Anti-explosion valve, battery cover plate and battery

Abstract

The utility model relates to the technical field of battery explosion-proof valve design, in particular to an explosion-proof valve, a battery cover plate and a battery, which comprises an explosion-proof valve body, nicks are arranged on the surface of the explosion-proof valve body, the explosion-proof valve body and the cover plate are integrally formed, and the nicks comprise a first nick and a second nick. The first nicks are formed along the symmetry axis of the surface of the anti-explosion valve body, one ends of the second nicks are connected with the ends of the first nicks, the second nicks are formed along the edge of the anti-explosion valve body, and the second nicks at the two ends of the first nicks extend in the direction away from each other, so that double-side valve opening of the anti-explosion valve body from the middle position is achieved. After the anti-explosion valve is opened, each side of the anti-explosion valve is U-shaped; the first nick and the second nick are arranged, and the valve is opened from the middle part of the valve body from two sides, so that the problems of insufficient instant opening area and insufficient pressure relief area caused by single-side valve opening can be reduced, and compared with single-side opening in the prior art, the valve opening rate can be increased, the circulation area can be increased, and the safety performance of the battery cell can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery explosion-proof valve design, in particular to an explosion-proof valve, a battery cover and a battery. Background Art

[0002] The explosion-proof valve plays a very important role in the safe operation of the battery cell. The main function of the explosion-proof valve of the secondary battery is to open and release the pressure in time when the pressure inside the battery cell increases rapidly due to abnormal conditions such as thermal runaway inside the battery, so as to reduce the consequences of accidents such as fire and explosion of the battery and ensure the safety of people and property.

[0003] The utility model patent with the authorization announcement number CN217848223U discloses an explosion-proof valve, a battery cover, a battery and an electronic device. The explosion-proof valve disclosed in the patent is a sheet structure, including a welding area and an explosion-proof area. The welding area is located at the edge of the explosion-proof valve and is connected to the cover of the battery cell by laser welding. The explosion-proof area is located inside the welding area, and a buffer zone and a notched area are provided in the explosion-proof area. Figure 3 It can be seen that the notch is set close to the edge of the explosion-proof valve, and the overall shape is ring-shaped or circular. This notch setting method causes the explosion-proof valve to split from the notch when it is opened, and it is opened on one side. There is a problem of low opening rate, and there is also the possibility of opening failure or insufficient opening area. In addition, there are two disadvantages of existing laser welding. The first is that there are certain welding defects in laser welding, which will increase the production cost of the explosion-proof valve and the cover. The second is that the explosion-proof valve will be deformed or even torn during the laser welding process. The opening pressure of the explosion-proof valve of the deformed battery cell is unstable, causing the explosion-proof valve to open prematurely. Severe deformation may even cause leakage of the battery cell, affecting the safety of the battery cell. Utility Model Content

[0004] In response to the shortcomings of the existing technology, the purpose of the present invention is to provide an explosion-proof valve, a battery cover and a battery. By setting a first notch and a second notch, the valve is opened from both sides of the middle part of the valve body, which can increase the valve opening rate and reduce the problems of insufficient instantaneous opening area and insufficient pressure relief area caused by unilateral valve opening.

[0005] In order to achieve the above purpose, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, an explosion-proof valve includes an explosion-proof valve body, the surface of the explosion-proof valve body is provided with notches, the explosion-proof valve body is a structure integrally formed with a cover plate, the notches include a first notch and a second notch, the first notch is opened along the symmetry axis of the surface of the explosion-proof valve body, one end of the second notch is connected to the end of the first notch, the second notch is opened along the edge of the explosion-proof valve body, and the second notches at both ends of the first notch extend in directions away from each other to enable the explosion-proof valve body to open on both sides from the middle position, and each side of the explosion-proof valve is U-shaped after opening.

[0007] As a further implementation, the explosion-proof valve body is in an oblong shape.

[0008] As a further implementation, the first notch is parallel to the straight edge of the explosion-proof valve body, both ends of the first notch are arranged close to the semicircular edge of the explosion-proof valve body, and the second notch extends along the semicircular edge of the explosion-proof valve body.

[0009] As a further implementation, the first notch is perpendicular to the straight edge of the explosion-proof valve body, both ends of the first notch are arranged close to the straight edge of the explosion-proof valve body, and the second notch extends along the straight edge of the explosion-proof valve body toward the semicircular edge.

[0010] As a further implementation, the explosion-proof valve body is circular in shape.

[0011] As a further implementation, the cross-sectional shapes of the first notch and the second notch are semicircular, V-shaped, or trapezoidal.

[0012] As a further implementation, the second notches on both sides of the first notch have different notch depths to achieve stepped valve opening under different pressure conditions.

[0013] In the second aspect, a battery cover is provided with an explosion-proof hole in the middle of the battery cover, and an explosion-proof valve body is provided at the explosion-proof hole. The explosion-proof valve body adopts any of the above-described explosion-proof valves, and the explosion-proof valve and the battery cover are an integrally formed structure.

[0014] As a further implementation, a boss structure is formed in the middle of the battery cover, and the explosion-proof valve is arranged at the boss.

[0015] In a third aspect, a battery is provided, comprising a shell and a cover plate, wherein the cover plate is the battery cover plate as described above.

[0016] The beneficial effects of the above utility model are as follows:

[0017] 1. The utility model provides a first notch and a second notch, and adopts a double-sided valve opening from the middle part of the valve body, which can reduce the problems of insufficient instantaneous opening area and insufficient pressure relief area caused by unilateral valve opening; compared with the unilateral opening of the prior art, this double-sided valve opening form can increase the valve opening rate, increase the flow area, and improve the safety performance of the battery cell. The explosion-proof valve and the battery cover are an integrated molding structure, which can solve the shortcomings of poor welding and deformation of the explosion-proof valve in the existing laser welding.

[0018] 2. The utility model can achieve a secondary valve opening effect under different pressures by adjusting the depth of the notch so that the depths of the second notches on both sides of the first notch are different. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0020] Figure 1 This is a schematic diagram of the overall structure of the first battery cover in the embodiment of the present utility model;

[0021] Figure 2 This is a schematic structural diagram of an explosion-proof valve in an embodiment of the present utility model;

[0022] Figure 3 This is a schematic diagram of the structure of the explosion-proof valve in the embodiment of the utility model, which is open on both sides;

[0023] Figure 4 yes Figure 2 Schematic diagram of the notched cross section of the middle explosion-proof valve;

[0024] Figure 5 This is a schematic diagram of the overall structure of the second battery cover in the embodiment of the present utility model;

[0025] Figure 6 This is a schematic diagram of the structure of the explosion-proof valve in the embodiment of the utility model, which is open on both sides;

[0026] Figure 7 This is a top view of the structure of the explosion-proof valve in the embodiment of the utility model;

[0027] Figure 8 yes Figure 7 Schematic diagram of the notched cross section of the explosion-proof valve.

[0028] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0029] Among them: 1. Positive pole hole; 2. Negative pole hole; 3. Explosion-proof hole; 4. Liquid injection hole;

[0030] 31. Explosion-proof valve body; 311. First notch; 312. Second notch; 313. Explosion-proof valve boss. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0032] Example 1

[0033] In a typical embodiment of the present invention, reference is made to Figures 1-8 The explosion-proof valve shown in the figure includes a valve body with notches on its surface. When the pressure inside the battery exceeds the valve's opening pressure, the notches break, thereby releasing pressure. The explosion-proof valve body of this embodiment is integrally formed with the battery cover, eliminating the drawbacks of laser welding.

[0034] The notches include a first notch 311 and a second notch 312. The first notch is opened along the symmetry axis of the surface of the explosion-proof valve body. One end of the second notch 312 is connected to the end of the first notch 311. The second notch is opened along the edge of the explosion-proof valve body. The second notches 312 at both ends of the first notch 311 extend away from each other to achieve bilateral opening of the explosion-proof valve body from the middle position. Each side of the explosion-proof valve is U-shaped after opening.

[0035] In order to enable the explosion-proof valve to open quickly and increase the valve opening rate when the pressure inside the battery is greater than the opening pressure of the explosion-proof valve, this embodiment improves the notch structure to achieve double-sided valve opening.

[0036] like Figure 2 As shown, the explosion-proof valve body of this embodiment is in the shape of an oblong, which is similar to the shape of a playground track, and has two parallel straight sides with both ends connected by semicircular edges.

[0037] like Figure 2 As shown, the first notch 311 is parallel to the straight edge of the explosion-proof valve body, with both ends of the first notch 311 positioned near the center of the semicircular edge of the explosion-proof valve body. The second notch 312 extends along the semicircular edge of the explosion-proof valve body. Because the second notches 312 at both ends of the first notch 311 need to extend away from each other along the edge of the explosion-proof valve, a total of four second notches are required in this embodiment.

[0038] The two second notches 312 on the left and right sides of the first notch 311 extend from the middle of the semicircular edge to the straight edge and are not connected. Specifically, the second notches 312 can extend to the connection between the end of the straight edge and the semicircular edge. The final notch is formed as follows: Figure 2 The structure shown.

[0039] like Figure 3 As shown, Figure 2 In the explosion-proof valve structure, when the pressure inside the battery is greater than the opening pressure of the explosion-proof valve, the notch of the explosion-proof valve will be broken. Since the first notch 311 is located in the middle of the explosion-proof valve, the stress is more concentrated than that at the edge. Even when the first notch 311 and the second notch 312 have the same depth, the first notch 311 is easier to break than the second notch 312, and the second notch 312 is broken accordingly. When all the notches are broken, the valve is opened on both sides from the middle position. After the explosion-proof valve is opened, the shape of the structure on each side is U-shaped, as shown in FIG. Figure 3 Compared with the single-sided opening method in the prior art, this double-sided valve opening method can increase the valve opening rate, increase the flow area, improve the safety performance of the battery cell, and reduce the possibility of opening failure or insufficient opening area.

[0040] In an optional example, when the explosion-proof valve body is in the shape of an oblong, the first notch 311 may also be arranged in a different direction, such as Figure 5 and Figure 6 As shown, the first notch 311 is perpendicular to the straight edge of the explosion-proof valve body 31, and both ends of the first notch 311 are set close to the straight edge of the explosion-proof valve body. One end of the four second notches 312 is connected to the end of the first notch 311, and the other end extends along the straight edge of the explosion-proof valve body toward the semicircular edge, extending to a position close to the middle of the semicircular edge. The first notch 311 and the second notch 312 are in the shape of the letter H as a whole.

[0041] When the valve is opened on both sides, the explosion-proof valve structure opens quickly to both sides along the notch, which can increase the opening rate, quickly increase the pressure relief area, and reduce the risk of explosion-proof valve failure.

[0042] like Figure 4 As shown, the cross-sectional shape of the first notch 311 and the second notch 312 is semicircular, V-shaped or trapezoidal. The cross-sectional shape of this embodiment is semicircular. In other examples, the cross-sectional shape may also be rectangular, triangular, etc.

[0043] The thickness of the explosion-proof valve body is 0.2-0.5mm, and the thickness of the notch is between 0.05-0.2mm. This cross-section shape ensures consistency across the notch, effectively improving the stability of the integrated explosion-proof top cover.

[0044] In other examples, the explosion-proof valve body may be circular in shape.

[0045] In order to eliminate the disadvantages of laser welding, such as Figure 4 As shown, an explosion-proof valve boss 313 is integrally formed in the middle of the battery cover, and an explosion-proof valve is provided at the explosion-proof valve boss 313. The explosion-proof valve body 31 and the explosion-proof valve boss 313 are both integrally formed structures on the battery cover, and no laser welding is required.

[0046] In an optional example, the second notches on both sides of the first notch have different notch depths to achieve stepped valve opening under different pressure conditions.

[0047] like Figure 7 and Figure 8 As shown, the depth of the second notch on the left side of the first notch 311 is greater than the depth of the second notch 312 on the right side. Therefore, the distance T1 between the bottom end of the second notch 312 on the left and the bottom surface of the explosion-proof valve body is less than the distance T2 between the bottom end of the second notch on the right and the bottom surface of the explosion-proof valve body. When the internal gas pressure of the battery exceeds the first threshold, the left side of the valve opens first. When the gas pressure exceeds the second threshold, the right side of the valve opens later. The second threshold is greater than the first threshold. This realizes the function of the battery explosion-proof valve to achieve double detonation according to the internal pressure of the battery, ensuring the safety of the battery. By changing the notch depth, a stepped valve opening effect at different rates is achieved.

[0048] Example 2

[0049] In a typical embodiment of the present invention, reference is made to Figures 1-8 The figure shows a battery cover with a positive electrode injection hole 1 and a negative electrode injection hole 2 at each end. An explosion-proof hole 3 is located in the center of the battery cover, and an explosion-proof valve body 31 is located at the explosion-proof hole 3. A valve boss 313 is formed in the center of the battery cover, and the explosion-proof valve is located at this boss 313. The explosion-proof valve body is machined from the battery cover and is an integral structure with the cover. The surrounding explosion-proof valve boss 313 is formed by stacking the explosion-proof valve cavity material. This simple manufacturing process can effectively prevent welding problems and explosion-proof valve failure caused by the welding process. The explosion-proof valve body 31 adopts the explosion-proof valve described in Example 1.

[0050] A liquid injection hole 4 is provided on the battery cover between the explosion-proof hole 3 and the positive electrode injection hole 1. The liquid injection hole 4, the positive electrode injection hole 1 and the negative electrode injection hole 2 are all existing technologies.

[0051] Example 3

[0052] In a typical embodiment of the present invention, reference is made to Figures 1-8 As shown, a battery includes a shell and a cover plate connected to each other, and the cover plate adopts the battery cover plate of embodiment 2.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An explosion-proof valve, comprising an explosion-proof valve body, the surface of which is provided with notches, characterized in that: The explosion-proof valve body is a structure integrally formed with the cover plate. The notches include a first notch and a second notch. The first notch is opened along the symmetry axis of the surface of the explosion-proof valve body. One end of the second notch is connected to the end of the first notch. The second notch is opened along the edge of the explosion-proof valve body. The second notches at both ends of the first notch extend in directions away from each other to enable the explosion-proof valve body to open on both sides from the middle position. Each side of the explosion-proof valve is U-shaped after opening.

2. The explosion-proof valve according to claim 1, characterized in that: The explosion-proof valve body is in an oblong shape.

3. The explosion-proof valve according to claim 2, characterized in that: The first notch is parallel to the straight edge of the explosion-proof valve body, both ends of the first notch are arranged close to the semicircular edge of the explosion-proof valve body, and the second notch extends along the semicircular edge of the explosion-proof valve body.

4. The explosion-proof valve according to claim 2, characterized in that: The first notch is perpendicular to the straight edge of the explosion-proof valve body, and both ends of the first notch are arranged close to the straight edge of the explosion-proof valve body. The second notch extends along the straight edge of the explosion-proof valve body toward the semicircular edge.

5. The explosion-proof valve according to claim 1, characterized in that: The explosion-proof valve body is circular in shape.

6. The explosion-proof valve according to claim 1, characterized in that: The cross-sectional shapes of the first notch and the second notch are semicircular, V-shaped or trapezoidal.

7. The explosion-proof valve according to claim 1, characterized in that: The second notches on both sides of the first notch have different notch depths, so as to achieve stepped valve opening under different pressure conditions.

8. A battery cover, characterized in that: An explosion-proof hole is provided in the middle of the battery cover, and an explosion-proof valve body is provided at the explosion-proof hole. The explosion-proof valve body adopts the explosion-proof valve according to any one of claims 1 to 7, and the explosion-proof valve and the battery cover are an integrally formed structure.

9. The battery cover according to claim 8, characterized in that: A boss structure is formed in the middle of the battery cover, and the explosion-proof valve is arranged on the boss.

10. A battery, characterized in that: The battery comprises a shell and a cover plate, and the cover plate is the battery cover plate as claimed in claim 8.

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