Battery exhaust valve and battery top cover

Abstract

This invention relates to the field of battery technology, and in particular to a battery vent valve and a battery top cover. The battery top cover includes a valve housing mounted on the battery casing. The valve housing has an inner cavity and a vent port that connects the outside of the battery to the inner cavity. A waterproof and breathable membrane is provided at the vent port. A movable valve core is slidably and sealingly mounted on the valve housing, and the movable valve core has a valve core channel. The battery vent valve also includes an elastic structure that acts between the movable valve core and the valve housing. When the movable valve core is in a first position, the inner cavity of the valve housing is separated from the inside of the battery. When the movable valve core is in a second position, gas inside the battery can enter the inner cavity of the valve housing through the valve core channel and be discharged to the outside of the battery through the vent port. When the movable valve core is in a third position, the valve core channel is located within the inner cavity of the valve core, and the inner cavity of the valve core is separated from the inside of the battery. The battery top cover uses a vent valve to discharge gas generated inside the battery, thereby improving the battery's lifespan.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery vent valve and a battery top cover. Background Technology

[0002] Lithium-ion batteries, as reliable energy storage devices, are widely used in new energy vehicles, energy storage, and other fields. During long-term use, factors such as the operating environment, charge / discharge rate, and overcharging / over-discharging can cause various side reactions within the lithium-ion battery, producing gas. The continuous accumulation of this gas inside the battery leads to a gradual increase in internal pressure, which can, in severe cases, cause a burst or explosion, posing a significant safety hazard. To prevent injury and property damage, lithium-ion batteries are typically equipped with explosion-proof valves on their top covers. When a large amount of gas is generated inside the battery and reaches a certain pressure, the explosion-proof valve ruptures to release the pressure and prevent the battery from exploding.

[0003] Chinese utility model patent CN215418488U discloses a piston-type lithium battery explosion-proof valve structure. The explosion-proof valve structure includes an explosion-proof sheet and a push rod. The push rod includes a piston ring, a pressure relief needle, and a sealing ring. The sealing ring is located between the piston ring and the explosion-proof sheet. The pressure relief needle passes through the sealing ring, and a vent hole is provided on the pressure relief needle at the contact point with the sealing ring, communicating with the battery's internal cavity. The sealing ring and the pressure relief needle cooperate to form a piston structure. When the battery malfunctions, pressure is applied to the piston ring, causing the pressure relief needle to puncture the explosion-proof sheet and release pressure. Although this battery eliminates the risk of explosion through the explosion-proof valve, once the explosion-proof valve is activated, the battery's interior will be connected to the external environment, thus rendering the battery unusable.

[0004] Therefore, the gas generated during battery use cannot escape from the battery, eventually causing the explosion-proof valve to activate and the battery to fail. Overall, the battery's lifespan is relatively short. Furthermore, before the explosion-proof valve activates, the gas accumulated between the positive and negative electrodes and the separator hinders the movement of lithium ions inside the battery, leading to lithium plating on the electrode surface. This results in a decrease in the battery's charge / discharge rate, and in severe cases, lithium plating can puncture the separator, causing a short circuit between the positive and negative electrodes, further reducing the battery's lifespan. Summary of the Invention

[0005] The purpose of this invention is to provide a battery vent valve to solve the technical problem of short battery life caused by internal gas accumulation in existing batteries. This invention also provides a battery top cover to solve the technical problem of short battery life caused by internal gas accumulation in existing batteries.

[0006] The technical solution for the battery vent valve of the present invention is as follows:

[0007] The battery vent valve includes a valve housing for mounting on the battery casing. The valve housing has an inner cavity and an vent for connecting the outside of the battery to the inner cavity of the valve housing. A waterproof and breathable membrane is provided at the vent. A movable valve core is slidably and sealed on the valve housing. The movable valve core has a valve core channel. The battery vent valve also includes an elastic structure that acts between the movable valve core and the valve housing.

[0008] When the air pressure inside the battery is less than the first set pressure, the active valve core is in the first position under the elastic force of the elastic structure. At this position, the valve core channel is outside the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery.

[0009] When the internal pressure of the battery is greater than the first set pressure and less than the second set pressure, under the combined action of the internal pressure of the battery and the elastic structure, the movable valve core moves into the inner cavity of the valve shell to the second position. At this position, the valve core channel connects the inner cavity of the valve shell with the inside of the battery. Gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged to the outside of the battery through the exhaust port.

[0010] When the internal air pressure of the battery is greater than the second set pressure, under the action of the internal air pressure of the battery, the movable valve core overcomes the elastic force of the elastic structure and moves into the inner cavity of the valve shell to the third position. At this position, the valve core channel is in the inner cavity of the valve shell, and the inner cavity of the valve core is separated from the inside of the battery.

[0011] Beneficial effects: When no gas is generated inside the battery or only a small amount of gas is generated with low internal gas pressure, venting is not required. The movable valve core is in the first position under the action of the elastic structure, separating the inner cavity of the valve shell from the inside of the battery, ensuring the battery's sealing performance. When a certain amount of gas is generated inside the battery but the internal gas pressure is within a controllable range, the movable valve core moves to the second position under the combined action of gas pressure and the elastic structure. At this time, the inner cavity of the valve shell is connected to the inside of the battery, and the gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged through the vent. This allows for timely and controlled discharge of gas from inside the battery, preventing lithium plating and the continuous accumulation of gas inside the battery, which could lead to the activation of the explosion-proof valve and ultimately battery failure. When the battery is in an abnormal situation and the internal gas pressure increases temporarily, the venting valve can no longer quickly release the gas. In this case, the movable valve core moves to the third position under the action of gas pressure, the venting valve is closed, and the battery can still activate the explosion-proof valve normally, preventing more dangerous situations such as battery explosion.

[0012] Furthermore, the movable valve core has a valve core cavity, and the movable valve core is provided with a first vent and a second vent that communicate with the valve core cavity. The first vent and the second vent are located on the side of the movable valve core perpendicular to the direction of movement of the movable valve core. The valve core cavity, the first vent, and the second vent constitute the valve core channel.

[0013] Beneficial effects: The movable valve core adopts a valve core structure with an inner cavity, making the movable valve core a hollow structure. The movable valve core is lighter, which is conducive to the weight reduction of the battery.

[0014] Furthermore, the first vent and the second vent are arranged at intervals along the direction of movement of the movable valve core.

[0015] Beneficial effects: The first and second vents are arranged at intervals along the direction of movement of the movable valve core, so that the valve shell can adopt a more regular shape, which not only facilitates processing, but also reduces the space occupied by the valve shell inside the battery, thus reducing the impact on the internal structural layout of the battery.

[0016] Furthermore, the movable valve core is cylindrical and slides and seals with the valve body through its outer circumferential surface.

[0017] Beneficial effect: The movable valve core is cylindrical, which facilitates the sliding seal between the movable valve core and the valve body.

[0018] Furthermore, the elastic structure is a compression spring, and it is installed between one end of the movable valve core located inside the valve housing cavity and the inner wall of the valve housing.

[0019] Beneficial effects: The elastic structure uses a compression spring, which is simple in structure and low in cost.

[0020] Furthermore, the surface of the compression spring is coated with a corrosion-resistant material.

[0021] Beneficial effects: Coating the surface of the compression spring with a corrosion-resistant material can enhance the corrosion resistance of the compression spring and effectively extend its service life.

[0022] Furthermore, the waterproof and breathable membrane is a gas-selective permeable membrane.

[0023] Beneficial effects: The waterproof and breathable membrane is a gas selectively permeable membrane, which allows only the gas generated by the internal reaction of the battery to pass through the gas selectively permeable membrane. This effectively prevents external gas from entering the battery through the exhaust port, thus avoiding damage to the battery from external air.

[0024] Furthermore, the movable valve core is a polytetrafluoroethylene (PTFE) valve core.

[0025] Beneficial effects: Polytetrafluoroethylene has self-lubricating properties, which can reduce friction between the moving valve core and the valve body, prevent the generation of wear debris from contaminating the inside of the battery, and ensure the reliability of battery operation.

[0026] The technical solution for the battery top cover of the present invention is as follows:

[0027] The battery top cover includes a cover plate on which a positive terminal and a negative terminal are mounted. The battery top cover also includes an exhaust valve disposed on the cover plate. The exhaust valve includes a valve housing for mounting on the battery casing. The valve housing has an inner cavity and an exhaust port for connecting the outside of the battery to the inner cavity of the valve housing. A waterproof and breathable membrane is provided at the exhaust port. A movable valve core is slidably and sealed on the valve housing. The movable valve core has a valve core channel. The battery exhaust valve also includes an elastic structure that acts between the movable valve core and the valve housing.

[0028] When the air pressure inside the battery is less than the first set pressure, the active valve core is in the first position under the elastic force of the elastic structure. At this position, the valve core channel is outside the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery.

[0029] When the internal pressure of the battery is greater than the first set pressure and less than the second set pressure, under the combined action of the internal pressure of the battery and the elastic structure, the movable valve core moves into the inner cavity of the valve shell to the second position. At this position, the valve core channel connects the inner cavity of the valve shell with the inside of the battery. Gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged to the outside of the battery through the exhaust port.

[0030] When the internal air pressure of the battery is greater than the second set pressure, under the action of the internal air pressure of the battery, the movable valve core overcomes the elastic force of the elastic structure and moves into the inner cavity of the valve shell to the third position. At this position, the valve core channel is in the inner cavity of the valve shell, and the inner cavity of the valve core is separated from the inside of the battery.

[0031] Beneficial effects: When no gas is generated inside the battery or only a small amount of gas is generated with low internal gas pressure, venting is not required. The movable valve core is in the first position under the action of the elastic structure, separating the inner cavity of the valve shell from the inside of the battery, ensuring the battery's sealing performance. When a certain amount of gas is generated inside the battery but the internal gas pressure is within a controllable range, the movable valve core moves to the second position under the combined action of gas pressure and the elastic structure. At this time, the inner cavity of the valve shell is connected to the inside of the battery, and the gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged through the vent. This allows for timely and controlled discharge of gas from inside the battery, preventing lithium plating and the continuous accumulation of gas inside the battery, which could lead to the activation of the explosion-proof valve and ultimately battery failure. When the battery is in an abnormal situation and the internal gas pressure increases temporarily, the venting valve can no longer quickly release the gas. In this case, the movable valve core moves to the third position under the action of gas pressure, the venting valve is closed, and the battery can still activate the explosion-proof valve normally, preventing more dangerous situations such as battery explosion.

[0032] Furthermore, the movable valve core has a valve core cavity, and the movable valve core is provided with a first vent and a second vent that communicate with the valve core cavity. The first vent and the second vent are located on the side of the movable valve core perpendicular to the direction of movement of the movable valve core. The valve core cavity, the first vent, and the second vent constitute the valve core channel.

[0033] Beneficial effects: The movable valve core adopts a valve core structure with an inner cavity, making the movable valve core a hollow structure. The movable valve core is lighter, which is conducive to the weight reduction of the battery.

[0034] Furthermore, the first vent and the second vent are arranged at intervals along the direction of movement of the movable valve core.

[0035] Beneficial effects: The first and second vents are arranged at intervals along the direction of movement of the movable valve core, so that the valve shell can adopt a more regular shape, which not only facilitates processing, but also reduces the space occupied by the valve shell inside the battery, thus reducing the impact on the internal structural layout of the battery.

[0036] Furthermore, the movable valve core is cylindrical and slides and seals with the valve body through its outer circumferential surface.

[0037] Beneficial effect: The movable valve core is cylindrical, which facilitates the sliding seal between the movable valve core and the valve body.

[0038] Furthermore, the elastic structure is a compression spring, and it is installed between one end of the movable valve core located inside the valve housing cavity and the inner wall of the valve housing.

[0039] Beneficial effects: The elastic structure uses a compression spring, which is simple in structure and low in cost.

[0040] Furthermore, the surface of the compression spring is coated with a corrosion-resistant material.

[0041] Beneficial effects: Coating the surface of the compression spring with a corrosion-resistant material can enhance the corrosion resistance of the compression spring and effectively extend its service life.

[0042] Furthermore, the waterproof and breathable membrane is a gas-selective permeable membrane.

[0043] Beneficial effects: The waterproof and breathable membrane is a gas selectively permeable membrane, which allows only the gas generated by the internal reaction of the battery to pass through the gas selectively permeable membrane. This effectively prevents external gas from entering the battery through the exhaust port, thus avoiding damage to the battery from external air.

[0044] Furthermore, the movable valve core is a polytetrafluoroethylene (PTFE) valve core.

[0045] Beneficial effects: Polytetrafluoroethylene has self-lubricating properties, which can reduce friction between the moving valve core and the valve body, prevent the generation of wear debris from contaminating the inside of the battery, and ensure the reliability of battery operation.

[0046] Furthermore, the exhaust valve is located between the positive and negative terminals.

[0047] Beneficial effects: The vent valve is located between the positive and negative terminals, which shortens the path of gas flow from all parts of the battery to the vent valve, allowing the gas to be discharged more smoothly. In addition, there is extra space inside the battery between the positive and negative terminals. Placing it in this position can make reasonable use of the internal space of the battery and help to achieve battery miniaturization.

[0048] Furthermore, the exhaust valve and the cover plate are integrally formed, and the exhaust port is located on the plate where the cover plate is located.

[0049] Beneficial effect: The exhaust valve and cover plate are integrally molded, which makes the connection between the exhaust valve and the cover plate stronger.

[0050] Furthermore, the exhaust valve is separately connected to the cover plate.

[0051] Beneficial effects: The separate connection between the exhaust valve and the cover plate facilitates the installation and replacement of the exhaust valve. Attached Figure Description

[0052] Figure 1 This is a simplified structural diagram of embodiment 1 of the battery top cover of the present invention;

[0053] Figure 2 This is a simplified structural diagram of the exhaust valve when the movable valve core is in the first position in Embodiment 1 of the battery top cover of the present invention;

[0054] Figure 3 This is a simplified structural diagram of the exhaust valve when the movable valve core is in the second position in Embodiment 1 of the battery top cover of the present invention;

[0055] Figure 4 This is a simplified structural diagram of the exhaust valve when the active valve core is in the third position in Embodiment 1 of the battery top cover of the present invention.

[0056] Explanation of reference numerals in the attached drawings: 1. Cover plate; 2. Positive terminal; 3. Negative terminal; 4. Exhaust valve; 5. Valve housing; 6. Valve housing inner cavity; 7. Exhaust port; 8. Top cover vent; 9. Movable valve core; 10. Valve core inner cavity; 11. First vent; 12. Second vent; 13. Valve core channel; 14. Elastic structure; 141. Compression spring. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0058] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0059] It should be noted that, in specific embodiments of the present invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply such an actual relationship or order between these entities or operations. Furthermore, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the use of phrases such as "comprising a…" to define an element does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0060] In the description of this invention, unless otherwise explicitly specified and limited, terms such as "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0061] In the description of this invention, unless otherwise explicitly specified and limited, the term "provided with" should be interpreted broadly. For example, the object "provided with" can be a part of the body, or it can be separately arranged from the body and connected to the body. This connection can be a detachable connection or a non-detachable connection. Those skilled in the art can understand the specific meaning of the above terms in this invention through specific circumstances.

[0062] The present invention will be further described in detail below with reference to the embodiments.

[0063] Traditional lithium batteries typically consist of a battery casing, which includes a bottom shell and a top cover. The top cover has positive and negative terminals. During battery use, gas is generated inside the battery, and the internal pressure gradually increases, posing a risk of explosion. To prevent battery explosions, existing solutions usually involve installing an explosion-proof valve. When a large amount of gas is generated inside the battery, the explosion-proof valve ruptures to release pressure and prevent explosion. For example, Chinese utility model patent CN215418488U discloses an explosion-proof valve. However, due to the limited space inside the battery, the amount of gas it can hold is limited. When the gas volume reaches its limit, the explosion-proof valve opens to expel the gas. After the explosion-proof valve opens, the battery is directly exposed to the air, leading to battery failure and reduced lifespan. Furthermore, gas accumulation can hinder the movement of lithium ions inside the battery, causing lithium plating and short circuits, further reducing battery lifespan. To improve battery lifespan, this invention provides a battery top cover.

[0064] Embodiment 1 of the battery top cover provided in this invention:

[0065] like Figures 1 to 4 As shown, the battery top cover includes a cover plate 1 and a positive terminal post 2 and a negative terminal post 3 disposed on the cover plate 1. The positive terminal post 2 and the negative terminal post 3 are respectively arranged on the left and right sides of the cover plate 1. In addition, an exhaust valve 4 is provided on the cover plate 1. The exhaust valve 4 is used to discharge the gas generated inside the battery to avoid the gas from accumulating inside the battery, thereby affecting the battery's service life.

[0066] The exhaust valve 4 includes a valve housing 5, which is rectangular in shape in this embodiment. However, in other embodiments, the valve housing may be cylindrical, prismatic, or similar. The upper wall of the valve housing 5 is fixed to the cover plate 1, and the valve housing 5 is hollow, giving it an inner cavity 6. An exhaust port 7 is provided on the upper wall of the valve housing 5, and correspondingly, a top cover vent 8 is provided on the cover plate 1. The top cover vent 8 communicates with the exhaust port 7, allowing the exhaust port 7 to connect the outside of the battery to the inner cavity 6 of the valve housing. A movable valve core 9 is slidably and sealingly installed on the lower wall of the valve housing 5. The movable valve core 9 can slide up and down on the valve housing 5 and has a valve core channel 13. During the up-and-down sliding process of the movable valve core 9, separation and communication between the inside of the battery and the inner cavity 6 of the valve housing can be achieved.

[0067] In this embodiment, the exhaust valve 4 and the cover plate 1 are connected separately. Specifically, the cover plate 1 and the upper shell wall of the exhaust valve 4 are connected by screws, and sealing rings are provided at the screw holes on both the upper shell wall of the valve housing 5 and the cover plate for sealing. In other embodiments, the exhaust valve and the cover plate can also be connected by adhesive. The separate connection between the exhaust valve 4 and the cover plate 1 facilitates the installation and replacement of the exhaust valve 4.

[0068] like Figures 2 to 4 As shown, the movable valve core 9 is cylindrical, which facilitates the sliding seal between the movable valve core 9 and the valve housing 5. The movable valve core 9 has a hollow structure, which provides a hollow cavity, namely the valve core inner cavity 10. The hollow structure of the movable valve core 9 makes it lighter, which is beneficial for achieving battery weight reduction. In addition, the movable valve core 9 is provided with a first vent 11 and a second vent 12 that communicate with the valve core cavity 10. Specifically, the first vent 11 and the second vent 12 are provided on the side wall of the movable valve core 9 that extends along the vertical movement direction of the movable valve core 9. The valve core cavity 10, the first vent 11 and the second vent 12 constitute the valve core channel 13 of the movable valve core 9, and the first vent 11 is located below the second vent 12, so that the first vent 11 and the second vent 12 are arranged alternately on the movable valve core 9 along the vertical movement direction of the movable valve core 9. In this way, the shape of the valve shell 5 can adopt a more regular shape, which is not only easy to process, but also occupies less space inside the battery, reducing the impact on the internal structural arrangement of the battery.

[0069] The exhaust valve 4 also includes an elastic structure 14. In this embodiment, the elastic structure 14 is a compression spring 141. The compression spring 141 is a cylindrical spring that extends in the vertical direction. The upper end of the compression spring 141 is fixedly connected to the inner wall of the valve housing 5, and the lower end of the compression spring 141 is fixedly connected to the upper end of the movable valve core 9. The movable valve core 9 compresses the compression spring 141 during its upward sliding process. To ensure that the compression spring 141 does not easily tilt to the left or right during compression, a cylindrical sleeve is fitted on the outside of the compression spring 141. The cylindrical sleeve is fixed to the inner wall of the valve housing 5. During the compression of the compression spring 141, the inner wall of the cylindrical sleeve will contact the compression spring 141 to prevent the compression spring 141 from tilting.

[0070] In addition, the surface of the compression spring 141 is coated with a corrosion-resistant material. Coating the surface of the compression spring 141 with a corrosion-resistant material can enhance the corrosion resistance of the compression spring 141 and effectively extend the service life of the compression spring 141. In this embodiment, the corrosion-resistant material on the surface of the compression spring 141 is a PP layer. In other embodiments, epoxy resin material can also be coated on the surface of the compression spring or it can be treated with zinc plating, nickel plating, etc.

[0071] In this embodiment, the movable valve core 9 is a polytetrafluoroethylene (PTFE) valve core. PTFE has self-lubricating properties, which can reduce the friction between the movable valve core 9 and the valve housing 5, prevent the generation of wear debris that contaminates the inside of the battery, and ensure the reliability of battery operation. In other embodiments, the movable valve core may also be made of materials with self-lubricating properties such as nylon or silicon nitride.

[0072] It should be noted that a waterproof and breathable membrane is provided at the vent 7 on the valve housing 5. Specifically, in this embodiment, the waterproof and breathable membrane is a gas-selective permeable membrane. This allows only gases generated by the internal reaction of the battery (such as CH4 / C2H4 / / C2H6 / C3H6 / C3H8, etc.) to pass through the gas-selective permeable membrane, effectively preventing external gases from entering the battery through the vent 7, thus avoiding damage to the battery from external air. Of course, in other embodiments, a common waterproof and breathable membrane with waterproof and breathable functions can also be used.

[0073] The working principle of exhaust valve 4 is:

[0074] When the internal pressure of the battery is less than the first set pressure, no gas is generated or only a small amount of gas is generated inside the battery, resulting in a low internal gas pressure. Therefore, it is not necessary to vent through the vent valve 4. The movable valve core 9 is in the first position under the elastic force of the compression spring 141. In this position, the valve core channel 13 is outside the valve housing cavity 6. That is, the first vent 11, the second vent 12, and the valve core cavity 10 are all outside the valve housing cavity 6. The vent valve 4 is in the closed state. The valve housing cavity 6 is separated from the inside of the battery to ensure the sealing performance of the battery.

[0075] When the internal pressure of the battery is greater than the first set pressure but less than the second set pressure, a certain amount of gas is generated inside the battery, so that the internal gas pressure is within a controllable range. Under the combined action of the internal gas pressure of the battery and the spring 141, the movable valve core 9 moves into the inner cavity 6 of the valve housing to the second position. At this position, the valve core channel 13 connects the inner cavity 6 of the valve housing with the inside of the battery. That is, the first vent 11 is outside the inner cavity 6 of the valve housing, and the second vent 12 is inside the inner cavity 6 of the valve housing. The gas inside the battery can enter the inner cavity 6 of the valve housing through the valve core channel 13 and be discharged to the outside of the battery through the exhaust port 7. In this way, the gas inside the battery can be discharged in a timely manner under controllable conditions, which not only avoids lithium plating, but also avoids the continuous accumulation of gas inside the battery, which would lead to the activation of the explosion-proof valve and ultimately the scrapping of the battery, effectively extending the service life of the battery.

[0076] When the internal pressure of the battery exceeds the second set pressure, and the internal pressure increases briefly due to an abnormal condition, the gas cannot be quickly released through the exhaust valve 4. Under the action of the internal pressure of the battery, the movable valve core 9 overcomes the elastic force of the compression spring 141 and moves into the inner cavity 6 of the valve housing to the third position. At this position, the valve core channel 13 is located inside the inner cavity 6 of the valve housing, that is, the first vent 11, the second vent 12, and the inner cavity 10 of the valve core are all inside the inner cavity 6 of the valve housing. The inner cavity 6 of the valve housing is separated from the inside of the battery, the exhaust valve 4 is in the closed state, the explosion-proof valve can be used normally, and it can effectively prevent more dangerous situations such as battery explosion.

[0077] It should be noted that in this embodiment, the first set pressure is 0.3 MPa and the second set pressure is 0.8 MPa. In other embodiments, the first set pressure and the second set pressure can be adjusted by adjusting the pressure spring.

[0078] In addition, in this embodiment, the exhaust valve 4 is located between the positive terminal 2 and the negative terminal 3. This arrangement makes the path of gas flow from all parts of the battery to the exhaust valve 4 shorter, and the gas can be discharged more smoothly through the exhaust valve 4. Moreover, there is extra space inside the battery between the positive and negative terminals. Placing it in this position can make reasonable use of the internal space of the battery and help to achieve battery miniaturization.

[0079] The second embodiment of the battery top cover in this invention differs from the first embodiment in that the movable valve core is a solid structure, and the surface of the movable valve core is provided with a venting groove that extends along the movement direction of the movable valve core, and the venting groove constitutes the valve core channel.

[0080] In Embodiment 3 of the battery top cover of this invention, unlike Embodiment 1, the movable valve core is slidably and sealed on the lower shell wall of the valve housing. The first and second vents are located on the movable valve core, and both vents are on the same horizontal plane along the direction of movement of the movable valve core. In this embodiment, the structure of the valve housing is relatively irregular. The lower shell wall of the valve housing is divided into two parts with equal left and right areas: a left lower shell wall connected to the left shell wall of the valve housing and a right lower shell wall connected to the right shell wall of the valve housing. The left lower shell wall is located above the right lower shell wall, and the left and right lower shell walls are connected by a vertically extending transition shell wall. A through hole is provided in the middle of the valve core, and the movable valve core is slidably sealed in the through hole. When the movable valve core is in the first position, the first vent, the second vent, and the valve core cavity are all outside the valve housing cavity. When the movable valve core moves to the second position, the first vent is outside the valve housing cavity, and the second vent is connected to the valve housing cavity. Gas inside the battery can enter the valve housing cavity through the valve core channel and be discharged to the outside of the battery through the exhaust port. When the movable valve core moves to the third position, the first vent, the second vent, and the valve core cavity are all inside the valve housing cavity. The valve housing cavity is separated from the inside of the battery, and the exhaust valve is in the closed state.

[0081] In Embodiment 4 of the present invention, the movable valve core differs from Embodiment 1 in that it is columnar with a square cross-section. In other embodiments, the cross-section of the movable valve core may also be triangular or other shapes.

[0082] In Embodiment 5 of the battery top cover of this invention, the elastic structure differs from Embodiment 1 in that it is a tension spring. A tension spring mounting plate extending laterally is provided inside the valve housing. The left and right ends of the tension spring mounting plate are slidably engaged with the left and right inner walls of the valve housing, respectively. The upper end of the tension spring is fixed to the tension spring mounting plate, and the lower end of the tension spring is fixed to the lower inner wall of the valve housing. Furthermore, the upper end of the movable valve core is fixed to the tension spring mounting plate. During the up-and-down movement of the movable valve core, the tension spring mounting plate will move up and down. In other embodiments, the compression spring can also be replaced by an air bladder, an elastic rubber tube, or other elastic structures.

[0083] In Embodiment 6 of the present invention, the vent valve is disposed on the cover plate and located on the left side of the positive terminal post, which differs from Embodiment 1. Alternatively, in other embodiments, the vent valve is disposed on the cover plate and located on the right side of the negative terminal post.

[0084] In Embodiment 7 of the present invention, the exhaust valve and the cover plate are integrally formed, and the exhaust port is set on the plate on which the cover plate is located. The integral setting of the exhaust valve and the cover plate makes the connection strength between the exhaust valve and the cover plate higher.

[0085] In Embodiment 8 of the present invention, the active valve core is slidably sealed and installed on the left shell wall of the valve housing, and the active valve core extends horizontally to the left and right. In this embodiment, the compression spring is also horizontally arranged to the left and right. The left end of the compression spring is fixedly connected to the right end of the active valve core, and the right end of the compression spring is fixedly connected to the inner wall of the valve housing. The first vent on the active valve core is located to the left of the second vent.

[0086] A specific embodiment of the battery vent valve of the present invention has the same structure as the vent valve in any embodiment of the battery top cover described above, and will not be repeated here.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. An exhaust valve for a battery, characterized by, The valve includes a valve housing for mounting on the battery casing. The valve housing has an inner cavity and an exhaust port for connecting the outside of the battery to the inner cavity of the valve housing. A waterproof and breathable membrane is provided at the exhaust port. A movable valve core is slidably and sealed on the valve housing. The movable valve core has a valve core channel. The battery exhaust valve also includes an elastic structure that acts between the movable valve core and the valve housing. When the air pressure inside the battery is less than the first set pressure, the active valve core is in the first position under the elastic force of the elastic structure. At this position, the valve core channel is outside the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. When the internal pressure of the battery is greater than the first set pressure and less than the second set pressure, under the combined action of the internal pressure of the battery and the elastic structure, the movable valve core moves into the inner cavity of the valve shell to the second position. At this position, the valve core channel connects the inner cavity of the valve shell with the inside of the battery. Gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged to the outside of the battery through the exhaust port. When the internal air pressure of the battery is greater than the second set pressure, under the action of the internal air pressure of the battery, the movable valve core overcomes the elastic force of the elastic structure and moves to the third position in the inner cavity of the valve shell. At this position, the valve core channel is in the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. The movable valve core has an inner cavity. The movable valve core is provided with a first vent and a second vent that communicate with the inner cavity. The first vent and the second vent are located on the side of the movable valve core perpendicular to the direction of movement of the movable valve core. The inner cavity of the valve core, the first vent and the second vent constitute the valve core channel. The first vent and the second vent are arranged at intervals along the direction of movement of the movable valve core.

2. The battery vent valve according to claim 1, characterized in that, The movable valve core is cylindrical and slides and seals with the valve body through its outer circumferential surface.

3. The battery vent valve according to claim 1, characterized in that, The elastic structure is a compression spring, which is installed between one end of the movable valve core located inside the valve housing cavity and the inner wall of the valve housing.

4. The battery vent valve according to claim 3, characterized in that, The surface of the compression spring is coated with a corrosion-resistant material.

5. The battery vent valve according to claim 1, characterized in that, Waterproof and breathable membranes are selectively permeable to gases.

6. The battery vent valve according to claim 1, characterized in that, The movable valve core is made of polytetrafluoroethylene.

7. A battery vent valve, characterized in that, The valve includes a valve housing for mounting on the battery casing. The valve housing has an inner cavity and an exhaust port for connecting the outside of the battery to the inner cavity of the valve housing. A waterproof and breathable membrane is provided at the exhaust port. A movable valve core is slidably and sealed on the valve housing. The movable valve core has a valve core channel. The battery exhaust valve also includes an elastic structure that acts between the movable valve core and the valve housing. When the air pressure inside the battery is less than the first set pressure, the active valve core is in the first position under the elastic force of the elastic structure. At this position, the valve core channel is outside the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. When the internal pressure of the battery is greater than the first set pressure and less than the second set pressure, under the combined action of the internal pressure of the battery and the elastic structure, the movable valve core moves into the inner cavity of the valve shell to the second position. At this position, the valve core channel connects the inner cavity of the valve shell with the inside of the battery. Gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged to the outside of the battery through the exhaust port. When the internal air pressure of the battery is greater than the second set pressure, under the action of the internal air pressure of the battery, the movable valve core overcomes the elastic force of the elastic structure and moves to the third position in the inner cavity of the valve shell. At this position, the valve core channel is in the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. The movable valve core has an inner cavity. The movable valve core is provided with a first and a second vent that communicate with the inner cavity. The two vents are on the same horizontal plane along the direction of movement of the movable valve core. The lower shell wall of the valve housing is divided into two parts with equal left and right areas, namely the lower left shell wall connected to the left shell wall of the valve housing and the lower right shell wall connected to the right shell wall of the valve housing. The lower left shell wall is located above the lower right shell wall. The lower left shell wall and the lower right shell wall are connected by a vertically extending transition shell wall. A through hole is provided in the middle of the lower shell wall, and the movable valve core is slidably sealed in the through hole.

8. The battery vent valve according to claim 7, characterized in that, The movable valve core is cylindrical and slides and seals with the valve body through its outer circumferential surface.

9. The vent valve for a battery according to claim 7, characterized in that, The elastic structure is a compression spring, which is installed between one end of the movable valve core located inside the valve housing cavity and the inner wall of the valve housing.

10. The vent valve for a battery according to claim 9, characterized in that, The surface of the compression spring is coated with a corrosion-resistant material.

11. The vent valve for a battery according to claim 7, characterized in that, Waterproof and breathable membranes are selectively permeable to gases.

12. The vent valve for a battery according to claim 7, characterized in that, The movable valve core is made of polytetrafluoroethylene.

13. A battery top cover, including a cover plate, on which a positive terminal and a negative terminal are mounted, characterized in that, The battery top cover also includes an exhaust valve disposed on the cover plate. The exhaust valve includes a valve housing for mounting on the battery casing. The valve housing has an inner cavity and an exhaust port for connecting the outside of the battery to the inner cavity of the valve housing. A waterproof and breathable membrane is provided at the exhaust port. A movable valve core is slidably and sealed on the valve housing. The movable valve core has a valve core channel. The battery exhaust valve also includes an elastic structure that acts between the movable valve core and the valve housing. When the air pressure inside the battery is less than the first set pressure, the active valve core is in the first position under the elastic force of the elastic structure. At this position, the valve core channel is outside the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. When the internal pressure of the battery is greater than the first set pressure and less than the second set pressure, under the combined action of the internal pressure of the battery and the elastic structure, the movable valve core moves into the inner cavity of the valve shell to the second position. At this position, the valve core channel connects the inner cavity of the valve shell with the inside of the battery. Gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged to the outside of the battery through the exhaust port. When the internal air pressure of the battery is greater than the second set pressure, under the action of the internal air pressure of the battery, the movable valve core overcomes the elastic force of the elastic structure and moves to the third position in the inner cavity of the valve shell. At this position, the valve core channel is in the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. The movable valve core has an inner cavity. The movable valve core is provided with a first and a second vent that communicate with the inner cavity. The two vents are on the same horizontal plane along the direction of movement of the movable valve core. The lower shell wall of the valve housing is divided into two parts with equal left and right areas, namely the lower left shell wall connected to the left shell wall of the valve housing and the lower right shell wall connected to the right shell wall of the valve housing. The lower left shell wall is located above the lower right shell wall. The lower left shell wall and the lower right shell wall are connected by a vertically extending transition shell wall. A through hole is provided in the middle of the lower shell wall, and the movable valve core is slidably sealed in the through hole.

14. The battery top cover according to claim 13, characterized in that, The movable valve core is cylindrical and slides and seals with the valve body through its outer circumferential surface.

15. The battery top cover according to claim 13, characterized in that, The elastic structure is a compression spring, which is installed between one end of the movable valve core located inside the valve housing cavity and the inner wall of the valve housing.

16. The battery top cover according to claim 15, characterized in that, The surface of the compression spring is coated with a corrosion-resistant material.

17. The battery top cover according to claim 13, characterized in that, Waterproof and breathable membranes are selectively permeable to gases.

18. The battery top cover according to claim 13, characterized in that, The movable valve core is made of polytetrafluoroethylene.

19. The battery top cover according to claim 13, characterized in that, The vent valve is located between the positive and negative terminals.

20. The battery top cover according to claim 13, characterized in that, The exhaust valve and the cover plate are integrally formed, and the exhaust port is located on the plate where the cover plate is located.

21. The battery top cover according to claim 13, characterized in that, The exhaust valve is connected separately from the cover plate.

22. A battery top cover, including a cover plate, on which a positive terminal and a negative terminal are mounted, characterized in that, The battery top cover also includes an exhaust valve disposed on the cover plate. The exhaust valve includes a valve housing for mounting on the battery casing. The valve housing has an inner cavity and an exhaust port for connecting the outside of the battery to the inner cavity of the valve housing. A waterproof and breathable membrane is provided at the exhaust port. A movable valve core is slidably and sealed on the valve housing. The movable valve core has a valve core channel. The battery exhaust valve also includes an elastic structure that acts between the movable valve core and the valve housing. When the air pressure inside the battery is less than the first set pressure, the active valve core is in the first position under the elastic force of the elastic structure. At this position, the valve core channel is outside the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. When the internal pressure of the battery is greater than the first set pressure and less than the second set pressure, under the combined action of the internal pressure of the battery and the elastic structure, the movable valve core moves into the inner cavity of the valve shell to the second position. At this position, the valve core channel connects the inner cavity of the valve shell with the inside of the battery. Gas inside the battery can enter the inner cavity of the valve shell through the valve core channel and be discharged to the outside of the battery through the exhaust port. When the internal air pressure of the battery is greater than the second set pressure, under the action of the internal air pressure of the battery, the movable valve core overcomes the elastic force of the elastic structure and moves to the third position in the inner cavity of the valve shell. At this position, the valve core channel is in the inner cavity of the valve shell, and the inner cavity of the valve shell is separated from the inside of the battery. The movable valve core has an inner cavity. The movable valve core is provided with a first vent and a second vent that communicate with the inner cavity. The first vent and the second vent are located on the side of the movable valve core perpendicular to the direction of movement of the movable valve core. The inner cavity of the valve core, the first vent and the second vent constitute the valve core channel. The first vent and the second vent are arranged at intervals along the direction of movement of the movable valve core.

23. The battery top cover according to claim 22, characterized in that, The movable valve core is cylindrical and slides and seals with the valve body through its outer circumferential surface.

24. The battery top cover according to claim 22, characterized in that, The elastic structure is a compression spring, which is installed between one end of the movable valve core located inside the valve housing cavity and the inner wall of the valve housing.

25. The battery top cover according to claim 24, characterized in that, The surface of the compression spring is coated with a corrosion-resistant material.

26. The battery top cover according to claim 22, characterized in that, Waterproof and breathable membranes are selectively permeable to gases.

27. The battery top cover according to claim 22, characterized in that, The movable valve core is made of polytetrafluoroethylene.

28. The battery top cover according to claim 22, characterized in that, The vent valve is located between the positive and negative terminals.

29. The battery top cover according to claim 22, characterized in that, The exhaust valve and the cover plate are integrally formed, and the exhaust port is located on the plate where the cover plate is located.

30. The battery top cover according to claim 22, characterized in that, The exhaust valve is connected separately from the cover plate.

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