Safety valve for secondary battery

Abstract

The utility model discloses a safety valve for a secondary battery, which relates to the technical field of secondary batteries and comprises a sealing plug, a fixing plate, a mounting valve gasket, a spring and a mounting valve bonnet. A boss is arranged on the battery shell, and a pressure relief hole is formed in the boss; the sealing plug comprises a cylinder arranged in the vertical direction and a sealing gasket fixedly arranged at the bottom of the cylinder, an inner concave part is arranged at the bottom of the sealing gasket, and a first through hole is formed in the fixing plate; the sealing gasket comprises a plane part and a cylindrical part, the plane part is arranged at the bottom of the cylinder, a second through hole is formed in the plane part, and the second through hole is matched with the cavity in the cylinder; a first protrusion is arranged on the lower surface of the plane part, and the outer diameter of the first protrusion is matched with the inner diameter of the pressure relief hole. The first protrusion of the plane part is embedded into the pressure relief hole and tightly attached to the pressure relief hole, and the sealing plug is pressed through mutual cooperation of the installation valve gasket, the spring and the installation valve bonnet, so that the lower surface of the plane part of the sealing gasket is tightly attached to the top end of the boss. The bottom end of the cylindrical part is tightly attached to the upper surface of the battery shell, and the cylindrical part is limited through the first through hole of the fixing plate.

Description

Technical Field

[0001] The utility model belongs to the technical field of secondary batteries, and particularly relates to a safety valve for secondary batteries. Background Art

[0002] A secondary battery is a battery that can be repeatedly charged and discharged, and has recently been miniaturized and increased in capacity. Representative secondary batteries mainly use nickel-metal hydride (Ni-MH) batteries and lithium-ion (Li-ion) batteries. As a widely used lithium-ion battery as such a secondary battery, a lithium transition metal oxide is used as a positive electrode active material, and carbon or a carbon composite is used as a negative electrode active material. A liquid electrolyte in which a lithium salt is dissolved is injected into an organic solution therebetween, and charging and discharging can be performed through an electrode generated by the movement of lithium ions between the positive electrode and the negative electrode.

[0003] In order to enable a secondary battery to have good safety performance during use, a safety valve assembly is generally provided on the battery case. When the internal pressure of the battery is small, the safety valve assembly functions to seal the exhaust hole; when the internal pressure of the battery suddenly increases due to an accidental reason (such as a short circuit) of the battery, the safety valve assembly will be activated in time to discharge gas and reduce the internal pressure of the battery in time.

[0004] However, in the prior art, the common safety valve assembly and the battery case often have insufficient tightness, which is extremely likely to cause leakage of its electrolyte, and the probability of soda creep is relatively high. However, the electrolyte has strong corrosiveness, and the leakage of the electrolyte is extremely likely to cause certain impacts on the battery body, equipment, safety valve assembly, human body, etc., not only increasing the cost of using the battery, but also increasing its potential safety hazards, etc. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a safety valve for secondary batteries to solve the technical problem in the background art that "the common safety valve assembly and the battery case often have insufficient tightness, which is extremely likely to cause leakage of its electrolyte, and the probability of soda creep is relatively high. However, the electrolyte has strong corrosiveness, and the leakage of the electrolyte is extremely likely to cause certain impacts on the battery body, equipment, safety valve assembly, human body, etc., not only increasing the cost of using the battery, but also increasing its potential safety hazards, etc.".

[0006] To achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A safety valve for secondary batteries, the safety valve is arranged on the battery case, and the safety valve includes: a sealing plug, a fixing plate, a mounting valve gasket, a spring and a mounting valve cap;

[0008] A boss is provided on the battery case, and a pressure relief hole is provided on the boss;

[0009] Further, the sealing plug includes: a cylinder disposed in the vertical direction, and a sealing gasket fixed to the bottom of the cylinder, the diameter of the cylinder being smaller than the diameter of the sealing gasket; an inner concave portion is provided at the bottom of the sealing gasket, and the size of the inner concave portion is adapted to the convex platform;

[0010] A first through hole is provided on the fixing plate, and the size of the first through hole is slightly larger than the outer diameter of the sealing gasket;

[0011] The sealing gasket includes a planar portion and a cylindrical portion. The planar portion is disposed at the bottom of the cylinder, and a second through hole is provided in the planar portion. The second through hole is adapted to the cavity inside the cylinder;

[0012] A first protrusion is provided on the lower surface of the planar portion, and the first protrusion is disposed at the edge of the second through hole. The outer diameter of the first protrusion is adapted to the inner diameter of the pressure relief hole;

[0013] Further, the first protrusion on the planar portion is embedded into the pressure relief hole and closely fitted. By the mutual cooperation among the mounting valve gasket, the spring and the mounting valve cap to press the sealing plug, the lower surface of the planar portion of the sealing gasket is closely fitted with the top end of the convex platform, and the bottom end of the cylindrical portion is closely fitted with the upper surface of the battery case. The cylindrical portion is limited by the first through hole of the fixing plate.

[0014] The beneficial effects of the above technical solutions: Compared with the prior art, for the safety valve of the secondary battery, the overall structures of the sealing plug and the fixing plate, and the assembly manner between the sealing plug and the mounting valve gasket, the spring and the mounting valve cap are effectively improved. By providing a first protrusion on the lower surface of the planar portion of the sealing gasket, the first protrusion is embedded into the pressure relief hole to ensure the tightness between the sealing plug and the pressure relief hole; through the mutual cooperation among the mounting valve gasket, the spring and the mounting valve cap, to ensure the tightness between the lower surface of the planar portion of the sealing gasket and the top end of the convex platform, and ensure the tightness between the bottom end of the cylindrical portion and the upper surface of the battery case; and to ensure preventing the electrolyte from flowing out of the pressure relief hole. By providing a first through hole on the fixing plate, to ensure the limitation of the edge of the cylindrical portion; to solve the technical problem that "the tightness between the commonly used safety valve assembly and the battery case is often insufficient, which is extremely likely to cause the leakage of the electrolyte. However, the electrolyte has strong corrosiveness, and the leakage of the electrolyte is extremely likely to cause certain impacts on the battery body, equipment, safety valve assembly, human body, etc., not only increasing the cost of battery use, but also increasing the potential safety hazards, etc. "; by designing a multi-layer sealing structure for the safety valve sealing gasket to increase the safety factor of the sealing effect, increasing the path of the electrolyte leakage, thereby reducing the probability of electrolyte leakage.

[0015] Preferably, the cavity is communicated with the pressure relief hole;

[0016] Further, the cavity is frustum-shaped, and the cross-sectional area of its top is smaller than that of its bottom.

[0017] Beneficial effects of the above technical solution: By connecting the cavity with the pressure relief hole, when the secondary battery causes a sharp increase in the internal pressure of the battery due to accidental reasons (such as short circuit), it is ensured that the gasket of the sealing plug is separated from the boss of the battery housing to discharge the high-pressure gas; after the gas is discharged, under the action of the spring, the gasket of the sealing plug is closely attached to the boss of the battery housing to achieve a sealing effect; by setting the cavity as frustum-shaped, it is ensured to increase its stress area and further ensure the exhaust effect of the sealing plug.

[0018] Preferably, several "strip-shaped" protrusions are further provided on the outer surface of the cylinder, and several "block-shaped" protrusions are provided on the top of the cylinder.

[0019] Beneficial effects of the above technical solution: By providing several "strip-shaped" protrusions on the outer surface of the cylinder and several "block-shaped" protrusions on the top of the cylinder, it is prevented that the sealing plug adheres to the installed battery housing after aging, and it is ensured that the battery can be safely opened after aging.

[0020] Preferably, the size of the first through hole is 1-5 mm larger than the outer diameter of the gasket.

[0021] Beneficial effects of the above technical solution: By making the size of the first through hole 1-5 mm larger than the outer diameter of the gasket, it is convenient for the installation and limitation of the sealing plug 2, and it is ensured that the sealing plug is closely attached to the battery housing.

[0022] Preferably, the fixing plate is fixed on the upper surface of the battery housing, and the installation valve cap is fixedly connected to the fixing plate;

[0023] Further, the installation valve gasket is arranged inside the installation valve cap, and the size of the installation valve gasket is adapted to that of the installation valve cap;

[0024] The cylinder of the sealing plug is arranged inside the installation valve gasket, and the gasket of the sealing plug is arranged between the battery housing and the installation valve gasket;

[0025] The spring is arranged between the installation valve cap and the installation valve gasket.

[0026] Beneficial effects of the above technical solution: Through the mutual cooperation among the installation valve cap, the installation valve gasket and the spring, it is further ensured that the sealing plug is closely attached to the battery housing to prevent the outflow of the electrolyte, and it is further ensured that the sealing plug can pop out smoothly.

[0027] Preferably, the installation valve gasket includes a support plate arranged at the bottom and a protrusion part arranged on the support plate.

[0028] Advantages of the above technical solution: By providing a support plate to cooperate with the spring and the mounting valve cap, the tight fit between the sealing plug and the battery housing is further ensured. The raised portion is used to wrap the cylinder of the sealing plug, for support and to prevent technical problems such as pressure relief failure caused by oxidation and corrosion of the sealing plug.

[0029] Preferably, the spring is disposed between the support plate and the mounting valve cap.

[0030] Advantages of the above technical solution: By providing a spring between the support plate and the mounting valve cap, when the battery's internal pressure suddenly increases due to unexpected reasons (such as short circuit), it ensures that the sealing plug can be smoothly ejected. And through the mutual cooperation of the support plate of the mounting valve gasket with the spring and the mounting valve cap, the tight fit between the sealing plug and the battery housing is further ensured, preventing the outflow of electrolyte, and further solving the technical problems of "the common safety valve assembly and the battery housing often have insufficient tightness, which is extremely likely to cause leakage of its electrolyte. However, the electrolyte has strong corrosiveness, and the leakage of the electrolyte is extremely likely to cause certain impacts on the battery body, equipment, safety valve assembly, human body, etc., not only increasing the cost of using the battery, but also increasing its potential safety hazards."

[0031] Preferably, the size of the support plate is smaller than the inner diameter of the mounting valve cap.

[0032] Advantages of the above technical solution: By making the size of the support plate smaller than the inner diameter of the mounting valve cap, it further ensures that the sealing plug of the safety valve can be smoothly ejected.

[0033] Preferably, an exhaust hole is provided at the top of the mounting valve cap.

[0034] Advantages of the above technical solution: By providing an exhaust hole at the top of the mounting valve cap, it ensures the excretion of gas and timely reduction of the battery's internal pressure, etc.

[0035] Preferably, the mounting valve cap and the fixing plate are fixed by welding, and the fixing plate and the battery housing are fixed by welding.

[0036] Advantages of the above technical solution: By fixing both the mounting valve cap and the fixing plate to the battery housing by welding, it ensures that the safety valve assembly is firmly installed on the battery housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0038] Figure 1 Schematic cross-sectional view of the safety valve assembly provided in Embodiment 1 of the present invention;

[0039] Figure 2 Schematic diagram of the assembly of the safety valve and the battery housing provided in Embodiment 1 of the present invention;

[0040] Figure 3 Schematic diagram of the overall structure of the sealing plug provided in Embodiment 1 of the present invention;

[0041] Figure 4 Schematic diagram of the structure of the mounting valve cap provided in Embodiment 1 of the present invention;

[0042] Figure 5 Schematic diagram of the structure of the mounting valve gasket provided in Embodiment 1 of the present invention;

[0043] Figure 6 Schematic diagram of the structure of the fixing plate provided in Embodiment 1 of the present invention;

[0044] Explanation of reference numerals;

[0045] 1 - Battery housing; 2 - Sealing plug; 21 - Cylinder; 22 - Sealing gasket; 221 - Flat part; 222 - Cylindrical part; 3 - Fixing plate; 4 - Mounting valve gasket; 41 - Support plate; 42 - Protruding part; 5 - Spring; 6 - Mounting valve cap; 7 - Boss; 8 - Pressure relief hole; 9 - Concave part; 10 - First through hole; 11 - Second through hole; 12 - Cavity; 13 - Exhaust hole. Specific embodiments

[0046] Embodiment 1

[0047] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following further details the present invention in combination with embodiments.

[0048] As Figures 1 to 6 shown, a safety valve for a secondary battery, the safety valve is provided on the battery housing 1, and the safety valve includes: a sealing plug 2, a fixing plate 3, a mounting valve gasket 4, a spring 5 and a mounting valve cap 6;

[0049] The battery housing 1 is provided with a boss 7, and the boss 7 is provided with a pressure relief hole 8;

[0050] The sealing plug 2 includes: a cylinder 21 arranged in the vertical direction, and a sealing gasket 22 fixed to the bottom of the cylinder. The diameter of the cylinder is smaller than that of the sealing gasket; a concave portion 9 is provided at the bottom of the sealing gasket, and the size of the concave portion 9 is adapted to the convex platform 7;

[0051] A first through hole 10 is provided on the fixing plate 3, and the size of the first through hole 10 is slightly larger than the outer diameter of the sealing gasket;

[0052] The sealing gasket 22 includes a flat portion 221 and a cylindrical portion 222. The flat portion 221 is arranged at the bottom of the cylinder 21, and a second through hole 11 is provided on the flat portion 221, and the second through hole 11 is adapted to the cavity 12 inside the cylinder 21;

[0053] A first protrusion 13 is provided on the lower surface of the flat portion 221, and the first protrusion 13 is arranged at the edge of the second through hole 11. The outer diameter of the first protrusion 13 is adapted to the inner diameter of the pressure relief hole 8;

[0054] Embed the first protrusion 13 of the flat portion 221 into the pressure relief hole 8 and fit tightly. Press the sealing plug 2 by the mutual cooperation among the mounting valve gasket 4, the spring 5 and the mounting valve cap 6, so that the lower surface of the flat portion 221 of the sealing gasket 22 is in tight contact with the top of the convex platform 7, and the bottom end of the cylindrical portion 222 is in tight contact with the upper surface of the battery case 1. The cylindrical portion 222 is limited by the first through hole 10 of the fixing plate 3.

[0055] Through effective improvements to the overall structures of the sealing plug 2 and the fixing plate 3 and the assembly manner between the sealing plug 2 and the mounting valve gasket 4, the spring 5 and the mounting valve cap 6, by providing the first protrusion 13 on the lower surface of the flat portion 221 of the sealing gasket 22, the first protrusion 13 is embedded into the pressure relief hole 8 to ensure the tightness between the sealing plug 2 and the pressure relief hole 8; through the mutual cooperation among the mounting valve gasket 4, the spring 5 and the mounting valve cap 6, to ensure the tightness between the lower surface of the flat portion 221 of the sealing gasket 22 and the top of the convex platform 7, and ensure the tightness between the bottom end of the cylindrical portion 222 and the upper surface of the battery case 1; and ensure to prevent the electrolyte from flowing out of the pressure relief hole 8, by providing the first through hole 10 on the fixing plate 3 to ensure the limitation of the edge of the cylindrical portion 222; by designing a multi-layer sealing structure for the safety valve sealing gasket to increase the safety factor of the sealing effect, the path of the electrolyte leakage is increased, thereby reducing the probability of electrolyte leakage.

[0056] In this embodiment, the cavity 12 is communicated with the pressure relief hole 8.

[0057] Specifically, the cavity 12 is frustum-shaped, and the cross-sectional area of its top is smaller than that of its bottom; by connecting the cavity 12 with the pressure relief hole 8, when the secondary battery experiences a sharp increase in internal pressure due to accidental reasons (such as short circuit), it is ensured that the gasket 22 of the sealing plug 2 disengages from the boss 7 of the battery case 1 to discharge high-pressure gas; after the gas is discharged, under the action of the spring 5, the gasket 22 of the sealing plug 2 closely fits with the boss 7 of the battery case 1 to achieve a sealing effect; by setting the cavity 12 to be frustum-shaped, it is ensured to increase its force-bearing area and further ensure the exhaust effect of the sealing plug 2.

[0058] In this embodiment, a number of "strip-shaped" protrusions are further provided on the outer surface of the cylinder 21, and a number of "block-shaped" protrusions are provided on the top of the cylinder 21; by providing a number of "strip-shaped" protrusions on the outer surface of the cylinder 21 and a number of "block-shaped" protrusions on the top of the cylinder 21, it is prevented that the sealing plug 2 adheres to the installation valve gasket 4 after aging, and it is ensured that the subsequent sealing plug 2 is easy to replace.

[0059] In this embodiment, the size of the first through hole 10 is 1-5 mm larger than the outer diameter of the gasket 22; by setting the size of the first through hole 10 to be 1-5 mm larger than the outer diameter of the gasket 22, it is convenient for the installation and limitation of the sealing plug 2, and it is ensured that the sealing plug 2 closely fits with the battery case 1.

[0060] In this embodiment, the fixing plate 3 is fixed on the upper surface of the battery case 1, and the installation valve cap 6 is fixedly connected to the fixing plate 3;

[0061] The installation valve gasket 4 is arranged inside the installation valve cap 6, and the size of the installation valve gasket 4 is adapted to that of the installation valve cap 6;

[0062] Specifically, the cylinder 21 of the sealing plug 2 is arranged inside the installation valve gasket 4, and the gasket 22 of the sealing plug 2 is arranged between the battery case 1 and the installation valve gasket 4;

[0063] More specifically, the spring 5 is arranged between the installation valve cap 6 and the installation valve gasket 4; through the mutual cooperation among the installation valve cap 6, the installation valve gasket 4 and the spring 5, it is further ensured that the sealing plug 2 closely fits with the battery case 1 to prevent the outflow of the electrolyte, and it is further ensured that the sealing plug 2 pops out smoothly.

[0064] In this embodiment, the installation valve gasket 4 includes a support disk 41 arranged at the bottom and a protrusion 42 arranged on the support disk 41; by arranging the support disk 41 to cooperate with the spring 5 and the installation valve cap 6, it is further ensured that the sealing plug 2 closely fits with the battery case 1, and by using the protrusion 42 to wrap the cylinder 21 of the sealing plug 2, it is used for support and to prevent technical problems such as pressure relief failure caused by the oxidation and corrosion of the sealing plug 2.

[0065] In this embodiment, the spring 5 is arranged between the support plate 41 and the mounting valve cap 6. By arranging the spring 5 between the upper surface of the support plate 41 and the mounting valve cap 6, when the battery's internal pressure suddenly increases due to accidental reasons (such as short circuit), it ensures that the sealing plug 2 can be smoothly ejected. And through the mutual cooperation among the support plate 41 of the mounting valve gasket 4, the spring 5, and the mounting valve cap 6, it further ensures the tight fit between the sealing plug 2 and the battery housing 1, preventing the outflow of the electrolyte.

[0066] In this embodiment, the size of the support plate 41 is smaller than the inner diameter of the mounting valve cap 6. By making the size of the support plate 41 smaller than the inner diameter of the mounting valve cap 6, it further ensures the smooth ejection of the sealing plug 2 of its safety valve.

[0067] In this embodiment, an exhaust hole 13 is provided at the top of the mounting valve cap 6. By providing the exhaust hole 13 at the top of the mounting valve cap 6, it ensures the discharge of gas and timely reduction of the battery's internal pressure, etc.

[0068] In this embodiment, the mounting valve cap 6 and the fixing plate 3 are fixed by welding, and the fixing plate 3 and the battery housing 1 are fixed by welding. By fixing both the mounting valve cap 6 and the fixing plate 3 and the fixing plate 3 and the battery housing 1 by welding, it ensures that its safety valve assembly is firmly arranged on the battery housing 1.

[0069] In this embodiment, the fixing plate 3, the mounting valve gasket 4, and the mounting valve cap 6 are all made of stainless steel.

[0070] In this embodiment, the sealing plug 2 is made of corrosion-resistant rubber material to ensure the tightness between the concave part 9, the convex platform 7, and the battery housing 1, and to prevent technical problems such as pressure relief failure caused by oxidation or corrosion of the sealing plug 2.

[0071] In this embodiment, a round hole is also provided at the top of the mounting valve gasket 4, which further ensures the prevention of adhesion between the sealing plug 2 and the mounting valve gasket 4 and ensures the replacement of the subsequent sealing plug 2, etc.

[0072] The specific usage method of this utility model:

[0073] Step 1: Arrange the spring 5 between the mounting valve cap 6 and the mounting valve gasket 4;

[0074] Step 2: Place the cylinder 21 of the sealing plug 2 inside the mounting valve gasket 4;

[0075] Step 3: Insert the first protrusion 13 of the flat part 221 into the pressure relief hole 8 and fit tightly;

[0076] Step 4: Fix both ends of the fixing plate 3 on the upper surface of the battery housing 1 by welding;

[0077] Step 5: Fix the installation valve cap 6 to the fixed plate 3 by welding.

[0078] It should be noted that in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0079] In this article, specific examples are used to elaborate on the principle and implementation mode of the present utility model. The description of the above examples is only used to help understand the method and its core idea of the present utility model.

[0080] The above is only the preferred implementation mode of the present utility model. It should be pointed out that due to the limited nature of written expression and the objectively infinite specific structures, for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements, refinements or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, refinements, changes or combinations, or the direct application of the concept and technical solution of the utility model to other occasions without improvement, shall all be regarded as the protection scope of the present utility model.

Claims

1. A safety valve for a secondary battery, the safety valve being arranged on a battery housing (1), characterized in that: The safety valve comprises: a sealing plug (2), a fixing plate (3), a mounting valve gasket (4), a spring (5) and a mounting valve cap (6); The battery housing (1) is provided with a boss (7), and the boss (7) is provided with a pressure relief hole (8); The sealing plug (2) comprises: a cylinder (21) arranged in a vertical direction, and a sealing gasket (22) fixed to the bottom of the cylinder, wherein the diameter of the cylinder is smaller than the diameter of the sealing gasket; an inner recess (9) is provided at the bottom of the sealing gasket (22), and the size of the inner recess (9) is adapted to the boss (7); The fixing plate (3) is provided with a first through hole (10), and the size of the first through hole (10) is slightly larger than the outer diameter of the sealing gasket (22); The sealing gasket (22) comprises a planar portion (221) and a cylindrical portion (222), wherein the planar portion (221) is arranged at the bottom of the cylinder (21), and the planar portion (221) is provided with a second through hole (11), and the second through hole (11) is adapted to the cavity (12) inside the cylinder (21); A first protrusion (13) is provided on the lower surface of the plane portion (221), and the first protrusion (13) is provided at the edge of the second through hole (11), and the outer diameter of the first protrusion (13) is matched with the inner diameter of the pressure relief hole (8); The first protrusion (13) of the planar portion (221) is embedded in the pressure relief hole (8) and fits tightly therein, and the sealing plug (2) is pressed by the cooperation between the installed valve gasket (4), the spring (5) and the installed valve cap (6), so that the lower surface of the planar portion (221) of the sealing gasket (22) fits tightly against the top of the boss (7), and the bottom end of the columnar portion (222) fits tightly against the upper surface of the battery housing (1), and the columnar portion (222) is limited by the first through hole (10) of the fixing plate (3).

2. A safety valve for a secondary battery according to claim 1, characterized in that: The cavity (12) is in communication with the pressure relief hole (8); The cavity (12) is in the shape of a truncated cone, and the cross-sectional area of ​​the top is smaller than the cross-sectional area of ​​the bottom.

3. The safety valve of a secondary battery according to claim 1, characterized in that: The outer surface of the cylinder (21) is also provided with a plurality of "strip-shaped" protrusions, and the top of the cylinder (21) is provided with a plurality of "block-shaped" protrusions.

4. The safety valve for a secondary battery according to claim 1, characterized in that: The size of the first through hole (10) is 1 to 5 mm larger than the outer diameter of the sealing gasket (22).

5. A safety valve for a secondary battery according to claim 1, characterized in that: The fixing plate (3) is fixedly arranged on the upper surface of the battery housing (1), and the mounting valve cap (6) is fixedly connected to the fixing plate (3); The mounting valve gasket (4) is arranged in the mounting valve bonnet (6), and the size of the mounting valve gasket (4) is compatible with the mounting valve bonnet (6); The cylindrical body (21) of the sealing plug (2) is arranged in the mounting valve gasket (4), and the sealing gasket (22) of the sealing plug (2) is arranged between the battery housing (1) and the mounting valve gasket (4); The spring (5) is arranged between the mounting valve cap (6) and the mounting valve gasket (4).

6. A safety valve for a secondary battery according to claim 5, characterized in that: The mounting valve gasket (4) comprises a support plate (41) arranged at the bottom and a protruding portion (42) arranged on the support plate (41).

7. The safety valve for a secondary battery according to claim 6, characterized in that: The spring (5) is arranged between the support plate (41) and the mounting valve cap (6).

8. The safety valve for a secondary battery according to claim 6, characterized in that: The size of the support plate (41) is smaller than the inner diameter of the mounting valve cap (6).

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