Battery cell, battery, and electrical device

Abstract

The present application discloses a battery cell, a battery, and an electrical device. The battery cell comprises a casing and a gas discharge assembly; the casing is provided with a wall portion; the gas discharge assembly is arranged on the wall portion and comprises a one-way valve and a gas-permeable film assembly; the gas discharge assembly is used for discharging gas inside the casing. By means of the arrangement, the gas inside the casing can be discharged out of the casing in time, so that the gas pressure of the interior of the casing is not too high, thereby reducing the risk that the valve of a pressure relief mechanism is opened in advance, and greatly prolonging the service life of the battery cell.

Description

Battery cells, batteries and electrical equipment 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, as one of the areas of sustainable development, is developing rapidly. Batteries are being used more and more widely as a new energy source, and there are high requirements for their reliability and service life. During the charging and discharging process of the battery, 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 and release the pressure in advance during use, resulting in poor stability 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 this application and do not necessarily constitute prior art.

[0003] Summary of the Invention

[0004] The main technical problem solved by this application is to provide a battery cell, a battery, and an electrical device that can promptly discharge the gas inside the battery casing to the outside of the casing, so that the air pressure inside the battery casing is not too high, and the risk of the pressure relief mechanism opening the valve prematurely is reduced, which can significantly increase the life of the battery cell. In order to solve the above technical problems, a technical solution adopted by this application is: to provide a battery cell, the battery cell includes a casing and an exhaust assembly, the casing has a wall portion, the exhaust assembly is arranged on the wall portion, the exhaust assembly includes a one-way valve and a breathable membrane assembly, the breathable membrane assembly includes a breathable membrane, and the exhaust assembly is used to discharge the gas inside the casing. Through this arrangement, the gas inside the casing can be promptly discharged to the outside of the casing, so that the air pressure inside the casing is not too high, and the risk of the pressure relief mechanism opening the valve prematurely is reduced, which can significantly increase the life of the battery cell.

[0005] In one embodiment, the one-way valve includes a valve body and a valve core. The valve body defines a valve cavity. The valve body is provided with an air inlet and an air outlet. The air inlet connects the valve cavity with the interior of the housing, while the air outlet connects the valve cavity with the exterior of the housing. The valve core is disposed within the valve cavity and blocks the air inlet passage of the valve cavity. The valve core is configured to open the air inlet passage in response to gas inside the housing, thereby releasing gas from the battery cell. This method allows for the discharge of gas from the housing while reducing the ingress of external moisture into the housing.

[0006] In one embodiment, the wall portion has a first vent hole that connects the interior of the housing with the exterior. The vent assembly is configured so that gas exhausted through the first vent hole flows through the one-way valve and the breathable membrane assembly. In this manner, the breathable membrane can prevent electrolyte overflow and the ingress of external moisture, while the one-way valve can be used to regulate intermittent venting of the battery cells, thereby maintaining the tightness of the housing.

[0007] In one embodiment, the breathable membrane of the breathable membrane assembly is positioned closer to the interior of the housing than the one-way valve along the thickness of the wall. This allows gas from the housing to be discharged first through the breathable membrane and then through the one-way valve, preventing electrolyte from entering the one-way valve and reducing the risk of electrolyte corrosion of the valve core of the one-way valve.

[0008] In one embodiment, the breathable membrane is disposed on the side of the air inlet of the valve cavity of the one-way valve. In this way, the breathable membrane can be used to prevent the electrolyte from entering the valve cavity of the one-way valve, and facilitate the assembly of the exhaust component.

[0009] In one embodiment, the breathable membrane is arranged on the side of the air inlet of the valve cavity of the one-way valve where air is discharged. In this way, the breathable membrane can be used to prevent the electrolyte from entering the valve cavity of the one-way valve.

[0010] In one embodiment, the breathable membrane is arranged on the air inlet side of the valve cavity of the one-way valve. In this way, the opening time of the one-way valve can be shortened, which is beneficial to maintaining the sealing of the housing.

[0011] In one embodiment, the breathable membrane is arranged on the side of the valve cavity of the one-way valve where the gas is discharged. In this way, the assembly of the exhaust component can be facilitated.

[0012] In one embodiment, the wall portion has an outer surface and an inner surface disposed in opposite directions, with the outer surface facing the exterior of the housing and the inner surface facing the interior of the housing. The one-way valve is disposed on the outer surface of the wall portion, with at least a portion of the valve body of the one-way valve protruding from the outer surface of the wall portion. The breathable membrane assembly is at least partially disposed on the outer surface. In this manner, the space occupied by the exhaust assembly within the housing can be reduced.

[0013] In one embodiment, the wall portion has an outer surface and an inner surface disposed in opposite directions, with the outer surface facing the exterior of the housing and the inner surface facing the interior of the housing. The one-way valve is disposed on the outer surface of the wall portion, with at least a portion of the valve body of the one-way valve protruding from the inner surface of the wall portion. The breathable membrane assembly is disposed on the portion of the valve body protruding from the inner surface. In this manner, when the one-way valve is open, the environment is within the interior of the housing, which helps maintain the sealing properties of the housing.

[0014] In one embodiment, the wall portion has an outer surface and an inner surface disposed opposite each other, with the outer surface facing the exterior of the housing and the inner surface facing the interior of the housing. The one-way valve is disposed on the outer surface of the wall portion, with at least a portion of the valve body of the one-way valve protruding from the outer surface of the wall portion. The breathable membrane assembly is at least partially disposed on the inner surface of the wall portion. This facilitates assembly of the exhaust assembly.

[0015] In one embodiment, the wall portion has an outer surface and an inner surface disposed in opposite directions, with the outer surface facing the exterior of the housing and the inner surface facing the interior of the housing. The one-way valve is disposed on the outer surface of the wall portion, with the valve body of the one-way valve facing the interior of the housing and at least a portion of the valve body protruding from the inner surface of the wall portion. The breathable membrane assembly is disposed on the side of the one-way valve facing the exterior of the housing. This facilitates assembly of the exhaust assembly.

[0016] In one embodiment, the breathable membrane assembly is connected to the one-way valve, and the one-way valve is connected to the wall. In this way, the assembly of the exhaust assembly can be facilitated.

[0017] In one embodiment, the one-way valve is connected to the breathable membrane assembly, and the breathable membrane assembly is connected to the wall. In this way, the assembly of the exhaust assembly can be facilitated.

[0018] In one embodiment, the breathable membrane assembly and the one-way valve are independently connected to the wall portion, thereby facilitating assembly of the exhaust assembly.

[0019] In one embodiment, the valve body includes a valve seat and a valve cover. The valve cover includes a cover top wall and a cover side wall connected to the cover top wall. The cover top wall, the cover side wall, and the valve seat enclose a valve cavity. The valve seat is provided with an air inlet for the valve cavity, and the valve cover is provided with an air outlet for the valve cavity. This facilitates the discharge of gas.

[0020] In one embodiment, the valve seat has a first through hole penetrating the valve seat, and the air inlet is the first through hole. In this way, the discharge of gas is facilitated.

[0021] In one embodiment, the cover sidewall has a second through hole penetrating the cover sidewall, and the gas outlet is the second through hole. In this way, the gas is easily discharged.

[0022] In one embodiment, the second through hole extends to the end of the cover side wall in a direction away from the cover top wall; in this way, the discharge of gas is facilitated.

[0023] In one embodiment, there are multiple second through holes, and the multiple second through holes are spaced apart in the circumferential direction of the side wall, thereby facilitating the discharge of gas.

[0024] In one embodiment, a first guide post is protruded from the side of the cover top wall facing the valve seat, and a third through hole is formed on the cover top wall, penetrating the cover top wall and the first guide post. The gas outlet is the third through hole. In this way, the gas is discharged more easily.

[0025] In one embodiment, the valve cover further comprises a flange wall, the cover side wall connects the cover top wall and the flange wall, the flange wall extends relative to the cover side wall toward a side away from the valve cavity, and the flange wall is connected to the valve seat. In this way, the assembly of the one-way valve is facilitated.

[0026] In one embodiment, a first recessed groove is provided on the side of the valve seat facing the valve cover, which is recessed relative to the surface of the valve seat. At least a portion of the flange wall is accommodated in the first recessed groove and connected to the valve seat. In this way, the installation height of the one-way valve can be reduced.

[0027] In one embodiment, the surface of the flange facing the top wall of the cover is flush with the surface of the valve seat facing the valve cover; or the surface of the flange facing the top wall of the cover is lower than the surface of the valve seat facing the valve cover. In this way, the connection strength can be improved while reducing the installation height of the one-way valve.

[0028] In one embodiment, the flange wall is welded to the valve seat; wherein, along the circumference of the cover sidewall, at least a portion of the first weld mark between the flange wall and the valve seat is offset from the second through hole in the cover sidewall. This reduces damage to the valve core component caused by high temperatures during the welding process.

[0029] In one embodiment, a connecting protrusion is provided on the outer circumference of the valve seat, and a receiving groove is provided on the inner circumference of the flange wall. The connecting protrusion is received in the receiving groove and connected to the flange wall. In this way, the connection strength can be improved while reducing the installation height of the one-way valve.

[0030] In one embodiment, the connecting protrusion is welded to the flange wall, wherein the flange wall has an upper surface and a lower surface disposed opposite each other, with the upper surface facing the top wall of the cover, and a second weld mark formed by welding the connecting protrusion to the flange wall is located on the lower surface of the flange wall. This method can reduce damage to the valve core component caused by high temperatures during the welding process.

[0031] In one embodiment, the wall portion is provided with a first vent hole, which includes a through-hole segment and a first hole segment. The through-hole segment and the first hole segment are arranged along the thickness direction of the wall portion. The through-hole segment connects the interior of the housing with the exterior of the housing. The first hole segment is located on the side of the through-hole segment facing away from the interior of the housing. The aperture of the first hole segment is larger than the aperture of the through-hole segment. The one-way valve is at least partially accommodated in the first hole segment. The valve body of the one-way valve faces the exterior of the housing, and at least a portion of the valve body protrudes from the outer surface of the wall portion. This facilitates assembly of the one-way valve.

[0032] In one embodiment, a breathable membrane assembly is disposed on a side of the wall portion facing the interior of the housing. The breathable membrane assembly includes a breathable membrane and a connector. The connector is provided with a first breathable hole. The breathable membrane is disposed on the connector and covers the first breathable hole. The connector is connected to the wall portion. This improves the connection strength.

[0033] In one embodiment, the wall portion has an outer surface and an inner surface disposed in opposite directions, with the outer surface facing the exterior of the housing and the inner surface facing the interior of the housing. The wall portion has a first recessed portion that is recessed relative to the inner surface. The first recessed portion is disposed around the through-hole section of the first vent, and the breathable membrane assembly is at least partially accommodated within the first recessed portion. In this manner, the space occupied by the breathable membrane assembly within the housing can be reduced.

[0034] In one embodiment, the wall further comprises a second recessed portion that is recessed relative to the inner surface. The first recessed portion is closer to the inner surface of the wall than the second recessed portion. The first recessed portion is disposed around the second recessed portion, and the second recessed portion is disposed around the through-hole section of the first vent. The connector is at least partially accommodated within the first recessed portion, and the breathable membrane is disposed on a side of the connector away from the wall. This facilitates gas discharge.

[0035] In one embodiment, the breathable membrane is arranged on a side of the connector away from the wall, thereby preventing the electrolyte from entering the connector area.

[0036] In one embodiment, the breathable membrane is arranged on a side of the connecting member close to the wall, thereby facilitating the discharge of gas.

[0037] In one embodiment, the orthographic projection of the first air hole on the wall is located in the region where the through hole section of the first exhaust hole is located. In this way, the exhaust of gas is facilitated.

[0038] In one embodiment, the orthographic projection of the first air hole on the wall does not overlap with the area where the through hole section of the first exhaust hole is located. In this way, the exhaust of gas is facilitated.

[0039] In one embodiment, the wall portion further comprises a third recessed portion that is recessed relative to the inner surface, the third recessed portion being closer to the inner surface of the wall portion than the first recessed portion, and the third recessed portion being disposed around the first recessed portion.

[0040] In one embodiment, the breathable membrane assembly is at least partially disposed on the outer surface of the wall portion, at least partially accommodated within the first vent, and located on the side of the one-way valve facing the wall portion. In this manner, the breathable membrane can be used to prevent electrolyte from entering the valve cavity of the one-way valve.

[0041] In one embodiment, the first vent further includes a second hole segment. The second hole segment is located between the through-hole segment and the first hole segment along the thickness direction of the wall portion. The second hole segment has a smaller aperture than the first hole segment and a larger aperture than the through-hole segment. The breathable membrane assembly is at least partially accommodated in the second hole segment. This facilitates assembly of the vent assembly.

[0042] In one embodiment, the breathable membrane assembly includes a breathable membrane and a connector, wherein the connector is provided with a first breathable hole, the breathable membrane is provided on the connector and covers the first breathable hole, and the connector is welded to the wall portion. In this way, the connection strength can be improved.

[0043] In one embodiment, a stress relief groove is provided around the weld mark between the connector and the wall portion, thereby improving the stability of the connection.

[0044] In one embodiment, a third stress relief groove is provided on the connector around the fifth weld mark between the connector and the wall portion, and / or a second stress relief groove is provided on the wall portion around the fifth weld mark between the connector and the wall portion. In this manner, the stability of the connection can be improved.

[0045] In one embodiment, a weld mark avoidance groove is provided on the surface of the one-way valve facing the breathable membrane assembly, and the weld mark avoidance groove covers the weld mark between the connector and the wall. In this way, the assembly of the exhaust assembly can be facilitated.

[0046] In one embodiment, the breathable membrane assembly is disposed on the side of the one-way valve facing the wall, and the breathable membrane assembly is connected to the one-way valve, which is in turn connected to the wall. In this way, the assembly of the exhaust assembly can be facilitated.

[0047] In one embodiment, the breathable membrane assembly is arranged on the side of the valve seat facing the valve cavity, and the one-way valve is connected to the wall portion. In this way, the assembly of the exhaust assembly can be facilitated.

[0048] In one embodiment, the valve cover / valve seat of the one-way valve is welded to the wall portion, thereby increasing the connection strength.

[0049] In one embodiment, a stress relief groove is provided around the weld mark between the valve cover / valve seat and the wall, thereby improving the stability of the connection.

[0050] In one embodiment, a first stress relief groove is provided on the valve cover / valve seat around the third weld mark between the valve cover / valve seat and the wall; and / or a second stress relief groove is provided on the wall around the third weld mark between the valve cover / valve seat and the wall. This improves the stability of the connection.

[0051] In one embodiment, the breathable membrane assembly is at least partially disposed on the outer surface of the wall portion. The breathable membrane assembly includes a breathable membrane and a connector. The connector is provided with a first breathable hole. The breathable membrane is disposed on the connector and covers the first breathable hole. The connector is connected to the wall portion. A one-way valve is disposed on a side of the connector facing the exterior of the housing and is connected to the connector. This facilitates assembly of the exhaust assembly.

[0052] In one embodiment, the breathable membrane assembly includes a breathable membrane, which is arranged on the inner surface of the wall, connected to the wall, and covers the through-hole section of the first exhaust hole on the wall; in this way, the installation height of the exhaust assembly can be reduced, and the occupation of the internal space of the shell can be reduced.

[0053] In one embodiment, the breathable membrane assembly includes a breathable membrane disposed on the outer surface of the wall portion, the breathable membrane located on the side of the one-way valve facing the wall portion, the one-way valve covering the breathable membrane, and the breathable membrane and the wall portion / one-way valve being connected. In this manner, the installation height of the exhaust assembly can be reduced.

[0054] In one embodiment, the valve body includes a valve cover, which includes a cover top wall and a cover side wall connected to the cover top wall. The cover top wall, the cover side wall, and the wall portion enclose a valve cavity. The wall portion is provided with an air inlet for the valve cavity, and the cover side wall is provided with an air outlet for the valve cavity. In this manner, the discharge of gas is facilitated.

[0055] In one embodiment, a second recessed groove is provided on a side of the wall portion facing the exterior of the housing, recessed relative to the outer surface of the wall portion. The valve cover further comprises a flanged wall. The cover sidewall connects the cover top wall and the flanged wall. The flanged wall extends relative to the cover sidewall toward a side away from the valve cavity. At least a portion of the flanged wall is accommodated in the second recessed groove and connected to the wall portion. In this manner, the installation height of the one-way valve can be reduced.

[0056] In one embodiment, a breathable membrane assembly is disposed on the inner surface of the wall; the breathable membrane assembly includes a breathable membrane connected to the wall, and the breathable membrane covers the through-hole section of the first exhaust hole in the wall. In this manner, the installation height of the exhaust assembly can be reduced.

[0057] In one embodiment, the breathable membrane assembly includes a breathable membrane and a connector. The connector is provided with a first breathable hole. The breathable membrane is disposed on the connector and covers the first breathable hole. The breathable membrane is disposed on the inner or outer surface of the wall. The connector is connected to the wall and the one-way valve. This improves the connection strength.

[0058] In one embodiment, the valve body includes a valve seat and a valve cover. The valve seat includes a seat bottom wall and a seat side wall connected to the seat bottom wall. The valve cover is disposed at an end of the valve seat away from the seat bottom wall. The valve cover, the seat side wall, and the seat bottom wall enclose a valve cavity. The valve seat is provided with a fourth through hole, and the air inlet of the valve cavity is the fourth through hole. This facilitates the discharge of gas.

[0059] In one embodiment, the valve cover has a fifth through hole penetrating the valve cover, and the gas outlet of the valve cavity includes the fifth through hole. In this way, the discharge of gas is facilitated.

[0060] In one embodiment, the valve cover is connected to the valve seat, and the gas outlet includes a first exhaust gap formed between the valve cover and the valve seat. In this way, the exhaust of gas is facilitated.

[0061] In one embodiment, the valve cover is connected to the wall portion, and the gas outlet includes a second exhaust gap formed between the valve cover and the wall portion. In this way, the exhaust of gas is facilitated.

[0062] In one embodiment, the valve body includes a valve seat, which includes a seat bottom wall and a seat side wall connected to the seat bottom wall. The seat bottom wall, the seat side wall, and the wall portion enclose a valve cavity. The valve seat is provided with a fourth through hole, which serves as an air inlet for the valve cavity. The wall portion is provided with a first exhaust hole, which connects the valve cavity with the exterior of the housing. The air outlet of the valve cavity is the first exhaust hole. In this manner, the installation height of the one-way valve can be reduced.

[0063] In one embodiment, the breathable membrane assembly is disposed on a side of the seat bottom wall away from the valve cavity, wherein the breathable membrane assembly includes a breathable membrane connected to the seat bottom wall and covering the fourth through hole. In this manner, the installation height of the exhaust assembly can be reduced.

[0064] In one embodiment, a breathable membrane assembly is disposed on a side of the seat bottom wall away from the valve cavity. The breathable membrane assembly includes a breathable membrane and a connector. The connector is provided with a first breathable hole. The breathable membrane is disposed on the connector and covers the first breathable hole. The connector is connected to the seat bottom wall. This improves the connection strength.

[0065] In one embodiment, the seat bottom wall has an inner wall surface and an outer wall surface disposed opposite each other, with the inner wall surface facing the valve cavity. A fourth recessed platform is formed on the side of the seat bottom wall facing away from the valve cavity, and is recessed relative to the outer wall surface of the seat bottom wall. The fourth recessed platform surrounds the fourth through hole, and the breathable membrane assembly is at least partially accommodated within the fourth recessed platform. In this manner, the installation height of the exhaust assembly can be reduced.

[0066] In one embodiment, the base bottom wall further comprises a fifth recessed portion recessed relative to the outer wall surface, the fourth recessed portion being closer to the outer wall surface of the base bottom wall than the fifth recessed portion, the fourth recessed portion being disposed around the fifth recessed portion, the fifth recessed portion being disposed around the fourth through hole, the connector being at least partially accommodated within the fourth recessed portion, and the breathable membrane being disposed on the side of the connector facing the base bottom wall. This facilitates gas discharge.

[0067] In one embodiment, the breathable membrane is disposed on the side of the connector facing the valve cavity, or the breathable membrane is disposed on the side of the connector away from the valve cavity. In this way, the discharge of gas is facilitated.

[0068] In one embodiment, the breathable membrane assembly is disposed on the side of the seat bottom wall facing the valve cavity. The valve cavity comprises a first cavity and a second cavity that are interconnected, with the second cavity being closer to the seat bottom wall. Along a direction parallel to the seat bottom wall, the cross-sectional area of ​​the first cavity is greater than that of the second cavity. The valve core is located in the first cavity, and the breathable membrane assembly is located in the second cavity. This facilitates gas discharge.

[0069] In one embodiment, the seat sidewall includes a first sidewall portion, a second sidewall portion, and a third sidewall portion. The first and second sidewall portions enclose a first cavity, while the third sidewall portion and the seat bottom wall enclose a second cavity. The valve core's sealing member abuts the second sidewall portion. This facilitates gas discharge.

[0070] In one embodiment, the breathable membrane assembly includes a breathable membrane and a connector, wherein the connector is provided with a first breathable hole, the breathable membrane is disposed on the connector and covers the first breathable hole, and the connector is connected to the third sidewall portion. In this manner, assembly of the exhaust assembly is facilitated.

[0071] In one embodiment, a surface of the breathable membrane assembly facing the valve cavity is lower than a surface of the second side wall portion facing the valve cavity, thereby facilitating the discharge of gas.

[0072] In one embodiment, the breathable membrane is arranged on the side of the connecting member facing the bottom wall of the seat; or the breathable membrane is arranged on the side of the connecting member away from the bottom wall of the seat. In this way, the discharge of gas is facilitated.

[0073] In one embodiment, the battery cell further includes a sealing ring disposed between the breathable membrane assembly and the bottom wall of the base, thereby facilitating the maintenance of the sealing inside the housing.

[0074] In one embodiment, a sealing ring is disposed between the breathable membrane and the base bottom wall, surrounding the fourth through hole. The sealing ring is provided with a second breathable hole having a larger diameter than the fourth through hole, and the breathable membrane covers the second breathable hole. This facilitates maintaining a tight seal between the breathable membrane and the base bottom wall.

[0075] In one embodiment, the connecting member is welded to the third side wall portion, or the connecting member is interference fit with the third side wall portion, thereby facilitating assembly of the exhaust assembly.

[0076] In one embodiment, the breathable membrane is spaced apart from the valve core, thereby reducing the risk of the valve core causing damage to the breathable membrane.

[0077] In one embodiment, the breathable membrane assembly is disposed on the side of the one-way valve facing the outside of the housing, and the breathable membrane assembly covers the air outlet of the one-way valve. In this way, the assembly of the exhaust assembly is facilitated.

[0078] In one embodiment, the breathable membrane assembly includes a breathable membrane and a connector. The connector is provided with a first breathable hole. The breathable membrane is disposed on the connector and covers the first breathable hole. The connector is connected to the side of the wall portion / valve cover facing the exterior of the housing. This improves the connection strength.

[0079] In one embodiment, a first exhaust hole is provided on the wall portion, and the first exhaust hole includes a through hole section and a first hole section, and the through hole section and the first hole section are arranged along the thickness direction of the wall portion, and the through hole section connects the interior of the shell with the exterior of the shell, and the first hole section is located on the side of the through hole section away from the interior of the shell, and the aperture of the first hole section is larger than the aperture of the through hole section, and the first hole section is recessed relative to the outer surface, and the one-way valve is at least partially accommodated in the first hole section, and the valve body of the one-way valve faces the interior of the shell and at least part of the valve body protrudes from the inner surface of the wall portion; in this way, the assembly of the exhaust component can be facilitated.

[0080] In one embodiment, the valve seat of the one-way valve is welded to the wall portion, and a stress relief groove is provided around the weld mark between the valve seat and the wall portion, thereby improving the stability of the connection.

[0081] In one embodiment, the battery cell further includes a shielding member mounted on the wall portion, located on the side of the wall portion facing the exterior of the housing. The shielding member covers the one-way valve and the breather membrane assembly. A first exhaust passage is formed between the shielding member and the wall portion, connecting the exhaust port of the one-way valve with the exterior of the housing. In this manner, the one-way valve and the breather membrane assembly are protected.

[0082] In one embodiment, the wall portion has an outer surface and an inner surface disposed opposite to each other, the outer surface facing the exterior of the housing, and the inner surface facing the interior of the housing. The wall portion has a first vent hole, which connects the interior of the housing with the exterior of the housing. The one-way valve and the breathable membrane assembly are at least partially accommodated in the first vent hole. The wall portion has a sixth recessed platform recessed relative to the outer surface, surrounding the first vent hole and closer to the outer surface than the first vent hole. The shielding member is at least partially accommodated within the sixth recessed platform. In this manner, the installation height of the shielding member can be reduced.

[0083] In one embodiment, the first exhaust channel includes a third exhaust gap formed between the shielding member and the side surface of the sixth sink, and the third exhaust gap is used to connect the gas outlet and the outside of the housing. In this way, the exhaust of gas is facilitated.

[0084] In one embodiment, the first exhaust channel further includes a fourth exhaust gap formed between the shielding member and the bottom surface of the sixth sink, and the fourth exhaust gap connects the third exhaust gap and the gas outlet, thereby facilitating gas discharge.

[0085] In one embodiment, a shielding member covers the valve cover of the one-way valve, and a seventh recessed platform is provided on the side of the valve cover facing the shielding member. The seventh recessed platform is recessed relative to the surface of the valve cover. The seventh recessed platform is disposed around the fifth through hole in the valve cover and is connected to the first exhaust passage. This facilitates the discharge of gas.

[0086] In one embodiment, the valve core includes an elastic member and a blocking member. The elastic member is disposed within the valve cavity. The blocking member is movably disposed within the valve cavity. The blocking member is used to block the air inlet passage under the action of the elastic member and to open the air inlet passage under the action of gas within the housing. In this manner, gas discharge can be facilitated.

[0087] In one embodiment, the valve body includes a valve cover and a valve seat, which form a valve cavity. A first guide column is protruding from the side of the valve cover facing the sealing member, and part of the elastic member is sleeved on the outside of the first guide column; in this way, the positioning and guiding of the elastic member can be achieved.

[0088] In one embodiment, the diameter of the first guide post is D1, and the inner diameter of the elastic member is D2, satisfying 0 mm < D2 - D1 ≤ 5 mm. In this way, the assembly of the elastic member and the first guide post can be facilitated.

[0089] In one embodiment, a second guide post is protruded from the side of the blocking member facing the valve cover, and a portion of the elastic member is sleeved on the outer side of the second guide post. In this way, the elastic member can be positioned and guided.

[0090] In one embodiment, the diameter of the second guide post is D3, and the inner diameter of the elastic member is D2, satisfying 0mm<D3-D1≤5mm. In this way, the assembly of the elastic member and the second guide post can be facilitated.

[0091] In one embodiment, a gap is defined between the end face of the first guide post facing away from the valve cover and the end face of the second guide post facing closer to the valve cover in the axial direction of the elastic member. Optionally, a height H1 of the gap satisfies 0 mm < H1 ≤ 0.5 mm. This improves space utilization.

[0092] In one embodiment, in the axial direction of the elastic member, the distance between the side surface of the valve cover facing the valve cavity and the side surface of the blocking member facing the valve cover is L1, and the physical length of the elastic member is L2, satisfying the condition L1>L2. The physical length of the elastic member is the physical length of the elastic member after it is fully compressed. Optionally, L1-L2>0.5mm. In this way, space is reserved for the elastic member to compress, thereby driving the blocking member to block / open the air inlet passage.

[0093] In one embodiment, the elastic member is a spring, and the physical length of the elastic member L2 = d1*n1+d2+d3, where d1 is the spring wire diameter, n1 is the maximum number of turns of the spring in the axial direction, d2 is the thickness of the outermost spring at one end of the spring, and d3 is the thickness of the outermost spring at the other end of the spring, d2≤d1, d3≤d1.

[0094] In one embodiment, the outer circumferential surface of the blocking member is provided with a plurality of limiting protrusions, which are arranged at intervals along the circumference of the blocking member. In this way, the blocking member can be guided and limited, thereby improving the stability of the blocking member's movement.

[0095] In one embodiment, the sealing member includes a pressing portion and a sealing portion. Along the thickness of the wall, the ends of the elastic member abut against the valve cover and the pressing portion, respectively. The sealing portion is connected to the side of the pressing portion facing away from the valve cover and is used to seal the air inlet passage. This helps maintain the tightness of the housing.

[0096] In one embodiment, the sealing portion is made of EPDM, fluororubber or Teflon.

[0097] In one embodiment, the elastic member is made of steel, iron or aluminum.

[0098] In one embodiment, the valve cover includes a sidewall having a second through-hole extending therethrough. The gas outlet is the second through-hole. Along the axis of the valve cavity, the sealing interface between the valve core and the valve seat is higher than or flush with the bottom wall of the second through-hole. This facilitates gas discharge.

[0099] In one embodiment, the breathable membrane assembly includes a breathable membrane and a connector. The connector is provided with a first breathable hole. The breathable membrane is disposed on the connector and covers the first breathable hole. The breathable membrane is configured to allow gas within the battery cell to pass through the breathable membrane and escape. This can improve connection strength and reduce the risk of breathable membrane deformation.

[0100] In one embodiment, the connector has a first annular surface that is recessed relative to the connector surface, the first annular surface is disposed around the first vent hole, and the breathable membrane is disposed on the first annular surface. This helps reduce the installation height of the breathable membrane assembly.

[0101] In one embodiment, the breathable membrane assembly further includes a backing member disposed between the breathable membrane and the connector; the backing member has a higher air permeability than the breathable membrane, thereby reducing the risk of deformation of the breathable membrane.

[0102] In one embodiment, the connector further comprises a second annular platform recessed relative to the surface of the connector, the second annular platform surrounding the first vent hole, and the backing member is disposed on the second annular platform. In this manner, the installation height of the breathable membrane assembly can be reduced.

[0103] In one embodiment, the connecting member is a metal member, which can improve the connection strength.

[0104] In one embodiment, the battery cell further includes an insulating member disposed on a side of the wall portion facing the interior of the housing; the insulating member is provided with a second vent hole extending through the insulating member body, the second vent hole being connected to the first vent hole in the wall portion. This facilitates the discharge of gas.

[0105] In one embodiment, the battery cell further includes a protective patch, which is arranged on the side of the wall portion facing the outside of the shell. The protective patch is provided with a first avoidance hole passing through the protective patch, and the first avoidance hole is used for the one-way valve to pass through.

[0106] In one embodiment, the battery cell further includes a protective patch disposed on a side of the wall portion facing the exterior of the housing, covering the exhaust assembly. A second exhaust passage is formed between the protective patch and the wall portion, connecting the exhaust outlet of the one-way valve with the exterior of the battery cell, thereby preventing foreign matter from entering the exhaust assembly.

[0107] In one embodiment, the battery cell further includes a shielding member, the shielding member covers the exhaust assembly, and the protective patch covers the shielding member and the first exhaust channel formed between the shielding member and the wall portion.

[0108] In one embodiment, an adhesive layer is provided on the side of the protective patch facing the wall, the adhesive layer adhering the protective patch and the wall, and the adhesive layer is provided with an escape groove, forming a second exhaust channel between the escape groove and the wall to facilitate gas discharge.

[0109] In one embodiment, a first vent hole is provided on the wall portion, and at least a portion of the vent assembly is installed within the first vent hole. The first vent hole serves as the liquid injection hole for the battery cell. Alternatively, the first vent hole and the liquid injection hole are spaced apart. In this way, the vent assembly replaces the original sealing structure of the liquid injection hole, which can facilitate the configuration of the battery cell structure.

[0110] In one embodiment, the housing includes a shell and an end cap. The shell defines an opening within the housing for accommodating the electrode assembly. The end cap seals the opening. The end cap is a wall, or the shell includes a wall, or the wall is located at the top of the housing when the battery cell is in a placed state. This facilitates gas discharge.

[0111] In one embodiment, the battery cell further includes a pressure relief mechanism disposed on the outer casing. The pressure relief mechanism is configured to activate and release the internal pressure of the battery cell in the event of thermal runaway. The actuation pressure of the pressure relief mechanism is greater than the opening pressure of the one-way valve. In this way, the safety of the battery can be improved.

[0112] In one embodiment, the wall portion has a first vent hole, which connects the interior and exterior of the housing and is connected to the exhaust assembly. The wall portion also has a pressure relief hole, which connects the interior and exterior of the housing and is connected to the pressure relief mechanism. The diameter of the pressure relief hole is larger than that of the first vent hole. In this way, the pressure relief capacity of the battery cell is improved.

[0113] In one embodiment, the exhaust rate of the one-way valve is lower than the exhaust rate of the pressure relief mechanism, thereby improving the pressure relief capability of the battery cell.

[0114] To solve the above technical problems, another technical solution adopted by the present application is to provide a battery comprising the above battery cells, which has at least the same advantages as the battery cells.

[0115] To solve the above technical problems, another technical solution adopted by the present application is to provide an electrical device comprising the above battery, which has at least the same advantages as the battery.

[0116] 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

[0117] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0118] FIG1 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0119] FIG2 is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0120] FIG3a is a schematic structural diagram of a blocking member of a one-way valve according to one or more embodiments;

[0121] FIG3 b is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0122] FIG3c is a schematic diagram of a state of an elastic member according to one or more embodiments;

[0123] FIG4 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0124] FIG5 is a front view of a one-way valve according to one or more embodiments;

[0125] FIG6 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0126] FIG7 is a schematic cross-sectional view of a one-way valve according to one or more embodiments;

[0127] FIG8 is a front view of a one-way valve according to one or more embodiments;

[0128] 9 is a bottom view of a one-way valve according to one or more embodiments;

[0129] FIG10 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0130] FIG11 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0131] FIG12 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0132] FIG13 is a front view of a one-way valve according to one or more embodiments;

[0133] FIG14 is a schematic diagram of an exploded structure of a one-way valve according to one or more embodiments;

[0134] FIG15 is a schematic diagram of a partial cross-sectional structure of a battery cell according to one or more embodiments;

[0135] FIG16 is a front view of a one-way valve according to one or more embodiments;

[0136] FIG17 is a schematic cross-sectional view of a breathable membrane assembly according to one or more embodiments;

[0137] FIG18 is a schematic cross-sectional view of a breathable membrane assembly according to one or more embodiments;

[0138] FIG19 is a schematic partial cross-sectional view of an end cap according to one or more embodiments;

[0139] FIG20 a is a schematic cross-sectional view of a battery cell according to one or more embodiments;

[0140] FIG20 b is a front view of an end cap of a battery cell according to one or more embodiments;

[0141] FIG20 c is a schematic diagram of a partially exploded structure of a battery cell according to one or more embodiments;

[0142] FIG21 is a schematic cross-sectional view of a battery cell according to one or more embodiments;

[0143] FIG22 is a schematic diagram of a partial cross-sectional structure of an end cap according to one or more embodiments;

[0144] FIG23 a is a schematic cross-sectional view of a battery cell according to one or more embodiments;

[0145] FIG23 b is a front view of an end cap of a battery cell according to one or more embodiments;

[0146] FIG23 c is a schematic diagram of a partially exploded structure of a battery cell according to one or more embodiments;

[0147] FIG24 is an exploded view of an exhaust assembly according to one or more embodiments;

[0148] FIG25 is a schematic cross-sectional view of an exhaust assembly according to one or more embodiments;

[0149] FIG26 is an exploded view of an exhaust assembly according to one or more embodiments;

[0150] FIG27 is a schematic cross-sectional view of an exhaust assembly according to one or more embodiments;

[0151] FIG28 is an exploded view of an exhaust assembly according to one or more embodiments;

[0152] FIG29 is a schematic cross-sectional view of an exhaust assembly according to one or more embodiments;

[0153] FIG30 is a schematic cross-sectional view of an exhaust assembly according to one or more embodiments;

[0154] FIG31 is a schematic cross-sectional view of a battery cell according to one or more embodiments;

[0155] FIG32 is a schematic diagram of an exploded structure of a battery cell according to one or more embodiments;

[0156] FIG33 is a schematic diagram of a partially exploded structure of a battery cell according to one or more embodiments;

[0157] 34 is a bottom view of an adhesive layer of a protective patch according to one or more embodiments;

[0158] FIG35 is a schematic diagram of an exploded structure of a battery according to one or more embodiments;

[0159] FIG36 is a schematic structural diagram of a vehicle according to one or more embodiments.

[0160] In the accompanying drawings: 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, second stress relief groove; 212, first weld mark avoidance groove; 291, first vent; 22, housing; 23, electrode assembly; 24, insulating member; 292, second vent; 25, electrode terminal; 280, through-hole section; 281, first hole section; 282, second hole section; 30, one-way valve; 31, valve body; 311, valve seat; 3111, first through-hole; 3112, first sink; 3113, connecting protrusion; 31 14. Fourth through hole; 3115. Bottom wall of seat; 3115a. Inner wall surface; 3115b. Outer wall surface; 3116. Side wall of seat; 3116a. First side wall portion; 3116b. Second side wall portion; 3116c. Third side wall portion; 3117. Second weld mark avoidance groove; 311a. First stress relief groove; 312. Valve cover; 312a. Protrusion; 3121. Top wall of cover; 31211. First guide post; 31212. Third through hole; 3122. Side wall of cover; 31221. Second through hole; 31222. Flanged wall; 31222a. Connecting surface; 31222b. Accommodating groove; 31222c. Upper surface; 31222d. Lower surface; 312 3. Fifth through hole; 313. Valve cavity; 313a. Air inlet; 313b. Air outlet; 313c. First exhaust gap; 3131. First cavity; 3132. Second cavity; 32. Valve core; 321. Blocking member; 3211. Sealing portion; 3212. Pressing portion; 3212a. Position-limiting protrusion; 3212b. Second guide column; 322. Elastic member; 40. Breathable membrane assembly; 41. Breathable membrane; 42. Metal member; 421. Third stress relief groove; 491. First air hole; 43. Backing member; 50. Shielding member; 501. Third exhaust gap; 60. Protective patch; 601. First avoidance hole; 602. Second avoidance hole; 603. Third avoidance hole ; 604, information collection hole; 610, adhesive layer; 611, avoidance groove; 70, pressure relief mechanism; 701, pressure relief hole; 80, sealing ring; 801, second air vent; 90, exhaust assembly; T1, first annular table; T2, second annular table; T3, transition surface; S1, first sinking platform; S2, second sinking platform; C1, first transition connection surface; S3, third sinking platform; C2, second transition connection surface; S4, fourth sinking platform; S5, fifth sinking platform; C3, third transition connection surface; S6, sixth sinking platform; S7, seventh sinking platform; W1, first weld mark; W2, second weld mark; W3, third weld mark; W4, fourth weld mark; W5, fifth weld mark; W6, sixth weld mark. DETAILED DESCRIPTION

[0161] In order to make the purpose, technical solution and effect of this application clearer and more specific, the following embodiments of the technical solution of this application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application and are therefore only examples and are not intended to limit the scope of protection of this application.

[0162] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0163] In the description of the embodiments of the present application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two (including two), and "multiple pieces" refers to more than two (including two), unless otherwise clearly and specifically defined.

[0164] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0165] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0166] Amounts, ratios, and other numerical values ​​are presented herein in a range format. It should be understood that such range format is used for convenience and brevity and should be interpreted flexibly to include not only the values ​​explicitly specified as limits of the range, but also all individual values ​​or sub-ranges encompassed within the range, as if each value and sub-range were explicitly specified.

[0167] In the description of the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and do not constitute any limitation on this application.

[0168] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0169] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0170] Batteries have a wide range of applications in the new energy sector, primarily in electric vehicles, energy storage systems, and renewable energy. In the electric vehicle sector, higher performance features such as longer driving range and faster charging are gradually being achieved. In energy storage systems, batteries are widely used for large-scale and distributed energy storage. They can balance grid loads, store renewable energy such as solar and wind power, and release the stored energy during peak periods. Furthermore, small rechargeable batteries are widely used in applications such as wearable devices, drones, and smart homes.

[0171] As the battery charges and discharges, some side reactions generate gases. If these gases are not promptly discharged, the internal pressure of the battery will increase. Excessive internal pressure can negatively impact the battery's performance and appearance. For example, in severe cases, this can have devastating effects on the battery's performance and appearance, such as leakage, bulging, increased internal resistance, and shortened discharge time and cycle life. Furthermore, batteries can be subject to abnormal operation during use, including overcharging, over-discharging, and internal failures. In these cases, the chemical reactions within the battery may become uncontrolled, accompanied by a violent release of gas, and even trigger thermal runaway. Battery thermal runaway refers to a chain reaction phenomenon triggered by various factors. The large amount of heat and harmful gases emitted by thermal runaway can cause the battery to catch fire and explode.

[0172] To improve the safety of battery cells, a pressure relief mechanism is typically installed on the outer casing of the battery cell to release the internal pressure of the battery cell, thereby effectively improving the safety of the battery cell. However, during the use of the battery cell, unstable internal pressure may cause the pressure relief mechanism of the battery cell to activate prematurely, 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.

[0173] Based on the above considerations, an embodiment of the present application provides a battery cell, on which an exhaust assembly is provided. The exhaust assembly can timely discharge the gas inside the battery cell to maintain a stable internal pressure of the battery cell.

[0174] Please refer to Figure 1, which is a schematic diagram of the exploded structure of a battery cell 20 according to one or more embodiments. A battery cell 20 is the smallest unit that makes up a battery 100. As shown in Figure 1, a battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0175] The end cap 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 22 to match the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). In this way, the end cap 21 is less likely to deform when squeezed or collided, so that the battery cell 20 can have a higher structural strength and improved safety performance. Functional components such as electrode terminals 25 can be provided on the end cap 21. The electrode terminals 25 can be used to electrically connect to the electrode assembly 23 to output or input electrical energy from the battery cell 20. Exemplarily, the battery cell 20 is provided with two electrode terminals 25, and both electrode terminals 25 are mounted on the end cap 21. The two electrode terminals 25 are respectively used to electrically connect to the two tabs of opposite polarity of the electrode assembly 23 to respectively output or input the positive and negative electrodes of the battery cell 20. In some embodiments, the end cap 21 may also be provided with a pressure relief mechanism 70 for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating member 24 may also be provided on the inner side of the end cap 21. The insulating member 24 may be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. Exemplarily, the insulating member 24 may be plastic, rubber, etc.

[0176] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface 31222a before other components are inserted into the housing. When the interior of the housing 22 is to be enclosed, the end cap 21 is placed over the housing 22. The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0177] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 22. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 23, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive and negative electrode tabs may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 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.

[0178] Please refer to Figure 32, which is a schematic diagram of a partially exploded structure of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the present application discloses a battery cell 20, which includes a housing and a vent assembly 90. The housing has a wall portion, and the vent assembly 90 is disposed on the wall portion. The vent assembly 90 includes a one-way valve 30 and a breathable membrane assembly 40, and the vent assembly 90 is used to exhaust gas from the interior of the housing.

[0179] The one-way valve 30 and the breathable membrane assembly 40 are used at the same time, so that the exhaust assembly 90 can discharge the gas inside the shell to the outside of the shell, so that when gas is generated inside the shell during normal use of the battery cell 20, it can be discharged to the outside of the shell through the exhaust assembly 90, so as to alleviate the phenomenon that the internal pressure of the battery cell 20 reaches the threshold value in advance due to the increase in the internal air pressure of the battery cell 20, causing the battery cell 20 to actuate and release pressure in advance, thereby effectively improving the use stability of the battery cell 20, thereby improving the service life and reliability of the battery cell 20.

[0180] According to some embodiments of the present application, the outer shell includes an end cover 21 and a shell 22, and the wall portion may be the wall of the end cover 21 or the wall of the shell 22. That is, the exhaust assembly 90 may be arranged on the end cover 21 or on the shell 22. In other words, the wall portion for mounting the exhaust assembly 90 may be the end cover 21 of the outer shell or a wall of the shell 22 of the outer shell. Exemplarily, the wall portion is the end cover 21. Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the wall portion may also be the bottom wall of the shell 22 and the end cover 21, and the wall portion may also be the side wall of the shell 22 and the end cover 21 adjacent to and connected to each other. The following will take the wall portion as the wall of the end cover 21 as an example to illustrate the present application, but this should not limit the present application.

[0181] According to some embodiments of the present application, the vent assembly 90 includes a one-way valve 30, which is configured to actuate and release gas from the battery cell 20 when the internal gas pressure of the battery cell 20 reaches a threshold value. In other words, the one-way valve 30 is used to exhaust gas from the interior of the housing. That is, the one-way valve 30 can be opened in one direction to exhaust gas, so that the gas inside the housing can be discharged to the outside of the housing through the one-way valve 30.

[0182] Please refer to Figure 2, which is a schematic cross-sectional view of a one-way valve 30 according to one or more embodiments. According to some embodiments of the present application, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 has a valve cavity 313 therein. The valve body 31 is provided with an air inlet 313a and an air outlet 313b. The air inlet 313a is used to connect the valve cavity 313 with the interior of the housing, and the air outlet 313b is used to connect the valve cavity 313 with the exterior of the housing. The valve core 32 is disposed within the valve cavity 313 and is used to block the air inlet passage of the valve cavity 313. The valve core 32 is configured to open the air inlet passage under the action of the gas inside the housing and release the gas inside the battery cell 20.

[0183] Among them, the air inlet 313a is used to connect the valve cavity 313 and the interior of the shell, that is, the gas inside the shell can enter the valve cavity 313 through the air inlet 313a; similarly, the air outlet 313b is used to connect the valve cavity 313 and the outside of the shell, that is, the gas in the valve cavity 313 can be discharged to the outside of the shell through the air outlet 313b; through this arrangement, the gas inside the shell of the battery cell 20 can be discharged to the outside of the shell through the valve cavity 313.

[0184] Specifically, when the gas inside the battery cell 20 casing is exhausted through the one-way valve 30, its exhaust path is from the inside of the battery cell 20 - air inlet 313a - valve cavity 313 - air outlet 313b - outside the battery cell 20. This entire exhaust path constitutes the exhaust channel; as shown in Figure 2(b), the path from A to B, A represents the inside of the casing, and B represents the outside of the casing. In other words, the gas inside the battery cell 20 casing enters the valve cavity 313 from the air inlet 313a, flows through the valve cavity 313, and is exhausted from the air outlet 313b of the valve cavity 313 to the outside of the battery 100 casing.

[0185] Furthermore, the valve core 32 is used to block the air inlet channel of the valve cavity 313, and is used to open the air inlet channel under the action of the gas inside the shell. The air inlet channel is the channel through which the gas inside the shell enters the valve cavity 313 and flows after entering the valve cavity 313, or the air inlet channel can be a part of the exhaust channel, more specifically, the partial path before the air outlet 313b of the exhaust channel. The valve core 32 blocks the air inlet channel, which means that the gas is not allowed to enter the valve cavity 313, or the gas is allowed to enter the valve cavity 313 but the gas is not allowed to flow out of the valve cavity 313. The valve core 32 can directly block the air inlet 313a and not allow the gas to enter the valve cavity 313; or it can block the flow path of the gas, that is, the gas can enter the valve cavity 313 through the air inlet 313a, but its flow path is blocked and cannot continue to flow to the air outlet 313b. When the valve core 32 blocks the air inlet passage, gas outside the housing cannot enter the interior of the housing, and gas inside the housing cannot be discharged outside the housing. When the pressure of the gas inside the housing reaches a certain threshold, the gas inside the housing can push the valve core 32 to open the air inlet passage, allowing the gas inside the housing to enter the valve cavity 313 and then be discharged outside the housing through the air outlet 313b. At the same time, the valve core 32 can only be opened in one direction by applying pressure from the interior of the housing, allowing gas to flow out, and cannot be reversed from the exterior of the housing.

[0186] Optionally, the structure of the valve core 32 can be various. For example, in Figure 2, the valve core 32 can include an elastic member 322 and a sealing member 321. The elastic member 322 is arranged in the valve cavity 313, and the sealing member 321 is movably arranged in the valve cavity 313. The sealing member 321 is used to block the air inlet channel under the action of the elastic member 322, and is used to open the air inlet channel under the action of the gas inside the shell.

[0187] Specifically, the elastic member 322 is disposed within the valve cavity 313, and the blocking member 321 is movably disposed within the valve cavity 313. The elastic member 322 is configured to provide elastic force to the blocking member 321. The sealing and opening of the valve cavity 313 are achieved through the deformation of the elastic member 322. The blocking member 321 is used to block the air inlet passage under the action of the elastic member 322, and to open the air inlet passage under the action of the gas inside the housing.

[0188] Among them, the blocking member 321 is movably arranged in the valve cavity 313, that is, the blocking member 321 can move in the valve cavity 313, so that the blocking member 321 can block the air inlet 313a when it moves close to the air inlet 313a, and conversely, when the blocking member 321 moves away from the air inlet 313a, it can open the air inlet 313a.

[0189] In some embodiments, the blocking member 321 is loosely fitted with the inner wall of the valve cavity 313 .

[0190] Illustratively, the air inlet 313a extends through the bottom surface of the valve cavity 313, and accordingly, the blocking member 321 is movably disposed within the valve cavity 313 along the axial direction of the valve cavity 313 (direction Y in the figure), such that the blocking member 321 can block the air inlet 313a when abutting against the bottom surface of the valve cavity 313. Of course, in other embodiments, the air inlet 313a may also be disposed on a radial side of the valve body 31, and accordingly, the blocking member 321 is movably disposed within the valve cavity 313 along the radial direction of the valve body 31.

[0191] The sealing member 321 is used to seal the air inlet 313a under the action of the elastic member 322, and is used to open the air inlet 313a under the action of the gas inside the shell. That is to say, the elastic member 322 can provide elastic force for the sealing member 321, so that the sealing member 321 can abut against the bottom surface of the valve cavity 313 to seal the air inlet 313a. Conversely, when the force of the gas inside the shell acting on the sealing member 321 is greater than the elastic force of the elastic member 322, the gas inside the shell can overcome the elastic force of the elastic member 322 and push the sealing member 321 to separate from the bottom surface of the valve cavity 313, so that the sealing member 321 opens the air inlet 313a, thereby allowing the gas inside the shell to enter the valve cavity 313 through the air inlet 313a and then be discharged through the air outlet 313b.

[0192] As shown in Figure 2, Figure 2 (a) is a schematic diagram of the one-way valve 30 in the closed state; Figure 2 (b) is a schematic diagram of the one-way valve 30 in the open state. The elastic member 322 provides an elastic force F1 to the blocking member 321, and the blocking member 321 is pressed to block the air inlet 313a. When the force F2 exerted by the gas inside the shell on the blocking member 321 is greater than the elastic force F1 of the elastic member 322, the gas inside the shell can overcome the elastic force of the elastic member 322 and push the blocking member 321 to open the air inlet 313a, allowing the gas inside the shell to enter the valve chamber 313 and then be discharged to the outside of the shell through the air outlet 313b. Conversely, after the gas inside the shell is discharged and the force F2 exerted by the gas inside the shell on the blocking member 321 is less than the elastic force F1 of the elastic member 322, the elastic member 322 can drive the blocking member 321 to reset, thereby blocking the air inlet 313a.

[0193] Optionally, the elastic member 322 is an elastic member, and its structure can be various, such as a shrapnel, a spring, or elastic rubber. Exemplarily, the elastic member 322 is a spring. Using a spring as the elastic member 322 disposed in the valve cavity 313, on the one hand, facilitates the assembly of the elastic member 322, which helps to reduce the difficulty of assembling the elastic member 322 in the valve cavity 313, and on the other hand, enables the direction in which the elastic member 322 applies the elastic force to the blocking member 321 to be relatively stable. In some embodiments, the material of the elastic member 322 includes steel, iron, or aluminum. The elastic member 322 made of steel, iron, or aluminum has good toughness and can alleviate the phenomenon of elastic failure of the elastic member 322, which helps to increase the service life of the elastic member 322.

[0194] Exemplarily, the elastic member 322 is a spring, and the sealing and opening of the valve chamber 313 are achieved through the deformation of the spring. When sealing the valve chamber 313, the spring's initial length can be set to L0, which is the natural length of the spring before compression. The spring's assembly space within the valve chamber 313 is L1, and the valve chamber 313 is configured such that L0 > L1. After assembly, the spring is compressed, exerting a compressive force F1 on the sealing member 321, forcing the sealing member 321 to tightly fit against the wall of the valve chamber 313, achieving a sealing effect.

[0195] When the air pressure inside the housing increases to a certain value P1, the air pressure exerts a force F2 on the lower surface 31222d of the sealing member 321. When F2 is greater than the spring compression force F1, the sealing interface fails, and the gas inside the housing enters the valve chamber 313 and is discharged to the outside of the housing through the channel within the valve chamber 313. As the gas inside the housing is discharged, the internal air pressure decreases. When the air pressure reaches a certain value P2, the valve body 31 closes to achieve a seal. The valve body 31 can be repeatedly opened and closed to exhaust air, so that the air pressure inside the housing is maintained between P1 and P2, thereby preventing the pressure relief mechanism 70 from opening prematurely due to excessive internal housing pressure.

[0196] Please refer to Figures 2, 3a, and 3b. Figure 3a is a schematic structural diagram of the blocking member 321 of the one-way valve 30 according to one or more embodiments; Figure 3b is a schematic cross-sectional structural diagram of the one-way valve 30 according to one or more embodiments. According to some embodiments of the present application, the elastic member 322 is arranged along the axial direction Y of the valve cavity 313, and the two ends of the elastic member 322 respectively abut against the blocking member 321 and the cavity top surface of the valve cavity 313, and the elastic member 322 is in a compressed state and is located between the cavity top surface of the valve cavity 313 and the blocking member 321, so that the elastic member 322 can apply elastic force to the blocking member 321, so that the blocking member 321 can abut against the cavity bottom surface of the valve cavity 313 to block the air inlet 313a.

[0197] Furthermore, a plurality of position-limiting protrusions 3212 a may be provided on the outer circumferential surface of the blocking member 321 , and the plurality of position-limiting protrusions 3212 a are arranged at intervals along the circumference of the blocking member 321 .

[0198] The limiting protrusion 3212a is configured to cooperate with the side surface of the valve cavity 313 to provide guidance and position limiting when the blocking member 321 moves along the axis of the valve cavity 313. The limiting protrusion 3212a may be provided with a clearance fit between the side surface of the valve cavity 313 and the side surface of the valve cavity 313. In other embodiments, the one-way valve 30 may have other structures. For example, the side surface of the valve cavity 313 may be provided with a guide groove (not shown) extending along the axis of the valve cavity 313, and the limiting protrusion 3212a may extend into the guide groove. The limiting protrusion 3212a may move in the guide groove along the axis of the valve cavity 313 when the blocking member 321 opens the air inlet 313a, thereby providing guidance and position limiting. A plurality of guide grooves may be provided, each of which cooperates with a plurality of limiting protrusions 3212a. Optionally, the limiting protrusion 3212a may have various shapes, such as semicircular, triangular, trapezoidal or rectangular structures. For example, in FIG. 3a , the limiting protrusion 3212a has a semicircular shape.

[0199] By providing a plurality of spaced-apart limiting protrusions 3212a on the outer peripheral surface of the blocking member 321, and the limiting protrusions 3212a cooperate with the side surfaces of the valve cavity 313 to guide the blocking member 321, the blocking member 321 can be guided and limited by the cooperation between the limiting protrusions 3212a and the side surfaces of the valve cavity 313 when the blocking member 321 moves along the axial direction of the valve cavity 313, thereby improving the stability of the movement of the blocking member 321.

[0200] Please refer to Figures 2, 3b, and 4. Figure 4 is a schematic diagram of the exploded structure of a one-way valve 30 according to one or more embodiments. The valve body 31 includes a valve seat 311 and a valve cover 312. The valve cover 312 and the valve seat 311 enclose a valve chamber 313. The ends of the elastic member 322 abut against the blocking member 321 and the top wall 3121 of the valve cover 312, respectively. The valve body 31 includes the valve cover 312. A first guide post 31211 is protruding from the side of the valve cover 312 facing the blocking member 321. A portion of the elastic member 322 is sleeved outside the first guide post 31211. Specifically, the first guide post 31211 can be protruding from the side of the top wall 3121 facing the blocking member 321. A portion of the elastic member 322 is sleeved outside the first guide post 31211 to achieve positioning of the elastic member 322.

[0201] Furthermore, the blocking member 321 includes a pressing portion 3212 and a sealing portion 3211. Along the axial direction of the valve chamber 313, the two ends of the elastic member 322 respectively abut against the valve cover 312 and the pressing portion 3212. The sealing portion 3211 is connected to the side of the pressing portion 3212 away from the valve cover 312. The sealing portion 3211 is used to block the air intake channel.

[0202] Among them, the stiffness of the clamping part 3212 is greater than the stiffness of the sealing part 3211, the sealing part 3211 is connected to the side of the clamping part 3212 away from the top wall 3121 of the cover, the sealing part 3211 is used to seal the air inlet 313a, and the elastic part 322 is arranged between the top wall 3121 of the cover and the clamping part 3212. The clamping part 3212 can be pressed against the sealing part 3211 under the elastic force of the elastic part 322, so that the upper surface 31222c of the sealing part 3211 is effectively in contact with the clamping part 3212, so that the sealing part 3211 is against the bottom surface of the valve cavity 313, thereby sealing the air inlet 313a through the sealing part 3211.

[0203] According to some embodiments of the present application, the rigidity of the pressing portion 3212 is greater than the rigidity of the sealing portion 3211, and the setting of the pressing portion 3212 can effectively transmit the force applied by the elastic member 322 to the sealing portion 3211. In other words, the rigidity of the pressing portion 3212 is greater than the rigidity of the sealing portion 3211, that is, the deformation resistance of the pressing portion 3212 is greater than the deformation resistance of the sealing portion 3211, so that the pressing portion 3212 can better press the sealing portion 3211 on the bottom surface of the installation cavity to seal the air inlet 313a. Exemplarily, the material of the pressing portion 3212 can be a variety, such as steel, iron or aluminum. Similarly, the material of the sealing portion 3211 can also be a variety, such as rubber, silicone or plastic.

[0204] Optionally, the connection structure between the pressing portion 3212 and the sealing portion 3211 can be various, such as clamping, bolting, or bonding.

[0205] By setting the sealing member 321 to include a pressing portion 3212 and a sealing portion 3211, the pressing portion 3212 is set on the side of the sealing portion 3211 facing the valve cover 312, and the sealing portion 3211 is used to seal the air inlet 313a, and the two ends of the elastic member 322 are respectively against the valve cover 312 and the pressing portion 3212, so that the elastic member 322 can exert an elastic force on the sealing portion 3211 through the pressing portion 3212, which is beneficial to improve the balance of the elastic force of the elastic member 322 acting on the sealing portion 3211, and thus can effectively improve the sealing effect of the sealing portion 3211 on the air inlet 313a.

[0206] According to some embodiments of the present application, the sealing portion 3211 is made of a material that is resistant to electrolyte, such as fluororubber, PFA, EPDM, etc. Different sealing materials have different physical properties, and accordingly, different forces are required to achieve sealing.

[0207] For example, the limiting protrusion 3212a is provided on the outer circumferential surface of the pressing portion 3212. Of course, in other embodiments, the blocking member 321 may be formed as a single sealing component, such as a rubber pad or a silicone pad. That is, the blocking member 321 only includes the sealing portion 3211, and the two ends of the elastic member 322 respectively abut against the valve cover 312 and the sealing portion 3211. Of course, in other embodiments, the valve core 32 may also be formed as a single elastic component, such as elastic rubber.

[0208] In one embodiment, a second guide post 3212b is protruding from the side of the blocking member 321 facing the valve cover 312, and a portion of the elastic member 322 is sleeved outside the second guide post 3212b. Alternatively, a second guide post 3212b may be protruding from the side of the pressing portion 3212 facing the cover top wall 3121, and a portion of the elastic member 322 is sleeved outside the second guide post 3212b.

[0209] The one-way valve 30 adopting this structure can, on the one hand, play a certain positioning role for the elastic member 322 through the first guide column 31211 and the second guide column 3212b, so as to facilitate the assembly of the elastic member 322 and help reduce the difficulty of assembling the elastic member 322. On the other hand, the first guide column 31211 and the second guide column 3212b can play a certain guiding role when the elastic member 322 is compressed, thereby reducing the radial deformation of the elastic member 322 during the compression process, thereby achieving stable compression of the elastic member 322, which is conducive to improving the reliability of the elastic member 322 and further reducing the risk of the sealing member 321 accidentally opening the air inlet 313a. The elastic member 322 can be a spring. Of course, in other embodiments, the elastic member 322 can also be a spring or elastic rubber.

[0210] Please refer to Figures 3b and 3c . Figure 3c is a schematic diagram of the elastic member 322 according to one or more embodiments. According to some embodiments of the present application, in the axial direction of the valve cavity 313, the ends of the elastic member 322 respectively abut against the valve cover 312 and the blocking member 321. The distance between the first abutting surface of the valve cover 312 and the second abutting surface of the blocking member 321 is L1, which represents the assembly space for the elastic member 322. Specifically, the ends of the elastic member 322 respectively abut against the side surface of the valve cover 312 facing the valve cavity 313 and the side surface of the pressing portion 3212 facing the valve cover 312. The distance between the two is L1, which represents the assembly space for the elastic member 322. Specifically, the cover top wall 3121 has a first abutting surface 3121a facing the valve cavity 313, and the pressing portion 3212 has a second abutting surface 3212c facing the cover top wall 3121. L1 represents the distance between the first abutting surface 3121a and the second abutting surface 3212c. The abutting surfaces are surfaces on the valve cover 312 and the blocking member 321 that abut against the elastic member 322 .

[0211] According to some embodiments of the present application, in the axial direction of the elastic member 322, there is a gap between the end surface of the first guide post 31211 away from the valve cover 312 and the end surface of the second guide post 3212b close to the valve cover 312. This gap can provide space for the blocking member 321 to move.

[0212] According to some embodiments of the present application, along the axis Y of the valve cavity 313, the gap dimension H1 between the valve cover 312 and the blocking member 321 satisfies the condition 0 mm < H1 ≤ 0.5 mm. In one embodiment, the gap dimension H1 between the valve cover 312 and the blocking member 321 is the spacing dimension when the blocking member 321 blocks the air inlet passage.

[0213] A first guide post 31211 is protruding from the side of the valve cover 312 facing the sealing member 321, and a second guide post 3212b is protruding from the side of the sealing member 321 facing the valve cover 312. The gap between the valve cover 312 and the sealing member 321 is the distance between the end surface of the first guide post 31211 facing away from the valve cover 312 and the end surface of the second guide post 3212b facing the valve cover 312. As shown in FIG3b , H1. In other words, in the axial direction Y of the valve cavity 313, the sum of the height H2 of the first guide post 31211 and the height H3 of the second guide post 3212b is less than the assembly space L of the elastic member 322. That is, in the axial direction, the height H2 of the first guide post 31211 + the height H3 of the second guide post 3212b < the spring compression space L1.

[0214] For example, the size H1 of the gap between the valve cover 312 and the blocking member 321 may be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0215] By setting the size of the gap between the valve cover 312 and the sealing member 321 in the axial direction Y to be greater than 0 mm and less than or equal to 5 mm, on the one hand, the obstruction of the valve cover 312 to the sealing member 321 can be reduced, so that there is space between the valve cover 312 and the sealing member 321 for the sealing member 321 to move along the axial direction Y, so that when the gas inside the shell pushes the sealing member 321, the sealing member 321 can open the air inlet 313a for exhaust. On the other hand, it can alleviate the phenomenon that the one-way valve 30 occupies too much space in the axial direction Y due to the excessive gap between the valve cover 312 and the sealing member 321, which is beneficial to improving the space utilization rate of the battery cell 20.

[0216] As shown in Figure 3c, taking the elastic member 322 as a spring as an example, the initial length L0 of the spring is the natural length of the spring before it is compressed; by configuring L0>L1, the spring can have a certain initial elastic force after being assembled into the valve cavity 313, so as to push the sealing part 3211 to be pressed against the wall of the valve cavity 313, thereby improving the sealing performance.

[0217] Furthermore, the physical length L2 of the spring is configured such that L1>L2. The physical length of the spring is the length of the spring body after it is fully compressed. As shown in Figure 3c, State 1 in Figure 3c represents the uncompressed state of the spring. In this state, there are gaps between the physical structures of the spring, allowing further compression. State 2 in Figure 3c represents the fully compressed state of the spring. In this state, there are no gaps between the physical structures of the spring, preventing further compression. The physical length of the spring L2 = d1*n1+d2+d3, where d1 is the spring wire diameter, n1 is the maximum number of axial turns of the spring, d2 is the thickness of the outermost spring at one end, and d3 is the thickness of the outermost spring at the other end. As shown in Figures 3b and 3c, the spring is a helical cylindrical coil, and the spring wire diameter d1 is the diameter of each spring body turn. As the number of turns increases, the physical length of the spring becomes the sum of the physical lengths of each turn, i.e., d1*n1. As shown in Figure 3b, the number of coils of the spring is 4, and the length of the entity of this part after being fully compressed is d1*4. The end of the spring can be ground flat for ease of assembly. The so-called grinding process refers to grinding a part of the originally cylindrical spring entity to make its top surface smoother. After the grinding process, the spring entity becomes thinner, that is, it is no longer a complete cylinder. Then the thickness d2 and d3 of the spring entity in this area will be less than the spring wire diameter d1; of course, in some embodiments, the end of the spring can also not be processed. In this case, the thickness of the spring entity is equal to the spring wire diameter d1, that is, d2≤d1, d3≤d1. Therefore, the overall length of the spring entity is L2=d1*n1+d2+d3. By setting L1>L2, the spring will not be completely compacted after assembly, and there is still room for compression activity.

[0218] According to some embodiments of the present application, the compression margin of the elastic member 322, which is located in a compressed state between the valve cover 312 and the sealing member 321, is greater than or equal to 0.5 mm, that is, L1-L2>0.5 mm. This allows the elastic member 322 to have sufficient compression margin for the sealing member 321 to move along the axial direction Y of the valve cavity 313, so that the sealing member 321 can open the air inlet 313a. If the elastic member 322 is a spring, then in the axial direction Y of the valve cavity 313, the sum of the gaps between the spring coils is greater than or equal to 0.5 mm. For example, L1-L2 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0219] Please continue to refer to FIG. 3 b . According to some embodiments of the present application, the diameter of the first guide column 3121131212 is D1 , and the inner diameter of the elastic member 322 is D2 , satisfying 0 mm < D2 - D1 ≤ 5 mm.

[0220] The elastic member 322 is a spring, and the inner diameter D2 of the elastic member 322 is the diameter of the cavity formed inside the spring. 0mm<D2-D1≤5mm. That is, when the first guide post 31211 and the elastic member 322 are coaxially arranged, the gap between the first guide post 31211 and the elastic member 322 is greater than 0mm and less than or equal to 5mm.

[0221] Exemplarily, the difference between the inner diameter of the elastic member 322 and the diameter of the first guide column 31211 can be 0mm, 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, etc.

[0222] By setting the difference between the inner diameter of the elastic part 322 and the diameter of the first guide column 31211 to be greater than 0 mm and less than or equal to 5 mm, on the one hand, the phenomenon that the elastic part 322 is not convenient to be assembled on the first guide column 31211 due to the difference between the inner diameter of the elastic part 322 and the diameter of the first guide column 31211 being less than or equal to 0 can be alleviated, so as to reduce the scratching phenomenon when the elastic part 322 is sleeved on the first guide column 31211. On the other hand, the phenomenon that the gap between the elastic part 322 and the first guide column 31211 is too large due to the large difference between the inner diameter of the elastic part 322 and the diameter of the first guide column 31211 can be alleviated, so as to reduce the radial movement or radial deformation of the elastic part 322, thereby improving the balance of the elastic force of the elastic part 322 acting on the blocking part 321, so as to reduce the risk of the blocking part 321 accidentally opening the air inlet 313a.

[0223] Continuing with Figure 3b, according to some embodiments of the present application, the diameter of the second guide post 3212b is D3. The diameter of the second guide post 3212b refers to the diameter of the main body of the second guide post 3212b and does not include the area surrounding the retaining protrusion 3212a provided on the second guide post 3212b. The inner diameter of the elastic member 322 is D2, satisfying the condition 0 mm < D3 - D1 ≤ 5 mm.

[0224] The elastic member 322 is a spring, and the inner diameter D2 of the elastic member 322 is the diameter of the cavity formed inside the spring.

[0225] 0mm<D3-D1≤5mm, that is, when the second guide post 3212b and the elastic member 322 are coaxially arranged, the size of the gap between the second guide post 3212b and the elastic member 322 is greater than 0mm and less than or equal to 5mm.

[0226] Exemplarily, the difference between the inner diameter of the elastic member 322 and the diameter of the second guide column 3212b can be 0mm, 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, etc.

[0227] By setting the difference between the inner diameter of the elastic member 322 and the diameter of the second guide post 3212b to be greater than 0 mm and less than or equal to 5 mm, on the one hand, the phenomenon that the elastic member 322 is not convenient to be assembled on the second guide post 3212b due to the difference between the inner diameter of the elastic member 322 and the diameter of the second guide post 3212b being less than or equal to 0 can be alleviated, thereby reducing the scratching phenomenon when the elastic member 322 is sleeved on the second guide post 3212b. On the other hand, the phenomenon that the gap between the elastic member 322 and the second guide post 3212b is too large due to the large difference between the inner diameter of the elastic member 322 and the diameter of the second guide post 3212b can be alleviated, thereby reducing the radial movement or radial deformation of the elastic member 322, thereby improving the balance of the elastic force of the elastic member 322 acting on the blocking member 321, thereby reducing the risk of the blocking member 321 accidentally opening the air inlet 313a.

[0228] In this embodiment, the valve core 32 is arranged in the valve cavity 313, so that the valve core 32 can block the air inlet channel, and when the pressure inside the shell rises, the gas inside the shell can act on the valve core 32 and drive the valve core 32 to open the air inlet channel, so as to realize the one-way exhaust function of the one-way valve 30, so that the one-way valve 30 can discharge the gas inside the shell to the outside of the shell.

[0229] According to some embodiments of the present application, the opening pressure of the one-way valve 30 is greater than or equal to 0.2 MPa; alternatively, greater than or equal to 0.4 MPa; and further alternatively, greater than or equal to 0.8 MPa. For example, the opening pressure of the valve core 32 can be 0.20 MPa, 0.25 MPa, 0.30 MPa, 0.35 MPa, 0.40 MPa, 0.45 MPa, 0.50 MPa, 0.55 MPa, 0.60 MPa, 0.65 MPa, 0.70 MPa, 0.75 MPa, 0.80 MPa, 0.90 MPa, or 1.00 MPa.

[0230] The one-way valve opening pressure test method and principle can be tested based on the helium leakage standard. The helium leakage standard is defined as follows: if the leakage rate is less than 10^-6Pa.m^3 / s, the system is considered to be sealed; if the leakage rate is greater than 10^-6Pa.m^3 / s, it indicates that there is a gas leak in the system.

[0231] During testing, the test chamber is sealed with a one-way valve and filled with helium. The amount of helium in the test chamber environment is monitored using a helium detector. If helium is detected and the leakage rate is greater than 10^-6Pa.m^3 / s, it means that the test chamber is no longer sealed and helium is leaking out. The helium leakage rate is continuously monitored. When the leakage rate is greater than 10^-5Pa.m^3 / s, the one-way valve is determined to be open for release. The pressure in the test chamber at this time is recorded as the opening pressure of the one-way valve.

[0232] According to some embodiments of the present application, a battery cell 20 includes an end cap 21. The end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite each other, with the outer surface 21a facing the exterior of the housing and the inner surface 21b facing the interior of the housing. A one-way valve 30 is disposed on the end cap 21. The valve body 31 of the one-way valve 30 may face the exterior of the housing and at least partially protrude from the outer surface 21a of the end cap 21, or the valve body 31 of the one-way valve 30 may face the interior of the housing and at least partially protrude from the inner surface 21b of the end cap 21.

[0233] Please refer to Figures 4, 5, and 6. Figure 5 is a front view of a one-way valve 30 according to one or more embodiments, and Figure 6 is a partial cross-sectional structural schematic diagram of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite each other, with the outer surface 21a facing the exterior of the housing and the inner surface 21b facing the interior of the housing. The one-way valve 30 is disposed on the end cap 21, and the valve body 31 of the one-way valve 30 is disposed on the outer surface 21a, with at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21.

[0234] In this embodiment, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve seat 311 and a valve cover 312. The valve cover 312 includes a cover top wall 3121 and a cover side wall 3122 connected to the cover top wall 3121. The cover top wall 3121, the cover side wall 3122, and the valve seat 311 enclose a valve cavity 313. The valve seat 311 is provided with an air inlet 313a for the valve cavity 313, which connects the valve cavity 313 with the interior of the housing. The valve cover 312 is provided with an air outlet 313b for the valve cavity 313, which connects the valve cavity 313 with the exterior of the housing.

[0235] The valve core 32 is used to block the air inlet passage of the valve cavity 313. The valve core 32 is configured to open the air inlet passage under the action of the gas inside the housing and release the gas inside the battery cell 20. In this embodiment, the valve core 32 directly blocks the air inlet 313a of the valve cavity 313. The air inlet passage includes a gas flow path from the interior of the battery cell 20 housing to the air inlet 313a of the valve cavity 313, and to the side where the gas is discharged from the air inlet 313a.

[0236] In this embodiment, the valve body 31 of the one-way valve 30 is provided with a valve seat 311 and a valve cover 312. The one-way valve 30 with this structure is provided with the valve body 31 as two parts, so that it is convenient to assemble the valve core 32 into the valve cavity 313, which is beneficial to reduce the difficulty of assembling the one-way valve 30.

[0237] Continuing with Figures 4 and 6 , according to some embodiments of the present application, the valve seat 311 has a first through hole 3111 extending through the valve seat 311, and the air inlet 313a is the first through hole 3111, that is, the first through hole 3111 serves as the air inlet 313a of the valve cavity 313. The cover sidewall 3122 has a second through hole 31221 extending through the cover sidewall 3122, and the air outlet 313b is the second through hole 31221, that is, the second through hole 31221 serves as the air outlet 313b of the valve cavity 313. This arrangement facilitates the outward transmission of gas from within the battery 100.

[0238] According to some embodiments of the present application, the valve cover 312 includes a cover side wall 3122, which has a second through hole 31221 passing through the cover side wall 3122, and the air outlet 313b is the second through hole 31221. Along the axial direction of the valve cavity 313, the sealing interface between the valve core 32 and the valve seat 311 is higher than or flush with the bottom wall of the second through hole 31221.

[0239] According to some embodiments of the present application, the second through hole 31221 extends to an end of the cover side wall 3122 in a direction away from the cover top wall 3121 .

[0240] As shown in Figure 4 , the direction away from the lid top wall 3121 is the direction from the lid top wall 3121 toward the valve seat 311 (direction X in the figure). The second through hole 31221 is formed by removing part of the structure of the lid side wall 3122. Along the X direction, the lid side wall 3122 is directly hollowed out to the bottom end of the lid side wall 3122. In a further embodiment, along the X direction, the lower opening surface of the second through hole 31221 can be flush with the sealing surface of the blocking member 321, that is, the sealing interface is higher than or flush with the bottom wall of the second through hole 31221. The so-called bottom wall of the second through hole 31221 refers to the lowest point of the second through hole 31221, as indicated by arrow P in Figure 4, and the lower opening surface of the second through hole 31221 along the X direction. Through this arrangement, when the one-way valve 30 is opened to exhaust, that is, when the sealing member 321 opens the sealing interface, the electrolyte liquid carried out with the gas can be discharged outward in time, so that the electrolyte is not easy to accumulate on the outer edge of the sealing member 321, thereby effectively ensuring the sealing and repeated opening function of the one-way valve 30.

[0241] According to some embodiments of the present application, there are multiple second through holes 31221, and the multiple second through holes 31221 are spaced apart in the circumferential direction of the cover side wall 3122. This arrangement allows for faster exhaust of gas when the one-way valve 30 is opened for exhaust, shortening the exhaust time, that is, shortening the time that the battery 100 housing is in the open state, thereby reducing the intrusion of external moisture into the battery 100 system during the valve opening period.

[0242] Please refer to Figure 7, which is a schematic cross-sectional view of a one-way valve 30 according to one or more embodiments. According to some embodiments of the present application, a first guide post 31211 is protruding from the side of the cover top wall 3121 facing the valve seat 311. The cover top wall 3121 has a third through hole 31212 extending through the cover top wall 3121 and the first guide post 31211, or the cover top wall 3121 has a third through hole 31212 extending through the cover top wall 3121. The air outlet 313b is the third through hole 31212.

[0243] Specifically, a first guide post 31211 is protruding from the side of the cover top wall 3121 facing the blocking member 321, and a portion of the elastic member 322 is sleeved around the outside of the first guide post 31211. A third through hole 31212 is formed on the cover top wall 3121, penetrating the cover top wall 3121 and the first guide post 31211. The gas outlet 313b is the third through hole 31212. In other words, the third through hole 31212 serves as the gas outlet 313b of the valve chamber 313. This arrangement facilitates the outward transmission of gas from within the battery 100.

[0244] Please continue to refer to Figures 4, 5, 6 and 7. According to some embodiments of the present application, the valve cover 312 also includes a flange wall 31222, the cover side wall 3122 connects the cover top wall 3121 and the flange wall 31222, the flange wall 31222 extends toward a side away from the valve cavity 313 relative to the cover side wall 3122, and the flange wall 31222 is connected to the valve seat 311.

[0245] According to some embodiments of the present application, the valve cover 312 is connected to the valve seat 311. Specifically, a first recessed groove 3112 is provided on the side of the valve seat 311 facing the valve cover 312, which is recessed relative to the surface of the valve seat 311. At least a portion of the flange wall 31222 is accommodated in the first recessed groove 3112 and connected to the valve seat 311.

[0246] In this embodiment, a first recess 3112 is provided on the side of the valve seat 311 facing the valve cover 312, and at least a portion of the flange wall 31222 is accommodated in the first recess 3112. The one-way valve 30 adopting such a structure can, on the one hand, save the space occupied by the valve body 31 in the thickness direction of the end cover 21, and on the other hand, improve the structural stability of the valve cover 312 assembled on the valve seat 311.

[0247] According to some embodiments of the present application, the flange wall 31222 is housed within the first recess 3112 and connected to the valve seat 311. The thickness of the flange wall 31222 is less than or equal to the depth of the first recess 3112, so that after the flange wall 31222 is connected to the valve seat 311, the surface of the flange wall 31222 facing the lid top wall 3121 is flush with the surface of the valve seat 311 facing the valve cover 312; or the surface of the flange wall 31222 facing the lid top wall 3121 is lower than the surface of the valve seat 311 facing the valve cover 312. As shown in Figures 6 and 7, after the valve cover 312 is connected to the valve seat 311, the flange wall 31222 is flush with the surface of the valve seat 311. This arrangement can reduce the overall installation height of the one-way valve 30.

[0248] According to some embodiments of the present application, the material of the valve seat 311 can be a metal material, such as copper, iron, aluminum, steel or aluminum alloy. Similarly, the material of the valve cover 312 can also be a metal material, such as copper, iron, aluminum, steel or aluminum alloy. The valve seat 311 and the valve cover 312 can be made of the same material or different materials. The valve cover 312 and the valve seat 311 can be assembled by welding (such as laser welding); they can also be assembled by mechanical interference, but the static friction generated by the interference must be greater than the rebound force of the elastic member 322.

[0249] According to some embodiments of the present application, the flange wall 31222 is welded to the valve seat 311 ; wherein, in the circumferential direction of the cover side wall 3122 , at least a portion of the first weld mark between the flange wall 31222 and the valve seat 311 is staggered with the second through hole 31221 on the cover side wall 3122 .

[0250] The flange wall 31222 is welded to the valve seat 311. Specifically, the flange wall 31222 is an annular component having a certain thickness. The outer peripheral surface of the flange wall 31222 serves as a connecting surface 31222a and is welded to the groove wall surface of the first groove 3112. Furthermore, the connecting surface 31222a of the flange wall 31222 can be configured as an inclined surface, and the groove wall surface of the first groove 3112 can also be configured as an inclined surface, so that the connecting surface 31222a of the flange wall 31222 is aligned with the groove wall surface of the first groove 3112. As shown in Figures 6 and 7, the flange wall 31222 and the first groove 3112 can form an interlocking structure. In this way, the welding quality can be improved, and the strength and stability of the connection can be enhanced. Furthermore, it is preferred that the valve cover 312 and the valve seat 311 are made of the same material to achieve better welding quality.

[0251] According to some embodiments of the present application, at least a portion of the first weld mark W1 of the flange wall 31222 welded to the valve seat 311 is staggered with the second through-hole 31221 along the circumference of the cover sidewall 3122. As shown in FIG5 , welding can be performed at a location on the cover sidewall 3122 where no second through-hole 31221 is formed. There can be multiple first weld marks W1, distributed along the circumference of the cover sidewall 3122, and the distribution of the first weld marks W1 can be staggered with the distribution of the second through-hole 31221. In other words, multiple second through-holes 31221 are spaced apart along the circumference of the cover sidewall 3122, and the locations between adjacent second through-holes 31221 where no holes are formed have a solid wall. Welding can be performed at locations with solid walls. In this way, the solid wall has a certain heat-blocking effect, which can protect the sealing part 321 of the valve core 32 and reduce the impact of high temperature during welding on the sealing part 321, so as to prevent the sealing part 321 from being deformed by heat, thereby causing the sealing interface to fail when the valve is not opened.

[0252] Please refer to Figures 8, 9, 10 and 11. Figure 8 is a front view of the one-way valve 30 according to one or more embodiments, Figure 9 is a bottom view of the one-way valve 30 according to one or more embodiments, and Figure 10 is a schematic diagram of the exploded structure of the one-way valve 30 according to one or more embodiments. Figure 11 is a 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 valve seat 311 is connected to the valve cover 312. Specifically, the valve cover 312 includes a flange wall 31222, and the valve seat 311 is connected to the flange wall 31222. In other words, the valve seat 311 is connected to the flange wall 31222 of the valve cover 312.

[0253] According to some embodiments of the present application, a connecting protrusion 3113 is convexly provided on the outer peripheral surface of the valve seat 311 , and a receiving groove 31222b is provided on the inner peripheral surface of the flange wall 31222 . The connecting protrusion 3113 is accommodated in the receiving groove 31222b and connected to the flange wall 31222 .

[0254] There are multiple connecting protrusions 3113, spaced apart along the circumference of the valve seat 311. There are multiple corresponding receiving grooves 31222b, with the number of connecting protrusions 3113 being the same as the number of receiving grooves 31222b. The shape of the connecting protrusions 3113 matches the shape of the receiving grooves 31222b, allowing the connecting protrusions 3113 to be accommodated within the receiving grooves 31222b. With this arrangement, after the valve cover 312 is connected to the valve seat 311, the flange wall 31222 is flush with the surface of the valve seat 311. In this manner, the valve seat 311 is embedded in the valve cover 312, reducing the overall installation height of the one-way valve 30. Comparing Figure 6 and Figure 11, in the scheme of Figure 6, the valve cover 312 is connected to the valve seat 311, and its installation height is the thickness of the valve cover 312 superimposed on the partial thickness of the valve seat 311; in the scheme of Figure 11, the valve seat 311 is connected to the valve cover 312, the valve seat 311 is completely accommodated, and its installation height is the thickness of the valve cover 312; compared with the former, the installation height of this embodiment is lower, reducing the space occupancy rate.

[0255] According to some embodiments of the present application, the connecting protrusion 3113 is welded to the flange wall 31222. The flange wall 31222 has an upper surface 31222c and a lower surface 31222d disposed opposite each other, with the upper surface 31222c facing the lid top wall 3121. A second weld mark W2, where the connecting protrusion 3113 is welded to the flange wall 31222 of the lid side wall 3122, is located on the lower surface 31222d of the flange wall 3122. In other words, welding is performed from the underside of the valve cover 312 and valve seat 311. As shown in FIG11 , the second weld mark W2 is located on the side away from the valve cavity 313. This provides a certain degree of heat insulation for the valve seat 311 and flange wall 31222, protecting the sealing member 321 of the valve core 32 and reducing the impact of high temperatures during welding on the sealing member 321. This prevents deformation of the sealing member 321 due to heat, which could lead to failure of the sealing interface when the valve is not opened.

[0256] Please refer to Figure 12, which is a schematic partial cross-sectional view of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, a one-way valve 30 is disposed on the outer surface 21a of the end cap 21, with the valve body 31 of the one-way valve 30 facing the exterior of the housing, and at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21.

[0257] In this embodiment, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve cover 312, which includes a cover top wall 3121 and a cover side wall 3122 connected to the cover top wall 3121. The cover top wall 3121, the cover side wall 3122, and the end cap 21 enclose the valve cavity 313. The end cap 21 is provided with an air inlet 313a for the valve cavity 313, connecting the valve cavity 313 with the interior of the housing; the valve cover 312 is provided with an air outlet 313b for the valve cavity 313, connecting the valve cavity 313 with the exterior of the housing. The valve core 32 is used to block the air inlet channel of the valve cavity 313. The valve core 32 is configured to open the air inlet channel in response to gas inside the housing, thereby releasing gas from the battery cell 20. In this embodiment, the valve core 32 directly blocks the air inlet 313a of the valve cavity 313. The air inlet passage includes a gas flow path from the inside of the battery cell 20 shell to the air inlet 313a of the valve cavity 313 and to the side where the air inlet 313a is discharged.

[0258] In this embodiment, the valve body 31 of the one-way valve 30 can consist solely of a valve cover 312 without a valve seat 311. The valve cover 312 is directly connected to the end cap 21; alternatively, the end cap 21 can serve as the valve seat 311 for the valve body 31. This approach reduces the installation height of the one-way valve 30. Comparing Figures 6, 11, and 12, in Figure 6, the valve cover 312 is connected to the valve seat 311, and its installation height is the thickness of the valve cover 312 superimposed on the thickness of the valve seat 311, and then on the thickness of the end cap 21. In Figure 11, the valve seat 311 is connected to the valve cover 312, completely enclosing it. Its installation height is the thickness of the valve cover 312 superimposed on the thickness of the end cap 21. In Figure 12, the valve cover 312 can be embedded in the end cap 21, and its installation height can be the thickness of the end cap 21. Compared to the three embodiments, this embodiment has a lower installation height, reducing space usage.

[0259] According to some embodiments of the present application, the end cap 21 is provided with a first vent 291, which connects the interior of the housing with the exterior of the housing. The air inlet 313a is the first vent 291, that is, the first vent 291 serves as the air inlet 313a of the valve chamber 313. The cover sidewall 3122 is provided with a second through hole 31221 that extends through the cover sidewall 3122. The air outlet 313b is the second through hole 31221, that is, the second through hole 31221 serves as the air outlet 313b of the valve chamber 313. This arrangement facilitates the outward transmission of gas from the interior of the battery cell 20. In other embodiments, the air outlet 313b may also be a third through hole 31212 located on the cover top wall 3121 and extending through the cover top wall 3121 and the first guide post 31211. For details, please refer to Figure 7 and the previous description, which will not be repeated here.

[0260] According to some embodiments of the present application, a second groove (not shown in the figure) is provided on the side of the end cover 21 facing the outside of the shell, which is recessed relative to the outer surface 21a of the end cover 21, and at least a portion of the flange wall 31222 of the valve cover 312 is accommodated in the second groove and connected to the end cover 21.

[0261] In this embodiment, a second groove is provided on the side of the end cover 21 facing the outside of the shell, and at least a portion of the flange wall 31222 is accommodated in the second groove. The one-way valve 30 adopting this structure can save the space occupied by the valve body 31 in the thickness direction of the end cover 21.

[0262] According to some embodiments of the present application, the flange wall 31222 is housed within the second recess and connected to the end cap 21. The thickness of the flange wall 31222 is less than or equal to the depth of the second recess, such that after the flange wall 31222 is connected to the end cap 21, the surface of the flange wall 31222 facing the cover top wall 3121 is flush with the surface of the end cap 21 facing the exterior of the housing; or the surface of the flange wall 31222 facing the cover top wall 3121 is lower than the surface of the end cap 21 facing the exterior of the housing. As shown in Figure 12, after the valve cover 312 is connected to the end cap 21, the flange wall 31222 is flush with the surface of the end cap 21. This arrangement can reduce the overall installation height of the one-way valve 30.

[0263] According to some embodiments of the present application, the flange wall 31222 is welded to the end cover 21. Specifically, the flange wall 31222 is an annular component having a certain thickness, and the outer peripheral surface of the flange wall 31222 is welded to the groove wall surface of the second sink trough as a connecting surface 31222a. Furthermore, the connecting surface 31222a of the flange wall 31222 can be set as an inclined surface, and the groove wall surface of the second sink trough can also be set as an inclined surface accordingly, so that the connecting surface 31222a of the flange wall 31222 fits with the groove wall surface of the second sink trough. As shown in Figure 12, the flange wall 31222 and the second sink trough can form an interlocking structure. In this way, the welding quality can be improved, and the strength and stability of the connection can be enhanced. Furthermore, it is preferred that the valve cover 312 and the end cover 21 are made of the same material to achieve better welding quality. For example, both are made of aluminum.

[0264] Please refer to Figures 13, 14, and 15. Figure 13 is a front view of a one-way valve 30 according to one or more embodiments, and Figure 14 is a schematic diagram of the exploded structure of the one-way valve 30 according to one or more embodiments. Figure 15 is a schematic diagram of the 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 includes an outer surface 21a and an inner surface 21b disposed opposite to each other, with the outer surface 21a facing the outside of the housing and the inner surface 21b facing the inside of the housing. The one-way valve 30 is disposed on the outer surface 21a of the end cap 21, and the valve body 31 of the one-way valve 30 faces the inside of the housing, and at least a portion of the valve body 31 protrudes from the inner surface 21b of the end cap 21. That is, the valve body 31 extends into the housing along the thickness direction of the end cap 21.

[0265] In this embodiment, the one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve seat 311 and a valve cover 312. The valve seat 311 includes a seat bottom wall 3115 and a seat sidewall 3116 connected to the seat bottom wall 3115. The valve cover 312 is disposed at one end of the valve seat 311 away from the seat bottom wall 3115. The valve cover 312, the seat sidewall 3116, and the seat bottom wall 3115 enclose the valve cavity 313. The valve seat 311 is provided with an air inlet 313a for the valve cavity 313, connecting the valve cavity 313 with the interior of the housing. The valve core 32 is used to block the air inlet passage of the valve cavity 313. The valve core 32 is configured to open the air inlet passage in response to gas within the housing, thereby releasing gas from the battery cell 20. In this embodiment, the valve core 32 directly blocks the air inlet 313a of the valve cavity 313. The air inlet passage includes a gas flow path from the inside of the battery cell 20 shell to the air inlet 313a of the valve cavity 313 and to the side where the air inlet 313a is discharged.

[0266] In this embodiment, the valve body 31 of the one-way valve 30 is provided with a valve seat 311 and a valve cover 312. The one-way valve 30 with this structure is provided with the valve body 31 as two parts, so that it is convenient to assemble the valve core 32 into the valve cavity 313, which is beneficial to reduce the difficulty of assembling the one-way valve 30.

[0267] Continuing with reference to Figures 13, 14, and 15, according to some embodiments of the present application, the valve seat 311 has a fourth through hole 3114 extending through the seat bottom wall 3115, and the air inlet 313a is the fourth through hole 3114, that is, the fourth through hole 3114 serves as the air inlet 313a of the valve cavity 313. Of course, in other embodiments, the air inlet 313a may also be provided on the outer circumferential surface of the portion of the valve body 31 extending into the housing. When the air inlet 313a is provided on the outer circumferential surface of the portion of the valve body 31 extending into the housing, the orientation of the valve core 32 will be changed accordingly, and the blocking member 321 is movably provided in the valve cavity 313 along the radial direction of the valve seat 311, so that the valve core 32 blocks the air inlet 313a.

[0268] Continuing with Figures 13, 14, and 15, according to some embodiments of the present application, the gas outlet 313b can be directly provided on the valve cover 312, that is, the gas outlet 313b is a channel provided on the valve cover 312. Specifically, the valve cover 312 has a fifth through hole 3123 extending therethrough, and the gas outlet 313b is the fifth through hole 3123, that is, the fifth through hole 3123 serves as the gas outlet 313b of the valve cavity 313. This arrangement facilitates the outward transmission of gas from within the battery 100.

[0269] The fifth through hole 3123 provided on the valve cover 312 can be one or more. For example, in Figures 13 and 14 , the valve cover 312 is provided with three fifth through holes 3123. Of course, in other embodiments, the valve cover 312 can also be provided with two, four, five, or six fifth through holes 3123. By way of example, the valve cover 312 is provided with multiple fifth through holes 3123, and the multiple fifth through holes 3123 are evenly spaced. By way of example, the multiple fifth through holes 3123 are evenly spaced around the center of the valve cover 312, which allows for smoother gas flow.

[0270] By arranging a fifth through hole 3123 on the valve cover 312 of the valve body 31 to form an air outlet 313b of the valve body 31, the valve cavity 313 of the valve body 31 can be connected with the outside of the shell through the fifth through hole 3123 arranged on the valve cover 312. The valve body 31 with such a structure can reduce the interference effect of the air outlet 313b on the connection between the valve cover 312 and the valve seat 311, which is conducive to reducing the difficulty of assembling the valve cover 312 and the valve seat 311.

[0271] Continuing with FIG15 , according to some embodiments of the present application, a first guide post 31211 is protruding from the side of the valve cover 312 facing the blocking member 321, and a portion of the elastic member 322 is sleeved on the outside of the first guide post 31211. The valve cover 312 may also be provided with a third through hole 31212 (not shown in FIG15 , for details, see FIG7 ) that passes through the valve cover 312 and the first guide post 31211. The gas outlet 313b is the third through hole 31212. That is, the third through hole 31212 serves as the gas outlet 313b of the valve cavity 313. This arrangement facilitates the outward transmission of gas from within the battery 100.

[0272] Please refer to Figure 16, which is a front view of the one-way valve 30 according to one or more embodiments. According to some embodiments of the present application, the air outlet 313b may also be provided between the valve cover 312 and the valve seat 311. That is, the air outlet 313b is the gap formed between the valve cover 312 and the valve seat 311. Specifically, the valve cover 312 is connected to the valve seat 311, and the air outlet 313b is the first exhaust gap 313c formed between the valve cover 312 and the valve seat 311.

[0273] The outer circumferential surface of the valve cover 312 is provided with a plurality of protrusions 312a, which are arranged at intervals along the circumference of the valve cover 312. The protrusions 312a have an interference fit with the valve seat 311. A first exhaust gap 313c is formed between the valve seat 311 and the area of ​​the outer circumferential surface of the valve cover 312 where the protrusions 312a are not provided. That is, along the circumference of the valve cover 312, an air outlet 313b is formed between two adjacent protrusions 312a. By providing the first exhaust gap 313c between the valve cover 312 and the valve seat 311 to form the air outlet 313b of the valve cavity 313, the valve cavity 313 of the valve body 31 can communicate with the exterior of the housing through the first exhaust gap 313c formed between the valve cover 312 and the valve seat 311, resulting in a simple structure and easy processing.

[0274] According to some embodiments of the present application, the valve cover 312 may be connected to the valve seat 311, which is then connected to the end cap 21 via the valve seat 311. Specifically, a first recess 3112 is provided at one end of the valve seat 311, facing away from the seat bottom wall 3115. At least a portion of the valve cover 312 is accommodated within the first recess 3112. The valve cover 312 may be entirely or partially located within the first recess 3112, meaning that the valve cover 312 may or may not extend beyond the first recess 3112. By providing a first recessed groove 3112 on the valve seat 311, and at least partially accommodating the valve cover 312 in the first recessed groove 3112, the one-way valve 30 adopting such a structure can, on the one hand, save space occupied by the valve body 31, and on the other hand, improve the structural stability of the valve cover 312 assembled on the valve seat 311, and can provide a certain degree of protection for the valve cover 312, thereby reducing wear or damage to the valve cover 312.

[0275] According to some embodiments of the present application, the valve cover 312 and the valve seat 311 may be separately connected to the end cover 21. Specifically, the valve cover 312 is connected to the end cover 21, and the air outlet 313b may be a second exhaust gap (not shown) formed between the valve cover 312 and the end cover 21. The valve cover 312 is connected to the end cover 21 so that the valve cover 312 and the valve seat 311 jointly define a valve cavity 313 for accommodating the valve core 32. When the valve is opened, the sealing member 321 opens the fourth through hole 3114, and the gas enters the valve cavity 313. At this time, any opening or gap on the upper part of the valve cavity 313 can be used as an outlet 313b; in other words, the sealing member 321 controls the sealing of the battery 100 system, and other areas of the valve cavity 313 do not play a sealing role. Openings or gaps can be set to discharge the gas in the valve cavity 313; the second exhaust gap between the valve cover 312 and the end cover 21 can be a gap left by local welding, or a protrusion 312a can be set on the connecting surface 31222a of the two, and the protrusion 312a is used for connection. The area without the protrusion 312a forms a second exhaust gap.

[0276] According to some embodiments of the present application, a one-way valve 30 is disposed on the end cap 21. The valve body 31 of the one-way valve 30 faces the interior of the housing, and at least a portion of the valve body 31 protrudes from the outer surface 21a21b of the end cap 21. The one-way valve 30 includes a valve body 31 and a valve core 32. The valve body 31 defines a valve cavity 313, and the valve core 32 is disposed within the valve cavity 313. The valve body 31 includes a valve seat 311, which includes a bottom wall 3115 and side walls 3116 connected to the bottom wall 3115. The bottom wall 3115, the side walls 3116, and the end cap 21 enclose a valve chamber 313. The end cap 21 is provided with an outlet 313b for the valve chamber 313. For example, the first vent 291 may serve as the outlet 313b to connect the valve chamber 313 with the exterior of the housing. The valve seat 311 is provided with an inlet 313a for the valve chamber 313 to connect the valve chamber 313 with the interior of the housing. For example, the fourth through hole 3114 extending through the bottom wall 3115 may serve as the inlet 313a. The valve core 32 is used to block the inlet passage of the valve chamber 313. The valve core 32 is configured to open the inlet passage in response to gas inside the housing and release gas from the battery cell 20. In this embodiment, the valve body 31 of the one-way valve 30 may only have the valve seat 311 without the valve cover 312, and the valve seat 311 may be directly connected to the end cover 21; or in other words, the end cover 21 may serve as the valve cover 312 of the valve body 31. In this way, the installation height of the one-way valve 30 can be reduced.

[0277] According to some embodiments of the present application, a third recessed groove (not shown) is provided on the side of the end cap 21 facing the interior of the housing, recessed relative to the inner surface 21b of the end cap 21. At least a portion of the seat sidewall 3116 is accommodated in the third recessed groove and connected to the end cap 21. This connection method is equivalent to the connection method between the cover sidewall 3122 and the end cap 21 in the embodiment shown in Figure 12 and is not illustrated here. In this embodiment, by providing a third recessed groove on the side of the end cap 21 facing the interior of the housing, and by at least a portion of the seat sidewall 3116 being accommodated in the third recessed groove, the one-way valve 30 adopting this structure can save space occupied by the valve body 31 in the thickness direction of the end cap 21.

[0278] According to some embodiments of the present application, the exhaust assembly 90 includes a breathable membrane assembly 40 , which includes a breathable membrane 41 . The breathable membrane 41 is configured to allow gas inside the battery cell 20 to be discharged through the breathable membrane 41 .

[0279] According to some embodiments of the present application, the breathable membrane assembly 40 includes a breathable membrane 41. The breathable membrane 41 is made of a breathable material with excellent air permeability, allowing gas molecules to pass through. By selecting the breathable membrane assembly 40 as the exhaust assembly 90, the battery cell 20 can discharge internal gas through the breathable membrane 41 while in a sealed state, promptly discharging the internal gas of the battery 100 housing to the outside of the housing. This prevents the internal pressure of the battery 100 housing from becoming excessively high, reduces the risk of premature valve opening of the pressure relief mechanism 70, and significantly improves the lifespan of the battery cell 20.

[0280] Furthermore, the breathable membrane 41 also has liquid-isolating properties, preventing liquid from passing through, and therefore, can prevent the overflow of the electrolyte while discharging the gas. In addition, the breathable membrane 41 can also block external water vapor, dust and impurities from entering the interior of the battery cell 20, 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 also needs to have oleophobicity. Therefore, the material of the breathable membrane 41 can be selected from polymer materials, such as polytetrafluoroethylene, polypropylene, 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.

[0281] Please refer to Figure 17, which is a schematic cross-sectional view of a breathable membrane assembly 40 according to one or more embodiments. According to some embodiments of the present application, the breathable membrane assembly 40 includes a breathable membrane 41 and a connector 42, which is used to support the breathable membrane 41. The connector 42 is provided with a first breathable hole 491, and the breathable membrane 41 is disposed on the connector 42. The breathable membrane 41 covers the first breathable hole 491. The breathable membrane 41 is configured to allow gas inside the battery cell 20 to pass through the breathable membrane 41 and be discharged.

[0282] 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 other components of the breathable membrane assembly 40. The breathable membrane 41 is connected to other components through the connector 42 to improve the stability of the connection. The connector 42 is provided with at least one first air hole 491, which serves 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 exhaust hole on the battery cell 20.

[0283] In one embodiment, the connector 42 may be a metal member 42, a resin member, or the like. The metal member 42 may be made of copper, iron, aluminum, steel, or an aluminum alloy. Selecting a metal connector 42 facilitates welding the connector to the wall. The following description of this embodiment utilizes a metal connector 42 as an example, but this is not intended to limit this embodiment and should not restrict this embodiment. The embodiment is also applicable to connectors made of non-metallic materials.

[0284] As shown in FIG17( a ), the breathable membrane 41 can be directly provided on the surface of the metal member 42. In other embodiments, a sink can also be provided on the metal member 42.

[0285] Continuing with Figure 17 , according to some embodiments of the present application, the metal member 42 has a first annular platform T1 that is recessed relative to the surface of the metal member 42 . The first annular platform T1 is disposed around the first vent 491 , and the breathable membrane 41 is disposed on the first annular platform T1 . This arrangement can reduce the installation height of the breathable membrane assembly 40 .

[0286] Please refer to Figure 18, which is a schematic cross-sectional view of a 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 metal member 42. The backing member 43 has a higher air permeability than the breathable membrane 41.

[0287] The breathable membrane assembly 40 includes a breathable membrane 41, a metal part 42 and a backing part 43. The breathable membrane 41 is arranged on the metal part 42, and the backing part 43 is arranged between the breathable membrane 41 and the metal part 42. The backing part 43 is used to support the breathable membrane 41 and allow gas to pass through the breathable membrane 41.

[0288] Backing member 43 supports breathable membrane 41, preventing it from deforming. Backing member 43 is made of a material with better air permeability than membrane 41 to ensure it does not interfere with the ventilation process of membrane 41. Backing member 43 is also corrosion-resistant and heat-resistant. A wide variety of materials are available for backing member 43, including porous polymers such as polypropylene, polyamide, polytetrafluoroethylene, and polyperfluoroethylene propylene. Metal-organic framework porous materials, carbon membranes, and ceramic porous materials are also possible, but are not limited here.

[0289] As shown in Figure 18(a), the metal component 42 also has a second annular surface T2 that is recessed relative to the surface of the metal component 42. This second annular surface T2 surrounds the first air vent 491, and the backing member 43 is mounted on this second annular surface T2. The second annular surface T2 supports the backing member 43, while the breathable membrane 41 can be directly attached to the surface of the metal component 42. In this configuration, due to the relatively small thickness of the breathable membrane 41, the overall height of the breathable membrane assembly 40 is relatively minimal. By reducing the number of recessed surfaces on the metal component 42, the manufacturing process is simplified while also improving the strength of the metal component 42.

[0290] As shown in (b) of Figure 18, the metal part 42 has a first annular table T1 and a second annular table T2 that are recessed relative to the surface of the metal part 42, and a transition surface T3. The first annular table T1 is arranged around the second annular table T2, and the transition surface T3 connects the first annular table T1 and the second annular table T2. The first annular table T1 is closer to the surface of the metal part 42 than the second annular table T2. The second annular table T2 is arranged around the first air hole 491. The backing member 43 is arranged on the second annular table T2, and the breathable membrane 41 is arranged on the first annular table T1.

[0291] The first annular table surface T1 and the second annular table surface T2 are formed by inward depressions on the surface of the metal member 42. This can be achieved by stamping the metal member 42 to form the inward depressions, or by etching the metal member 42 to remove a portion of the structure. The depth of the depressions of the first annular table surface T1 and the second annular table surface T2 relative to the surface of the metal member 42 can be set based on the thickness of the breathable membrane 41 and the backing member 43. Preferably, the depth of the depression of the second annular table surface T2 relative to the first annular table surface T1 (i.e., the height of the transition surface T3) is equal to the thickness of the backing member 43, so that the second annular table can accommodate the backing member 43, and the surface of the backing member 43 facing the breathable membrane 41 is flush with the first annular table surface T1. Furthermore, the depression depth of the first annular platform T1 relative to the surface of the metal component 42 is equal to the thickness of the breathable membrane 41 , so that the first annular platform can accommodate the breathable membrane 41 , and the side surface of the breathable membrane 41 away from the metal component 42 is flush with the surface of the metal component 42 .

[0292] 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 and, in turn, the installation height of the breathable membrane assembly 40. In other embodiments, if the breathable membrane assembly 40 does not include a backing member 43, only the first annular platform T1 can be provided to support the breathable membrane 41.

[0293] 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 nanotechnology. 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-level microporation treatment through a specific solution. The main purpose is to better combine the metal surface with the plastic and improve the connection strength.

[0294] According to some embodiments of the present application, the end cover 21 has a first exhaust hole 291, which connects the inside of the shell with the outside of the shell, and the exhaust assembly 90 is configured so that the gas discharged through the first exhaust hole 291 flows through the one-way valve 30 and the breathable membrane assembly 40.

[0295] The first vent 291 connects the interior of the housing with the exterior of the housing, meaning that the first vent 291 is a through-hole. Gas within the battery cell 20 housing can be discharged through the first vent 291 to regulate the pressure within the battery cell 20 housing. The vent assembly 90 is configured so that the gas discharged through the first vent 291 flows through the one-way valve 30 and the breathable membrane assembly 40. This means that when the gas flows through the first vent 291, it also flows through the one-way valve 30 and the breathable membrane assembly 40, which are part of the same vent assembly 90; in other words, the gas's discharge path requires it to flow through both the one-way valve 30 and the breathable membrane assembly 40 simultaneously. Alternatively, the one-way valve 30 and the breathable membrane assembly 40 within the same vent assembly 90 are connected in series, so that when the gas flows through the vent assembly 90, it flows sequentially through the one-way valve 30 and the breathable membrane assembly 40 within the vent assembly 90. The gas may first flow through the breathable membrane assembly 40 and then through the one-way valve 30, or it may first flow through the one-way valve 30 and then through the breathable membrane assembly 40. The order of flow can be set as needed, but both structures need to flow through, rather than having some gas flow only through the one-way valve 30 and be discharged, while another portion of gas flows only through the breathable membrane assembly 40. The end cap 21 may be provided with a single first exhaust hole 291, or it may be provided with multiple first exhaust holes 291. When there are multiple first exhaust holes 291, each first exhaust hole 291 is equipped with a set of exhaust assemblies 90, and when the gas is discharged through the first exhaust hole 291, it will flow through the one-way valve 30 and breathable membrane assembly 40 in the exhaust assembly 90 provided at the first exhaust hole 291. The first vent holes 291 can be located anywhere on the end cap 21, and the diameter of the first vent holes 291 can be adjusted as needed. The size and number of the vent holes can be designed based on the capacity of the battery cell 20, the type and volume of the battery 100, the gas production volume, the gas production rate, etc. As mentioned above, the first vent holes 291 can also be located on any wall of the housing 22.

[0296] In this embodiment, by providing a breathable membrane assembly 40 and a one-way valve 30 in series, the presence of the one-way valve 30 can control the system from being constantly ventilated. Instead, the one-way valve 30 is activated to vent air only when a certain threshold is reached. This protects the sealing of the battery cell 20 system and reduces the probability of external water vapor entering the battery cell 20 system. Furthermore, the presence of the breathable membrane 41 can, on the one hand, prevent electrolyte from overflowing. On the other hand, when the one-way valve 30 is open, the breathable membrane 41 can achieve a closed battery 100 system, allowing the battery cell 20 to vent internal gas through the breathable membrane 41 and the one-way valve 30 while in a sealed state. This alleviates the disadvantage that when the one-way valve 30 is venting, the battery cell 20 system is open and easily invaded by external water vapor. In other embodiments, the one-way valve 30 and the breathable membrane assembly 40 in the vent assembly 90 can also be arranged in parallel, that is, a portion of the gas can be discharged through the one-way valve 30, and the remaining portion of the gas can be discharged through the breathable membrane assembly 40. It can also be a hybrid, that is, there can be exhaust components 90 connected in series or in parallel.

[0297] According to some embodiments of the present application, the exhaust assembly 90 includes a one-way valve 30 and a breathable membrane assembly 40, the breathable membrane assembly 40 includes a breathable membrane 41, the one-way valve 30 includes a valve body 31, the valve body 31 has a valve cavity 313 inside, the valve body 31 is provided with an air inlet 313a and an air outlet 313b, the air inlet 313a is used to connect the valve cavity 313 with the inside of the shell, and the air outlet 313b is used to connect the valve cavity 313 with the outside of the shell; the battery cell 20 has an exhaust channel connecting the air inlet 313a of the valve cavity 313, the valve cavity 313 and the air outlet 313b of the valve cavity 313, the exhaust channel is used to discharge the gas inside the shell, and the breathable membrane 41 is arranged on the exhaust channel.

[0298] In this embodiment, when the gas is discharged through the one-way valve 30, its discharge path is the interior of the battery cell 20 - the air inlet 313a - the valve cavity 313 - the air outlet 313b - the outside of the battery cell 20, and the entire exhaust path constitutes an exhaust channel; that is, the gas inside the battery cell 20 enters the valve cavity 313 from the air inlet 313a, flows through the valve cavity 313, and is discharged from the air outlet 313b of the valve cavity 313 to the outside of the battery cell 20; by arranging the breathable membrane 41 on this exhaust channel, it means that the gas also flows through the breathable membrane 41 when passing through this exhaust channel, that is, it flows through the one-way valve 30 and the breathable membrane assembly 40 at the same time, further indicating the series relationship between the one-way valve 30 and the breathable membrane assembly 40. Among them, the breathable membrane 41 can be in any node section of the exhaust channel. For example, it can pass through the breathable membrane 41 before entering the valve cavity 313 of the one-way valve 30, that is, before entering the air inlet 313a, and then enter the valve cavity 313; it can also flow through the breathable membrane 41 after entering the valve cavity 313 of the one-way valve 30 but before flowing out of the valve cavity 313, that is, before flowing out of the valve cavity 313 from the air outlet 313b; it can also be after flowing out of the valve cavity 313, that is, after flowing out from the air outlet 313b, and then discharged to the outside of the battery cell 20 through the breathable membrane 41.

[0299] According to some embodiments of the present application, the breathable membrane 41 is disposed on the air intake side of the air inlet 313 a of the valve cavity 313 of the one-way valve 30 .

[0300] According to some embodiments of the present application, the breathable membrane 41 is arranged on the side of the air inlet 313a for air intake; and / or the breathable membrane 41 is arranged on the side of the air inlet 313a for air outlet; and / or the breathable membrane 41 is arranged on the side of the air outlet 313b for air intake; and / or the breathable membrane 41 is arranged on the side of the air outlet 313b for air outlet.

[0301] According to some embodiments of the present application, the breathable membrane 41 is disposed between the air inlet 313a and the air outlet 313b of the valve cavity 313 of the one-way valve 30. For example, the breathable membrane 41 may be disposed on the outlet side of the air inlet 313a of the valve cavity 313 of the one-way valve 30; or the breathable membrane 41 may be disposed on the inlet side of the air outlet 313b of the valve cavity 313 of the one-way valve 30.

[0302] According to some embodiments of the present application, the breathable membrane 41 is disposed on the side of the gas outlet 313 b of the valve cavity 313 of the one-way valve 30 .

[0303] According to some embodiments of the present application, along the thickness direction of the end cap 21, the breathable membrane 41 of the breathable membrane assembly 40 is closer to the interior of the housing than the one-way valve 30. Specifically, the end cap 21 includes an outer surface 21a and an inner surface 21b disposed in opposite directions, with the outer surface 21a facing the exterior of the housing and the inner surface 21b facing the interior of the housing. The thickness direction of the end cap 21 is the direction from the inner surface 21b to the outer surface 21a. By positioning the breathable membrane 41 of the breathable membrane assembly 40 closer to the interior of the housing than the one-way valve 30, gas from the battery cell 20 can be discharged through the breathable membrane 41 before passing through the one-way valve 30. In this manner, while the gas is being discharged, the breathable membrane 41 can be used to block the overflow of the electrolyte, preventing the electrolyte from entering the one-way valve 30, reducing electrolyte erosion on the components of the one-way valve 30, and preventing the electrolyte from accumulating within the one-way valve 30 and blocking the exhaust passage.

[0304] According to some embodiments of the present application, the one-way valve 30 is disposed on the outer surface 21a of the end cap 21, with the valve body 31 of the one-way valve 30 facing the exterior of the housing, and at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21. The breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the exterior of the housing. At least a portion of the breathable membrane assembly 40 is disposed on the outer surface 21a.

[0305] According to some embodiments of the present application, the one-way valve 30 is disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the interior of the housing, and at least a portion of the valve body 31 protruding from the inner surface 21b of the end cap 21. The breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the interior of the housing. Specifically, the valve body 31 of the one-way valve 30 is disposed on the outer surface 21a, with at least a portion of the valve body 31 protruding from the inner surface 21b. The breathable membrane assembly 40 is disposed on the portion of the valve body 31 protruding from the inner surface 21b.

[0306] According to some embodiments of the present application, the one-way valve 30 is disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the exterior of the housing and at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21. The breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the interior of the housing. The valve body 31 of the one-way valve 30 is disposed on the outer surface 21a, with at least a portion of the valve body 31 protruding from the outer surface 21a. The breathable membrane assembly 40 is at least partially disposed on the inner surface 21b.

[0307] According to some embodiments of the present application, the one-way valve 30 is disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the interior of the housing and at least a portion of the valve body 31 protruding from the inner surface 21b of the end cap 21. The breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the exterior of the housing. The valve body 31 of the one-way valve 30 is disposed on the outer surface 21a, with at least a portion of the valve body 31 protruding from the inner surface 21b. The breathable membrane assembly 40 is disposed on the side of the one-way valve 30 facing the exterior of the housing.

[0308] According to some embodiments of the present application, the breathable membrane assembly 40 is connected to the one-way valve 30, which is connected to the end cap 21; or the one-way valve 30 is connected to the breathable membrane assembly 40, which is connected to the end cap 21. In this embodiment, the one-way valve 30 and the breathable membrane assembly 40 can be combined and then connected to the end cap 21. In other words, one of the one-way valve 30 and the breathable membrane assembly 40 is directly connected to the end cap 21, and both do not need to be directly connected to the end cap 21. This method can simplify the assembly process.

[0309] According to some embodiments of the present application, the breathable membrane assembly 40 and the one-way valve 30 may be independently connected to the end cover 21 .

[0310] Please refer to Figures 19 and 20. Figure 19 is a schematic diagram of a partial cross-sectional structure of the end cover 21 according to one or more embodiments; Figure 20a is a schematic diagram of a cross-sectional structure of a battery cell 20 according to one or more embodiments. Figure 20b is a front view of the end cover 21 of the battery cell 20 according to one or more embodiments. Figure 20c is a schematic diagram of a partial decomposition structure of the battery cell 20 according to one or more embodiments. According to some embodiments of the present application, a one-way valve 30 is provided on the end cover 21, the valve body 31 of the one-way valve 30 faces the outside of the outer shell and at least part of the valve body 31 protrudes from the outer surface 21a of the end cover 21, and the breathable membrane assembly 40 is provided on the side of the end cover 21 facing the inside of the outer shell; the one-way valve 30 and the breathable membrane assembly 40 are respectively and independently connected to the end cover 21.

[0311] Among them, the end cover 21 is provided with a first exhaust hole 291, the first exhaust hole 291 includes a through hole section 280 and a first hole section 281, the through hole section 280 and the first hole section 281 are arranged along the thickness direction of the end cover 21, the through hole section 280 connects the inside of the shell with the outside of the shell, the first hole section 281 is located on the side of the through hole section 280 away from the inside of the shell, the first hole section 281 is recessed relative to the outer surface 21a, the aperture of the first hole section 281 is larger than the aperture of the through hole section 280, the one-way valve 30 is at least partially accommodated in the first hole section 281, the valve body 31 of the one-way valve 30 faces the outside of the shell and at least part of the valve body 31 protrudes from the outer surface 21a of the end cover 21.

[0312] As shown in Figure 19, the first exhaust hole 291 is a countersunk hole recessed relative to the outer surface 21a of the end cover 21. When the one-way valve 30 is connected to the end cover 21, part of the structure of the one-way valve 30 can be embedded in the first exhaust hole 291 to reduce the installation height.

[0313] According to some embodiments of the present application, the one-way valve 30 is welded to the end cap 21. As shown in Figure 20 , the valve seat 311 of the one-way valve 30 can be welded to the end cap 21; specifically, the valve cap 312 of the one-way valve 30 is connected to the valve seat 311, and the valve seat 311 is welded to the end cap 21. In other embodiments, when the one-way valve 30 adopts the embodiment shown in Figure 11 , the valve seat 311 of the one-way valve 30 can also be connected to the valve cap 312, and the valve cap 312 is welded to the end cap 21.

[0314] According to some embodiments of the present application, stress relief grooves are provided around the weld mark between the valve cover 312 / valve seat 311 and the end cover 21. These grooves may be provided only on the end cover 21, only on the valve cover 312 / valve seat 311, or on both the end cover 21 and the valve cover 312 / valve seat 311. As shown in FIG20 , a second stress relief groove 211 is provided on the end cover 21 around the third weld mark W3 between the valve seat 311 and the end cover 21.

[0315] According to some embodiments of the present application, at least a portion of the breathable membrane assembly 40 is disposed on the inner surface 21b of the end cover 21, the breathable membrane assembly 40 includes a breathable membrane 41 and a metal part 42, the metal part 42 is provided with a first breathable hole 491, the breathable membrane 41 is disposed on the metal part 42 and covers the first breathable hole 491, and the metal part 42 is connected to the end cover 21.

[0316] That is, the breathable membrane 41 is connected to the end cap 21 by the metal member 42. The metal member 42 can 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.

[0317] Please continue to refer to Figures 19 and 20. According to some embodiments of the present application, the end cover 21 has an outer surface 21a and an inner surface 21b arranged in opposite directions, the outer surface 21a is arranged toward the outside of the shell, and the inner surface 21b is arranged toward the inside of the shell. The end cover 21 has a first sink S1 that is recessed relative to the inner surface 21b. The first sink S1 is arranged around the first exhaust hole 291, and the breathable membrane assembly 40 is at least partially accommodated in the first sink S1.

[0318] Among them, the first depression S1 is formed by the inner surface 21b of the end cover 21 being recessed in the direction of the outer surface 21a of the end cover 21. The end cover 21 can be stamped to form the recessed first depression S1, or the end cover 21 can be etched to remove part of the structure to form the recessed first depression S1. The recessed depth of the first depression S1 relative to the inner surface 21b of the end cover 21 can be set according to the thickness of the breathable membrane assembly 40. The thickness of the breathable membrane assembly 40 is the overall thickness including the breathable membrane 41, the metal part 42 and the backing part 43. As mentioned above, the breathable membrane 41 and the backing part 43 can be accommodated in the annular platform on the metal part 42 that is recessed relative to the surface of the metal part 42, that is, the overall thickness of the breathable membrane assembly 40 can be equal to the thickness of the metal part 42. Preferably, the depth of the first recessed portion S1 relative to the inner surface 21b of the end cap 21 is equal to the thickness of the breathable membrane assembly 40, so that the breathable membrane assembly 40 is accommodated within the first recessed portion S1, and the surface of the breathable membrane assembly 40 facing the interior of the housing is flush with the inner surface 21b of the end cap 21. In this way, the installation height of the breathable membrane assembly 40 can be reduced, thereby reducing the space occupied by the battery cell 20 interior housing and improving the space utilization inside the housing.

[0319] As shown in Figure 20 , the breathable membrane 41 can be positioned on the side of the metal member 42 facing the interior of the housing; that is, the breathable membrane 41 is positioned below the metal member 42. This arrangement reduces the impact of the operating environment of the battery cell 20 on the breathable membrane 41. In other embodiments, the breathable membrane 41 can also be positioned on the side of the metal member 42 facing the exterior of the housing, that is, between the metal member 42 and the end cap 21. This arrangement reduces erosion of the breathable membrane 41 by the electrolyte system.

[0320] Please refer to Figures 19 and 21 in conjunction. Figure 21 is a schematic cross-sectional view of a battery cell 20 according to one or more embodiments. According to some embodiments of the present application, the end cap 21 further includes a second recessed portion S2 that is recessed relative to the inner surface 21b. The second recessed portion S2 is connected to the first recessed portion S1 via a first transition connection surface 31222aC1. The first recessed portion S1 is closer to the inner surface 21b of the end cap 21 than the second recessed portion S2. The first recessed portion S1 is disposed around the second recessed portion S2, and the second recessed portion S2 is disposed around the first vent 291. The metal member 42 is at least partially accommodated within the first recessed portion S1.

[0321] Specifically, the first sink S1 and the second sink S2 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 setting the first sink S1 is to carry and accommodate the breathable membrane assembly 40. 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 setting the second sink S2 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 second sink S2 relative to the first sink S1 (i.e., the height of the first transition connection surface 31222aC1) is set according to demand.

[0322] According to some embodiments of the present application, the breathable membrane 41 is disposed on a side of the metal component 42 away from the end cap 21 , or the breathable membrane 41 is disposed on a side of the metal component 42 close to the end cap 21 .

[0323] According to some embodiments of the present application, the orthographic projection of the first vent 491 on the end cap 21 is located within the region where the through-hole section 280 of the first exhaust hole 291 is located. In other embodiments, the orthographic projection of the first vent 491 on the end cap 21 may not overlap with the region where the through-hole section 280 of the first exhaust hole 291 is located. In other words, the through-hole section 280 of the first exhaust hole 291 and the first vent 491 are not arranged in a corresponding manner in the thickness direction of the end cap 21, thereby facilitating the regulation of gas discharge.

[0324] Please continue to refer to Figures 19, 20, and 21. According to some embodiments of the present application,

[0325] The end cover 21 further has a third sunken platform S3 that is recessed relative to the inner surface 21 b. The third sunken platform S3 is closer to the inner surface 21 b of the end cover 21 than the first sunken platform S1, and the third sunken platform S3 is disposed around the first sunken platform S1.

[0326] The end cover 21 also has a third sink S3 that is recessed relative to the inner surface 21b. The third sink S3 is connected to the first sink S1 through a second transition connection surface 31222aC2. The third sink S3 is closer to the inner surface 21b of the end cover 21 than the first sink S1, and the third sink S3 is arranged around the first sink S1.

[0327] The third sink S3 accommodates a portion of the breathable membrane assembly 40. As shown in Figures 20 and 21, the breathable membrane 41 is positioned on the metal component 42 and protrudes from its surface. This allows the metal component 42 to be housed within the first sink S1, while the breathable membrane 41 is housed within the third sink S3. Furthermore, this allows for space to be left when the end cap 21 and the insulating member 24 are assembled, avoiding weld marks between the metal component 42 and the end cap 21. As shown in Figures 20 and 21, a first weld mark avoidance groove 212 is provided between the insulating member 24 and the end cap 21 to avoid a fourth weld mark W4 between the metal component 42 and the end cap 21.

[0328] According to some embodiments of the present application, a breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the interior of the housing. The breathable membrane assembly 40 includes a breathable membrane 41, and the breathable membrane 41 is connected to the end cap 21. That is, the breathable membrane assembly 40 may only include the breathable membrane 41, and the breathable membrane 41 is directly composited with the end cap 21 to cover the through-hole section 280 of the first exhaust hole 291. This allows the gas to pass through the breathable membrane 41 before being discharged through the first exhaust hole 291. As mentioned above, the end cap 21 may be nano-processed, and then the breathable membrane 41 may be compositely connected to the end cap 21. The breathable membrane 41 may be directly attached to the surface of the end cap 21, or a sunken platform may be provided on the end cap 21 that is recessed relative to the surface of 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. In this embodiment, the provision of a breathable membrane 41 allows the gas within the battery 100 to be promptly discharged while sealed, preventing electrolyte overflow and the ingress of external moisture, thereby protecting the internal environment of the battery cell 20 and effectively improving the reliability of the battery 100. Furthermore, the breathable membrane assembly 40 comprises only one layer of breathable membrane 41, which is relatively thin and has minimal impact on the installation height of the battery cell 20. In this embodiment, the valve core 32 directly blocks the air inlet 313a of the valve cavity 313. The air inlet passage comprises a gas flow path from the interior of the battery cell 20 housing to the breathable membrane assembly 40, to the air inlet 313a of the valve cavity 313, and to the outlet side of the air inlet 313a.

[0329] According to some embodiments of the present application, the aforementioned positional relationship, connection method, etc., when the breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the interior of the housing, are also applicable to the one-way valve 30 shown in FIG11 . In other words, when the one-way valve 30 structure shown in FIG12 is used, the breathable membrane assembly 40 of the exhaust assembly 90 is disposed on the side of the end cap 21 facing the interior of the housing.

[0330] Please refer to Figures 22 and 23 . Figure 22 is a schematic diagram of a partial cross-sectional structure of an end cap 21 according to one or more embodiments; Figure 23a is a schematic diagram of a cross-sectional structure of a battery cell 20 according to one or more embodiments; Figure 23b is a front view of the end cap 21 of a battery cell 20 according to one or more embodiments; and Figure 23c is a 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 one-way valve 30 is disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the exterior of the housing and at least a portion of the valve body 31 protruding from the outer surface 21a of the end cap 21. A breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the exterior of the housing; the one-way valve 30 and the breathable membrane assembly 40 are independently connected to the end cap 21.

[0331] As before, the end cap 21 is provided with a first vent hole 291, which includes a first hole section 281. The one-way valve 30 is at least partially accommodated in the first hole section 281. The valve body 31 of the one-way valve 30 faces the exterior of the housing, and at least a portion of the valve body 31 protrudes from the outer surface 21a of the end cap 21. In this embodiment, the breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the exterior of the housing. The breathable membrane assembly 40 is at least partially accommodated within the first vent hole 291, and the breathable membrane assembly 40 is located on the side of the one-way valve 30 facing the end cap 21.

[0332] Specifically, the first exhaust hole 291 also includes a second hole section 282. Along the thickness direction of the end cover 21, the second hole section 282 is located between the through hole section 280 and the first hole section 281. The aperture of the second hole section 282 is smaller than the aperture of the first hole section 281, and the aperture of the second hole section 282 is larger than the aperture of the through hole section 280. The breathable membrane assembly 40 is at least partially accommodated in the second hole section 282.

[0333] According to some embodiments of the present application, the breathable membrane assembly 40 includes a breathable membrane 41 and a metal part 42, the metal part 42 is provided with a first breathable hole 491, the breathable membrane 41 is arranged on the metal part 42 and covers the first breathable hole 491, and the metal part 42 is welded to the end cover 21.

[0334] According to some embodiments of the present application, stress relief grooves are provided around the weld mark between the metal member 42 and the end cap 21. These grooves may be provided only on the end cap 21, only on the metal member 42, or on both the end cap 21 and the metal member 42. As shown in FIG23 , a third stress relief groove 421 is provided on the metal member 42 around the fifth weld mark W5 between the metal member 42 and the end cap 21.

[0335] According to some embodiments of the present application, a weld mark avoidance groove 611 is provided on the side of the one-way valve 30 facing the breathable membrane assembly 40. The weld mark avoidance groove 611 covers the weld mark between the metal component 42 and the end cap 21. As shown in FIG23 , a second weld mark avoidance groove 3117 is provided on the valve seat 311 of the one-way valve 30 on the side facing the breathable membrane assembly 40 to avoid the fifth weld mark W5 between the metal component 42 and the end cap 21.

[0336] According to some embodiments of the present application, a breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the exterior of the housing. The breathable membrane assembly 40 includes a breathable membrane 41, which is connected to the end cap 21. Specifically, the breathable membrane assembly 40 may include only the breathable membrane 41, which is directly composited with the end cap 21 and covers the through-hole section 280 of the first vent 291. Alternatively, the breathable membrane 41 may be press-fitted between the valve seat 311 of the one-way valve 30 and the end cap 21.

[0337] According to some embodiments of the present application, when the one-way valve 30 is arranged on the end cover 21, the valve body 31 of the one-way valve 30 faces the outside of the shell and at least a portion of the valve body 31 protrudes from the outer surface 21a of the end cover 21, and the breathable membrane assembly 40 is arranged on the side of the end cover 21 facing the outside of the shell; the one-way valve 30 and the breathable membrane assembly 40 can also be compounded together, and one of them is connected to the end cover 21.

[0338] According to some embodiments of the present application, a breathable membrane assembly 40 is disposed on the side of the one-way valve 30 facing the end cap 21. The breathable membrane assembly 40 is connected to the one-way valve 30, and the one-way valve 30 is connected to the end cap 21. The breathable membrane assembly 40 may consist solely of a breathable membrane 41, which is attached to the side of the valve seat 311 of the one-way valve 30 facing the end cap 21 and covers the first through hole 3111. Alternatively, the breathable membrane assembly 40 may include a breathable membrane 41 and a metal member 42, which is welded to the valve seat 311 of the one-way valve 30. Alternatively, a recessed platform, recessed relative to the surface of the valve seat 311, may be provided on the side of the valve seat 311 facing the end cap 21 to accommodate the breathable membrane assembly 40. This approach can reduce the installation height and simplify the assembly process.

[0339] According to some embodiments of the present application, the breathable membrane assembly 40 may include a breathable membrane 41 and a metal member 42, the one-way valve 30 being disposed on the side of the metal member 42 facing the exterior of the housing, the one-way valve 30 being connected to the metal member 42, and the metal member 42 being connected to the end cap 21. In this manner, the installation height can be reduced and the assembly process can be simplified.

[0340] According to some embodiments of the present application, the one-way valve 30 may be disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the interior of the housing and at least a portion of the valve body 31 protruding from the inner surface 21b of the end cap 21. The breathable membrane assembly 40 is connected to the one-way valve 30, and the one-way valve 30 is connected to the end cap 21. In other words, the one-way valve 30 and the breathable membrane assembly 40 are first assembled and then connected to the end cap 21.

[0341] Please refer to Figures 24 and 25. Figure 24 is a schematic diagram of the exploded structure of the exhaust assembly 90 according to one or more embodiments; Figure 25 is a schematic diagram of the cross-sectional structure of the exhaust assembly 90 according to one or more embodiments. According to some embodiments of the present application, the breathable membrane 41 membrane assembly is arranged on the side of the seat bottom wall 3115 of the one-way valve 30 away from the valve cavity 313. The breathable membrane assembly 40 includes a breathable membrane 41, which is connected to the seat bottom wall 3115 and covers the fourth through hole 3114. In this embodiment, the breathable membrane assembly 40 is compounded with the one-way valve 30, and the breathable membrane 41 is attached to the seat bottom wall 3115 of the one-way valve 30, which can reduce the installation height; at the same time, only the one-way valve 30 needs to be connected to the end cover 21, which can simplify the assembly process.

[0342] As previously described, the end cap 21 is provided with a first vent hole 291, which includes a first hole section 281. The one-way valve 30 is at least partially accommodated in the first hole section 281. The valve body 31 of the one-way valve 30 faces the interior of the housing, and at least a portion of the valve body 31 protrudes from the inner surface 21b of the end cap 21. In this embodiment, the valve seat 311 of the one-way valve 30 is welded to the end cap 21, and a stress relief groove is provided around the weld mark between the valve seat 311 and the end cap 21. The stress relief groove may be provided only on the end cap 21, only on the valve seat 311, or on both the end cap 21 and the valve seat 311. As shown in FIG. 25 , a first stress relief groove 311a is provided on the valve seat 311 around the sixth weld mark W6 between the valve seat 311 and the end cap 21.

[0343] Please refer to Figures 26 and 27 . Figure 26 is a schematic diagram of the exploded structure of the exhaust assembly 90 according to one or more embodiments; Figure 27 is a schematic diagram of the cross-sectional structure of the exhaust assembly 90 according to one or more embodiments. According to some embodiments of the present application, a breathable membrane assembly 40 is disposed on a side of the seat bottom wall 3115 of the one-way valve 30 away from the valve cavity 313. The breathable membrane assembly 40 includes a breathable membrane 41 and a metal member 42. The metal member 42 is provided with a first breathable hole 491. The breathable membrane 41 is disposed on the metal member 42 and covers the first breathable hole 491. The metal member 42 is connected to the seat bottom wall 3115. In this embodiment, by utilizing the metal member 42 to connect to the seat bottom wall 3115, the connection strength can be improved.

[0344] Continuing with reference to FIG. 27 , according to some embodiments of the present application, the seat bottom wall 3115 has an inner wall surface 3115a and an outer wall surface 3115b disposed opposite each other, with the inner wall surface 3115a facing the valve cavity 313. The side of the seat bottom wall 3115 away from the valve cavity 313 has a fourth recessed platform S4 that is recessed relative to the outer wall surface 3115b of the seat bottom wall 3115. The fourth recessed platform S4 surrounds the fourth through hole 3114, and the breathable membrane assembly 40 is at least partially accommodated within the fourth recessed platform S4. In this manner, the installation height of the breathable membrane assembly 40 can be reduced, thereby reducing the space occupied by the internal housing of the battery cell 20 and improving the space utilization rate inside the housing. The breathable membrane 41 can be disposed on the side of the metal part 42 facing the interior of the housing; that is, the breathable membrane 41 is below the metal part 42. This arrangement can reduce the impact of the external working environment of the battery cell 20 on the breathable membrane 41. In other embodiments, the breathable membrane 41 may be arranged on the side of the metal part 42 facing the seat bottom wall 3115, that is, the breathable membrane 41 is arranged between the metal part 42 and the seat bottom wall 3115; through this arrangement, the erosion of the electrolyte system on the breathable membrane 41 can be reduced.

[0345] 27 , according to some embodiments of the present application, the seat bottom wall 3115 further includes a fifth sink S5 that is recessed relative to the outer wall surface 3115b. The fifth sink S5 is connected to the fourth sink S4 via the third transition connection surface 31222aC3. The fourth sink S4 is closer to the outer wall surface 3115b of the seat bottom wall 3115 relative to the fifth sink S5. The fourth sink S4 is arranged around the fifth sink S5, and the fifth sink S5 is arranged around the fourth through hole 3114. The metal part 42 is at least partially accommodated within the fourth sink S4. Through this arrangement, a certain cavity is left between the breathable membrane 41 and the seat bottom wall 3115 to allow gas to be discharged smoothly. The depth of the recess of the fifth sink S5 relative to the fourth sink S4 (i.e., the height of the third transition connection surface 31222aC3) is set according to demand.

[0346] In one embodiment, the breathable membrane 41 is disposed on the side of the metal member 42 facing the seat bottom wall 3115. Alternatively, the breathable membrane 41 is disposed on the side of the metal member 42 away from the valve cavity 313. This facilitates the regulation of gas discharge.

[0347] Referring to Figures 28 and 29 , Figure 28 is an exploded view of the exhaust assembly 90 according to one or more embodiments, and Figure 29 is a cross-sectional view of the exhaust assembly 90 according to one or more embodiments. According to some embodiments of the present application, the breathable membrane assembly 40 is disposed on the side of the seat bottom wall 3115 facing the valve cavity 313.

[0348] The valve chamber 313 includes a first chamber 3131 and a second chamber 3132 that are interconnected. The second chamber 3132 is closer to the seat bottom wall 3115. Along a direction parallel to the seat bottom wall 3115, the cross-sectional area of ​​the first chamber 3131 is larger than that of the second chamber 3132. The valve core 32 is located in the first chamber 3131, and the breathable membrane assembly 40 is located in the second chamber 3132. This arrangement allows gas to enter the valve chamber 313, first pass through the breathable membrane assembly 40, and then reach the valve core 32, thereby preventing electrolyte from overflowing.

[0349] Furthermore, the seat sidewall 3116 includes a first sidewall portion 3116a, a second sidewall portion 3116b, and a third sidewall portion 3116c. The first sidewall portion 3116a and the second sidewall portion 3116b enclose a first cavity 3131, while the third sidewall portion 3116c and the seat bottom wall 3115 enclose a second cavity 3132. The sealing member 321 of the valve core 32 abuts the second sidewall portion 3116b. In this embodiment, the second cavity 3132 is open to communicate with the first cavity 3131. The sealing member 321 of the valve core 32 located in the first cavity 3131 abuts the second sidewall portion 3116b, allowing the sealing member 321 to seal the second cavity 3132. When the internal pressure of the battery cell 20 is low, gas cannot enter the first cavity 3131 from the second cavity 3132. When the internal pressure of the battery cell 20 is high, gas enters the second cavity 3132, pushes open the sealing member 321, enters the first cavity 3131, and then exits through the gas outlet 313b of the valve cavity 313. In this embodiment, the valve core 32 blocks the second cavity 3132 of the valve cavity 313. The gas inlet passage includes a gas flow path from the interior of the battery cell 20 housing to the gas inlet 313a of the valve cavity 313, to the side where gas is discharged from the gas inlet 313a, to the breathable membrane assembly 40, and to the top of the second cavity 3132 of the valve cavity 313.

[0350] 29 , according to some embodiments of the present application, the breathable membrane assembly 40 is located in the second cavity 3132 , so that the gas passes through the breathable membrane assembly 40 before being discharged from the first cavity 3131 through the second cavity 3132 .

[0351] In which, the breathable membrane assembly 40 can only include a breathable membrane 41, which is attached to the side of the seat bottom wall 3115 facing the valve cavity 313 and covers the fourth through hole 3114. In this case, the gas entering from the fourth through hole 3114 passes through the breathable membrane 41, blocking the electrolyte from entering the second cavity 3132.

[0352] In another embodiment, the breathable membrane assembly 40 may include a breathable membrane 41 and a metal part 42, and the breathable membrane 41 is arranged on the metal part 42. The metal part 42 is connected to the wall of the second cavity 3132 (the third side wall portion 3116c), which can improve the stability of the connection and prevent the breathable membrane 41 from being displaced by the gas top.

[0353] The breathable membrane 41 can be disposed on the side of the metal member 42 facing the seat bottom wall 3115, so that the metal member 42 provides support for the breathable membrane 41 and prevents the breathable membrane 41 from being displaced by the gas. In other embodiments, the breathable membrane 41 can also be disposed on the side of the metal member 42 away from the seat bottom wall 3115.

[0354] Please continue to refer to Figure 29. According to some embodiments of the present application, when the breathable membrane 41 is arranged on the side of the metal part 42 facing the seat bottom wall 3115, the surface of the side of the metal part 42 away from the breathable membrane 41 is lower than the surface of the second side wall portion 3116b. Through this arrangement, a certain cavity can be created between the metal part 42 and the sealing part 321, which is conducive to the discharge of gas.

[0355] 29 , according to some embodiments of the present application, the battery cell 20 further includes a sealing ring 80 disposed between the breathable membrane assembly 40 and the seat bottom wall 3115. This arrangement can improve the sealing between the breathable membrane assembly 40 and the seat bottom wall 3115.

[0356] Furthermore, a sealing ring 80 is disposed between the breathable membrane 41 and the seat bottom wall 3115. The sealing ring 80 is disposed around the fourth through hole 3114 and is provided with a second breathable hole 801. The aperture of the second breathable hole 801 is larger than the aperture of the fourth through hole 3114. The breathable membrane 41 covers the second breathable hole 801. This arrangement improves the sealing between the breathable membrane 41 and the seat bottom wall 3115, and the sealing ring 80 does not block the flow of gas.

[0357] According to some embodiments of the present application, the metal member 42 is welded to the third side wall portion 3116c, or the metal member 42 is interference fit with the third side wall portion 3116c. In this way, the assembly of the exhaust assembly 90 is facilitated.

[0358] According to some embodiments of the present application, the breathable membrane 41 is spaced apart from the valve core 32. As shown in FIG29 , the breathable membrane 41 and the valve core 32 are spaced apart by the metal part 42 and a portion of the second cavity 3132. As shown in FIG27 , the breathable membrane 41 and the valve core 32 are spaced apart by the space of the fifth sink and the hole depth of the fourth through hole 3114. As shown in FIG25 , the breathable membrane 41 and the valve core 32 are spaced apart by the hole depth of the fourth through hole 3114, that is, the blocking member 321 does not extend into the fourth through hole 3114, or even if the blocking member 321 partially extends into the fourth through hole 3114, it will not extend to the end of the fourth through hole 3114 on one side away from the valve cavity 313. By spacing the breathable membrane 41 and the valve core 32 so as to form a cavity therebetween, it is beneficial for the gas passing through the breathable membrane 41 to exert a force on the valve core 32.

[0359] According to some embodiments of the present application, the aforementioned positional relationship and connection method when the breathable membrane assembly 40 is disposed on the side of the seat bottom wall 3115 facing the valve cavity 313 are also applicable to a solution in which the one-way valve 30 is disposed on the end cap 21, the valve body 31 of the one-way valve 30 faces the exterior of the housing, and at least a portion of the valve body 31 protrudes from the outer surface 21a of the end cap 21. In other words, when the one-way valve 30 structure shown in Figures 6, 11, and 12 is used, the breathable membrane assembly 40 of the exhaust assembly 90 is disposed on the side of the valve seat 311 / end cap 21 facing the valve cavity 313.

[0360] Please refer to Figure 30, which is a schematic cross-sectional view of an exhaust assembly 90 according to one or more embodiments. According to some embodiments of the present application, a one-way valve 30 is disposed on the end cap 21, with the valve body 31 of the one-way valve 30 facing the interior of the housing, and at least a portion of the valve body 31 protruding from the inner surface 21b of the end cap 21. A breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the exterior of the housing, and covers the exhaust port of the one-way valve 30.

[0361] The breathable membrane assembly 40 may include only the breathable membrane 41, which is attached to the side of the valve cover 312 facing the outside of the housing and covers the fifth through hole 3123. In this case, the gas exhausted from the fifth through hole 3123 passes through the breathable membrane 41, preventing the electrolyte from escaping. In other embodiments, the breathable membrane 41 may be attached to the side of the valve cover 312 facing the inside of the housing and covers the fifth through hole 3123.

[0362] In another embodiment, the breathable membrane assembly 40 may include a breathable membrane 41 and a metal part 42. The breathable membrane 41 is set on the metal part 42 and connected to the valve cover 312 using the metal part 42. This can improve the stability of the connection and prevent the breathable membrane 41 from being displaced by the gas.

[0363] In another embodiment, when the air outlet 313b of the one-way valve 30 is the first exhaust gap 313c and / or the second exhaust gap, the breathable membrane assembly 40 includes a breathable membrane 41 and a metal part 42, and the metal part 42 is connected to the end cover 21 so that the breathable membrane 41 covers the first exhaust gap 313c and / or the second exhaust gap.

[0364] Please refer to Figure 31, which is a schematic cross-sectional view 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 shielding member 50, which is mounted on the end cap 21. The shielding member 50 is located on the side of the end cap 21 facing the outside of the housing and shields the exhaust assembly 90.

[0365] In this embodiment, the one-way valve 30 of the exhaust assembly 90 is disposed on the end cap 21, and the valve body 31 of the one-way valve 30 protrudes from the inner surface 21b of the end cap 21. The breathable membrane assembly 40 is disposed on the side of the end cap 21 facing the interior of the housing. The shielding member 50 can shield the exhaust assembly 90, providing a certain degree of protection and shielding for the exhaust assembly 90. On the one hand, it can reduce wear and damage to the exhaust assembly 90 in the external environment and reduce the risk of impurities or particulate matter from the external environment entering the exhaust assembly 90, which is beneficial for improving the service life of the exhaust assembly 90. On the other hand, covering the exhaust assembly 90 with the shielding member 50 can improve the aesthetics of the outer surface 21a of the battery cell 20. On the other hand, it can facilitate the connection of other components such as detection elements on the side of the shielding member 50 facing away from the exhaust assembly 90, thereby reducing the interference caused by the area of ​​the end cap 21 where the exhaust assembly 90 is disposed on the connection of other components such as detection elements.

[0366] According to some embodiments of the present application, the end cap 21 includes an outer surface 21a and an inner surface 21b disposed opposite to each other, with the outer surface 21a facing the exterior of the housing and the inner surface 21b facing the interior of the housing. A recessed platform recessed relative to the outer surface 21a of the end cap 21 may be provided on the end cap 21 to accommodate the shielding member 50. Specifically, the outer surface 21a of the end cap 21 may be provided with a sixth recessed platform S6 recessed relative to the outer surface 21a of the end cap 21. The sixth recessed platform S6 is disposed around the first exhaust hole 291. The one-way valve 30 and the breathable membrane assembly 40 are at least partially accommodated in the first exhaust hole 291. The sixth recessed platform S6 is closer to the outer surface 21a than the first exhaust hole 291. The shielding member 50 is at least partially accommodated within the sixth recessed platform S6.

[0367] The shielding member 50 may be at least partially contained within the sixth sink S6, that is, the shielding member 50 may be entirely or partially located within the sixth sink S6. For example, in FIG31 , the shielding member 50 is entirely located within the sixth sink S6. In other words, the shielding member 50 has a first surface facing the exterior of the housing, the first surface being lower than or flush with the outer surface 21a of the end cap 21.

[0368] By setting up the sixth sinker S6 and accommodating at least part of the shielding member 50 in the sixth sinker S6, on the one hand, the space occupied by the shielding member 50 in the thickness direction of the end cover 21 can be reduced, which is beneficial to optimizing the volume of the battery cell 20. On the other hand, the sixth sinker S6 can play a certain positioning and limiting role on the shielding member 50, which is beneficial to reducing the assembly difficulty of the shielding member 50 connected to the end cover 21.

[0369] According to some embodiments of the present application, the shielding member 50 may be installed on the end cover 21 by welding, interference fit, bolt connection, clamping or bonding.

[0370] According to some embodiments of the present application, the shielding member 50 covers the valve cover 312 of the one-way valve 30, and a seventh sink S7 is provided on the side of the valve cover 312 facing the shielding member 50. The seventh sink S7 is provided around the fifth through hole 3123, so that a first discharge channel can be left between the shielding member 50 and the valve cover 312, which is conducive to the discharge of gas.

[0371] 31 , a first exhaust passage is formed between the shielding member 50 and the end cover 21 , and the first exhaust passage communicates with the gas outlet 313 b of the one-way valve 30 and the outside of the battery cell 20 .

[0372] The first exhaust channel includes a third exhaust gap 501 formed between the shielding member 50 and the side surface of the sixth sink S6 . The third exhaust gap 501 is used to connect the air outlet 313 b and the outside of the housing.

[0373] The third exhaust gap 501 is used to connect the air outlet 313b and the outside of the shell. The third exhaust gap 501 can be directly connected to the air outlet 313b. For example, at least part of the projection of the third exhaust gap 501 in the thickness direction X of the wall is located in the first exhaust hole 291, so that the air outlet 313b of the one-way valve 30 arranged in the first exhaust hole 291 can be directly connected to the third exhaust gap 501. Of course, the third exhaust gap 501 can also be indirectly connected to the air outlet 313b. For example, the exhaust channel can also include a fourth exhaust gap. The fourth exhaust gap is formed between the shielding member 50 and the bottom surface of the sink of the sixth sink. The fourth exhaust gap connects the third exhaust gap 501 and the air outlet 313b of the one-way valve 30.

[0374] By setting the third exhaust gap 501, the gas exhausted from the one-way valve 30 can be discharged to the outside of the shell through the third exhaust gap 501. With this structure, the battery cell 20 does not need to have a channel opened on the shielding member 50, which is conducive to reducing the processing difficulty and improving the appearance of the battery cell 20.

[0375] In one embodiment, the side of the shielding member 50 abuts and is connected to the side of the sixth sinker, and a protrusion (or groove) can be set on the side of the shielding member 50 to form a third exhaust gap 501 between the side of the shielding member 50 and the side of the sixth sinker.

[0376] In one embodiment, the first exhaust channel further includes a fourth exhaust gap (not shown), which is formed between the shielding member 50 and the bottom surface of the sixth sinker, and connects the third exhaust gap 501 and the air outlet 313b.

[0377] 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 fourth exhaust gap is formed between the side surface of the shielding member 50 facing the end cover 21 and the bottom surface of the sixth sink.

[0378] Please refer to Figure 32, which is a schematic diagram of the exploded 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 protective patch 60, which is disposed on the side of the end cap 21 facing the exterior of the housing. Specifically, 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 protective patch 60 can be made of a variety of materials, such as rubber, silicone, or plastic.

[0379] According to some embodiments of the present application, a first avoidance hole 601 penetrating the protective patch 60 is provided on the protective patch 60 , and the first avoidance hole 601 is used for the one-way valve 30 to pass through.

[0380] According to some embodiments of the present application, in an embodiment in which an electrode terminal 25 is provided on the end cap 21, as shown in FIG32 , the protective patch 60 is provided with a second avoidance hole 602 at the position corresponding to the electrode terminal 25. The second avoidance hole 602 runs through both sides of the protective patch 60. The second avoidance hole 602 is used to allow the electrode terminal 25 to pass through, avoiding the electrode terminal 25. Exemplarily, two electrode terminals 25 are provided on the end cap 21, and correspondingly, the protective patch 60 is provided with two second avoidance holes 602, each of which is used to allow one electrode terminal 25 to pass through.

[0381] In an embodiment in which a pressure relief mechanism 70 is provided on the end cover 21, as shown in Figure 32, a third avoidance hole 603 is provided on the protective patch 60 at a position corresponding to the pressure relief mechanism 70. The third avoidance hole 603 passes through both sides of the protective patch 60. The positive projection of the pressure relief mechanism 70 on the protective patch 60 is located in the third avoidance hole 603, so that the third avoidance hole 603 can avoid the pressure relief mechanism 70.

[0382] Please refer to Figure 33, which is a 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, a protective patch 60 is used to cover the shielding member 50. The protective patch 60 is provided with an information collection hole 604 that penetrates the protective patch 60. The information collection hole 604 serves to expose a portion of the end cap 21, so as to facilitate setting an information code on the end cap 21 or connecting a detection element for sampling. The orthographic projection of the information collection hole 604 on the end cap 21 is located within the shielding member 50. That is, the information collection hole 604 is provided corresponding to the shielding member 50, so that the exposed area of ​​the information collection hole 604 is the surface of the shielding member 50, thereby enabling setting an information code on the shielding member 50 or connecting a detection element for sampling.

[0383] According to some embodiments of the present application, the protective patch 60 may be provided on the end cover 21 in various structures, and the protective patch 60 may be provided on the end cover 21 by bonding, adsorption, or the like.

[0384] When the adhesive method is used, the adhesive layer 610 adheres the protective patch 60 and the end cover 21 , and the adhesive 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 .

[0385] Please refer to Figure 34, which is a bottom view of the adhesive layer of a protective patch 60 according to one or more embodiments. Adhesive layer 610 is provided with an escape groove 611. Furthermore, the orthographic projection of air outlet 313b on protective patch 60 is located within the escape groove 611.

[0386] Continuing with FIG. 31 , according to some embodiments of the present application, the battery cell 20 further includes an insulating member 24 . The insulating member 24 is disposed on the side of the end cap 21 facing the interior of the housing; that is, an insulating member 24 may also be disposed on the inner side of the end cap 21 . The insulating member 24 can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. Exemplarily, the insulating member 24 may be made of plastic, rubber, or the like.

[0387] 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 cause 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 prevent contact with the electrode assembly 23 to cause a short circuit.

[0388] The insulating member 24 is provided with a second exhaust hole 292 that passes through the main body 242 of the insulating member 24, so that the gas inside the battery 100 enters the exhaust assembly 90 area through the first exhaust hole 291. Furthermore, the second exhaust hole 292 is connected to the first exhaust hole 291 to facilitate exhaust.

[0389] 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 shell, and / or the valve body 31 of the one-way valve 30 protrudes from the inner surface 21b of the end cover 21, the exhaust assembly 90 will cause the end cover 21 to have a protruding area facing the inside of the 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 exhaust assembly 90.

[0390] According to some embodiments of the present application, referring to FIG. 1 , FIG. 20 c , and FIG. 23 c , the battery cell 20 further includes a pressure relief mechanism 70 , which is disposed on the outer shell and configured to actuate and release the internal pressure of the battery cell 20 when the battery cell 20 thermally runs away.

[0391] The pressure relief mechanism 70 is provided on the outer shell, and may be provided on the end cover 21 or on the shell 22 . For example, in FIG. 1 , the pressure relief mechanism 70 is provided on the end cover 21 .

[0392] The pressure relief mechanism 70 is configured to activate and release the internal pressure of the battery cell 20 when the battery cell 20 experiences thermal runaway. Specifically, when thermal runaway occurs within the battery cell 20, the pressure relief mechanism 70 can activate and open to release gases generated within the battery cell 20 due to thermal runaway. It should be noted that when thermal runaway occurs within the battery cell 20, the gas inside the outer casing of the battery cell 20 rapidly surges, causing the pressure relief mechanism 70 to open and release the pressure. However, during normal use, gases generated within the outer casing of the battery cell 20 can be discharged through the vent assembly 90, but this does not allow the pressure relief mechanism 70 to open.

[0393] Optionally, the pressure relief mechanism 70 and the housing can be an integrally formed structure or a separately provided structure. If the pressure relief mechanism 70 and the housing are an integrally formed structure, the pressure relief mechanism 70 is an area on the housing where a weak structure is provided, for example, an area on the housing where a notched groove is provided; if the pressure relief mechanism 70 can be a separate structure from the housing, the pressure relief mechanism 70 can be connected to the housing by welding, hot melting, injection molding, or bonding. For example, in Figures 20c and 23c, the pressure relief mechanism 70 and the housing are separately provided structures, and the pressure relief mechanism 70 is provided 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.

[0394] For example, in Figure 1, 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.

[0395] By providing the exhaust assembly 90, when gas is generated inside the shell during normal use of the battery cell 20, it can be discharged to the outside of the shell through the exhaust assembly 90, thereby alleviating 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 in 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 reliability of the battery cell 20.

[0396] In some embodiments, the vent assembly 90 and the pressure relief mechanism 70 may be disposed on the same wall of the housing. For example, the vent assembly 90 and the pressure relief mechanism 70 may both be disposed on the end cap 21. A battery cell 20 employing this structure helps conserve space within the battery cell 20, thereby increasing the energy density of the battery cell 20.

[0397] In some embodiments, the vent assembly 90 and the pressure relief mechanism 70 can be located on different walls of the housing. For example, the vent assembly 90 can be located on the housing 22, while the pressure relief mechanism 70 can be located on the end cap 21. A battery cell 20 employing this structure can reduce the interaction between the vent assembly 90 and the pressure relief mechanism 70 and adapt to different usage environments. Preferably, the vent assembly 90 and the pressure relief mechanism 70 are located on the top wall of the battery 100 when it is in a resting position to facilitate gas discharge.

[0398] In some embodiments, the actuation pressure of the pressure relief mechanism 70 is greater than the opening pressure of the one-way valve 30. That is, the pressure of the gas inside the housing to open the pressure relief mechanism 70 is greater than the pressure of the gas inside the housing to open the one-way valve 30. When a battery cell 20 experiences thermal runaway, the gas inside the housing of the battery cell 20 will rapidly surge, causing the pressure relief mechanism 70 to open and release pressure. However, during normal use of the battery cell 20, when the gas generated inside the housing 21 reaches a threshold, the one-way valve 30 can be opened, but the pressure relief mechanism 70 cannot be opened.

[0399] In some embodiments, the exhaust rate of the one-way valve 30 is less than the exhaust rate of the pressure relief mechanism 70 .

[0400] By setting the exhaust rate of the one-way valve 30 to be lower than the exhaust rate of the pressure relief mechanism 70, the phenomenon that the one-way valve 30 exhausts too quickly and the pressure relief mechanism 70 cannot be actuated to open can be alleviated when the battery cell 20 has thermal runaway. This allows the pressure relief mechanism 70 to actuate and stably discharge the internal pressure of the battery cell 20 when the battery cell 20 has thermal runaway, making it easier to relieve pressure, thereby helping to reduce the risk of fire and explosion of the battery cell 20 when the battery cell 20 has thermal runaway.

[0401] The end cap 21 is provided with a pressure relief hole 701, which is connected to the pressure relief mechanism 70. The diameter of the pressure relief hole 701 may be larger than the diameter of the first exhaust hole 291 connected to the exhaust assembly 90, so that the exhaust rate of the pressure relief mechanism 70 is greater than the exhaust rate of the exhaust assembly 90.

[0402] In some embodiments, the one-way valve 30 and the breathable membrane assembly 40 in the vent assembly 90 are arranged in series, and gas is discharged simultaneously through the breathable membrane assembly 40 and the one-way valve 30. The exhaust rate depends on the permeability rate of the breathable membrane 41. The permeability rate of the breathable membrane 41 is 3-10 mL / day. It can be 3-4 mL / day, 5-8 mL / day, or 9-10 mL / day. By setting the exhaust rate of the breathable membrane 41 to 3-10 mL / day, the phenomenon of the vent assembly 90 exhausting too quickly, causing the pressure relief mechanism 70 to be unable to actuate and open, can be alleviated when the battery cell 20 experiences thermal runaway. This allows the pressure relief mechanism 70 to actuate and stably release the internal pressure of the battery cell 20 when the battery cell 20 experiences thermal runaway, thereby helping to reduce the risk of fire and explosion of the battery cell 20 during thermal runaway. At the same time, the airtightness of the system is also taken into consideration to prevent the airtightness from being deteriorated due to excessive exhaust rate, so that the airtightness of the battery 100 system is maintained while the gas is discharged.

[0403] The test method for the exhaust rate of the breathable membrane 41 may be carried out in accordance with GB / T1038-2000.

[0404] In some embodiments, the end cap 21 is provided with a liquid injection hole, and the first vent hole 291 for mounting the one-way valve 30 can also serve as the liquid injection hole. Specifically, after the battery cell 20 is fully injected, the one-way valve 30 is mounted on the liquid injection hole, replacing the original sealing structure of the liquid injection hole with the one-way valve 30. By configuring the first vent hole 291 for mounting the one-way valve 30 as the liquid injection hole, liquid can be injected into the housing through the first vent hole 291 before the one-way valve 30 is mounted in the first vent hole 29128. This eliminates the need for a separate liquid injection hole in the housing, improving the production efficiency of the battery cell 20 and reducing the manufacturing cost of the battery cell 20. Alternatively, the first vent hole 291 and the liquid injection hole can be spaced apart.

[0405] 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, or a magnesium metal battery 100. The alkali metal battery 100 is used in conjunction with the exhaust assembly 90 to promptly exhaust gases generated by the alkali metal battery 100 during normal operation, thereby extending the service life of the alkali metal battery 100.

[0406] 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 containing 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 the tabs. The positive and negative electrode tabs can 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 and negative electrode active materials react with the electrolyte, and the tabs are connected to the electrode terminals 25 to form a current circuit.

[0407] In one embodiment, the positive electrode sheet includes a positive electrode current collector and a positive electrode active layer disposed on at least one side of the positive electrode current collector, wherein the positive electrode active layer includes a positive electrode active material.

[0408] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active layer may be provided on either or both of the two facing surfaces of the positive electrode current collector.

[0409] In one embodiment, the positive electrode current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0410] In one embodiment, the positive electrode material includes one or more of a polyanion-based positive electrode material, a phosphate-based positive electrode material, a sulfate-based positive electrode material, a silicate-based positive electrode material, and a borate-based positive electrode material. For example, in the positive electrode active material of the sodium battery 100, the polyanion-based compound includes compounds based on phosphoric acid and fluorophosphate. Phosphate-based compounds include Nax1Fey1Pm1On1, for example, sodium iron phosphate with a higher capacity and sodium iron pyrophosphate with a higher voltage platform. The polyanion-based 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, where M and M are one or more of Fe, Mn, Co, Ni, Cu, Zn, Cr, Ti, V, Zr, and Ce, and 0 < x ≤ 2. The positive electrode active material in the lithium metal battery 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.

[0411] 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. The negative electrode active layer includes a negative electrode active material. In this embodiment, the battery cell 20 is an ion battery 100. During the charge and discharge process of the battery 100, active ions (such as Li+ and Na+) are intercalated and deintercalated in the negative electrode active material.

[0412] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active layer may be disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0413] In one embodiment, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base material. The composite current collector may be obtained by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer base material (such as a base material of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0414] In one embodiment, the negative electrode active material may include one or more of a silicon-based material, a silicon-carbon material, a carbon material, and a selenium-based material. Specifically, it includes one or more of artificial graphite, natural graphite, hard carbon, soft carbon, a silicon-based material, and a selenium-based material. The silicon-based material may be selected from one or more of elemental silicon, a silicon oxide (e.g., silicon 2 oxide), a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The selenium-based material may be selected from one or more of elemental selenium, a selenium oxide, and a selenium alloy.

[0415] In one embodiment, the negative electrode plate includes a negative electrode current collector and a carbon-containing coating provided 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, or an aluminum metal battery 100. This type of battery 100 can also be called 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 the carbon-containing coating facilitates more uniform metal deposition. The carbon-containing material includes one or more of conductive carbon, graphite, hard carbon, and carbon nanotubes.

[0416] In other embodiments, a conductive film layer may be deposited on the negative electrode current collector. Examples include alloy materials, titanium-based materials, active metals (e.g., sodium metal), carbon-based materials deposited with metals, composite materials containing metals, and alloy materials containing metals. Such alloy materials include, but are not limited to, sodium-tin alloys, sodium-germanium alloys, and sodium-antimony alloys. Such titanium-based materials include, but are not limited to, titanium dioxide, titanates, and titanium phosphates.

[0417] In one embodiment, the positive electrode active layer and the negative electrode active layer may further include a binder and a conductive agent. As an example, the binder may include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and at least one of a fluorine-containing acrylate resin. As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.

[0418] In one embodiment, the isolation membrane can be any known porous structure isolation membrane with good chemical stability and mechanical stability.

[0419] In one embodiment, the material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0420] The electrolyte conducts ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid.

[0421] 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.

[0422] In one embodiment, the electrolyte salt in the sodium battery 100 includes sodium salts such as sodium hexafluorophosphate (NaPF6), sodium bis(fluorosulfonyl)imide (NaFSI), sodium trifluoromethanesulfonate (CF3NaO3S), and sodium sulfide (Na2S). The lithium battery 100 includes at least one lithium salt selected from the group consisting of lithium perchlorate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bis(trifluoromethylsulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium difluorooxalatoborate, lithium tetrafluoroborate, and lithium trifluoromethanesulfonate.

[0423] In one embodiment, the solvent includes one or more solvents selected from the group consisting of chain ethers, ethylene glycol dimethyl ether and its derivatives, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclic ethers, specifically including dimethyl ether (DME), diethylene glycol diethyl ether, tetraethylene glycol dimethyl ether, 2,2,2,2-trifluoroethyl ether, ethylene glycol diethyl ether, triethylene glycol dimethyl ether, ethylene glycol dimethyl ether derivatives, trifluoroethyl methyl carbonate (FEMC), dioxolane (DOL), acetonitrile (AN), fluorobenzene, triethyl phosphate (TEP), sulfolane, 2-methyltetrahydrofuran, tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylacetamide, and the like.

[0424] In one embodiment, the electrolyte may further include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives capable of improving certain properties of the battery 100, such as additives that improve the overcharge performance of the battery 100, and additives that improve the high or low temperature performance of the battery 100.

[0425] According to some embodiments of the present application, a battery 100 is provided, comprising a battery cell 20 according to any of the above-described embodiments. Please refer to FIG34 , which is a schematic diagram of an exploded structure of the battery 100 according to one or more embodiments. The battery 100 comprises a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 is configured to provide a storage space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap with each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open, and the first portion 11 can be a plate-like structure, overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. Alternatively, the first portion 11 and the second portion 12 can each be a hollow structure with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0426] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 100 may be housed within the housing 10. Of course, the battery 100 may also be in the form of a battery module 100, in which multiple battery cells 20 are first connected in series, in parallel, or in a hybrid connection, and then the multiple battery modules 100 are further connected in series, in parallel, or in a hybrid connection to form an entire battery 100, and then housed within the housing 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for electrically connecting the multiple battery cells 20.

[0427] Each battery cell 20 may be a secondary battery 100 or a primary battery 100; specific examples 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. A 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. Alternatively, it may 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 have other shapes.

[0428] In some embodiments, the battery 100 may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0429] According to some embodiments of the present application, the present application further provides an electric device, which includes a battery cell 20 according to 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.

[0430] 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, laptop 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.

[0431] The electric device can select a battery cell 20, a battery 100 module or a battery 100 pack according to its usage requirements.

[0432] Please refer to Figure 35, which is a schematic structural diagram of a vehicle 1000 according to one or more embodiments. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0433] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0434] In the above embodiment, the provision of a breathable membrane assembly 40 enables the battery cell 20 to discharge internal gas through the breathable membrane 41 while in a sealed state, promptly discharging the internal gas of the battery 100 housing to the outside of the housing. This prevents excessive pressure inside the battery 100 housing, reduces the risk of premature valve opening of the pressure relief mechanism 70, and significantly improves the lifespan of the battery cell 20. One or more breathable membrane assemblies 40 can be provided on a single battery cell 20, and the placement and manner of each breathable membrane assembly 40 can vary. For example, one breathable membrane assembly 40 can be provided on the side of the end cap 21 facing the interior of the battery 100 housing, and another breathable membrane assembly 40 can be provided on the side of the end cap 21 facing the exterior of the battery 100 housing. Alternatively, one breathable membrane assembly 40 can be provided on the end cap 21, and another breathable membrane assembly 40 can be provided on the housing 22.

[0435] The above is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery cell, characterized in that, it includes: a housing having a wall portion; an exhaust assembly disposed on the wall portion, the exhaust assembly including a check valve and a breathable film assembly, the breathable film assembly including a breathable film, and the exhaust assembly being configured to discharge the gas inside the housing.

2. The battery cell according to claim 1, characterized in that, the check valve includes a valve body and a valve core, the valve body having a valve cavity inside, the valve body being provided with an air inlet and an air outlet, the air inlet being configured to communicate the valve cavity with the inside of the housing, and the air outlet being configured to communicate the valve cavity with the outside of the housing; the valve core is disposed in the valve cavity, and the valve core is configured to block the air inlet passage of the valve cavity, and the valve core is configured to open the air inlet passage under the action of the gas inside the housing.

3. The battery cell according to claim 1 or 2, characterized in that, the wall portion has a first exhaust hole, the first exhaust hole communicating the inside of the housing with the outside of the housing, and the exhaust assembly is configured such that the gas discharged through the first exhaust hole flows through the check valve and the breathable film assembly.

4. The battery cell according to any one of claims 1 to 3, characterized in that, along the thickness direction of the wall portion, the breathable film is closer to the inside of the housing than the check valve.

5. The battery cell according to any one of claims 2 to 3, characterized in that, the breathable film is disposed on the side where air enters through the air inlet; and / or the breathable film is disposed on the side where air exits through the air inlet; and / or the breathable film is disposed on the side where air enters through the air outlet; and / or the breathable film is disposed on the side where air exits through the air outlet.

6. The battery cell according to any one of claims 1 to 5, characterized in that, the wall portion has an outer surface and an inner surface disposed opposite to each other, the outer surface facing the outside of the housing and the inner surface facing the inside of the housing; the valve body of the check valve is disposed on the outer surface, and at least a part of the valve body protrudes from the outer surface; at least a part of the breathable film assembly is disposed on the outer surface.

7. The battery cell according to any one of claims 1 to 5, characterized in that, the wall portion has an outer surface and an inner surface disposed opposite to each other, the outer surface facing the outside of the housing and the inner surface facing the inside of the housing; the valve body of the check valve is disposed on the outer surface; and at least a part of the valve body protrudes from the inner surface; the breathable film assembly is disposed on the part of the valve body that protrudes from the inner surface.

8. The battery cell according to any one of claims 1 to 5, characterized in that, the wall portion has an outer surface and an inner surface disposed opposite to each other, the outer surface facing the outside of the housing and the inner surface facing the inside of the housing; the valve body of the check valve is disposed on the outer surface; and at least a part of the valve body protrudes from the outer surface; at least a part of the breathable film assembly is disposed on the inner surface.

9. The battery cell according to any one of claims 1 to 3, 5, characterized in that, The wall portion has an outer surface and an inner surface disposed opposite to each other. The outer surface faces the outside of the housing, and the inner surface faces the inside of the housing; The valve body of the one-way valve is disposed on the outer surface; and at least a part of the valve body protrudes from the inner surface; The breathable membrane assembly is disposed on a side of the one-way valve facing the outside of the housing.

10. The battery cell according to any one of claims 1 to 7, characterized in that the breathable membrane assembly is connected to the one-way valve, and the one-way valve is connected to the wall portion; or the one-way valve is connected to the breathable membrane assembly, and the breathable membrane assembly is connected to the wall portion.

11. The battery cell according to any one of claims 1 to 9, characterized in that the breathable membrane assembly and the one-way valve are respectively and independently connected to the wall portion.

12. The battery cell according to any one of claims 2-6, 8, 10-11, characterized in that the valve body includes: a valve seat; a valve cover, including a cover top wall and a cover side wall connected to the cover top wall. The cover top wall, the cover side wall and the valve seat enclose the valve cavity. The air inlet is provided on the valve seat, and the air outlet is provided on the valve cover.

13. The battery cell according to claim 12, characterized in that the valve seat has a first through hole penetrating the valve seat, and the air inlet is the first through hole.

14. The battery cell according to claim 12 or 13, characterized in that the cover side wall has a second through hole penetrating the cover side wall, and the air outlet is the second through hole.

15. The battery cell according to claim 14, characterized in that along the direction away from the cover top wall, the second through hole extends to the end of the cover side wall; Optionally, there are a plurality of the second through holes, and the plurality of second through holes are spaced apart in the circumferential direction of the cover side wall.

16. The battery cell according to any one of claims 12 to 15, characterized in that a first guiding post protrudes from a side of the cover top wall facing the valve seat. The cover top wall has a third through hole penetrating the cover top wall and the first guiding post, or the cover top wall has a third through hole penetrating the cover top wall, and the air outlet is the third through hole.

17. The battery cell according to any one of claims 12 to 16, characterized in that the valve cover further includes a flanging wall. The cover side wall connects the cover top wall and the flanging wall. The flanging wall extends away from the valve cavity relative to the cover side wall, and the flanging wall is connected to the valve seat.

18. The battery cell according to claim 17, characterized in that a first sinking groove recessed relative to the surface of the valve seat is provided on a side of the valve seat facing the valve cover, and at least a part of the flanging wall is received in the first sinking groove and connected to the valve seat.

19. The battery cell according to claim 18, characterized in that the surface of the flanging wall facing the cover top wall is flush with the surface of the valve seat facing the valve cover; or the surface of the flanging wall facing the cover top wall is lower than the surface of the valve seat facing the valve cover.

20. The battery cell according to any one of claims 17 to 19, characterized in that, the flanging wall is welded to the valve seat; wherein, in the circumferential direction of the cover side wall, at least part of the first welding mark between the flanging wall and the valve seat is offset from the second through hole on the cover side wall.

21. The battery cell according to claim 17, characterized in that, a connecting protrusion is convexly provided on the outer peripheral surface of the valve seat, a receiving groove is provided on the inner peripheral surface of the flanging wall, and the connecting protrusion is received in the receiving groove and connected to the flanging wall.

22. The battery cell according to claim 21, characterized in that, the connecting protrusion is welded to the flanging wall, wherein the flanging wall has an upper surface and a lower surface arranged opposite to each other, the upper surface faces the cover top wall, and the second welding mark of the connection between the connecting protrusion and the flanging wall is located on the lower surface of the flanging wall.

23. The battery cell according to any one of claims 12 to 22, characterized in that, the wall portion has an outer surface and an inner surface arranged opposite to each other, the outer surface faces the outside of the housing, the inner surface faces the inside of the housing, the wall portion is provided with a first exhaust hole, the first exhaust hole includes a through hole section and a first hole section, the through hole section and the first hole section are arranged along the thickness direction of the wall portion, the through hole section communicates the inside of the housing with the outside of the housing, the first hole section is located on the side of the through hole section away from the inside of the housing, the aperture of the first hole section is larger than that of the through hole section, the first hole section is recessed relative to the outer surface, at least part of the one-way valve is received in the first hole section, and at least part of the valve body protrudes from the outer surface.

24. The battery cell according to claim 23, characterized in that, at least part of the breathable film assembly is arranged on the inner surface, wherein the breathable film assembly includes a breathable film and a connecting member, the connecting member is provided with a first breathable hole, the breathable film is arranged on the connecting member and covers the first breathable hole, and the connecting member is connected to the wall portion.

25. The battery cell according to claim 24, characterized in that, the wall portion has a first sinking platform recessed relative to the inner surface, the first sinking platform surrounds the through hole section of the first exhaust hole, and at least part of the breathable film assembly is received in the first sinking platform.

26. The battery cell according to claim 25, characterized in that, the wall portion further has a second sinking platform recessed relative to the inner surface, the first sinking platform is closer to the inner surface of the wall portion than the second sinking platform, the first sinking platform surrounds the second sinking platform, the second sinking platform surrounds the through hole section of the first exhaust hole, and at least part of the connecting member is received in the first sinking platform.

27. The battery cell according to any one of claims 24 to 26, characterized in that, the breathable film is arranged on the side of the connecting member away from the wall portion; or the breathable film is arranged on the side of the connecting member close to the wall portion.

28. The battery cell according to any one of claims 24 to 27, characterized in that, The orthographic projection of the first ventilation hole on the wall portion is located within the region where the through-hole section of the first exhaust hole is located; or The orthographic projection of the first ventilation hole on the wall portion does not overlap with the region where the through-hole section of the first exhaust hole is located.

29. The battery cell according to any one of claims 24 to 28, characterized in that the wall portion further has a third sunk platform recessed relative to the inner surface, the third sunk platform is closer to the inner surface of the wall portion than the first sunk platform, and the third sunk platform surrounds the first sunk platform.

30. The battery cell according to claim 23, characterized in that at least a part of the ventilation membrane assembly is disposed on the outer surface, at least a part of the ventilation membrane assembly is received in the first exhaust hole, and the ventilation membrane assembly is located on the side of the one-way valve facing the wall portion.

31. The battery cell according to claim 30, characterized in that the first exhaust hole further includes a second hole section, along the thickness direction of the wall portion, the second hole section is located between the through-hole section and the first hole section, the aperture of the second hole section is smaller than the aperture of the first hole section, the aperture of the second hole section is larger than the aperture of the through-hole section, and at least a part of the ventilation membrane assembly is received in the second hole section.

32. The battery cell according to claim 30 or 31, characterized in that the ventilation membrane assembly includes a ventilation membrane and a connecting member, the connecting member is provided with a first ventilation hole, the ventilation membrane is disposed on the connecting member and covers the first ventilation hole, and the connecting member is welded to the wall portion.

33. The battery cell according to claim 32, characterized in that a stress relief groove is provided around the welding mark between the connecting member and the wall portion; Optionally, a third stress relief groove is provided on the connecting member around the fifth welding mark between the connecting member and the wall portion; and / or a second stress relief groove is provided on the wall portion around the fifth welding mark between the connecting member and the wall portion.

34. The battery cell according to claim 32 or 33, characterized in that a welding mark avoidance groove is provided on the surface of the one-way valve facing the ventilation membrane assembly, and the welding mark avoidance groove covers the welding mark between the connecting member and the wall portion.

35. The battery cell according to any one of claims 12 to 23, characterized in that the ventilation membrane assembly is disposed on the side of the one-way valve facing the wall portion, and the ventilation membrane assembly is connected to the one-way valve, and the one-way valve is connected to the wall portion.

36. The battery cell according to any one of claims 12 to 23, characterized in that the ventilation membrane assembly is disposed on the side of the valve seat facing the valve cavity, and the one-way valve is connected to the wall portion.

37. The battery cell according to any one of claims 12 to 36, characterized in that the valve cover / valve seat of the one-way valve is welded to the wall portion; Optionally, a stress relief groove is provided around the welding mark between the valve cover / valve seat and the wall portion; Optionally, a first stress relief groove is provided on the valve cover / valve seat around the third welding mark between the valve cover / valve seat and the wall portion; and / or A second stress relief groove is provided on the wall portion around the third weld mark of the valve cover / valve seat and the wall portion.

38. The battery cell according to any one of claims 12 to 23, characterized in that at least part of the breathable membrane assembly is disposed on the outer surface. The breathable membrane assembly includes a breathable membrane and a connecting member. The connecting member is provided with a first breathable hole. The breathable membrane is disposed on the connecting member and covers the first breathable hole. The one-way valve is disposed on a side of the connecting member facing the outside of the housing. The one-way valve is connected to the connecting member, and the connecting member is connected to the wall portion.

39. The battery cell according to any one of claims 12-23, 30, 35-37, characterized in that the breathable membrane assembly includes a breathable membrane, wherein: the breathable membrane is disposed on the inner surface of the wall portion, the breathable membrane is connected to the wall portion, and covers the through-hole section of the first exhaust hole on the wall portion; or the breathable membrane is disposed on the outer surface of the wall portion, the breathable membrane is located on a side of the one-way valve facing the wall portion, the one-way valve covers the breathable membrane, and the breathable membrane is connected to the wall portion / one-way valve.

40. The battery cell according to any one of claims 2-6, 8, 10-11, characterized in that the valve body includes a valve cover. The valve cover includes a cover top wall and a cover side wall connected to the cover top wall. The cover top wall and the cover side wall enclose the valve cavity with the wall portion. The air inlet is provided on the wall portion, and the air outlet is provided on the cover side wall.

41. The battery cell according to claim 40, characterized in that a second sinking groove recessed with respect to the outer surface of the wall portion is provided on a side of the wall portion facing the outside of the housing. The valve cover further includes a flanging wall. The cover side wall connects the cover top wall and the flanging wall. The flanging wall extends away from the valve cavity with respect to the cover side wall. At least part of the flanging wall is received in the second sinking groove and connected to the wall portion.

42. The battery cell according to claim 40 or 41, characterized in that the breathable membrane assembly includes a breathable membrane. The breathable membrane is disposed on the inner surface / outer surface of the wall portion. The breathable membrane is connected to the wall portion. The breathable membrane covers the through-hole section of the first exhaust hole on the wall portion; or the breathable membrane assembly includes a breathable membrane and a connecting member. The connecting member is provided with a first breathable hole. The breathable membrane is disposed on the connecting member and covers the first breathable hole. The breathable membrane is disposed on the inner surface / outer surface of the wall portion. The connecting member is connected to the wall portion / one-way valve.

43. The battery cell according to any one of claims 2-6, 7, 9, 11, characterized in that the valve body includes: a valve seat, including a seat bottom wall and a seat side wall connected to the seat bottom wall; a valve cover, disposed at an end of the valve seat away from the seat bottom wall. The valve cover and the seat side wall and the seat bottom wall enclose the valve cavity. A fourth through hole is provided on the valve seat, and the air inlet is the fourth through hole.

44. The battery cell according to claim 43, characterized in that The valve cover has a fifth through-hole penetrating the valve cover, and the air outlet includes the fifth through-hole.

45. The battery cell according to claim 43 or 44, characterized in that the valve cover is connected to the valve seat, and the air outlet includes a first exhaust gap formed between the valve cover and the valve seat.

46. The battery cell according to claim 43 or 44, characterized in that the valve cover is connected to the wall portion, and the air outlet includes a second exhaust gap formed between the valve cover and the wall portion.

47. The battery cell according to any one of claims 2-6, 7, 9, 11, characterized in that the valve body includes a valve seat, the valve seat includes a seat bottom wall and a seat side wall connected to the seat bottom wall, the seat bottom wall, the seat side wall and the wall portion enclose to form the valve cavity, a fourth through-hole is provided on the valve seat, the air inlet is the fourth through-hole, a first exhaust hole is provided on the wall portion, the first exhaust hole communicates the valve cavity with the outside of the housing, and the air outlet is the first exhaust hole.

48. The battery cell according to any one of claims 43 to 47, characterized in that the breathable membrane assembly is arranged on a side of the seat bottom wall away from the valve cavity, wherein the breathable membrane assembly includes a breathable membrane, and the breathable membrane is connected to the seat bottom wall, and the breathable membrane covers the fourth through-hole.

49. The battery cell according to any one of claims 43 to 47, characterized in that the breathable membrane assembly is arranged on a side of the seat bottom wall away from the valve cavity, wherein the breathable membrane assembly includes a breathable membrane and a connecting member, the connecting member is provided with a first breathable hole, the breathable membrane is arranged on the connecting member and covers the first breathable hole, and the connecting member is connected to the seat bottom wall.

50. The battery cell according to claim 49, characterized in that the seat bottom wall has an inner wall surface and an outer wall surface arranged opposite to each other, the inner wall surface faces the valve cavity, a fourth sunk platform recessed relative to the outer wall surface of the seat bottom wall is provided on a side of the seat bottom wall away from the valve cavity, the fourth sunk platform surrounds the fourth through-hole, and at least part of the breathable membrane assembly is accommodated in the fourth sunk platform.

51. The battery cell according to claim 50, characterized in that the seat bottom wall further has a fifth sunk platform recessed relative to the outer wall surface, the fourth sunk platform is closer to the outer wall surface of the seat bottom wall than the fifth sunk platform, the fourth sunk platform surrounds the fifth sunk platform, the fifth sunk platform surrounds the fourth through-hole, and at least part of the connecting member is accommodated in the fourth sunk platform.

52. The battery cell according to claims 49 to 51, characterized in that the breathable membrane is arranged on a side of the connecting member facing the valve cavity; or the breathable membrane is arranged on a side of the connecting member away from the valve cavity.

53. The battery cell according to any one of claims 43 to 47, characterized in that the breathable membrane assembly is arranged on a side of the seat bottom wall facing the valve cavity, wherein, The valve cavity includes a first cavity and a second cavity that are in communication with each other. The second cavity is closer to the bottom wall of the seat. Along a direction parallel to the bottom wall of the seat, the cross-sectional area of the first cavity is larger than that of the second cavity. The valve core is located in the first cavity, and the breathable membrane assembly is located in the second cavity.

54. The battery cell according to claim 53, wherein, the side wall of the seat includes a first side wall portion, a second side wall portion, and a third side wall portion. The first side wall portion and the second side wall portion enclose the first cavity, and the third side wall portion and the bottom wall of the seat enclose the second cavity. The sealing member of the valve core abuts against the second side wall portion.

55. The battery cell according to claim 54, wherein, the breathable membrane assembly includes a breathable membrane and a connecting member. The connecting member is provided with a first breathable hole, and the breathable membrane is disposed on the connecting member and covers the first breathable hole. The connecting member is connected to the third side wall portion.

56. The battery cell according to claim 54 or 55, wherein, one surface of the breathable membrane assembly facing the valve cavity is lower than one surface of the second side wall portion facing the valve cavity.

57. The battery cell according to claim 55 or 56, wherein, the breathable membrane is disposed on one side of the connecting member facing the bottom wall of the seat; or the breathable membrane is disposed on one side of the connecting member away from the bottom wall of the seat.

58. The battery cell according to any one of claims 53 to 57, wherein, the battery cell further includes a sealing ring, and the sealing ring is disposed between the breathable membrane assembly and the bottom wall of the seat.

59. The battery cell according to claim 58, wherein, the sealing ring is disposed between the breathable membrane and the bottom wall of the seat. The sealing ring is disposed around the fourth through hole. The sealing ring is provided with a second breathable hole, and the aperture of the second breathable hole is larger than that of the fourth through hole. The breathable membrane covers the second breathable hole.

60. The battery cell according to any one of claims 55 to 59, wherein, the connecting member is welded to the third side wall portion; or the connecting member is in interference fit with the third side wall portion.

61. The battery cell according to any one of claims 48 to 60, wherein, the breathable membrane is spaced apart from the valve core.

62. The battery cell according to any one of claims 43 to 47, wherein, the breathable membrane assembly is disposed on a side of the one-way valve facing the outside of the housing, and the breathable membrane assembly covers the air outlet of the one-way valve.

63. The battery cell according to claim 62, wherein, the breathable membrane assembly includes a breathable membrane and a connecting member. The connecting member is provided with a first breathable hole, and the breathable membrane is disposed on the connecting member and covers the first breathable hole. The connecting member is connected to the wall portion / valve cover.

64. The battery cell according to any one of claims 43 to 63, wherein, The wall portion has an outer surface and an inner surface that are arranged opposite to each other, the outer surface is arranged toward the outside of the shell, and the inner surface is arranged toward the inside of the shell, the wall portion is provided with a first exhaust hole, the first exhaust hole includes a through hole section and a first hole section, the through hole section and the first hole section are arranged along the thickness direction of the wall portion, the through hole section communicates the inside of the shell with the outside of the shell, the first hole section is located on a side of the through hole section away from the inside of the shell, the aperture of the first hole section is larger than the aperture of the through hole section, the first hole section is recessed relative to the outer surface, the one-way valve is at least partially accommodated in the first hole section, and at least a portion of the valve body protrudes from the inner surface; Optionally, the valve seat of the one-way valve is connected to the wall portion by welding, and a stress relief groove is arranged around a weld mark between the valve seat and the wall portion.

65. The battery cell according to any one of claims 43 to 64, It is characterized in that The battery cell further comprises: A shielding member, mounted on the wall portion, the shielding member is located on a side of the wall portion facing the outside of the housing, and the shielding member covers the one-way valve and the breathable membrane assembly; Wherein, a first exhaust passage is formed between the shielding member and the wall portion, and the first exhaust passage communicates with the gas outlet of the one-way valve and the outside of the battery cell.

66. The battery cell according to claim 65, It is characterized in that The wall portion has an outer surface and an inner surface arranged opposite to each other, the outer surface is arranged toward the outside of the shell, and the inner surface is arranged toward the inside of the shell, the wall portion has a first exhaust hole, the first exhaust hole connects the inside of the shell with the outside of the shell, the one-way valve and the breathable membrane assembly are at least partially accommodated in the first exhaust hole, the wall portion has a sixth sinker recessed relative to the outer surface, the sixth sinker is arranged around the first exhaust hole, the sixth sinker is closer to the outer surface than the first exhaust hole, and the shielding member is at least partially accommodated in the sixth sinker.

67. A battery cell according to claim 65 or 66, It is characterized in that The first exhaust passage includes a third exhaust gap formed between the shielding member and a side surface of the sixth sinker, and the third exhaust gap is used to connect the air outlet and the outside of the shell.

68. The battery cell according to claim 67, It is characterized in that The first exhaust passage further includes a fourth exhaust gap formed between the shielding member and the bottom surface of the sixth sinker, and the fourth exhaust gap communicates with the third exhaust gap and the air outlet.

69. The battery cell according to any one of claims 65 to 68, It is characterized in that The shielding member covers the valve cover of the one-way valve, and a seventh sink recessed relative to the surface of the valve cover is provided on the side of the valve cover facing the shielding member. The seventh sink is provided around the fifth through hole on the valve cover, and the seventh sink is connected to the first discharge channel.

70. The battery cell according to any one of claims 2 to 69, It is characterized in that The valve core comprises: An elastic member, disposed in the valve cavity; A plugging member is movably disposed in the valve cavity. The plugging member is used to plug the intake passage under the action of the elastic member and is used to open the intake passage under the action of the gas inside the housing.

71. The battery cell according to claim 70, wherein, the valve body includes a valve cover, and a first guiding post protrudes from a side of the valve cover facing the plugging member. A part of the elastic member is sleeved outside the first guiding post.

72. The battery cell according to claim 71, wherein, the diameter of the first guiding post is D1, and the inner diameter of the elastic member is D2, satisfying 0mm < D2 - D1 ≤ 5mm.

73. The battery cell according to claim 71 or 72, wherein, a second guiding post protrudes from a side of the plugging member facing the valve cover. A part of the elastic member is sleeved outside the second guiding post.

74. The battery cell according to claim 73, wherein, the diameter of the second guiding post is D3, and the inner diameter of the elastic member is D2, satisfying 0mm < D3 - D1 ≤ 5mm.

75. The battery cell according to claim 73 or 74, wherein, in the axial direction of the elastic member, there is a gap between an end face of the first guiding post away from the valve cover and an end face of the second guiding post close to the valve cover; optionally, the height H1 of the gap satisfies 0mm < H1 ≤ 0.5mm.

76. The battery cell according to any one of claims 70 to 75, wherein, in the axial direction of the valve cavity, two ends of the elastic member respectively abut against the valve cover and the plugging member. The distance between a first abutting face of the valve cover and a second abutting face of the plugging member is L1, and the solid length of the elastic member is L2, satisfying L1 > L2, where the solid length of the elastic member is the length occupied by the solid of the elastic member after being fully compacted; optionally, L1 - L2 > 0.5mm.

77. The battery cell according to claim 76, wherein, the elastic member is a spring, and the solid length L2 of the elastic member = d1 * n1 + d2 + d3, where d1 is the wire diameter of the spring, n1 is the maximum number of turns of the spring in the axial direction, d2 is the thickness of the outermost spring at one end of the spring, d3 is the thickness of the outermost spring at the other end of the spring, d2 ≤ d1, and d3 ≤ d1.

78. The battery cell according to any one of claims 70 to 77, wherein, a plurality of limiting protrusions protrude from the outer peripheral surface of the plugging member, and the plurality of limiting protrusions are arranged at intervals along the circumferential direction of the plugging member.

79. The battery cell according to any one of claims 70 to 78, wherein, the plugging member includes a pressing part and a sealing part. In the axial direction of the valve cavity, two ends of the elastic member respectively abut against the valve cover and the pressing part, and the sealing part is connected to a side of the pressing part facing away from the valve cover. The sealing part is used to plug the intake passage.

80. The battery cell according to claim 79, wherein, The material of the sealing part includes ethylene propylene diene monomer (EPDM), fluororubber or polytetrafluoroethylene (PTFE); and / or The material of the elastic part includes steel, iron or aluminum.

81. The battery cell according to any one of claims 12 to 80, characterized in that the valve cover includes a cover side wall, and a second through hole penetrating the cover side wall is formed on the cover side wall, the air outlet is the second through hole, and along the axis direction of the valve cavity, the sealing interface between the valve core and the valve seat is higher than or flush with the bottom wall of the second through hole.

82. The battery cell according to any one of claims 1 to 81, characterized in that the breathable film assembly includes a breathable film and a connecting piece, the connecting piece is provided with a first breathable hole, and the breathable film is arranged on the connecting piece and covers the first breathable hole; the breathable film is configured to allow the gas inside the battery cell to pass through the breathable film and be discharged.

83. The battery cell according to claim 82, characterized in that the connecting piece has a first annular table surface recessed relative to the surface of the connecting piece, the first annular table surface surrounds the first breathable hole, and the breathable film is arranged on the first annular table surface.

84. The battery cell according to claim 82 or 83, characterized in that the breathable film assembly further includes a backing piece, the backing piece is arranged between the breathable film and the connecting piece, and the air permeability rate of the backing piece is greater than that of the breathable film.

85. The battery cell according to claim 84, characterized in that the connecting piece further has a second annular table surface recessed relative to the surface of the connecting piece, the second annular table surface surrounds the first breathable hole, and the backing piece is arranged on the second annular table surface.

86. The battery cell according to any one of claims 82 to 85, characterized in that the connecting piece is a metal piece.

87. The battery cell according to any one of claims 1 to 86, characterized in that the battery cell further includes: an insulating member, which is arranged on one side of the wall portion facing the inside of the housing; a second exhaust hole penetrating the insulating member body is formed on the insulating member, and the second exhaust hole is communicated with the first exhaust hole on the wall portion.

88. The battery cell according to any one of claims 1-42, 70-87, characterized in that the battery cell further includes: a protection patch, which is arranged on one side of the wall portion facing the outside of the housing, and a first avoidance hole penetrating the protection patch is formed on the protection patch, and the first avoidance hole is used for the one-way valve to pass through.

89. The battery cell according to any one of claims 43 to 87, characterized in that the battery cell further includes: a protection patch, which is arranged on one side of the wall portion facing the outside of the housing, the protection patch covers the exhaust assembly, and a second discharge channel is formed between the protection patch and the wall portion, and the second discharge channel communicates the air outlet of the one-way valve with the outside of the battery cell.

90. The battery cell according to claim 89, characterized in that The battery cell further includes a shielding member that covers the exhaust assembly, and the protective patch covers the shielding member and a second discharge channel formed between the shielding member and the wall portion.

91. The battery cell according to claim 89 or 90, wherein, a bonding layer is provided on a side of the protective patch facing the wall portion, the bonding layer bonds the protective patch and the wall portion, and an avoidance groove is provided in the bonding layer, and a first discharge channel is formed between the avoidance groove and the wall portion.

92. The battery cell according to any one of claims 1 to 91, wherein, the wall portion is provided with a first exhaust hole, at least a part of the exhaust assembly is installed in the first exhaust hole, and the first exhaust hole is a liquid injection hole of the battery cell; or the first exhaust hole is spaced apart from the liquid injection hole.

93. The battery cell according to any one of claims 1 to 92, wherein, the outer casing includes: a housing having an accommodation cavity with an opening formed therein, and the accommodation cavity is used to accommodate the electrode assembly; an end cap that closes the opening; wherein, the end cap is the wall portion; or the housing includes the wall portion; or the wall portion is a wall at the top of the outer casing when the battery cell is in a placed state.

94. The battery cell according to any one of claims 1 to 93, wherein, the battery cell further includes: a pressure relief mechanism provided in the outer casing, and the pressure relief mechanism is configured to be actuated and release the internal pressure of the battery cell when the battery cell is in thermal runaway, and the actuation pressure of the pressure relief mechanism is greater than the opening pressure of the one-way valve.

95. The battery cell according to claim 94, wherein, the wall portion has a first exhaust hole that communicates the inside of the outer casing with the outside of the outer casing, and the first exhaust hole communicates with the exhaust assembly; the wall portion has a pressure relief hole that communicates the inside of the outer casing with the outside of the outer casing, and the pressure relief mechanism is installed in the pressure relief hole; the aperture of the pressure relief hole is larger than the aperture of the first exhaust hole.

96. The battery cell according to claim 94 or 95, wherein, the exhaust rate of the one-way valve is less than the exhaust rate of the pressure relief mechanism.

97. A battery, wherein, it includes the battery cell according to any one of claims 1 - 96.

98. An electrical device, wherein, it includes the battery cell according to any one of claims 1 - 96, and the battery cell is used to provide electrical energy.

Images