Anti-exposure valve plate and secondary battery

Abstract

The utility model discloses an anti-exposure valve plate and a secondary battery, the anti-exposure valve plate comprises a valve plate body, the middle part of the valve plate body is sunken downwards through stamping to form a groove, and a welding platform is formed in a non-sunken area on the periphery of the groove; an arc-shaped convex part which arches upwards is formed in the middle of the groove, so that an annular concave part is formed between the side wall of the groove and the arc-shaped convex part, and an anti-exposure nick is formed at the bottom of the annular concave part through stamping. According to the anti-exposure valve plate, the arc-shaped convex part is formed in the middle of the groove to release stress, so that the stress of a material in a groove area can be reduced, the fluctuation of bursting pressure of the anti-exposure valve plate is reduced, and the stability of a bursting value of the anti-exposure valve plate is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of energy storage battery, especially relates to a kind of anti-exposure valve piece and a secondary battery. BACKGROUND

[0002] In recent years, the product (such as new energy vehicle) of application new energy battery develops rapidly, and its safety requirement to new energy battery is higher and higher, because of the easy weldability of stainless steel battery shell, high strength, material is not limited and the advantages such as, fill the shortcomings of aluminum material and tinplate material battery shell, the existing new energy battery more and more uses stainless steel battery shell, when forming anti-explosion notch on stainless steel battery shell by stamping process, there are generally higher blasting value, poor stability and consistency of blasting value and other problems, these are the problems that stainless steel battery shell urgently needs to solve in application process. SUMMARY

[0003] In view of the above technical problems of the prior art, the technical problems to be solved by the utility model are to provide an anti-exposure valve piece and a secondary battery.

[0004] To solve the above technical problems, the utility model provides the following technical scheme:

[0005] An anti-exposure valve piece, comprising a valve piece body, the middle part of the valve piece body is formed with a groove by stamping downwardly concave, the area of the periphery of the groove without downwardly concave forms a welding platform, the middle part of the groove is formed with an arc-shaped convex part arched upward, so that an annular recess is formed between the sidewall of the groove and the arc-shaped convex part, and the bottom of the annular recess is formed with an anti-explosion notch by stamping.

[0006] Further, the valve piece body is a stainless steel sheet of 316L material.

[0007] Further, the error of notch residual thickness of the anti-explosion notch is less than or equal to 2 μm.

[0008] Further, the top end of the arc-shaped convex part is lower than or flush with the plane of the welding platform.

[0009] Further, the contour line of the groove is in the shape of an ellipse or a racetrack.

[0010] Further, the cross section of the anti-explosion notch is a trapezoid with narrow bottom and wide top.

[0011] A secondary battery, comprising:

[0012] A battery shell, the battery shell has a pressure relief hole; and

[0013] An explosion-proof valve plate is welded and fixed with the battery shell and seals the pressure relief hole.

[0014] Further, the battery shell is a cuboid, comprising a top cover, a bottom cover opposite to the top cover, two wide sides and two narrow sides, and the pressure relief hole is arranged on the narrow side.

[0015] Further, the outer contour of the explosion-proof valve plate is adapted to the shape and size of the inner contour of the pressure relief hole, the explosion-proof valve plate is arranged in the pressure relief hole, a reinforcing ring is arranged directly below the connection position of the explosion-proof valve plate and the pressure relief hole, the inner side area of the reinforcing ring is welded and fixed with the welding platform of the explosion-proof valve plate, and the outer side area of the reinforcing ring is welded and fixed with the battery shell around the pressure relief hole.

[0016] Further, the reinforcing ring is a stainless steel ring with a thickness of 0.5mm-1mm.

[0017] In the utility model, the arc convex part is formed in the middle of the groove to release stress, the stress of the material in the groove area (including the explosion-proof notch area) can be reduced, the precision of the notch residual thickness of the explosion-proof notch is improved, the fluctuation of the burst pressure of the explosion-proof valve plate is reduced, and the stability of the burst value of the explosion-proof valve plate is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings described herein are used to provide further understanding of the present application, constitute a part of the present application, the schematic embodiments of the present application and the description thereof are used to explain the present application, and do not constitute improper limitation on the present application. In the drawings:

[0019] Figure 1 It is a structure schematic view of one embodiment of the explosion-proof valve plate of the utility model.

[0020] Figure 2 It is a structure schematic view of one embodiment of the explosion-proof valve plate of the utility model. Figure 1 It is a top view.

[0021] Figure 3 It is an A-A sectional view of the explosion-proof valve plate. Figure 2 It is an A-A sectional view of the explosion-proof valve plate.

[0022] Figure 4 It is an explosion view of the shell of the secondary battery.

[0023] Figure 5 It is a sectional view schematic view at the reinforcing ring.

[0024] The description of the drawings is as follows:

[0025] Explosion-proof valve plate - 100; groove - 110; arc convex part - 111; annular recess - 112; explosion-proof notch - 113; welding platform - 120;

[0026] Reinforcing ring - 200; battery case - 300; narrow side - 310; pressure relief hole - 311; wide side - 320; opening - 330; top cover - 400; bottom cover - 500; gap - 600. DETAILED DESCRIPTION

[0027] The embodiments of the present application will be described in detail below with specific examples. The drawings provided in the following examples only schematically illustrate the basic concept of the present application, and the following examples and features in the examples can be combined with each other without conflict.

[0028] Please refer to Figure 1 , Figure 1 is a structural schematic view of an embodiment of the anti-exposure valve plate of the present application. The anti-exposure valve plate of the present embodiment comprises a valve plate body. In the present embodiment, the valve plate body is preferably a stainless steel sheet made of 316L material, and the wall thickness of the stainless steel sheet is preferably 0.18mm±0.005mm.

[0029] The valve plate body is generally made of stainless steel material with a wall thickness of 0.15mm to 0.20mm. In the present embodiment, the wall thickness of the stainless steel material is preferably 0.18mm±0.005mm. After many tests, it is found that different stainless steel materials have a relatively obvious influence on the stability of the burst value of the anti-exposure valve plate 100 after annealing treatment. After comparing a plurality of stainless steel materials, it is finally found that the anti-exposure valve plate 100 made of 316L stainless steel material has the best stability of burst value after annealing treatment.

[0030] Please refer to Figure 2 and Figure 3 The middle part of the valve plate body is formed with a groove 110 by stamping downwardly concave. The profile line of the groove 110 is preferably elliptical or track-shaped to facilitate stamping formation. On this basis, the shape of the valve plate body can also be preferably elliptical or track-shaped. Of course, the shape of the valve plate body can also be other shapes.

[0031] The area of the periphery of the groove 110 which is not concave downwardly forms a welding platform 120, which is used for welding the valve plate body with the battery shell. The middle part of the groove 110 is formed with an arc-shaped convex part 111 which is arched upwardly. By forming the arc-shaped convex part 111 in the middle part of the groove 110, the stress generated by the deformation of the valve plate body during the stamping formation of the groove 110 can be released, so that the material consistency of the area of the groove 110 is better.

[0032] The top end of the arc-shaped convex part 111 is lower than or flush with the plane where the welding platform 120 is located, so that more installation space of the battery shell can be avoided when the arc-shaped convex part 111 is higher than the plane where the welding platform 120 is located.

[0033] The annular recess 112 is formed between the side wall of the groove 110 and the arc-shaped convex part 111, the bottom of the annular recess 112 is formed with the anti-exposure notch 113 by stamping, the anti-exposure notch 113 has a trapezoidal cross section with a narrow upper part and a wide lower part, the notch residual thickness of the anti-exposure notch 113 is generally 0.03mm-0.05mm, preferably 0.04mm, and the error of the notch residual thickness of the anti-exposure notch 113 is less than or equal to 2μm. The notch residual thickness represents the remaining thickness of the stainless steel sheet at the anti-exposure notch 113.

[0034] Of course, in order to eliminate the stress generated when the anti-exposure notch 113 is formed by stamping, the anti-explosion valve sheet 100 can also be treated by annealing process, so that the hardness of the anti-explosion valve sheet 100 in the anti-explosion notch area is reduced, the stress of the anti-explosion sheet in the anti-explosion notch area is reduced, and the smaller and more stable explosion value is realized.

[0035] In the embodiment, by forming the arc-shaped convex part 111 in the middle of the groove 110 to release stress, the stress of the material in the groove 110 area (including the anti-explosion notch 113 area) can be reduced, and by improving the precision of the notch residual thickness of the anti-explosion notch 113, the fluctuation of the explosion pressure of the anti-explosion valve sheet 100 can be reduced, and the stability of the explosion value of the anti-explosion valve sheet 100 can be improved.

[0036] Please refer to Figure 4 , Figure 4 It is an explosion diagram of one embodiment of the secondary battery. The secondary battery can be a power battery or an energy storage battery, and the secondary battery of the embodiment comprises a battery shell 300 and an anti-explosion valve sheet 100, of course, the secondary battery also comprises a battery core accommodated in the battery shell 300 and other structures necessary for a conventional secondary battery, which are all prior art and will not be described here.

[0037] The battery case 300 has a pressure relief hole 311. The explosion-proof valve sheet 100 of any of the above embodiments is welded to the battery case 300 and seals the pressure relief hole 311. In this embodiment, the battery case 300 is a cuboid, including a top cover 400, a bottom cover 500 opposite to the top cover 400, two wide sides 320 and two narrow sides 310. The two wide sides 320 and the two narrow sides 310 form a rectangular cylinder with two openings 330 at the two ends, and the top cover 400 and the bottom cover 500 are arranged at the two openings 330 of the rectangular cylinder respectively. The pressure relief hole 311 is arranged on the narrow side 310. Of course, the top cover 400 is also provided with electrodes, liquid injection holes and other structures, which are all prior art and irrelevant to the improvement of the present application, and therefore not shown in the figure.

[0038] To avoid increasing the height of the battery case 300 after installing the explosion-proof valve sheet 100, the shape and size of the outer contour of the explosion-proof valve sheet 100 are matched with the shape and size of the inner contour of the pressure relief hole 311, and the explosion-proof valve sheet 100 is arranged in the pressure relief hole 311.

[0039] Please refer to Figure 5 To ensure the welding strength of the explosion-proof valve sheet 100, a reinforcing ring 200 is arranged directly below the connection position between the explosion-proof valve sheet 100 and the pressure relief hole 311, the inner side of the reinforcing ring 200 is welded to the welding platform 120 of the explosion-proof valve sheet 100, and the outer side of the reinforcing ring 200 is welded to the battery case 300 around the pressure relief hole 311. By arranging the reinforcing ring 200, the gap 600 between the explosion-proof valve sheet 100 and the pressure relief hole 311 can be sealed, so that the welding slag generated during the welding process of the explosion-proof valve sheet 100 does not fall into the inside of the battery case 300 from the gap 600 between the explosion-proof valve sheet 100 and the pressure relief hole 311.

[0040] In addition, if the reinforcing ring 200 is too thick, the capacity of the battery case 300 will be reduced, and if the reinforcing ring 200 is too thin, the required strength cannot be achieved; therefore, in this embodiment, the reinforcing ring 200 is a stainless steel ring with a thickness of 0.5mm-1mm, and the thickness of the reinforcing ring 200 is preferably 0.8mm.

[0041] The secondary battery of this embodiment has a lower burst value and better burst stability, can avoid the problem that the welding position of the explosion-proof valve sheet is first broken by high pressure before the explosion-proof notch is broken due to the welding process, can avoid the welding slag generated during welding from falling into the inside of the secondary battery from the gap 600 between the explosion-proof valve sheet 100 and the pressure relief hole 311 to affect the quality of the secondary battery, and has good safety stability.

[0042] The above embodiment only expresses the preferred implementation of the utility model, the description is more specific and detailed, but can not therefore be understood as the limitation of the utility model patent range. It should be pointed out that for ordinary skilled person in the art, without departing from the concept of the utility model, a number of variations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. An exposure prevention valve plate, characterized by: The valve plate body is punched downward to form a groove in the middle part, and the outer periphery of the groove forms a welding platform without being punched downward; the middle part of the groove forms an arc-shaped convex part arched upward, so that an annular recess is formed between the sidewall of the groove and the arc-shaped convex part, and the bottom of the annular recess is formed by punching to have an anti-exposure notch.

2. A flood prevention valve as claimed in claim 1, wherein: The valve plate body is made of 316L stainless steel.

3. A flood prevention valve as claimed in claim 2, wherein: The error of the notch residual thickness of the anti-exposure notch is less than or equal to 2μm.

4. A valve sheet according to any one of claims 1 to 3, characterized in that: The top end of the arc-shaped convex part is lower than or flush with the plane of the welding platform.

5. A valve sheet according to any one of claims 1 to 3, characterized in that: The profile of the groove is in the shape of an ellipse or a racetrack.

6. A flood prevention valve according to any one of claims 1 to 3, wherein: The cross section of the anti-exposure notch is in the shape of a trapezoid with a narrow bottom and a wide top.

7. A secondary battery characterized by comprising: The battery shell has a pressure relief hole, and the explosion-proof valve plate is welded and fixed to the battery shell to close the pressure relief hole. The battery shell is a cuboid, including a top cover, a bottom cover opposite to the top cover, two wide sides and two narrow sides, and the pressure relief hole is arranged on the narrow side. The shape and size of the outer contour of the explosion-proof valve plate are matched with the shape and size of the inner contour of the pressure relief hole, the explosion-proof valve plate is arranged in the pressure relief hole, a reinforcing ring is arranged directly below the connection position between the explosion-proof valve plate and the pressure relief hole, the inner side of the reinforcing ring is welded and fixed to the welding platform of the explosion-proof valve plate, and the outer side of the reinforcing ring is welded and fixed to the battery shell around the pressure relief hole. The reinforcing ring is made of stainless steel with a thickness of 0.5mm-1mm.

8. A secondary battery as claimed in claim 7, characterized in that: ​ 9. The secondary battery of claim 7, wherein: ​ 10. The secondary battery of claim 9, wherein: ​

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