodiments, the wall also has a third sinker S3 recessed relative to the inner surface 21b of the wall, the first sinker S1 is arranged around the third sinker S3, the first sinker S1 is closer to the inner surface 21b than the third sinker S3, and the third sinker S3 is arranged around the first exhaust hole 491.

[0132] Among them, the end cover 21 has a first sinker S1, a third sinker S3 and a second transition connection surface C2 which are recessed relative to the inner surface 21b of the end cover 21. The first sinker S1 is arranged around the third sinker S3. The second transition connection surface C2 connects the first sinker S1 and the third sinker S3. The first sinker S1 is closer to the inner surface 21b of the end cover 21 than the third sinker S3. The third sinker S3 is arranged around the first exhaust hole 291. The breathable membrane assembly 40 is located on the first sinker S1, and the breathable membrane 41 is arranged on the side of the metal part 42 facing the inside of the shell.

[0133] Specifically, the first sinker S1 and the third sinker S3 are formed by the inner surface 21b of the end cover 21 being recessed toward the outer surface 21a of the end cover 21. The purpose of the first sinker S1 is to carry and accommodate the breathable membrane assembly 40, and the depth of the recess relative to the inner surface 21b of the end cover 21 can be set according to the thickness of the breathable membrane assembly 40 so as to accommodate the breathable membrane assembly 40. The purpose of the third sinker S3 is to form a certain cavity between the breathable membrane assembly 40 and the end cover 21 so that the gas can be discharged smoothly. The depth of the recess of the third sinker S3 relative to the first sinker S1 (i.e., the height of the second transition connection surface C2) is set according to demand.

[0134] Please refer to Figure 7 According to some embodiments of the present application, the orthographic projection of the first air hole 491 on the end cover 21 does not overlap with the area where the first exhaust hole 291 is located.

[0135] like Figure 7 As shown, the first exhaust hole 291 and the first air hole 491 are not arranged correspondingly, which is beneficial to regulating the discharge of gas on the one hand; on the other hand, it reduces the risk of external medium entering the first air hole 491 and affecting the normal operation of the air permeable membrane 41.

[0136] Please continue to refer to Figure 5 and Figure 6 The metal member 42 can be connected to the end cover 21 by welding. The first sinker S1 includes a bearing surface S11 parallel to the surface of the end cover 21 , and the bearing surface S11 is used to bear the breathable membrane assembly 40 .

[0137] Please continue to refer to Figure 5 and Figure 6 The metal part 42 can be connected to the end cover 21 by welding. The first sinker S1 includes a connecting surface S12 perpendicular to the bearing surface S11. The metal part 42 is a metal sheet with a certain thickness, and can be connected to the end cover 21 by the side of the metal sheet. Specifically, the side of the metal sheet can be welded to the connecting surface S12 of the first sinker S1, and can be assembled by laser welding. Figure 5 and Figure 6 The W1 position shown in the figure is the welding position of the two.

[0138] Please refer to Figure 8 , Figure 8 Schematic diagram of a partial cross-sectional structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the battery cell 20 further includes a seal 44, which is disposed between the breathable membrane assembly 40 and the end cap 21. The arrangement of the seal 44 can maintain the seal between the breathable membrane assembly 40 and the end cap 21.

[0139] Among them, the connection interface between the breathable membrane 41 and the metal part 42 is formed by two structures with greatly different properties after all, and its sealing has certain limitations. In particular, with the continuous exhaust, the connection interface between the breathable membrane 41 and the metal part 42 is prone to failure, resulting in poor sealing, so that the gas is discharged through the connection interface between the breathable membrane 41 and the metal part 42, and it is also easy for external water vapor to enter the battery 100 along this path. In some embodiments, the metal part 42 is connected to the end cover 21 by welding, and the sealing of its welding interface is limited by the accuracy of the welding process, and it is also easy to have the problem of poor sealing. By setting a seal 44 between the breathable membrane assembly 40 and the end cover 21, the sealing of two sealing interfaces is achieved, that is, the sealing between the lower surface of the seal 44 and the end cover 21, and the sealing between the upper surface 242a of the seal 44 and the breathable membrane assembly 40. It can reduce the sealing requirements for the connection interface between the breathable membrane 41 and the metal part 42 and the weld W1, and can reduce its process technology accuracy, thereby reducing manufacturing costs.

[0140] Please refer to Figure 8 and Fig. 9 , Fig. 9 Schematic diagram of a partial exploded structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, a sealing member 44 is disposed between the gas permeable membrane 41 and the wall portion.

[0141] The seal 44 is disposed between the breathable membrane 41 and the end cap 21 to achieve a seal between the breathable membrane 41 and the end cap 21, so that the gas is discharged through the breathable membrane 41 without leaking to other areas. At the same time, it can also prevent external water vapor, oxygen, etc. from entering the battery 100.

[0142] In some embodiments, the seal 44 is arranged around the first vent 291, and the seal 44 is provided with a second vent 492, the aperture of the second vent 492 is larger than the aperture of the first vent 291, and the breathable membrane 41 covers the second vent 492. By arranging the seal 44 around the first vent 291, the seal 44 can be used to limit the gas passing through the first vent 291 to the space enclosed by the seal 44 between the end cover 21 and the breathable membrane 41, so that the gas can continue to be discharged only after passing through the breathable membrane 41. In other words, the seal 44 is an annular sealing ring, which is arranged around the first vent 291. In this way, the sealing around the first vent 291 can also be achieved, and the external water vapor can be prevented from entering the battery 100 through the first vent 291.

[0143] Please continue to refer to Figure 8 and Fig. 9The breathable membrane assembly 40 also includes a connecting member 42 , the connecting member 42 is provided with a first breathable hole 491 , the breathable membrane 41 is provided on the connecting member 42 , the breathable membrane 41 covers the first breathable hole 491 , and the breathable membrane 41 is provided between the connecting member 42 and the sealing member 44 .

[0144] In which, taking the connecting member 42 as a metal member 42 as an example, the sealing member 44 is arranged between the metal member 42 and the end cover 21, and the breathable membrane 41 is arranged between the metal member 42 and the sealing member 44. That is, from the stacking direction, the sealing member 44 is stacked on the end cover 21, the breathable membrane 41 is stacked on the sealing member 44, and the metal member 42 is stacked on the breathable membrane 41. In this way, the sealing member 44 can be fixed by the connection between the metal member 42 and the end cover 21 to achieve the sealing between the sealing member 44 and the end cover 21, and between the sealing member 44 and the breathable membrane 41. In other words, the sealing member 44 can be pressed onto the end cover 21 by the metal member 42, and the sealing member 44 can be combined with the end cover 21 and the breathable membrane 41 by the pressing force to form a sealing interface. Figure 8 The seal 44 shown in the figure is pressed between the breathable membrane 41 and the end cover 21. In other embodiments, the setting position of the seal 44 can also be moved to the left and right sides and directly pressed between the metal part 42 and the end cover 21.

[0145] Please refer to Figure 8 , Fig. 9 , Fig.10 and Fig.11 , Fig.10 for Fig. 9 A magnified schematic diagram of area A in the middle. Fig.11 2 is a schematic diagram of a partial cross-sectional structure of an end cap 21 according to one or more embodiments. According to some embodiments of the present application,

[0146] The end cover 21 has a first sinker S1 and a second sinker S2 which are recessed relative to the surface of the end cover 21. The first sinker S1 is arranged around the second sinker S2. The first sinker S1 is closer to the surface of the end cover 21 than the second sinker S2. The second sinker S2 is arranged around the first exhaust hole 291. The seal 44 is located on the second sinker S2, and the breathable membrane assembly 40 is located on the first sinker S1.

[0147] Among them, the end cover 21 has a first sinker S1, a second sinker S2 and a first transition connection surface C1 which are recessed relative to the surface of the end cover 21. The first sinker S1 is arranged around the second sinker S2. The first transition connection surface C1 connects the first sinker S1 and the second sinker S2. The first sinker S1 is closer to the surface of the end cover 21 than the second sinker S2. The second sinker S2 is arranged around the first exhaust hole 291. The sealing member 44 is located on the second sinker S2, and the breathable membrane assembly 40 is located on the first sinker S1.

[0148] As mentioned above, the end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite to each other, the outer surface 21a is disposed toward the outside of the shell, and the inner surface 21b is disposed toward the inside of the shell. The breathable membrane assembly 40 can be disposed on the side of the end cap 21 facing the inside of the shell, or on the side of the end cap 21 facing the outside of the shell.

[0149] like Figure 8 As shown in (a), the breathable membrane assembly 40 is disposed on the side of the end cover 21 facing the outside of the housing.

[0150] The end cover 21 has a first depression S1 that is recessed relative to the outer surface 21 a , and the breathable membrane assembly 40 is at least partially located in the first depression S1 .

[0151] The above solution can reduce the installation height of the breathable membrane assembly 40.

[0152] In some examples, the first depression S1 and the second depression S2 are recessed relative to the outer surface 21a of the end cover 21, that is, the first depression S1 and the second depression S2 are recessed from the outer surface 21a of the end cover 21 toward the inner surface 21b of the end cover 21. Similarly, the recess depth of the first depression S1 relative to the outer surface 21a of the end cover 21 can be equal to the thickness of the breathable membrane assembly 40. Figure 8 As shown in (b), the breathable membrane assembly 40 is disposed on the side of the end cover 21 facing the inside of the housing. Specifically, the first sinking platform S1 and the second sinking platform S2 are recessed relative to the inner surface 21b of the end cover 21, that is, the first sinking platform S1 and the second sinking platform S2 are recessed from the inner surface 21b of the end cover 21 toward the outer surface 21a of the end cover 21.

[0153] According to some embodiments of the present application, Figure 8 As shown in (a) and (b), the breathable membrane assembly 40 is located on the first sinking platform S1, and the sealing member 44 is located on the second sinking platform S2.

[0154] The depth of the first depression S1 relative to the surface of the end cap 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 of the breathable membrane 41, the metal member 42 and the backing member 43. As mentioned above, the breathable membrane 41 and the backing member 43 can be accommodated in an annular platform on the metal member 42 that is recessed relative to the surface of the metal member 42, that is, the overall thickness of the breathable membrane assembly 40 can be equal to the thickness of the metal member 42. Preferably, the depth of the first depression S1 relative to the surface 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 in the first depression S1, and the surface of the breathable membrane assembly 40 is flush with the surface of the end cap 21. In this way, the installation height of the breathable membrane assembly 40 can be reduced.

[0155] The depth of the depression of the second sinker S2 relative to the first sinker S1 (i.e., the height of the first transition connection surface C1) is set according to the thickness of the seal 44. Among them, the depression depth of the second sinker S2 relative to the first sinker S1 can be equal to the thickness of the seal 44, so that the second sinker S2 can accommodate the seal 44. In a further embodiment, the depression depth of the second sinker S2 relative to the first sinker S1 can be slightly less than the thickness of the seal 44. In this case, when assembling the battery cell 20, the height of the space between the breathable membrane assembly 40 and the end cover 21 is slightly less than the thickness of the seal 44, so as to form an extrusion effect on the seal 44, or to make the seal 44 have an interference fit effect with the end cover 21 and the breathable membrane assembly 40. Through this setting, the interface between the seal 44 and the end cover 21, and the interface between the seal 44 and the breathable membrane assembly 40 can be made more tightly bonded, thereby improving the sealing performance. Among them, the seal 44 can be selected from a polymer material with a certain elasticity, which has a certain rebound tendency after being squeezed, further enhancing the bonding force between the interfaces.

[0156] In this embodiment, since the setting of the seal 44 can maintain the seal between the breathable membrane assembly 40 and the end cover 21, the connection between the breathable membrane assembly 40 and the end cover 21 only needs to provide sufficient strength to press the seal 44 without causing failure of the sealing interface of the seal 44, and the connection between the breathable membrane assembly 40 and the end cover 21 itself no longer needs to assume the sealing function.

[0157] According to some embodiments of the present application, the breathable membrane assembly 40 is connected to the end cap 21 by a metal member 42. The metal member 42 and the end cap 21 may be welded. At this time, the precision requirement for the welding process may be relatively low, as long as the connection strength between the metal member 42 and the end cap 21 is able to press the sealing interface of the seal 44 without failure.

[0158] The first sink S1 includes a bearing surface S11 parallel to the surface of the end cover 21 and a connecting surface S12 perpendicular to the bearing surface S11. The metal member 42 is a metal sheet with a certain thickness and can be connected to the end cover 21 by using the side surface of the metal sheet. Figure 7 The W1 position shown in the figure is the welding position of the two. By providing the sealing member 44, the sealing requirement for the weld W1 can be reduced.

[0159] According to some embodiments of the present application, the metal member 42 may also be interference fit with the end cover 21. Specifically, the first sinker S1 is an annular sinker, and the annular side wall of the annular sinker is surrounded to form a receiving space, and the metal member 42 may be inserted into the space of the first sinker S1, so that the side of the metal member 42 is interference fit with the connecting surface S12 of the first sinker S1 to achieve the connection effect.

[0160] Please continue to refer to Figure 8 , Fig. 9 , Fig.10 and Fig.11 The second sinking platform includes a platform surface S22, and a first boss 211 protruding from the platform surface S22 is further provided on the second sinking platform S2, and the first boss 211 is spaced apart from the breathable membrane 41. The risk of damaging the membrane can be reduced by spacing.

[0161] In some embodiments, the height of the first boss 211 is less than the height of the first transition connection surface C1. The arrangement of the first boss 211 can effectively position the seal 44. By controlling the height of the first boss 211 to be less than the height of the first transition connection surface C1, the first boss 211 can prevent the breathable membrane assembly 40 from being touched while positioning the seal 44, thereby preventing damage to the breathable membrane assembly 40.

[0162] According to some embodiments of the present application, Fig. 9 As shown, the first boss 211 is an annular boss surrounding the first exhaust hole 291. It can effectively prevent the seal 44 from shifting and achieve a positioning effect. In other embodiments, the first boss 211 can also be a plurality of non-continuous bosses, and the plurality of first bosses 211 are arranged at intervals in the circumferential direction of the first exhaust hole 291.

[0163] Please refer to Fig.12 and Fig.13 , Fig.12 is a schematic diagram of a partial exploded structure of a battery cell 20 according to one or more embodiments. Fig.13 The schematic diagram of the partial cross-sectional structure of the battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the battery cell 20 further includes a shielding member 50, which is mounted on the end cover 21, and is located on the side of the end cover 21 facing the outside of the housing, and shields the breathable membrane assembly 40.

[0164] In this embodiment, the breathable membrane assembly 40 is arranged on the side of the end cover 21 facing the inside of the shell, and the shielding member 50 can shield the breathable membrane assembly 40. The shielding member 50 can provide certain protection and shielding for the breathable membrane assembly 40. On the one hand, it can reduce the wear or damage of the breathable membrane assembly 40 in the external environment, and can reduce the risk of impurities or particulate matter in the external environment entering the breathable membrane assembly 40, which is beneficial to improving the service life of the breathable membrane assembly 40. On the other hand, covering the breathable membrane assembly 40 by the shielding member 50 can enhance the aesthetics of the outer surface 21a of the battery cell 20. On the other hand, it is convenient to connect other components such as detection elements on the side of the shielding member 50 away from the breathable membrane assembly 40, so as to reduce the interference of the area of ​​the end cover 21 where the breathable membrane assembly 40 is set on the connection detection elements and other components.

[0165] Please refer to Fig.10 , Fig.11 , Fig.12 and Fig.13 According to some embodiments of the present application, the end cover 21 includes an outer surface 21a and an inner surface 21b arranged opposite to each other, 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 sinker S1 and a fourth sinker S4 recessed relative to the outer surface 21a of the end cover 21, the fourth sinker S4 is arranged around the first sinker S1, and the fourth sinker S4 is closer to the outer surface 21a of the end cover 21 relative to the first sinker S1, the breathable membrane assembly 40 is at least partially arranged on the first sinker S1, and the shielding member 50 is at least partially arranged on the fourth sinker S4.

[0166] The depth of the fourth depression S4 relative to the outer surface 21a of the end cover 21 can be set according to the thickness of the shielding member 50. So that the shielding member 50 is accommodated in the fourth depression S4, and the surface of the shielding member 50 is flush with the outer surface 21a of the end cover 21. In this way, on the one hand, the space occupied by the shielding member 50 and the end cover 21 in the thickness direction of the end cover 21 can be reduced, and the installation height of the shielding member 50 can be reduced, which is conducive to optimizing the volume of the battery cell 20. On the other hand, the fourth depression S4 can play a certain positioning and limiting role on the shielding member 50, which is conducive to reducing the difficulty of assembling the shielding member 50 connected to the end cover 21.

[0167] Please continue to refer to Fig.10 , Fig.11 , Fig.12 and Fig.13 According to some embodiments of the present application, the end cover 21 further has a fifth sinker S5 that is recessed relative to the outer surface 21a of the end cover 21, the fourth sinker S4 is arranged around the fifth sinker S5, and the fifth sinker S5 is located between the first sinker S1 and the fourth sinker S4.

[0168] Specifically, the end cover 21 also has a fifth sinker S5 recessed relative to the outer surface 21a of the end cover 21, a third transition connection surface C3 and a fourth transition connection surface C4, the fourth sinker S4 is arranged around the fifth sinker S5, the fifth sinker S5 is arranged around the first sinker S1, the third transition connection surface C3 connects the fifth sinker S5 and the first sinker S1, the fourth transition connection surface C4 connects the fifth sinker S5 and the fourth sinker S4, and the fourth sinker S4 is closer to the outer surface 21a of the end cover 21 than the fifth sinker S5.

[0169] Specifically, the first sinker S1, the fourth sinker S4, and the fifth sinker S5 are formed by the outer surface 21a of the end cover 21 being recessed in the direction of the inner surface 21b of the end cover 21. The purpose of setting the first sinker S1 is to carry and accommodate the breathable membrane assembly 40, and its recess depth relative to the fifth sinker S5 (i.e., the height of the third transition connection surface C3) can be set according to the thickness of the breathable membrane assembly 40 to accommodate the breathable membrane assembly 40. The purpose of setting the fourth sinker S4 is to carry and accommodate the shielding member 50, and its recess depth relative to the outer surface 21a of the end cover 21 can be set according to the thickness of the shielding member 50 to accommodate the shielding member 50. The purpose of setting the fifth sinker S5 is to form a certain cavity between the breathable membrane assembly 40 and the shielding member 50 so that the gas can be discharged smoothly. The recess depth of the fifth sinker S5 relative to the fourth sinker S4 (i.e., the height of the fourth transition connection surface C4) is set according to demand. At the same time, the fifth sinking platform S5 can also avoid the welding mark protrusion caused by the welding connection between the metal part 42 and the wall.

[0170] According to some embodiments of the present application, the shielding member 50 may be mounted on the end cover 21 by welding, interference fit, bolting, clamping or bonding. In order to smoothly exhaust gas, a gas exhaust channel needs to be reserved when the shielding member 50 is assembled with the end cover 21.

[0171] Please continue to refer to Fig.13 A first exhaust passage is formed between the shielding member 50 and the end cap 21, and the first exhaust passage connects the air outlet of the breathable membrane assembly 40 with the outside of the battery cell 20. The air outlet of the breathable membrane assembly 40 is a first air hole 491 provided on the connecting member in the breathable membrane assembly 40, or a first exhaust hole provided on the end cap 21, depending on the setting position of the breathable membrane assembly 40.

[0172] In one embodiment, the first exhaust channel includes a first exhaust gap 501 formed between the shielding member 50 and the side surface of the fourth sink S4, and the first exhaust gap 501 is used to connect the air outlet and the outside of the housing.

[0173] The first exhaust gap 501 is used to connect the air outlet and the outside of the shell. The first exhaust gap 501 can be directly connected to the air outlet. For example, at least part of the projection of the first exhaust gap 501 in the thickness direction X of the wall is located in the first exhaust hole, so that the air outlet of the breathable membrane assembly 40 arranged in the first exhaust hole can be directly connected to the first exhaust gap 501. Of course, the first exhaust gap 501 can also be indirectly connected to the air outlet. For example, the exhaust channel can also include a second exhaust gap, which is formed between the shielding member 50 and the bottom surface of the fourth sinker. The second exhaust gap connects the first exhaust gap 501 and the air outlet of the breathable membrane assembly 40.

[0174] By setting the first exhaust gap 501, the gas exhausted from the breathable membrane assembly 40 can be discharged to the outside of the shell through the first exhaust gap 501. The battery cell 20 using this structure does not need to have a hole on the shielding member 50, which helps to reduce the processing difficulty and improve the appearance of the battery cell 20.

[0175] In one embodiment, the side of the shielding member 50 abuts and is connected to the side of the fourth sinker S4, and a protrusion (or groove) may be provided on the side of the shielding member 50 to form a first exhaust gap 501 between the side of the shielding member 50 and the side of the fourth sinker.

[0176] In one embodiment, the first exhaust channel further includes a second exhaust gap (not shown), which is formed between the shielding member 50 and the bottom surface of the fourth sinker S4, and connects the first exhaust gap 501 and the air outlet.

[0177] The shielding member 50 has a second surface facing the end cover 21 , and a recessed groove may be provided on the second surface. A second exhaust gap is formed between a side surface of the shielding member 50 facing the end cover 21 and the bottom surface of the fourth sinking platform.

[0178] Please refer to Fig.17a and Fig.17b , Fig.17a Schematic diagram of the exploded structure of the battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the battery cell 20 further includes a protective patch 60, which is disposed on the side of the end cap 21 facing the outside of the housing. That is, the protective patch 60 is disposed on the outer surface 21a of the end cap 21 to provide a certain degree of protection for the end cap 21. The material of the protective patch 60 can be various, such as rubber, silicone or plastic.

[0179] According to some embodiments of the present application, the protective patch 60 is provided with an information collection hole 601 that penetrates the protective patch 60 , and the information collection hole 601 serves as a part of the exposed end cover 21 to facilitate setting an information code on the end cover 21 or connecting a detection element for sampling, etc.

[0180] According to some embodiments of the present application, in an embodiment where an electrode terminal 25 is provided on the end cap 21, see Fig.17a As shown, the protective patch 60 is provided with a first avoidance hole 602 at the position where the electrode terminal 25 is located, and the first avoidance hole 602 runs through both sides of the protective patch 60. The first avoidance hole 602 is used to allow the electrode terminal 25 to pass through to avoid the electrode terminal 25. Exemplarily, two electrode terminals 25 are provided on the end cover 21, and correspondingly, the protective patch 60 is provided with two first avoidance holes 602, each of which is used for one electrode terminal 25 to pass through.

[0181] In the embodiment where the pressure relief mechanism 70 is provided on the end cover 21, see Fig.17a As shown, a second avoidance hole 603 is provided at the position of the protective patch 60 corresponding to the pressure relief mechanism 70. The second avoidance hole 603 runs through both sides of the protective patch 60. The orthographic projection of the pressure relief mechanism 70 on the protective patch 60 is located in the second avoidance hole 603, so that the second avoidance hole 603 can avoid the pressure relief mechanism 70.

[0182] According to some embodiments of the present application, the breathable membrane assembly 40 can be disposed on the side of the end cap 21 facing the inside of the housing. In this case, the first exhaust hole 291 is exposed from the appearance of the end cap 21. Fig.17a The first exhaust hole 291-1 in Fig.17a The first exhaust hole 291-1 and the first exhaust hole 291-2 shown in the figure are to respectively show the difference between the end cap 21 in two cases where the breathable membrane assembly 40 is arranged on the side of the end cap 21 facing the inside of the shell and the breathable membrane assembly 40 is arranged on the side of the end cap 21 facing the outside of the shell. In the actual product, one of the breathable membrane assemblies 40 will be selectively arranged according to the position of the breathable membrane assembly 40. Of course, two breathable membrane assemblies 40 can also be arranged on the battery cell 20, and both can exist at the same time.) In this embodiment, the protective patch 60 can be directly used to cover the first exhaust hole 291. On the one hand, it can reduce the risk of impurities or particulate matter in the external environment entering the first exhaust hole 291 to prevent poor exhaust. On the other hand, it can keep the appearance of the end cap 21 unchanged, which is conducive to expanding the application to different products without affecting the appearance of the original product.

[0183] According to some embodiments of the present application, the breathable membrane assembly 40 may be disposed on a side of the end cap 21 facing the outside of the housing, and in this case, the shielding member 50 covering the breathable membrane assembly 40 is exposed from the appearance of the end cap 21 .

[0184] According to some embodiments of the present application, the orthographic projection of the information collection hole 601 on the end cover 21 is located inside the shielding member 50. That is, the information collection hole 601 is arranged corresponding to the shielding member 50, so that the exposed area of ​​the information collection hole 601 is the surface of the shielding member 50, so that the information code can be set on the shielding member 50 or the detection element for sampling can be connected.

[0185] According to some embodiments of the present application, the protective patch 60 may be disposed on the end cover 21 in various structures, and the protective patch 60 may be disposed on the end cover 21 by bonding, adsorption, or the like.

[0186] When the bonding method is used, the bonding layer 610 bonds the protective patch 60 and the end cover 21 , and the bonding layer 610 is provided with an avoidance groove 611 , and a second discharge channel is formed between the avoidance groove 611 and the end cover 21 , and the second discharge channel connects the first exhaust hole and the outside of the battery cell 20 .

[0187] Please refer to Fig.17b , Fig.17b 6 is a bottom view of the adhesive layer of the protective patch 60 according to one or more embodiments. The adhesive layer 610 is provided with an avoidance groove 611. In some embodiments, the orthographic projection of the air outlet on the protective patch 60 is located in the avoidance groove 611 area.

[0188] Please continue to refer to Fig.13 The end cover 21 includes an end cover 21 body 210, and the end cover 21 body 210 has an outer surface 21a and an inner surface 21b arranged opposite to each other, 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, and the end cover 21 has a wall boss 212 protruding relative to the inner surface 21b; the orthographic projection of the wall boss 212 on the end cover 21 body at least partially overlaps with the orthographic projection of the breathable membrane assembly 40 on the end cover 21 body.

[0189] In other words, from the thickness direction of the end cover 21, the wall boss 212 strengthens the thickness of the end cover 21 where the breathable membrane assembly 40 is located, which can increase the strength of the end cover 21 and compensate for the decrease in strength of the end cover 21 caused by the formation of the sink.

[0190] Please refer to Fig.14 , Fig.15 and Fig.16a , Fig.14 is a schematic diagram of a partial exploded structure of a battery cell 20 according to one or more embodiments. Fig.15 is a schematic diagram of a partial cross-sectional structure of an insulating member 24 according to one or more embodiments, Fig.16a 2 is a schematic diagram of a partial cross-sectional structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the battery cell 20 further includes an insulating member 24, which is disposed on the side of the end cap 21 facing the inside of the housing; that is, an insulating member 24 may also be disposed on the inner side of the end cap 21, and 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.

[0191] For example, the insulating member 24 may be made of plastic, rubber, etc.

[0192] The insulating member 24 includes a main body 242 , which is made of a material that will not contact the electrode assembly 23 inside the battery 100 to form a short circuit. The main body 242 is used to protect the end cap 21 from being directly exposed to the electrode assembly 23 in the height direction to avoid contact with the electrode assembly 23 to form a short circuit.

[0193] The insulating member 24 is provided with a second exhaust hole 292 penetrating the main body 242 of the insulating member 24, so that the gas inside the battery 100 enters the area of ​​the breathable membrane assembly 40 through the first exhaust hole 291. In some embodiments, the second exhaust hole 292 is connected to the first exhaust hole 291 to make the exhaust smoother.

[0194] Please continue to refer to Fig.14 , Fig.15 and Fig.16a According to some embodiments of the present application, the insulating member 24 is provided with a second boss 241 protruding from the main body 242, the second boss 241 is arranged around the second exhaust hole 292, and the second boss 241 extends toward the end cover 21 into the first exhaust hole 291. By arranging the second boss 241 to extend to the first exhaust hole 291 area of ​​the end cover 21, the side wall of the first exhaust hole 291 can be blocked outside the second boss 241 to achieve an insulation effect.

[0195] In one embodiment, the second boss 241 is spaced apart from the air-permeable membrane 41. The spaced apart arrangement can reduce the risk of damaging the membrane.

[0196] In some embodiments, the extension height of the second boss 241 is lower than the top of the first exhaust hole 291, that is, the second boss 241 can extend into the first exhaust hole 291, but will not penetrate beyond the area of ​​the first exhaust hole 291, so that the second boss 241 will not touch the breathable membrane assembly 40 to prevent damage to the breathable membrane assembly 40.

[0197] According to some embodiments of the present application, when the breathable membrane assembly 40 is arranged on the side of the end cover 21 facing the outside of the outer shell, the sink design on the end cover 21 will cause the end cover 21 to have a protruding area facing the inside of the outer shell. At this time, an accommodating portion that is recessed relative to the surface of the insulating member 24 can be provided on the main body 242 of the insulating member 24 to accommodate the protruding portion of the end cover 21.

[0198] See also Fig.16a The main body 242 of the insulating member 24 has an upper surface 242a, which is disposed toward the end cover 21. The main body 242 of the insulating member 24 has a sixth depression S6 that is recessed relative to the upper surface 242a, and the wall boss 212 is at least partially located on the sixth depression S6. With this arrangement, the wall boss 212 can be accommodated, the installation height can be reduced, and the occupation of the internal space of the housing can be reduced.

[0199] See also Fig.16b , Fig.16b Schematic diagram of a partial cross-sectional structure of a battery cell 20 according to one or more embodiments. The battery cell 20 further includes a transfer plate 26, the transfer plate 26 having a first surface 26a, the first surface 26a being arranged toward the insulating member 24, the transfer plate 26 having a seventh depression S7 recessed relative to the first surface 26a, the body portion 242 of the insulating member 24 having a body boss 2421 protruding relative to the lower surface of the body portion 242 of the insulating member 24, and the body boss 2421 being at least partially located at the seventh depression S7. Through this arrangement, the wall boss 212 can be accommodated, the installation height can be reduced, and the occupation of the internal space of the housing can be reduced.

[0200] In some examples, a portion of the lower surface of the adapter plate 26 that is opposite to the seventh sink S7 protrudes toward the inside of the battery cell 20 to enhance the strength of the adapter plate 26 .

[0201] According to some embodiments of the present application, see Figure 1 and Figure 2 As shown, the battery cell 20 further includes a pressure relief mechanism 70 , which is disposed on the housing and configured to be activated and release the internal pressure of the battery cell 20 when the battery cell 20 thermally runs away.

[0202] The pressure relief mechanism 70 is disposed on the housing, and may be disposed on the end cover 21 or on the housing 22. Figure 1 In the embodiment, the pressure relief mechanism 70 is disposed on the end cover 21 .

[0203] The pressure relief mechanism 70 is configured to actuate and release the internal pressure of the battery cell 20 when the battery cell 20 is in thermal runaway, that is, when thermal runaway occurs inside the battery cell 20, the pressure relief mechanism 70 can be actuated and opened to release the gas generated inside the battery cell 20 due to thermal runaway. It should be noted that when thermal runaway occurs in the battery cell 20, the gas inside the shell of the battery cell 20 will increase rapidly to open the pressure relief mechanism 70 for pressure relief, while the gas generated inside the shell of the battery cell 20 during normal use can be discharged through the breathable membrane assembly 40, but the pressure relief mechanism 70 cannot be opened.

[0204] Optionally, the pressure relief mechanism 70 and the housing can be an integral structure or a separate structure. If the pressure relief mechanism 70 and the housing are an integral structure, the pressure relief mechanism 70 is an area on the housing where a weak structure is provided, such as an area on the housing where a notch is provided; if the pressure relief mechanism 70 and the housing are a separate structure, the pressure relief mechanism 70 can be connected to the housing by welding, hot melting, injection molding, or bonding. For example, in Figure 2In the embodiment, the pressure relief mechanism 70 and the housing are separately arranged, and the pressure relief mechanism 70 is arranged on the end cover 21 of the housing. The pressure relief mechanism 70 can be a pressure relief component such as an explosion-proof valve, an explosion-proof disk, a pressure relief valve or a safety valve.

[0205] For example, in Figure 1 In the embodiment, the electrode terminal 25 and the pressure relief mechanism 70 are both arranged on the end cover 21. The battery cell 20 adopting this structure can save the space occupied by the battery cell 20. Of course, in other embodiments, the electrode terminal 25 and the pressure relief mechanism 70 can also be arranged on different walls of the outer shell. The battery cell 20 adopting this structure can make the electrode terminal 25 of the battery cell 20 used to output or input electrical energy and the pressure relief mechanism 70 used to release internal pressure stay away from each other to reduce the risk of using the battery cell 20. For example, the pressure relief mechanism 70 is arranged on the shell 22, and the electrode terminal 25 is arranged on the end cover 21.

[0206] By providing the breathable membrane assembly 40, when gas is generated inside the outer shell during normal use of the battery cell 20, it can be discharged to the outside of the outer shell through the breathable membrane assembly 40, so as to alleviate the phenomenon that the pressure relief mechanism 70 is prematurely actuated to relieve pressure before the thermal runaway of the battery cell 20 due to the increase of internal air pressure of the battery cell 20, thereby effectively improving the use stability of the battery cell 20, thereby improving the service life and use reliability of the battery cell 20.

[0207] In some embodiments, the breathable membrane assembly 40 and the pressure relief mechanism 70 may be disposed on the same wall of the housing. For example, the breathable membrane assembly 40 and the pressure relief mechanism 70 are both disposed on the end cap 21. The battery cell 20 using this structure is conducive to saving the space occupied by the battery cell 20, so as to improve the energy density of the battery cell 20.

[0208] In some embodiments, the breathable membrane assembly 40 and the pressure relief mechanism 70 may be disposed on different walls of the housing. For example, the breathable membrane assembly 40 is disposed on the housing 22, and the pressure relief mechanism 70 is disposed on the end cap 21. The battery cell 20 adopting such a structure can reduce the mutual influence between the breathable membrane assembly 40 and the pressure relief mechanism 70, and can be applied to different use environments.

[0209] In some embodiments, the breathable membrane assembly 40 is arranged on the wall at the top of the housing when the battery cell 20 is in the placed state. That is, no matter what working environment the battery cell 20 is in, when it is placed, the upward wall is the top wall; the breathable membrane assembly 40 is arranged on the top wall, on the one hand, it can not affect the stable placement of the battery 100, on the other hand, the exhaust channel is not easily covered by objects in the external environment, and the exhaust space is larger; furthermore, the gas generally has a low density, is relatively light, and tends to move upward, and the breathable membrane assembly 40 is arranged on the top wall, which is more conducive to smooth exhaust.

[0210] In some embodiments, the air permeability rate of the air permeable membrane 41 is 3-10 mL / day, 3-4 mL / day, 4-6 mL / day, 5-8 mL / day, 9-10 mL / day. The test method of the air permeability rate of the air permeable membrane 41 can be tested according to GB / T1038-2000.

[0211] By setting the air permeability rate of the air permeable membrane 41 to 3-10 mL / day, the phenomenon that the pressure relief mechanism 70 cannot be actuated and opened due to the excessive exhaust of the air permeable membrane assembly 40 can be alleviated when the battery cell 20 has thermal runaway, so that the pressure relief mechanism 70 can be actuated and stably discharge the internal pressure of the battery cell 20 when the battery cell 20 has thermal runaway, thereby helping to reduce the risk of fire and explosion of the battery cell 20 when the battery cell 20 has thermal runaway. At the same time, the air tightness of the system is also considered to prevent the exhaust rate from being too fast, resulting in poor air tightness, so that the air tightness of the battery 100 system can be maintained while the gas is discharged.

[0212] In some embodiments, the thickness of the breathable membrane 41 is 0.1-3.0 mm, and optionally, the thickness is 0.2-0.8 mm, such as 0.1 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, etc. The air permeability rate of the breathable membrane 41 can be adjusted.

[0213] In some embodiments, the battery cell 20 is an alkali metal battery 100, such as a sodium metal battery 100, a lithium metal battery 100, etc. The alkali metal battery 100 is used in conjunction with the breathable membrane assembly 40 to timely discharge the gas generated by the alkali metal battery 100 during normal operation, thereby increasing the service life of the alkali metal battery 100.

[0214] Among them, the electrode assembly 23 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 23, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode tab can be located at one end of the main body or at both ends of the main body respectively. During the charge and discharge process of the battery 100, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals 25 to form a current loop.

[0215] In one embodiment, the positive electrode plate includes a positive electrode current collector and a positive electrode active layer disposed on at least one side of the positive electrode current collector, and the positive electrode active layer includes a positive electrode active material.

[0216] As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode active layer may be disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0217] 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 and a metal layer formed on at least one surface of the polymer material base. 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.).

[0218] 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 the sodium battery 100, the polyanion compound includes a compound based on phosphoric acid and fluorophosphate. The phosphoric acid-based compound includes Nax1Fey1Pm1On1, for example, sodium iron phosphate with a higher capacity and sodium iron pyrophosphate with a higher voltage platform. The polyanion compound includes one or more of sodium vanadium trifluorophosphate Na3V2(PO4)2F3, sodium vanadium fluorophosphate NaVPO4F, sodium vanadium phosphate Na3V2(PO4)3, Na4Fe3(PO4)2P2O7, NaFePO4, and Na3V2(PO4)3. The Prussian blue compound is NaxMM(CN)6, wherein M and M are one or more of Fe, Mn, Co, Ni, Cu, Zn, Cr, Ti, V, Zr, and Ce, and wherein 0<x≤2. The positive electrode active material in the lithium metal battery 100 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.

[0219] 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, and the negative electrode active layer includes a negative electrode active material. In this embodiment, the battery cell 20 is an ion battery 100, and during the charge and discharge process of the battery 100, active ions (such as Li+, Na+) are embedded / de-embedded in the negative electrode active material.

[0220] As an example, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode active layer may be disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0221] In one embodiment, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, a copper foil may be used. 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 substrate. 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 material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0222] 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, silicon oxide compounds (such as silicon monoxide), silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The selenium-based material may be selected from one or more of elemental selenium, selenium oxide compounds, and selenium alloys.

[0223] In one embodiment, the negative electrode plate includes a negative electrode current collector and a carbonaceous coating disposed on at least one surface of the negative electrode current collector. In this embodiment, the battery cell 20 is a metal battery 100, and during the charge and discharge process of the battery 100, active ions are deposited / stripped at the negative electrode plate. The metal battery 100 can be an alkali metal battery 100, such as a lithium metal battery 100, a sodium metal battery 100, a potassium metal battery 100, a zinc metal battery 100, and an aluminum metal battery 100. This type of battery 100 can also be referred to as a "negative electrode-free battery 100". During the charging process, sodium metal is formed by depositing active ions (such as Na+) released from the positive electrode active material onto the negative electrode current collector. The provision of a carbonaceous coating facilitates more uniform metal deposition. Carbonaceous materials include one or more of conductive carbon, graphite, hard carbon, and carbon nanotubes.

[0224] In other embodiments, a conductive film layer may also be deposited on the negative electrode current collector. For example, alloy materials, titanium-based materials, active metals (such as sodium metal), carbon-based materials deposited with metals, composite materials containing metals, alloy materials containing metals, etc. The above alloy materials include but are not limited to sodium-tin alloys, sodium-germanium alloys, and sodium-antimony alloys. The above titanium-based materials include but are not limited to titanium dioxide, titanates, and titanium phosphates.

[0225] In one embodiment, the positive electrode active layer and the negative electrode active layer may also include a binder and a conductive agent. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and 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.

[0226] In one embodiment, the isolation membrane can be any known porous structure isolation membrane with good chemical stability and mechanical stability.

[0227] In one embodiment, the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The isolation membrane can be a single-layer film or a multi-layer composite film, without particular limitation. When the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0228] The electrolyte conducts ions between the positive electrode and the negative electrode. The electrolyte can be liquid, gel or all-solid.

[0229] 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.

[0230] In one embodiment, in the sodium battery 100, the electrolyte salt includes sodium hexafluorophosphate (NaPF6), sodium bis(fluorosulfonyl)imide (NaFSI), sodium trifluoromethanesulfonate (CF3NaO3S), sodium sulfide (Na2S) and other sodium salts. The lithium battery 100 includes at least one lithium salt selected from lithium perchlorate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium difluorooxalatoborate, lithium tetrafluoroborate and lithium trifluoromethanesulfonate.

[0231] In one embodiment, the solvent includes one or more solvents selected from chain ethers, ethylene glycol dimethyl ether and its derivatives, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclic ethers, 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, methyl trifluoroethyl carbonate (FEMC), dioxolane (DOL), acetonitrile (AN), fluorobenzene, triethyl phosphate (TEP), sulfolane, 2-methyltetrahydrofuran, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylacetamide, etc.

[0232] 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 may also include additives capable of improving certain properties of the battery 100, such as additives that improve the overcharge performance of the battery 100, additives that improve the high temperature or low temperature performance of the battery 100, and the like.

[0233] According to some embodiments of the present application, the present application further provides a battery 100, the battery 100 comprising a battery cell 20 of any of the above solutions. Fig.18 , Fig.18 1 is a schematic diagram of the exploded structure of a battery 100 according to one or more embodiments. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is accommodated in the box 10. The box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 may be a hollow structure with one end open, the first part 11 may be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0234] 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 mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery 100 module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery 100 modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0235] Each battery cell 20 may be a secondary battery 100 or a primary battery 100; specific examples thereof include all types of primary batteries 100 or secondary batteries 100. For example, it may be a lithium battery 100, a sodium battery 100, a potassium battery 100, or other types of secondary batteries 100. The lithium secondary battery 100 may include a lithium metal secondary battery 100, a lithium ion secondary battery 100, a lithium polymer secondary battery 100, or a lithium ion polymer secondary battery 100. It may also be a lithium sulfur battery 100, a sodium ion battery 100, or a magnesium ion battery 100, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0236] In some embodiments, the battery 100 may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0237] According to some embodiments of the present application, the present application further provides an electric device, which includes a battery cell 20 of any of the above solutions, and the battery cell 20 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 20.

[0238] In some embodiments, the purpose of the electric equipment of the present application is not particularly limited, and it can be used for any electronic device known in the prior art. The battery 100 disclosed in the embodiment of the present application can be used for electric equipment using the battery 100 as a power source or various energy storage systems using the battery 100 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, notebook computers, pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted stereo headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini-discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, bicycles, ships, spacecraft, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large-scale household batteries 100 and lithium-ion capacitors, etc.

[0239] The electric device can select the battery cell 20, the battery module 100 or the battery pack according to its usage requirements.

[0240] Please refer to Fig.19 , Fig.19: is a schematic diagram of the structure of a vehicle 1000 according to one or more embodiments. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, the head or the tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for the starting, navigation and working power requirements of the vehicle 1000 during driving.

[0241] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve 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.

[0242] In the above embodiments, by providing the breathable membrane assembly 40, the battery cell 20 can discharge internal gas through the breathable membrane 41 in a sealed state, and the internal gas of the battery 100 shell can be discharged to the outside of the shell in time, so that the air pressure inside the battery 100 shell will not be too high, and the risk of the pressure relief mechanism 70 opening the valve in advance can be reduced, which can greatly improve the life of the battery 100. One or more breathable membrane assemblies 40 can be provided on a battery cell 20, and the location and manner of each breathable membrane assembly 40 can be different, for example, one breathable membrane assembly 40 is provided on the side of the end cap 21 facing the inside of the battery 100 shell, and one breathable membrane assembly 40 is provided on the side of the end cap 21 facing the outside of the battery 100 shell. One breathable membrane assembly 40 can be provided on the end cap 21, and the other breathable membrane assembly 40 can be provided on the shell 22.

[0243] The above are only implementation methods of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: The housing has a wall portion, the wall portion has a first exhaust hole, and the first exhaust hole communicates the interior of the housing with the exterior of the housing; A breathable membrane assembly is arranged on the wall portion, the breathable membrane assembly includes a breathable membrane, a connecting member and a backing member, the breathable membrane assembly covers the first exhaust hole, the connecting member is provided with a first air hole, the breathable membrane is arranged on the connecting member, the breathable membrane covers the first air hole, the backing member is arranged between the breathable membrane and the connecting member, and the air permeability rate of the backing member is greater than the air permeability rate of the breathable membrane.

2. The battery cell according to claim 1, characterized in that: The battery cell further includes a sealing member disposed between the breathable membrane assembly and the wall portion.

3. The battery cell according to claim 2, characterized in that: The sealing member is arranged between the air permeable membrane and the wall portion.

4. The battery cell according to claim 2 or 3, characterized in that: The sealing member is arranged around the first exhaust hole, the sealing member is provided with a second air-permeable hole, the aperture of the second air-permeable hole is larger than the aperture of the first exhaust hole, and the air-permeable membrane covers the second air-permeable hole.

5. The battery cell according to claim 2 or 3, characterized in that: The breathable membrane is arranged between the connecting member and the sealing member.

6. The battery cell according to claim 2 or 3, characterized in that: The wall portion has a first sinker and a second sinker which are recessed relative to the surface of the wall portion. The first sinker is arranged around the second sinker. The first sinker is closer to the surface of the wall portion than the second sinker. The second sinker is arranged around the first exhaust hole. At least a portion of the seal is located on the second sinker, and at least a portion of the breathable membrane assembly is located on the first sinker.

7. The battery cell according to claim 6, characterized in that: The second sinking platform comprises a platform surface, and a first boss protruding from the platform surface is further arranged on the second sinking platform, and the first boss is spaced apart from the breathable membrane.

8. The battery cell according to claim 7, characterized in that: The first boss is an annular boss surrounding the first exhaust hole; or There are a plurality of first bosses, and the plurality of first bosses are arranged at intervals in the circumferential direction of the first exhaust hole.

9. The battery cell according to claim 5, characterized in that: The connecting member is connected to the wall portion by welding; or The connecting piece is interference fit with the wall portion.

10. The battery cell according to claim 1, characterized in that: The wall portion has a first sunken platform that is recessed relative to the surface of the wall portion. The first sunken platform is arranged around the first exhaust hole, and at least a portion of the breathable membrane assembly is located on the first sunken platform.

11. The battery cell according to claim 10, characterized in that: 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, and the wall portion has a first depression that is recessed relative to the inner surface of the wall portion.

12. The battery cell according to claim 11, characterized in that: The wall portion also has a third sinker recessed relative to the inner surface of the wall portion, the first sinker is arranged around the third sinker, the first sinker is closer to the inner surface than the third sinker, and the third sinker is arranged around the first exhaust hole.

13. The battery cell according to claim 11 or 12, characterized in that: The connecting member is arranged on the first sinking platform, and the connecting member is provided with a first air hole; The breathable membrane is disposed on a side of the connecting member facing the interior of the housing, and the breathable membrane covers the first breathable hole; or The breathable membrane is arranged on a side of the connecting member facing the wall portion, and the breathable membrane covers the first breathable hole.

14. The battery cell according to claim 13, characterized in that: The orthographic projection of the first air hole on the wall portion does not overlap with the area where the first exhaust hole is located.

15. The battery cell according to any one of claims 1 to 3, characterized in that: The breathable membrane assembly is arranged on a side of the wall portion facing the interior of the shell.

16. The battery cell according to any one of claims 1 to 3, characterized in that: The breathable membrane assembly is arranged on a side of the wall portion facing the outside of the shell.

17. The battery cell according to claim 16, characterized in that: The wall portion has an outer surface and an inner surface arranged in opposite directions, 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 has a first sinking platform recessed relative to the outer surface, and the breathable membrane assembly is at least partially located in the first sinking platform.

18. The battery cell according to claim 17, characterized in that: The connecting member is arranged on the first sinking platform, and is provided with a first air hole; the air-permeable membrane is arranged on a side of the connecting member facing the wall portion, and the air-permeable membrane covers the first air hole.

19. The battery cell according to claim 16, characterized in that: The wall portion includes a wall body, which has an outer surface and an inner surface arranged opposite to each other, the outer surface is arranged toward the outside of the outer shell, and the inner surface is arranged toward the inside of the outer shell, and the wall portion has a wall boss protruding relative to the inner surface; the orthographic projection of the wall boss on the wall body at least partially overlaps with the orthographic projection of the breathable membrane assembly on the wall body.

20. The battery cell according to claim 16, characterized in that: The battery cell further comprises: The insulating member is arranged on a side of the wall portion facing the interior of the shell; the insulating member is provided with a second exhaust hole penetrating the insulating member, and the second exhaust hole is communicated with the first exhaust hole.

21. The battery cell according to claim 20, characterized in that: The insulating member is provided with a second boss protruding from the insulating member, the second boss is arranged around the second exhaust hole, and the second boss extends toward the wall portion into the first exhaust hole.

22. The battery cell according to claim 21, characterized in that: The second boss is spaced apart from the breathable membrane.

23. The battery cell according to claim 20, characterized in that: The insulating member has an upper surface, which is arranged toward the wall portion. The insulating member has a sixth sink relative to the upper surface. The wall portion has a wall boss protruding relative to the inner surface of the wall portion. The wall boss is at least partially located on the sixth sink.

24. The battery cell according to claim 16, characterized in that: The battery cell further comprises: The adapter plate has a first surface, the first surface is arranged toward the insulating member, the adapter plate has a seventh sink relative to the first surface, the insulating member has a main body boss protruding relative to the lower surface of the insulating member, and the main body boss is at least partially located on the seventh sink.

25. The battery cell according to claim 17, characterized in that: The battery cell further comprises: A shielding member is installed on the wall portion, the shielding member is located on the side of the wall portion facing the outside of the shell, and shields the breathable membrane assembly; wherein a first discharge channel is formed between the shielding member and the wall portion, and the first discharge channel connects the air outlet of the breathable membrane assembly with the outside of the battery cell.

26. The battery cell according to claim 25, characterized in that: The wall portion has a fourth sinker which is recessed relative to the outer surface of the wall portion. The fourth sinker is arranged around the first sinker and is closer to the outer surface than the first sinker. The breathable membrane assembly is at least partially arranged on the first sinker, and the shielding member is at least partially arranged on the fourth sinker.

27. The battery cell according to claim 26, characterized in that: The wall portion further has a fifth sunken platform recessed relative to the outer surface, the fourth sunken platform is arranged around the fifth sunken platform, and the fifth sunken platform is located between the fourth sunken platform and the first sunken platform.

28. The battery cell according to claim 26, characterized in that: The first exhaust passage includes a first exhaust gap formed between the shielding member and a side surface of the fourth sinker, and the first exhaust gap is used to connect the air outlet and the outside of the shell.

29. The battery cell according to claim 28, characterized in that: The first exhaust channel further includes a second exhaust gap, which is formed between the shielding member and the bottom surface of the fourth sinker, and the second exhaust gap communicates with the first exhaust gap and the air outlet.

30. The battery cell according to claim 25, characterized in that The battery cell further comprises: A protective patch is arranged on a side of the wall portion facing the outside of the shell, and the protective patch covers the shielding member.

31. The battery cell according to claim 30, characterized in that: The protection patch is provided with an information collection hole penetrating the protection patch, and the orthographic projection of the information collection hole on the wall portion is located within the shielding member.

32. The battery cell according to claim 1, characterized in that The battery cell further comprises: A protective patch is arranged on a side of the wall portion facing the outside of the shell, and the protective patch covers the first exhaust hole.

33. The battery cell according to claim 30, characterized in that An adhesive layer is provided on the side of the protective patch facing the wall portion, the adhesive layer bonds the protective patch and the wall portion, the adhesive layer is provided with an avoidance groove, a second exhaust channel is formed between the avoidance groove and the wall portion, and the second exhaust channel connects the first exhaust hole and the outside of the battery cell.

34. The battery cell according to claim 1, characterized in that The connecting member has a first annular table surface which is recessed relative to the surface of the connecting member. The first annular table surface is arranged around the first air permeable hole, and the air permeable membrane is arranged on the first annular table surface.

35. The battery cell according to claim 1, characterized in that The connecting member further comprises a second annular table surface which is recessed relative to the surface of the connecting member, the second annular table surface is arranged around the first air vent, and the backing member is at least partially arranged on the second annular table surface; The area of ​​the groove where the second annular table is located is 30mm 2 -250mm 2 .

36. The battery cell according to claim 1, characterized in that The connecting member further comprises a second annular table surface which is recessed relative to the surface of the connecting member, the second annular table surface is arranged around the first air vent, and the backing member is at least partially arranged on the second annular table surface; The area of ​​the groove where the second annular table is located is 60mm 2 -200mm 2 .

37. The battery cell according to claim 1, characterized in that The first air-permeable holes include a plurality of circular through holes, and the diameter of the circular through holes is less than 3.0 mm.

38. The battery cell according to claim 1, characterized in that The connecting piece is a metal piece.

39. The battery cell according to claim 1, characterized in that: The thickness of the breathable membrane is 0.1-3.0 mm.

40. The battery cell according to claim 1, characterized in that The thickness of the breathable membrane is 0.2-0.8 mm.

41. The battery cell according to claim 1, characterized in that The air permeability rate of the air permeable membrane is 3-10 mL / day.

42. The battery cell according to claim 1, characterized in that The air permeability rate of the breathable membrane is 4-6 mL / day.

43. The battery cell according to claim 1, characterized in that The housing comprises: A housing having an opening formed therein, wherein the housing is used to accommodate the electrode assembly; an end cap for closing the opening; Wherein, the end cover is the wall portion; or The housing includes the wall portion; or The wall portion is a wall located at the top of the housing when the battery cell is in a placed state.

44. The battery cell according to claim 1, characterized in that A pressure relief mechanism is provided on the housing, and is configured to be activated and release the internal pressure of the battery cell when the battery cell thermally runs away.

45. A battery, characterized in that: Comprising a battery cell as described in any one of claims 1-44.

46. ​​An electrical device, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 44, wherein the battery cell is used to provide electrical energy.

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