Lithium battery explosion-proof cover cap integrated with explosion-proof safety valve

Abstract

This utility model provides an explosion-proof cap for lithium batteries with an integrated explosion-proof safety valve, relating to the technical field of explosion-proof caps for lithium batteries. It includes a cap body with a rotating exhaust channel inside. This rotating exhaust channel employs a scanning process, with the channel located on the inner wall of the cap body. Gas passing through the spiral channel needs to make multiple turns, significantly extending the path compared to a straight orifice, thus reducing the flow velocity and effectively preventing electrolyte from flowing out with the gas. This, combined with a filter membrane or microporous structure, enhances liquid separation, greatly reducing the risk of liquid backflow. Simultaneously, the high-speed gas in the rotating channel generates centrifugal force, throwing the liquid against the sidewall, and then allowing it to naturally flow back into the inner cavity by gravity, further preventing liquid from entering downstream structures, such as labyrinth filters or rupture zones. During low pressure or the initial stage of pressure increase, the rotating channel maintains relatively high resistance, allowing only a small amount of gas to depressurize; as the pressure continues to rise, it still assists in slow exhaust and delays liquid impact.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery explosion-proof cap technology, and in particular to a lithium battery explosion-proof cap with an integrated explosion-proof safety valve. Background Technology

[0002] According to Chinese Patent Publication No. CN201918444U, a power lithium-ion battery explosion-proof cap is disclosed, including a top cover (1), an aluminum explosion-proof valve (3), and a sealing ring (4). The top cover (1) protrudes outward from the battery, and the aluminum explosion-proof valve (3) protrudes inward from the battery. The top cover (1) and the aluminum explosion-proof valve (3) are fitted together, and the edge of the aluminum explosion-proof valve (3) has a flanged structure that wraps around the edge of the top cover (1). By adopting the above technical solution, the nickel ring structure is eliminated, and an integral separator sleeve is used, so that the battery avoids internal short circuits after the explosion-proof effect, thereby eliminating the risk of spontaneous combustion or explosion of the power lithium-ion battery and improving the safety performance of the power lithium-ion battery.

[0003] The aforementioned prior art and related documents have the following technical problems:

[0004] Traditional through-hole or blow-hole structures cannot effectively prevent electrolyte from being ejected with gas, which can easily cause liquid to flow back into the battery structure, affecting the normal operation of functional components and potentially causing safety hazards such as short circuits or corrosion. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing an explosion-proof cap for lithium batteries that integrates an explosion-proof safety valve.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an explosion-proof cap for lithium batteries with an integrated explosion-proof safety valve, comprising a cap body, wherein the cap body has a rotating exhaust groove inside, which is attached to the inner side wall of the cap body, the cap body has a burst groove inside, and one side of the burst groove is rounded, a second film is provided on one side of the burst groove, and the second film is embedded in one side of the burst groove, and a blind hole is provided at the bottom of the second film.

[0007] Preferably, the top of the cap body is provided with a top cover, and the bottom of the top cover is positioned and connected to the top of the cap body.

[0008] Preferably, the top cover has four air holes on one side, and the four air holes are arranged in a matrix.

[0009] Preferably, the cap body has a circular sealing ring inside, and the circular sealing ring is fitted inside the cap body.

[0010] Preferably, the cap body has a film support ring inside, and the film support ring is subjected to a boss stretching treatment, and the top of the cap body is treated with rounded corners.

[0011] Preferably, a microporous breathable membrane is provided on one side of the thin film support ring, and the microporous breathable membrane is connected to the microporous breathable membrane.

[0012] Preferably, the blind hole is cut at the center of the second film.

[0013] Beneficial effects

[0014] In this invention, a rotating exhaust channel is provided on the inner wall of the cap body. Gas must travel multiple turns through the spiral channel, significantly extending its path compared to a straight orifice, thus reducing its flow velocity and effectively preventing electrolyte from flowing out with the gas. This, combined with a filter membrane or microporous structure, enhances liquid separation, greatly reducing the risk of liquid backflow. Simultaneously, the high-speed gas in the rotating channel generates centrifugal force, throwing the liquid against the sidewall and then allowing it to naturally flow back into the inner cavity by gravity, further preventing liquid from entering downstream structures such as labyrinth filters or burst areas. During low pressure or the initial stage of pressure increase, the rotating channel maintains relatively high resistance, allowing only minor gas pressure relief. As pressure continues to rise, it still assists in slow exhaust and delays liquid impact. Under high pressure, it can still work with the downstream burst mechanism to form a highly efficient, staged exhaust system. Furthermore, the spiral channel can be precisely designed during manufacturing to ensure consistent gas resistance characteristics, and, in conjunction with a protective membrane or high-pressure valve, ensures that pressure relief does not damage the cap seal. It also effectively reduces heat buildup in the inner cavity and stabilizes the internal pressure of the battery.

[0015] In this invention, a blind hole is provided at the bottom of the second film. By reserving the blind hole, a weak area is formed at the bottom of the second film. The thickness and rupture position of the bursting film can be controlled and accurately set, avoiding accidental cracking in other areas and improving structural reliability. At the same time, the blind hole can be formed by stamping, laser processing or mold processing in one step, and is integrally formed with the film area without additional welding, reducing costs and improving consistency.

[0016] In this invention, a thin film support ring and a microporous breathable membrane are provided inside the cap body. The support ring and the cap are positioned by a snap fastener. The microporous membrane can be fixed by hot pressing or adhesive bonding. The entire assembly is suitable for stamping and automated assembly. Gas can be safely discharged through the membrane, avoiding long-term pressure accumulation. The electrolyte is blocked from contacting the circuit components, reducing chemical reactions. At the same time, it can also extend the battery cycle and reduce the risk of thermal runaway. Attached Figure Description

[0017] Figure 1 This is an isometric view of the present invention;

[0018] Figure 2 This is a bottom view of the present invention;

[0019] Figure 3 This is an internal top view of the present invention;

[0020] Figure 4 For the present utility model Figure 3 A cross-sectional view of BB;

[0021] Figure 5 This is a top view of the present invention.

[0022] Legend:

[0023] 1. Cap body; 2. Rotary exhaust groove; 3. Membrane support ring; 4. Microporous breathable membrane; 5. Air hole; 6. Top cover; 7. Bursting groove; 8. Second membrane; 9. Blind hole; 10. Circular sealing ring. Detailed Implementation

[0024] To make the technical means, creative features, and achieved objectives and effects of this utility model easier to understand, the present utility model is further described below with reference to specific embodiments and accompanying drawings. However, the following embodiments are merely preferred embodiments of this utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments described in the implementation plan without creative effort are all within the protection scope of this utility model.

[0025] The specific embodiments of this utility model are described below with reference to the accompanying drawings. Specific Implementation Example 1:

[0027] Reference Figure 1-5An explosion-proof cap for lithium batteries with an integrated explosion-proof safety valve includes a cap body 1. The cap body 1 has a rotating venting groove 2 inside, which is fitted to the inner wall of the cap body 1. A top cover 6 is provided on the top of the cap body 1, and the bottom of the top cover 6 is positioned to the top of the cap body 1. Four air holes 5 are provided on one side of the top cover 6, and the four air holes 5 are arranged in a matrix. A circular sealing ring 10 is provided inside the cap body 1, and the circular sealing ring 10 is embedded inside the cap body 1. The cap body 1 has a membrane support ring 3 inside, which is made of a boss and stretched. The top of the cap body 1 is rounded. A microporous breathable membrane 4 is provided on one side of the membrane support ring 3, and the microporous breathable membrane 4 is connected to the microporous breathable membrane 8. The blind hole 9 is cut at the center of the second membrane 8. The cap body 1 has a bursting groove 7 inside, and one side of the bursting groove 7 is rounded. A second membrane 8 is provided on one side of the bursting groove 7, and the second membrane 8 is embedded in one side of the bursting groove 7. The bottom of the second membrane 8 is provided with a blind hole 9. A rotating exhaust groove 2 is provided on the inner wall of the cap body 1, which makes the gas need to go around multiple times through the spiral channel. The path is much longer than that of a straight hole, which reduces the flow rate and effectively prevents the electrolyte from flowing out with the gas. This design, combined with filter membranes or microporous structures, enhances liquid separation, significantly reducing the risk of liquid backflow. Simultaneously, the high-speed gas within the rotating tank generates centrifugal force, throwing the liquid against the sidewalls and allowing it to naturally flow back into the inner cavity by gravity. This further prevents liquid from entering downstream structures, such as labyrinth filters or burst areas. During low or initial pressurization, the rotating channel maintains relatively high resistance, allowing only minor gas depressurization. As pressure continues to rise, it still assists in slow venting and delays liquid impact. Under high pressure, it can still work with downstream burst mechanisms to form a highly efficient, staged venting system. Furthermore, the spiral channel can be precisely designed during manufacturing to ensure consistent gas resistance characteristics, and with the aid of protective membranes or high-pressure valves, pressure relief is ensured without damaging the cap seal. It can also effectively reduce internal heat accumulation and stabilize the internal pressure of the battery. A blind hole 9 is provided at the bottom of the second film 8, which forms a weak area at the bottom of the second film 8. The thickness and rupture position of the burst film can be controlled and accurately set, avoiding accidental rupture in other areas and improving structural reliability. At the same time, the blind hole 9 can be formed by stamping, laser processing or mold processing, and is integrally formed with the film area without additional welding, reducing costs and improving consistency. Inside the cap body 1, there is a film support ring 3 and a microporous breathable membrane 4. The support ring and the cap are positioned by snap-fit, and the microporous membrane can be fixed by hot pressing or adhesive. The entire component is suitable for stamping processing and automated assembly. Gas can be safely discharged through the membrane to avoid long-term pressure accumulation. The electrolyte is blocked and does not come into contact with the circuit components, reducing chemical reactions. At the same time, it can also extend the battery cycle and reduce the risk of thermal runaway. Specific Implementation Example 2:

[0029] Reference Figure 1-5The method employs a freely rotatable air guide plate or micro impeller inside the cap body 1. When the gas is released rapidly, the guide plate generates centrifugal force to assist the liquid in being thrown away from the channel, which helps prevent liquid from entering. Based on the basic structure in Specific Embodiment 1, the further technical solution solves the problem that the traditional cap has a straight ventilation path, and the liquid is easy to enter the subsequent structure with the airflow, affecting the filter membrane and the burst zone, and even causing short circuits or malfunctions.

[0030] In summary:

[0031] 1. A rotating exhaust channel 2 is provided on the inner wall of the cap body 1. This allows gas to pass through the spiral channel multiple times, significantly extending the path compared to a straight hole, thus reducing the flow velocity and effectively preventing electrolyte from flowing out with the gas. This can be combined with a filter membrane or microporous structure to enhance liquid separation, greatly reducing the risk of liquid backflow. Simultaneously, the high-speed gas in the rotating channel generates centrifugal force, throwing the liquid against the sidewall and then allowing it to flow back into the inner cavity by gravity, further preventing liquid from entering downstream structures such as labyrinth filters or burst areas. In low-pressure or initial pressure-boosting phases, the rotating channel maintains relatively high resistance, allowing only minor gas pressure relief. As pressure continues to rise, it still assists in slow exhaust and delays liquid impact. Under high pressure, it can still work with downstream burst mechanisms to form a highly efficient, staged exhaust system. Furthermore, the spiral channel can be precisely designed during manufacturing to ensure consistent gas resistance characteristics, and with the help of a protective membrane or high-pressure valve, pressure relief is ensured without damaging the cap seal. It also effectively reduces heat buildup in the inner cavity and stabilizes the internal pressure of the battery.

[0032] 2. By using a blind hole 9 at the bottom of the second film 8, a weak area is formed at the bottom of the second film 8 through the pre-reserved blind hole 9. The thickness and rupture position of the burst film can be controlled and accurately set, avoiding accidental cracking in other areas and improving structural reliability. At the same time, the blind hole 9 can be formed by stamping, laser processing or mold processing in one step, and is integrally formed with the film area without additional welding, reducing costs and improving consistency.

[0033] 3. The cap body 1 has a thin film support ring 3 and a microporous breathable membrane 4 inside. The support ring and the cap are positioned by snap-fit, which realizes that the microporous membrane can be fixed by hot pressing or adhesive. The whole component is suitable for stamping and automated assembly. Gas can be safely discharged through the membrane, avoiding long-term pressure accumulation. The electrolyte is blocked and does not come into contact with the circuit components, reducing chemical reactions. At the same time, it can also extend the battery cycle and reduce the risk of thermal runaway.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An explosion-proof cap for a lithium battery integrated with an explosion-proof safety valve, comprising a cap body (1), characterized in that: The cap body (1) has a rotating exhaust groove (2) inside, which is attached to the inner side wall of the cap body (1). The cap body (1) has a burst groove (7) inside, and one side of the burst groove (7) is rounded. A second film (8) is provided on one side of the burst groove (7), and the second film (8) is embedded in one side of the burst groove (7). A blind hole (9) is provided at the bottom of the second film (8).

2. The integrated explosion relief safety valve lithium battery explosion relief cap of claim 1, wherein: The cap body (1) has a top cover (6) on its top, and the bottom of the top cover (6) is connected to the top of the cap body (1) by positioning.

3. The integrated explosion relief safety valve lithium battery explosion relief cap of claim 2, wherein: The top cover (6) has four air holes (5) on one side, and the four air holes (5) are arranged in a matrix.

4. The integrated explosion relief safety valve lithium battery explosion relief cap of claim 1, wherein: The cap body (1) is provided with a circular sealing ring (10) inside, and the circular sealing ring (10) is fitted inside the cap body (1).

5. The integrated explosion relief safety valve lithium battery explosion relief cap of claim 1, wherein: The cap body (1) is provided with a film support ring (3) inside, and the film support ring (3) is subjected to a boss stretching treatment, and the top of the cap body (1) is subjected to a rounded corner treatment.

6. An integrated explosion relief safety valve lithium battery explosion relief cap according to claim 5, wherein: The film support ring (3) has a microporous breathable membrane (4) on one side, and the microporous breathable membrane (4) is connected to the microporous breathable membrane (4).

7. The integrated explosion relief safety valve lithium battery explosion relief cap of claim 1, wherein: The blind hole (9) is cut at the center of the second film (8).

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