Battery cell cover plate pressure relief structure

Abstract

The utility model relates to a battery cell cover plate pressure relief structure which comprises a top cover, a pressure relief assembly is arranged on the top cover, the pressure relief assembly comprises a valve body, a push block and an elastic piece, the valve body is arranged on the top cover in a penetrating mode, a cavity for containing the push block and the elastic piece is arranged in the valve body, and the elastic piece is arranged in the cavity. A liquid injection hole and an exhaust groove are formed in the two ends of the valve body respectively, one end of the push block covers the liquid injection hole, the elastic piece is arranged at the other end of the push block, and the two ends of the elastic piece abut against the inner side surface of the valve body and the push block respectively. The valve body and the liquid injection hole are integrated, the pressure relief assembly can be installed after liquid injection, the situation that the pressure relief assembly is polluted due to the fact that electrolyte overflows is avoided, meanwhile, the push block and the elastic piece are further arranged, automatic pressure relief of the battery cell can be completed, the internal pressure can be stabilized, the safety of the battery cell can be enhanced, and the service life of the battery cell can be prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of battery cell manufacturing, and in particular, to a pressure relief structure for a battery cell cover plate. Background Art

[0002] During the charging and discharging process of a battery cell, a certain amount of gas will be generated. When the gas inside the battery cell reaches the critical value, if it is not discharged in time, the internal pressure of the battery cell will be too high, which may cause the battery cell to expand and even explode. Therefore, currently, a pressure relief valve or an explosion-proof valve is usually installed on the cover plate of the battery cell to relieve pressure when the internal pressure of the battery cell is too high, ensuring the safety performance of the battery cell.

[0003] Currently, a liquid injection hole for injecting liquid into the battery cell is usually installed on the cover plate. Since the area of the cover plate is usually small, during liquid injection, the electrolyte may overflow and contaminate the pressure relief valve that has been installed beside it, which may cause the pressure relief valve to fail to perform the pressure relief function normally. At the same time, the existing pressure relief valves are usually for one-time use. As shown in CN220692252U, such pressure relief valves mainly release the internal pressure of the battery cell quickly by destroying the seal in the pressure relief valve. Although it can effectively ensure the safety of the battery cell and prevent the battery cell from expanding and exploding, since it cannot be reused, the battery cell loses the pressure relief function after the pressure relief valve is damaged. In some special occasions, the battery cell without the pressure relief function cannot continue to be used normally and needs to be replaced, so the service life of the battery cell is shortened to a certain extent. Summary of the Utility Model

[0004] In view of this, to solve the above problems, the utility model provides a pressure relief structure for a battery cell cover plate.

[0005] A pressure relief structure for a battery cell cover plate includes a top cover. A pressure relief component is provided on the top cover. The pressure relief component includes a valve body, a push block, and an elastic member. The valve body passes through the top cover. A cavity for accommodating the push block and the elastic member is provided inside the valve body. A liquid injection hole and an exhaust groove are respectively opened at both ends of the valve body. One end of the push block covers the liquid injection hole. The elastic member is provided at the other end of the push block. Both ends of the elastic member are respectively abutted against the inner side surface of the valve body and the push block.

[0006] In the above technical solution, the top cover is installed on the top of the battery cell to seal the inside of the battery cell. There is a hole on the top cover for installing the valve body. The valve body passes through the top cover through this hole. One end of the valve body is provided with a liquid injection hole, and the liquid injection hole is used to inject electrolyte into the battery cell. Specifically, during implementation, after the valve body is installed on the top cover and before other structures inside the valve body are installed, liquid can be injected through the liquid injection hole provided on the valve body, and then other structures can be installed after injection, so as to avoid electrolyte overflow during injection, resulting in contamination of the top cover and the pressure relief component; one end of the push block covers the liquid injection hole to seal the inside of the battery cell. The other end of the push block is provided with an elastic member, and both ends of the elastic member abut against the push block and the inner end face of the valve body. When the gas generated during the charge and discharge process of the battery cell reaches the critical value, the gas pushes the push block through the liquid injection hole, and the elastic member contracts. At this time, the sealing effect of the push block on the liquid injection hole fails, and the gas leaks into the valve body through the liquid injection hole and then is discharged from the exhaust groove on the other side of the valve body for pressure relief. After the gas is discharged, the push block resets under the elastic force of the elastic member and covers and seals the liquid injection hole again, realizing automatic adjustment of the internal pressure of the battery cell, effectively stabilizing the internal air pressure of the battery cell, enhancing the safety of the battery cell, and extending the service life of the battery cell.

[0007] As an optional implementation manner, a sealing ring is provided between the push block and the liquid injection hole, and both ends of the sealing ring abut against the inner surface of the valve body and the push block respectively.

[0008] In the above technical solution, the sealing ring is provided between the end face of the push block and the liquid injection hole and surrounds the liquid injection hole. Through the sealing ring, the sealing effect between the push block and the liquid injection hole is enhanced, air leakage is avoided, and the pressure relief function can be realized normally.

[0009] As an optional implementation manner, an installation groove is provided around the periphery of the liquid injection hole, and the sealing ring is installed in the installation groove.

[0010] In the above technical solution, the installation groove surrounds the liquid injection hole, and the sealing ring is installed in the installation groove to fix the sealing ring.

[0011] As an optional implementation manner, the valve body includes a valve sleeve and a valve seat. One end of the valve seat is open, and the other end is provided with the liquid injection hole, and the valve sleeve is installed in the valve seat.

[0012] In the above technical solution, the valve seat cooperates with the valve sleeve. One end of the valve seat is provided with an opening for installing other components. After the assembly of the remaining components is completed, the valve sleeve is installed to close the opening of the valve seat.

[0013] As an optional implementation manner, a hollow part is provided inside the valve sleeve, and the push block and the elastic member are located inside the hollow part of the valve sleeve.

[0014] In the above technical solution, the inside of the valve sleeve is hollow and used to accommodate the push block and the elastic member. One end of the valve sleeve is provided with an opening. After the push block and the elastic member are installed, the valve sleeve sleevs the push block and the elastic member through this opening.

[0015] As an alternative implementation, the elastic member is sleeved on the push block. One end of the push block is provided with a convex ring, and both ends of the elastic member respectively abut against the convex ring and the inner side of the valve sleeve.

[0016] In the above technical solution, the convex ring protrudes and distributes on the circumferential side of the push block. The elastic member is sleeved on the push block. One end of it abuts against the end face of the convex ring, and the other end abuts against the inner end face of the valve sleeve.

[0017] As an alternative implementation, a plurality of limiting grooves are formed on the circumferential surface of the valve sleeve, and a plurality of limiting blocks are provided on the circumferential side of the convex ring and are matched with the limiting grooves.

[0018] In the above technical solution, the valve sleeve is limited by the cooperation of the limiting groove and the limiting block, avoiding relative rotation between the valve sleeve and the push block and ensuring stable installation.

[0019] As an alternative implementation, one end of the valve sleeve is provided with a protruding annular portion. The exhaust groove is provided at the edge position of the annular portion, and a gap is formed between the side surface of the annular portion and the side wall of the valve seat.

[0020] In the above technical solution, the valve sleeve is provided with a ring of annular portion. The exhaust groove is provided at the edge position of the annular portion. The opening of the exhaust groove extends to the side surface of the annular portion. After the valve sleeve and the valve seat are installed, a gap is left between the annular portion and the side wall of the valve seat. When gas enters the inside of the valve body from the liquid injection hole, it can enter the exhaust groove from this gap and then be discharged to the outside of the valve body from the exhaust groove position.

[0021] As an alternative implementation, one end of the valve seat away from the liquid injection hole is bent inward to form a limiting end face, and the annular portion abuts against the limiting end face.

[0022] In the above technical solution, the annular portion of the valve sleeve abuts against the limiting end face, thereby limiting and fixing the valve sleeve. After the annular portion abuts against the limiting end face, other positions except the exhaust groove are in a closed structure. The inside and outside of the valve body can only communicate and exchange through the exhaust groove, effectively preventing foreign objects from entering the inside of the valve body and protecting the battery cell.

[0023] Compared with the prior art, the present utility model has the following beneficial effects:

[0024] Good reliability. In this application, a liquid injection hole for injecting liquid into the internal of the battery cell is provided on the valve body. By integrating the valve body and the liquid injection hole, the installation of the pressure relief component can be carried out after liquid injection, avoiding the pollution of the pressure relief component caused by the overflow of electrolyte when injecting liquid alone, ensuring the liquid injection quality and improving the reliability.

[0025] Improving the safety and service life of the battery cell. In this application, a push block and an elastic member are provided. When the gas generated during the charge and discharge process of the battery cell reaches the critical value, the gas can push the push block and leak into the valve body through the liquid injection hole, and then be discharged from the exhaust groove on the other side of the valve body to complete automatic pressure relief, thus effectively stabilizing the internal pressure of the battery cell, avoiding the expansion of the battery cell, strengthening the safety of the battery cell. In addition, after the gas is discharged, the push block can be reset under the elastic force of the elastic member to re-cover and seal the liquid injection hole, without the need to replace the pressure relief component, and can be reused, which helps to extend the service life of the battery cell. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of this application, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0027] Figure 1 An exploded view of the pressure relief structure of the battery cell cover for an embodiment.

[0028] Figure 2 A perspective view of the pressure relief structure of the battery cell cover of this application.

[0029] Figure 3 A bottom view of the pressure relief structure of the battery cell cover of this application.

[0030] Figure 4 A top view of the pressure relief structure of the battery cell cover of this application.

[0031] Figure 5 For Figure 4 The sectional view at A-A in

[0032] Figure 6 For Figure 5 The enlarged view of position A in

[0033] Explanation of the reference numerals in the drawings:

[0034] 1 - Top cover; 2 - Valve body; 21 - Valve sleeve; 211 - Exhaust groove; 212 - Limiting groove; 213 - Ring part; 22 - Valve seat; 221 - Liquid injection hole; 222 - Installation groove; 223 - Limiting end face; 3 - Push block; 31 - Convex ring; 32 - Limiting block; 4 - Elastic member; 5 - Sealing ring. Detailed implementation manners

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0037] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0038] Please refer to Figures 1 to 6 , in a preferred embodiment of the present application, a pressure relief structure for a battery cell cover plate is provided, which includes a top cover 1. A pressure relief component is provided on the top cover 1. The pressure relief component includes a valve body 2, a push block 3 and an elastic member 4. The valve body 2 penetrates through the top cover 1. A cavity for accommodating the push block 3 and the elastic member 4 is provided inside the valve body 2. Liquid injection holes 221 and exhaust grooves 211 are respectively formed at both ends of the valve body 2. One end of the push block 3 covers the liquid injection hole 221. The elastic member 4 is provided at the other end of the push block 3. Both ends of the elastic member 4 are respectively abutted against the inner surface of the valve body 2 and the push block 3.

[0039] Specifically, the top cover 1 is installed on the top of the battery cell. There is a hole on the top cover 1 for installing the valve body 2. The valve body 2 passes through the top cover 1 through this hole. There is a liquid injection hole 221 at the bottom end of the valve body 2. The liquid injection hole 221 is used to inject electrolyte into the battery cell. Specifically, after the valve body 2 is installed on the top cover 1 and before other structures inside the valve body 2 are installed, liquid injection is carried out through the liquid injection hole 221 provided on the valve body 2. Thus, other structures can be installed after liquid injection, avoiding electrolyte overflow during liquid injection, which may contaminate the top cover 1 and the pressure relief component. The bottom end of the push block 3 covers the liquid injection hole 221 to seal the inside of the battery cell. There is an elastic member 4 at the other end of the push block 3. Both ends of the elastic member 4 abut against the push block 3 and the top end inside the valve body 2. When the gas generated during the charging and discharging process of the battery cell reaches the critical value, the gas pushes the push block 3 above through the liquid injection hole 221, causing the elastic member 4 to contract. At this time, a gap is generated between the push block 3 and the liquid injection hole 221, resulting in the failure of the sealing effect of the push block 3 on the liquid injection hole 221. The gas leaks into the valve body 2 and is discharged from the exhaust groove 211 on the other side of the valve body 2, thus completing pressure relief. After the gas is discharged, the push block 3 resets under the elastic force of the elastic member 4 and covers and seals the liquid injection hole 221 again, realizing the automatic adjustment of the internal pressure of the battery cell, effectively stabilizing the internal air pressure of the battery cell, enhancing the safety of the battery cell, and prolonging the service life of the battery cell.

[0040] Specifically, the elastic member 4 is selected as a spring. Besides using a spring, other structures with elastic functions can also be selected.

[0041] Please refer to Figure 1 and Figure 5 , in this embodiment, a sealing ring 5 is provided between the push block 3 and the liquid injection hole 221. Both ends of the sealing ring 5 abut against the bottom inside the valve body 2 and the bottom of the push block 3 respectively. The sealing ring 5 is arranged between the end face of the push block 3 and the liquid injection hole 221 and surrounds the liquid injection hole 221. Through the sealing ring 5, the sealing effect between the push block 3 and the liquid injection hole 221 is enhanced, avoiding air leakage and ensuring the normal realization of the pressure relief function. Specifically, when the gas inside the battery cell reaches the critical value, the push block 3 is pushed upward. The pressure on the contact surface between the bottom of the push block 3 and the sealing ring 5 is insufficient and cannot effectively seal, so that the gas can leak into the valve body 2.

[0042] Please refer to Figure 1 and Figure 5 , in this embodiment, a mounting groove 222 is circumferentially arranged around the periphery of the liquid injection hole 221 (as shown in Figure 5 ). The mounting groove 222 surrounds the liquid injection hole 221. The sealing ring 5 is installed in the mounting groove 222, thereby fixing the sealing ring 5 and ensuring the sealing effect.

[0043] Please refer to Figures 1 to 5, in this embodiment, the valve body 2 includes a valve sleeve 21 and a valve seat 22. The top of the valve seat 22 is open, and a liquid injection hole 221 is provided at the bottom. The valve sleeve 21 is installed inside the valve seat 22. A hollow part for accommodating the push block 3 and the elastic member 4 is provided inside the valve sleeve 21. Both the push block 3 and the elastic member 4 are located inside the hollow part of the valve sleeve 21. One end of the valve sleeve 21 is also open. After the components inside the valve seat 22 are installed, the valve sleeve 21 sleevs the push block 3 and the elastic member 4 through the open end, thus completing the assembly of the pressure relief component.

[0044] Please refer to Figure 1 and Figure 5 , in this embodiment, a protruding ring 31 is provided at the bottom end of the push block 3. The elastic member 4 is sleeved on the push block 3. The bottom end of the elastic member 4 abuts against the ring 31, and the other end abuts against the top end inside the valve sleeve 21.

[0045] Please refer to Figure 1 , in this embodiment, a plurality of limiting grooves 212 are formed on the circumferential surface of the valve sleeve 21. A plurality of limiting blocks 32 are provided on the circumference of the ring 31 and are matched with the limiting grooves 212. Through the cooperation of the limiting grooves 212 and the limiting blocks 32, the valve sleeve 21 is limited to prevent relative rotation between the valve sleeve 21 and the push block 3 and ensure stable installation.

[0046] Please refer to Figures 1 to 6 , in this embodiment, the valve sleeve 21 is provided with a protruding annular portion 213. The exhaust groove 211 is provided at the edge of the annular portion 213. There are 4 exhaust grooves 211, which are distributed around the edge of the top surface of the annular portion 213, and the exhaust groove 211 penetrates through to the side surface of the annular portion 213, so that an opening is formed on the side surface of the annular portion 213. After the valve sleeve 21 is installed with the valve seat 22, a certain gap is left between the annular portion 213 and the side wall of the valve seat 22 (as shown in Figure 6 ). When the gas enters the inside of the valve body 2 from the liquid injection hole 221, it can enter the exhaust groove 211 through this gap, and then be discharged to the outside of the valve body 2 from the position of the exhaust groove 211.

[0047] Please refer to Figure 6 , in this embodiment, the top end of the valve seat 22 is bent inward to form a limiting end surface 223. The top surface of the annular portion 213 abuts against the bottom of the limiting end surface 223, thereby limiting and fixing the valve sleeve 21. After the annular portion 213 abuts against the limiting end surface 223, other positions except the exhaust groove 211 are in a closed structure. The inside and outside of the valve body 2 can only communicate and exchange through the exhaust groove 211, which can effectively prevent foreign objects from entering the inside of the valve body 2 and protect the battery cell.

[0048] Specifically, after the valve sleeve 21 is installed, the top end of the valve seat 22 is spun by a spinning device to form the limiting end surface 223, so that the valve sleeve 21 is fixed inside the valve seat 22.

[0049] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model.

[0050] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0051] In the present utility model, unless otherwise clearly specified and defined, terms such as "mounted", "connected", "connected to", "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0052] Although the description of the present utility model is made in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and variations based on the above content. Therefore, all such substitutions, improvements and variations are included within the spirit and scope of the appended claims.

Claims

1. A battery cover pressure relief structure, comprising a top cover, wherein a pressure relief component is provided on the top cover, characterized in that: The pressure relief assembly includes a valve body, a push block and an elastic member. The valve body is inserted through the top cover. A cavity for accommodating the push block and the elastic member is provided inside the valve body. Liquid injection holes and exhaust grooves are respectively provided at two ends of the valve body. One end of the push block covers the liquid injection hole. The elastic member is provided at the other end of the push block. The two ends of the elastic member respectively abut against the inner surface of the valve body and the push block.

2. The battery cover pressure relief structure according to claim 1, characterized in that: A sealing ring is arranged between the push block and the liquid injection hole, and two ends of the sealing ring are respectively against the inner surface of the valve body and the push block.

3. The battery cover pressure relief structure according to claim 2, characterized in that: A mounting groove is arranged around the periphery of the liquid injection hole, and the sealing ring is installed in the mounting groove.

4. The battery cover pressure relief structure according to claim 1, characterized in that: The valve body comprises a valve sleeve and a valve seat. One end of the valve seat is open, and the other end is provided with the injection hole. The valve sleeve is installed in the valve seat.

5. The battery cover pressure relief structure according to claim 4, characterized in that: A hollow portion is provided in the valve sleeve, and the push block and the elastic member are located in the hollow portion of the valve sleeve.

6. The battery cover pressure relief structure according to claim 5, characterized in that: The elastic member is sleeved on the push block, a convex ring is arranged at one end of the push block, and two ends of the elastic member are respectively against the convex ring and the inner side of the valve sleeve.

7. The battery cover pressure relief structure according to claim 6, characterized in that: A plurality of limiting grooves are formed on the peripheral surface of the valve sleeve, and a plurality of limiting blocks matching with the limiting grooves are provided on the peripheral side of the convex ring.

8. The cell cover pressure relief structure according to claim 4, characterized in that: A protruding annular portion is provided at one end of the valve sleeve, the exhaust groove is provided at the edge of the annular portion, and a gap is formed between the side surface of the annular portion and the side wall of the valve seat.

9. The battery cover pressure relief structure according to claim 8, characterized in that: One end of the valve seat away from the liquid injection hole is bent inwardly to form a limiting end surface, and the annular portion abuts against the limiting end surface.

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