Top cover structure of double-layer anti-explosion valve

Abstract

The invention relates to the technical field of battery explosion prevention, in particular to a top cover structure of a double-layer explosion-proof valve, which comprises a base with a hollow inner cavity and two open ends, an inner explosion-proof membrane and an outer explosion-proof membrane are respectively arranged on the base, a redundant cavity is formed between the inner explosion-proof membrane and the outer explosion-proof membrane, and an exhaust component is arranged in the redundant cavity; the exhaust assembly comprises a hollow fixing plate fixedly arranged in the inner cavity of the base, the redundant cavity is divided into an outer cavity and an inner cavity by the fixing plate, a one-way valve is arranged between the fixing plate and the base, and the one-way valve is arranged in the outer cavity. When the inner explosion-proof membrane is broken, gas generated in the lithium battery enters the redundant cavity, the internal pressure of the lithium battery is relieved, the risk of swelling deformation of a battery cell caused by gas production is reduced, in addition, the gas in the redundant cavity can be exhausted to the outside through the one-way valve by the exhaust assembly, the gas pressure in the lithium battery is further reduced, and the safety of the lithium battery is improved. And the safety design of the square battery cell is improved to a new height.

Description

Technical Field

[0001] The invention relates to the technical field of battery explosion-proof, and in particular to a top cover structure of a double-layer explosion-proof valve. Background Art

[0002] In order to avoid explosion, an explosion-proof valve structure is generally added to the structure of the power battery. Usually, an indentation is made on the battery shell or a metal film is laminated on the cover plate. It can withstand a certain pressure. When the pressure exceeds the range it can withstand, the explosion-proof valve will rupture, so a large amount of gas can be discharged before the power battery explodes, thereby converting the explosion into smoke and reducing the degree of danger.

[0003] During long-term use, lithium batteries will produce a large amount of gas inside, causing the internal pressure of the lithium battery to increase sharply. When the pressure difference between the inside and outside of the lithium battery reaches the design value of the explosion-proof valve, the explosion-proof valve ruptures to discharge the internal gas of the lithium battery. However, after the explosion-proof valve ruptures, external impurities such as moisture and dust can easily enter the lithium battery, producing corrosive substances, further damaging the electrodes, diaphragms and other components inside the battery, causing the service life of the lithium battery to decrease rapidly and posing serious safety hazards. Summary of the invention

[0004] The object of the present invention is to provide a top cover structure of a double-layer explosion-proof valve to solve the above-mentioned deficiencies in the prior art.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A top cover structure of a double-layer explosion-proof valve comprises a base having a hollow inner cavity and openings at both ends, an inner explosion-proof membrane and an outer explosion-proof membrane are respectively arranged on the base, a redundant cavity is formed between the inner explosion-proof membrane and the outer explosion-proof membrane, an exhaust component is arranged in the redundant cavity; the exhaust component comprises a hollow fixing plate fixedly arranged in the inner cavity of the base, the fixing plate separates the redundant cavity into an outer cavity and an inner cavity, a one-way valve is arranged between the fixing plate and the base, and the one-way valve is arranged in the outer cavity.

[0007] Furthermore, the redundant chamber is set at a negative pressure.

[0008] Furthermore, the one-way valve includes a connecting tube fixedly arranged on a fixed plate and a base, wherein elastic parts and limit blocks are respectively arranged in the connecting tube, and a valve core is also slidably connected in the connecting tube, wherein the valve core is adapted to the connecting tube, and the valve core is located between the elastic part and the limit block, and the elastic part is arranged on a side close to the outer explosion-proof membrane.

[0009] Furthermore, the limit block is arranged in a circular ring and is fixedly arranged on the inner wall of the connecting pipe.

[0010] Furthermore, the elastic member includes a mounting plate fixedly arranged in the connecting pipe, the mounting plate is hollowed out, and a compression spring is arranged between the mounting plate and the valve core.

[0011] Furthermore, at least one through groove is provided on the outer surface of the valve core sliding with the inner wall of the connecting pipe, and the through groove is provided along the length direction of the valve core.

[0012] Furthermore, a sealing ring is provided on the side of the limit block facing the valve core.

[0013] Furthermore, an annular block is fixedly arranged on the top of the base, the outer explosion-proof membrane is arranged on the annular block, and the connecting pipe is fixedly connected to the annular plate.

[0014] Furthermore, a blocking block adapted to the through groove is also provided on the inner wall of the connecting pipe, and the blocking block is arranged on a side close to the outer explosion-proof membrane.

[0015] Furthermore, the number of the one-way valve is at least one.

[0016] In the above technical solution, the top cover structure of a double-layer explosion-proof valve provided by the present invention has the following beneficial effects:

[0017] 1. The double-layer explosion-proof design, which consists of an inner explosion-proof mold and an outer explosion-proof membrane, can effectively prevent abnormal rupture of a single explosion-proof membrane, thereby protecting the battery from external environmental intrusion.

[0018] 2. Through the exhaust assembly, when the inner explosion-proof membrane ruptures, the gas generated in the lithium battery enters the redundant cavity, relieving the internal pressure of the lithium battery and reducing the risk of battery cell swelling and deformation caused by gas production. In addition, the exhaust assembly can discharge the gas in the redundant cavity to the outside through a one-way valve, further reducing the air pressure inside the lithium battery and avoiding direct contact between the lithium battery and the outside air, bringing the safety design of the square battery to a new level.

[0019] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0020] This application document provides an overview of various implementations or examples of the technology described in the present disclosure, and is not a comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 A schematic diagram of the overall structure provided by an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of an overall cross-sectional structure provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the explosion structure of a one-way valve provided in an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of the structure of an elastic member provided in an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of a cross-sectional structure of a one-way valve provided in an embodiment of the present invention;

[0027] Figure 6 A schematic diagram of a local enlarged structure of an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 100. Base; 101. Inner explosion-proof membrane; 102. Outer explosion-proof membrane; 103. Redundant cavity; 104. Ring block; 105. Fixed plate; 210. One-way valve; 211. Connecting pipe; 220. Elastic piece; 221. Mounting plate; 222. Compression spring; 230. Limit block; 240. Valve core; 241. Through groove; 242. Guide block; 250. Sealing ring; 300. Blocking block. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0031] See also Figure 1-6A double-layer explosion-proof valve top cover structure includes a base 100 with a hollow inner cavity and openings at both ends, an inner explosion-proof membrane 101 and an outer explosion-proof membrane 102 are respectively arranged on the base 100, a redundant cavity 103 is formed between the inner explosion-proof membrane 101 and the outer explosion-proof membrane 102, and an exhaust component is arranged in the redundant cavity 103; the exhaust component includes a hollow fixed plate 105 fixedly arranged in the inner cavity of the base 100, the fixed plate 105 separates the redundant cavity 103 into an outer cavity and an inner cavity, a one-way valve 210 is arranged between the fixed plate 105 and the base 100, and the one-way valve 210 is arranged in the outer cavity. The hollow fixed plate 105 makes the outer cavity and the inner cavity communicate; it can be understood that the outer explosion-proof membrane 102 can withstand a higher air pressure value than the inner explosion-proof membrane 101, so that the inner explosion-proof membrane 101 breaks before the outer explosion-proof membrane 102.

[0032] Furthermore, the redundant chamber 103 is set at a negative pressure. When the inner explosion-proof membrane 101 is broken, the gas generated inside the lithium battery enters the redundant chamber 103, increasing the activity range of the gas, thereby reducing the gas pressure inside the battery.

[0033] Furthermore, the one-way valve 210 includes a connecting pipe 211 fixedly arranged on the fixing plate 105 and the base 100, wherein the connecting pipe 211 is respectively provided with an elastic member 220 and a stop block 230, and the connecting pipe 211 is also slidably connected with a valve core 240, wherein the valve core 240 is adapted to the connecting pipe 211, and the valve core 240 is located between the elastic member 220 and the stop block 230, and the elastic member 220 is arranged on a side close to the outer explosion-proof membrane 102. The connecting pipe 211 is used to connect the redundant cavity 103 and the outside of the base 100, so as to discharge the gas inside the battery to the outside of the base 100, thereby reducing the pressure inside the battery. The elastic member 220 makes the valve core 240 abut against the stop block 230, thereby making the valve core 240 and the stop block 230 sealed.

[0034] When the gas pressure in the redundant chamber 103 is high, the gas pushes the valve core 240 to move, causing the valve core 240 to disengage from the limit block 230, thereby releasing the sealing state between the valve core 240 and the limit block 230. After passing through the valve core 240, the gas is discharged from the outside of the base 100 along the connecting pipe 211, thereby reducing the pressure inside the lithium battery, and external air cannot enter the lithium battery through the one-way valve 210, thereby effectively extending the life of the lithium battery.

[0035] Furthermore, the stop block 230 is provided in a circular ring and fixedly provided on the inner wall of the connecting pipe 211. The stop block 230 is completely in contact with the valve core 240, which limits the moving range of the valve core 240 on the one hand, and on the other hand, under the action of the elastic member 220, the valve core 240 and the stop block 230 seal the connecting pipe 211.

[0036] Furthermore, the elastic member 220 includes a mounting plate 221 fixedly disposed in the connecting pipe 211, the mounting plate 221 is hollowed out, and a compression spring 222 is disposed between the mounting plate 221 and the valve core 240. The hollow mounting plate 221 allows the gas inside the lithium battery to pass through the mounting plate 221.

[0037] Furthermore, at least one through groove 241 is provided on the outer surface of the valve core 240 that slides with the inner wall of the connecting pipe 211, and the through groove 241 is provided along the length direction of the valve core 240. When the valve core 240 and the stop block 230 are separated from the abutment, the gas moves along the through groove 241 on the outer surface of the valve core 240 and is discharged to the outside of the base 100 through the mounting plate 221.

[0038] Furthermore, a sealing ring 250 is also provided on the side of the stop block 230 facing the valve core 240. The sealing ring 250 strengthens the sealing effect between the valve core 240 and the stop block 230. It can be understood that the sealing ring 250 should be provided between the through groove 241 and the inner wall of the stop block 230 to ensure that when the valve core 240 abuts against the sealing ring 250 on the stop block 230, the gas inside the lithium battery and the space outside the base 100 are not connected, that is, to prevent external air from entering the lithium battery and causing damage to the lithium battery.

[0039] Furthermore, an annular block 104 is fixedly arranged on the top of the base 100 , the outer explosion-proof membrane 102 is arranged on the annular block 104 , and the connecting pipe 211 is fixedly connected to the annular plate. The connecting pipe 211 passes through the annular plate and communicates with the air outside the base 100 .

[0040] Furthermore, a blocking block 300 adapted to the through groove 241 is also provided on the inner wall of the connecting pipe 211, and the blocking block 300 is provided on a side close to the outer explosion-proof membrane 102. When a lithium battery fails and the internal gas pressure increases sharply, the slow exhaust of the one-way valve 210 cannot meet the exhaust demand, and the outer explosion-proof membrane 102 needs to be ruptured to accelerate the exhaust of gas in the lithium battery to avoid the lithium battery from exploding. In other words, when the gas pressure in the lithium battery increases rapidly, the gas should be discharged rapidly from the position of the outer explosion-proof membrane 102. Specifically, when the gas pressure in the lithium battery increases rapidly, the gas further pushes the valve core 240 to move toward the outer explosion-proof membrane 102. When the valve core 240 moves to the blocking block 300, the blocking block 300 blocks the through groove 241, thereby sealing the connecting pipe 211, so that the gas in the lithium battery cannot be discharged, until the gas pressure reaches the design strength of the outer explosion-proof membrane 102, the outer explosion-proof membrane 102 ruptures, and the gas inside the lithium battery is quickly discharged from the outer explosion-proof membrane 102. It can be understood that a guide block 242 and a guide groove are provided between the valve core 240 and the inner wall of the connecting pipe 211, so that when the valve core 240 moves, the through groove 241 can be aligned with the blocking block 300.

[0041] Furthermore, the number of the one-way valve 210 is at least one, so as to accelerate the exhaust speed of the gas generated inside the lithium battery on a daily basis.

[0042] Working principle: When the gas inside the lithium battery reaches a certain pressure, the internal explosion-proof membrane 101 ruptures, and the gas generated inside the lithium battery enters the redundant chamber 103, initially reducing the pressure inside the battery; when the gas in the redundant chamber 103 reaches a certain value, the gas pushes the valve core 240 to move, so that the valve core 240 and the limit block 230 are separated from each other, and the sealing state between the valve core 240 and the limit block 230 is released, and the gas passes through the through groove 241 on the valve core 240 along the connecting pipe 211 and is discharged through the mounting plate 221. When the gas pressure inside the lithium battery increases sharply, the gas further pushes the valve core 240 to move toward the outer explosion-proof membrane 102. When the valve core 240 moves to the blocking block 300, the blocking block 300 blocks the through groove 241, thereby sealing the connecting pipe 211, so that the gas inside the lithium battery cannot be discharged until the gas pressure reaches the design strength of the outer explosion-proof membrane 102, the outer explosion-proof membrane 102 ruptures, and the gas inside the lithium battery is quickly discharged from the outer explosion-proof membrane 102. The present invention can discharge the gas generated in the lithium battery in stages, avoid direct contact between the lithium battery and the outside world, and effectively improve the service life of the lithium battery.

[0043] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A top cover structure of a double-layer explosion-proof valve, comprising a base (100) having a hollow inner cavity and openings at both ends, characterized in that: An inner explosion-proof membrane (101) and an outer explosion-proof membrane (102) are respectively arranged on the base (100), a redundant cavity (103) is formed between the inner explosion-proof membrane (101) and the outer explosion-proof membrane (102), and an exhaust component is arranged in the redundant cavity (103); The exhaust assembly comprises a hollow fixing plate (105) fixedly arranged in the inner cavity of the base (100), the fixing plate (105) dividing the redundant cavity (103) into an outer cavity and an inner cavity, a one-way valve (210) is arranged between the fixing plate (105) and the base (100), and the one-way valve (210) is arranged in the outer cavity.

2. A double-layer explosion-proof valve top cover structure according to claim 1, characterized in that: The redundant chamber (103) is set at a negative pressure.

3. A top cover structure of a double-layer explosion-proof valve according to claim 2, characterized in that: The one-way valve (210) comprises a connecting pipe (211) fixedly arranged on a fixing plate (105) and a base (100), wherein an elastic member (220) and a limit block (230) are respectively arranged in the connecting pipe (211), and a valve core (240) is also slidably connected in the connecting pipe (211), wherein the valve core (240) is adapted to the connecting pipe (211), and the valve core (240) is located between the elastic member (220) and the limit block (230), and the elastic member (220) is arranged on a side close to the outer explosion-proof membrane (102).

4. A double-layer explosion-proof valve top cover structure according to claim 3, characterized in that: The limiting block (230) is arranged in a circular ring and is fixedly arranged on the inner wall of the connecting pipe (211).

5. The top cover structure of a double-layer explosion-proof valve according to claim 3, characterized in that: The elastic member (220) comprises a mounting plate (221) fixedly arranged in the connecting pipe (211); the mounting plate (221) is hollowed out; and a compression spring (222) is further arranged between the mounting plate (221) and the valve core (240).

6. The top cover structure of a double-layer explosion-proof valve according to claim 3, characterized in that: At least one through groove (241) is provided on the outer surface of the valve core (240) sliding with the inner wall of the connecting pipe (211), and the through groove (241) is provided along the length direction of the valve core (240).

7. The top cover structure of a double-layer explosion-proof valve according to claim 3, characterized in that: A sealing ring (250) is also provided on the side of the limit block (230) facing the valve core (240).

8. The top cover structure of a double-layer explosion-proof valve according to claim 3, characterized in that: An annular block (104) is fixedly arranged on the top of the base (100), the outer explosion-proof membrane (102) is arranged on the annular block (104), and the connecting pipe (211) is fixedly connected to the annular plate.

9. The top cover structure of a double-layer explosion-proof valve according to claim 6, characterized in that: A blocking block (300) adapted to the through groove (241) is also provided on the inner wall of the connecting pipe (211), and the blocking block (300) is arranged on a side close to the outer explosion-proof membrane (102).

10. A top cover structure of a double-layer explosion-proof valve according to any one of claims 1 to 9, characterized in that: The number of the one-way valve (210) is at least one.

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