Explosion-proof valve, battery cell cover plate and battery cell

Abstract

The invention relates to the technical field of batteries, and discloses an explosion-proof valve, a battery cell cover plate and a battery cell. The anti-explosion valve comprises a valve body and a valve core, wherein the valve body comprises an opening part and a transition part connected to the peripheral side of the opening part; an annular nick surrounding the opening part is arranged between the opening part and the transition part; the annular nick comprises a first groove and a second groove communicated with the first groove, and the groove bottom of the first groove is higher than the groove bottom of the second groove in the thickness direction of the valve body; the projection area of the opening part on the horizontal plane is S, and the value range of S is that S is larger than or equal to 80 mm < 2 > and smaller than or equal to 1000 mm < 2 >. The length of the first groove is L, and the value range of L is 5 mm < = L < = 15 mm. In the length direction of the first groove, the groove bottom excess material sectional area of the first groove is S1; s1, L and S meet the relation that (L * S1) / S is larger than or equal to 2.7 * 10 <-4 > mm and smaller than or equal to 8.0 * 10 <-4 > mm. The size of the annular nick at the first groove is set according to the parameters, so that the thickness of excess materials at the bottom of the second groove can be increased under the same opening pressure, and the overall structural strength of the anti-explosion valve is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to an explosion-proof valve, a battery cell cover plate and a battery cell. Background Art

[0002] Batteries are usually provided with explosion-proof valves. The main function of the explosion-proof valve is to relieve pressure and exhaust gas. When the battery undergoes thermal runaway due to reasons such as mechanical impact and abnormal internal short circuit, the high-temperature and high-pressure gas inside can be directionally released through the explosion-proof valve, thereby ensuring the safety of the battery.

[0003] Specifically, the reason why the explosion-proof valve can timely discharge the high-temperature and high-pressure gas inside the battery during thermal runaway is that the explosion-proof valve is provided with a groove-shaped notch. Since the structural strength at the notch is less than that of other areas of the explosion-proof valve, when the battery undergoes thermal runaway, the explosion-proof valve can break from the notch to release the high-temperature and high-pressure gas inside the battery. However, due to the insufficient strength at the notch currently, it is easy to cause the notch to open prematurely or break abnormally, thus affecting the normal use of the battery. Summary of the Invention

[0004] In view of this, the present invention provides an explosion-proof valve, a battery cell cover plate and a battery cell to solve the problem that the notch of the existing explosion-proof valve has insufficient strength, resulting in the explosion-proof valve being lifted and opened or the notch breaking abnormally.

[0005] In a first aspect, the present invention provides an explosion-proof valve, including: a valve body, the valve body includes an opening part and a transition part connected to the periphery of the opening part; an annular notch is provided between the opening part and the transition part; the annular notch includes a first groove and a second groove communicating with the first groove, and in the thickness direction of the valve body, the bottom of the first groove is higher than the bottom of the second groove;

[0006] The projected area of the opening part on the horizontal plane is S, and the value range of S is: 80mm 2 ≤S≤1000mm 2 ;

[0007] The length of the first groove is L, and the value range of L is: 5mm≤L≤15mm;

[0008] Along the length direction of the first groove, the cross-sectional area of the remaining material at the bottom of the first groove is S1; the relationship among S1, L and S satisfies: 2.7×10 -4 mm≤(L×S1) / S≤8.0×10 -4 mm.

[0009] Beneficial effects: By setting the dimensions of the annular notch at the first groove according to the above parameters, the residual notch thickness of the annular notch at the second groove can be significantly increased under the same opening pressure, improving the overall structural strength of the explosion-proof valve and reducing the risk of abnormal cracking or premature opening of the explosion-proof valve. Specifically, the explosion-proof valve is designed with a first groove and a second groove. After the second groove breaks during the opening process, the opening part of the explosion-proof valve flips, allowing the high-temperature and high-pressure gas flow to be discharged smoothly. After flipping, the remaining material part at the bottom of the first groove of the explosion-proof valve is connected to the cover body of the battery cell cover, enabling the explosion-proof valve to open along the designed path. Then, by reasonably setting the length of the first groove and the cross-sectional area S1 of the remaining material at the bottom of the first groove according to the above parameters, the opening pressure of explosion-proof valves with the same structure and the same effective opening area can be minimized. In this way, if it is desired to maintain the opening pressure of the explosion-proof valve within the original design range, the remaining material thickness at the second groove of the explosion-proof valve can be increased, thereby improving the ability of the second groove of the explosion-proof valve to resist external force pulling and deformation.

[0010] In addition, the bottom of the first groove in the present invention is higher than the bottom of the second groove, which means that the residual notch thickness of the annular notch at the first groove is greater than that at the second groove. That is to say, the connection strength between the opening part and the transition part at the first groove is greater than that at the second groove. Thus, when the battery cell undergoes thermal runaway, the annular notch will only break at the second groove, and the annular notch at the first groove will still remain connected, so as to prevent the entire opening part from directly detaching from the battery cell under the impact of the high-temperature gas flow. With such a setting, on the one hand, it can ensure that the high-pressure gas inside the battery cell can be released orderly through the fracture; on the other hand, the connection state at the first groove can maintain the structural integrity of the explosion-proof valve to a certain extent, reducing the possibility of the opening part interfering with the surrounding structure compared with the direct detachment of the opening part from the explosion-proof valve.

[0011] In an optional embodiment, the annular notch includes a straight section and arc sections located at both ends of the straight section, and the first groove is located within the straight section.

[0012] Beneficial effects: Compared with setting the first groove within the arc section, the first groove located within the straight section can more effectively disperse stress and reduce the risk of stress concentration in the thermal runaway state, thereby ensuring that the opening part can be stably connected to the transition part and reducing the possibility of it directly detaching completely from the explosion-proof valve.

[0013] In an alternative embodiment, along the thickness direction of the valve body, the thickness of the remaining material at the bottom of the first groove is H, and the value range of H is: 0.09 mm ≤ H ≤ 0.23 mm; along the width direction of the first groove, the width of the remaining material at the bottom of the first groove is W, and the value range of W is: 0.05 mm ≤ W ≤ 0.12 mm; the relationship among W, H, and S1 satisfies: S1 = W × H.

[0014] Beneficial effects: By setting H and W according to the above parameters, it can be ensured that under the same opening pressure, the residual thickness of the annular notch at the second groove is greater, so that before the explosion-proof valve reaches the set opening pressure, it will not open the valve in advance due to insufficient strength at the notch.

[0015] In an alternative embodiment, the opening portion protrudes from the upper surface of the transition portion and its cross-sectional shape is arc-shaped.

[0016] Beneficial effects: During the normal operation of the battery cell, a certain amount of gas will also be generated inside the battery cell, forming a pressure difference between the inside of the battery cell and the external environment. Therefore, before this part of the gas is discharged from the inside of the battery cell, it will continuously act on the opening portion, causing the opening portion to have a tendency to move or deform away from the battery cell electrode group. In this way, the notch on the explosion-proof valve may break prematurely under the pulling of the opening portion. Based on this, the opening portion in the present invention protrudes relative to the transition portion, which can pre-reserve space for the possible deformation amount of the opening portion during the normal operation of the battery cell, preventing the opening portion from generating a pulling force on the annular notch due to deformation during the operation of the battery cell, thereby avoiding the situation of premature opening or abnormal fracture. In addition, setting the cross-section of the opening portion as arc-shaped can timely disperse the stress acting on the annular notch to the opening portion, avoiding abnormal rupture or premature opening of the annular notch due to stress concentration.

[0017] In an alternative embodiment, the periphery of the opening portion uniformly transitions to the top of the opening portion.

[0018] Beneficial effects: The uniform transition of the periphery of the opening portion to the top of the opening portion means that the stress acting on each region of the annular notch can be gradually transmitted to the top along the curved surface of the opening portion, making the pressure borne by each part of the annular notch relatively balanced and avoiding the situation of premature rupture due to stress concentration in a certain region. In addition, the uniform transition of the opening portion from the periphery to the top can also make the pressure evenly distributed on the opening portion, preventing excessive local stress from causing excessive deformation, and thus avoiding premature rupture of the annular notch due to deformation and stretching.

[0019] In an alternative embodiment, the opening portion, the annular notch, and the transition portion are integrally formed.

[0020] Beneficial effects: The one-piece forming process is adopted to prepare the opening part, the annular notch and the transition part, which can not only reduce the time cost in the production process, but also improve the overall structural strength of the explosion-proof valve.

[0021] In an alternative embodiment, the explosion-proof valve further includes a skirt surrounding the outer periphery of the transition part, and the thickness of the skirt is greater than the thickness of the transition part.

[0022] Beneficial effects: By providing a skirt on the outer periphery of the transition part and making the thickness of the skirt greater than the thickness of the transition part, on the one hand, the self-structural strength of the explosion-proof valve can be improved; on the other hand, when the explosion-proof valve is installed at a preset position on the housing or the cell cover plate, the thicker skirt can increase the connection area between the explosion-proof valve and the housing or the cell cover plate.

[0023] In an alternative embodiment, in the thickness direction of the valve body, the thickness of the opening part is B, and the value range of the thickness B of the opening part is 0.15 mm ≤ B ≤ 0.32 mm; the relationship between B and H satisfies: 0.05 mm ≤ (B - H) ≤ 0.12 mm; the thickness of the remaining material at the bottom of the second groove is C, and the relationship between C and H satisfies: C / H ≥ 0.45.

[0024] Beneficial effects: By setting the opening part according to the above parameters, the opening part can be ensured to have a certain strength. When the cell operates normally and generates a pressure difference, the opening part can withstand a certain pressure by its own strength and will not deform easily due to being too thin. And by setting the thickness H of the remaining material at the bottom of the first groove according to the above parameters, the opening part can be stably connected to the transition part in the open state, avoiding the complete separation of the opening part and the transition part. Further, by setting the difference between B and H according to the above parameters, it can be ensured that the opening part can be stably connected to the transition part through the bottom of the first groove, and at the same time, the stress at the annular notch can be evenly diffused to the opening part. Secondly, by setting H and C according to the above parameters, it can be realized that under the condition that the opening pressure of the explosion-proof valve remains unchanged, the notch thickness at the second groove of the annular notch (i.e., the thickness C of the remaining material at the bottom of the second groove) is increased, thereby avoiding the mis-opening of the explosion-proof valve during the normal operation pressure fluctuation of the cell due to the notch being too thin, and improving the accuracy and stability of the explosion-proof valve.

[0025] In the second aspect, the present invention also provides a cell cover plate, including:

[0026] A cover plate body provided with a mounting hole;

[0027] The above-mentioned explosion-proof valve is arranged in the mounting hole.

[0028] Beneficial effects: This cell cover plate includes the above-mentioned explosion-proof valve and has all the beneficial technical effects of this cell cover plate, which will not be elaborated here.

[0029] In a third aspect, the present invention further provides an electric cell, comprising:

[0030] a housing having an opening on one side;

[0031] the above-mentioned electric cell cover plate, covering and sealing the opening.

[0032] Beneficial effects: This electric cell, including the above-mentioned electric cell cover plate, has all the beneficial technical effects of this electric cell, which will not be elaborated here. Description of the Drawings

[0033] In order 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 following drawings 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.

[0034] Figure 1 It is a schematic structural diagram of an explosion-proof valve according to an embodiment of the present invention;

[0035] Figure 2 is Figure 1 a partial enlarged schematic diagram of M in;

[0036] Figure 3 is Figure 1 a sectional schematic diagram of the explosion-proof valve shown;

[0037] Figure 4 is Figure 1 a partial enlarged schematic diagram of N in;

[0038] Figure 5 It is a schematic structural diagram of an electric cell according to an embodiment of the present invention.

[0039] Description of the Reference Numerals:

[0040] 1. Valve body; 101. Opening part; 102. Transition part; 103. Annular groove; 1031. First groove; 1032. Second groove; 1033. Straight section; 1034. Arc section; 2. Skirt; 3. Electric cell cover plate; 4. Housing; 401. Opening. Detailed Embodiments

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0042] The embodiments of the present invention will be described below with reference to Figures 1 to 5 .

[0043] According to an embodiment of the present invention, on the one hand, as Figures 1 to 4 shown, an explosion-proof valve is provided, including: a valve body 1, the valve body 1 including an opening part 101 and a transition part 102 connected to the periphery of the opening part 101; an annular notch 103 surrounding the opening part 101 is provided between the opening part 101 and the transition part 102; the annular notch 103 includes a first groove 1031 and a second groove 1032 communicating with the first groove 1031, and in the thickness direction of the valve body 1, the bottom of the first groove 1031 is higher than the bottom of the second groove 1032; the projected area of the opening part 101 on the horizontal plane is S, and the value range of S is: 80 mm 2 ≤ S ≤ 1000 mm 2 ; the length of the first groove 1031 is L, and the value range of L is: 5 mm ≤ L ≤ 15 mm; along the length direction of the first groove 1031, the cross-sectional area of the remaining material at the bottom of the first groove 1031 is S1; the relationship among S1, L, and S satisfies: 2.7×10 -4 mm ≤ (L × S1) / S ≤ 8.0×10 -4 mm.

[0044] In this embodiment, by setting the dimensions of the annular notch 103 at the first groove 1031 according to the above parameters, the remaining notch thickness of the annular notch 103 at the second groove 1032 can be significantly increased under the same opening pressure, improving the overall structural strength of the explosion-proof valve and reducing the risk of abnormal cracking or premature opening of the explosion-proof valve. Specifically, the explosion-proof valve is designed with a first groove 1031 and a second groove 1032. The opening method is that after the fracture at the second groove 1032, the opening part 101 of the explosion-proof valve flips, so that the high-temperature and high-pressure gas can be discharged smoothly. After flipping, the remaining material part at the bottom of the first groove 1031 of the explosion-proof valve is connected to the cover body of the cell cover plate 3, so that the explosion-proof valve opens along the designed path. Then, by reasonably setting the length of the first groove 1031 and the cross-sectional area S1 of the remaining material at the bottom of the first groove 1031 according to the above parameters, the opening pressure of the explosion-proof valves with the same structure and the same effective opening area can be reduced to the lowest. In this way, if you want to keep the opening pressure of the explosion-proof valve within the original design range, you can increase the remaining material thickness at the second groove 1032 of the explosion-proof valve, thereby improving the anti-external force pulling and deformation ability at the second groove 1032 of the explosion-proof valve.

[0045] In addition, in this embodiment, the bottom of the first groove 1031 is higher than the bottom of the second groove 1032, which means that the remaining notch thickness of the annular notch 103 at the first groove 1031 is greater than the remaining notch thickness of the annular notch 103 at the second groove 1032, that is, the connection strength between the opening part 101 and the transition part 102 at the first groove 1031 is greater than the connection strength between the opening part 101 and the transition part 102 at the second groove 1032. In this way, when the thermal runaway of the cell occurs, the annular notch 103 will only break from the second groove 1032, and the annular notch 103 will still remain connected at the first groove 1031 to prevent the entire opening part 101 from directly detaching from the cell under the impact of the high-temperature gas. With this setting, on the one hand, it can ensure that the high-pressure gas inside the cell can be released orderly through the fracture; on the other hand, the connection state at the first groove 1031 can maintain the structural integrity of the explosion-proof valve to a certain extent, reducing the possibility of the opening part 101 interfering with the surrounding structure compared with the direct detachment of the opening part 101 from the explosion-proof valve.

[0046] According to an embodiment of the present invention, as Figure 1 and Figure 2As shown, the annular notch 103 includes a straight section 1033 and arc sections 1034 located at both ends of the straight section 1033. The first groove 1031 is located within the straight section 1033. Compared with setting the first groove 1031 within the arc section 1034, in a thermal runaway state, the first groove 1031 located within the straight section 1033 can more effectively disperse stress, reducing the risk of stress concentration, and thus ensuring that the opening part 101 can be stably connected to the transition part 102 and reducing the possibility of its direct complete detachment from the explosion-proof valve.

[0047] In one embodiment, as Figure 1 and Figure 2 shown, the extending direction of the straight section 1033 is consistent with the length direction of the valve body 1.

[0048] According to an embodiment of the present invention, as Figure 3 shown, along the thickness direction of the valve body 1, the remaining thickness of the bottom of the first groove 1031 is H, and the value range of H is: 0.09 mm ≤ H ≤ 0.23 mm; along the width direction of the first groove 1031, the remaining width of the bottom of the first groove 1031 is W, and the value range of W is: 0.05 mm ≤ W ≤ 0.12 mm; the relationship among W, H, and S1 satisfies: S1 = W × H. By setting H and W according to the above parameters in this embodiment, it can be ensured that under the same opening pressure, the remaining thickness of the annular notch 103 at the second groove 1032 is greater, so that the explosion-proof valve will not open in advance due to insufficient strength at the notch before reaching the set opening pressure.

[0049] It should be noted that in this embodiment, along the length direction of the first groove 1031, the bottom cross-section of the first groove 1031 is generally a regular square structure, such as a square or a rectangle.

[0050] According to an embodiment of the present invention, as Figure 1 and Figure 3As shown, the opening part 101 protrudes from the upper surface of the transition part 102 and its cross-sectional shape is arc-shaped. During the normal operation of the battery cell, a certain amount of gas is also generated inside the battery cell, creating a pressure difference between the inside of the battery cell and the external environment. Therefore, before this part of the gas is discharged from the inside of the battery cell, it continuously acts on the opening part 101, causing the opening part 101 to have a tendency to move or deform away from the battery cell electrode group. In this way, the notch on the explosion-proof valve may break prematurely under the pulling of the opening part 101. Based on this, the opening part 101 in this embodiment protrudes compared to the transition part 102, which can reserve space in advance for the possible deformation amount of the opening part 101 during the normal operation of the battery cell, preventing the opening part 101 from generating a pulling force on the annular notch 103 due to deformation during the operation of the battery cell, thereby avoiding the situation of premature opening or abnormal fracture. In addition, setting the cross-section of the opening part 101 as arc-shaped can timely disperse the stress acting on the annular notch 103 to the opening part 101, avoiding the abnormal rupture or premature opening of the annular notch 103 due to stress concentration.

[0051] According to an embodiment of the present invention, as Figure 1 and Figure 3 shown, the periphery of the opening part 101 uniformly transitions to the top of the opening part 101. The uniform transition of the periphery of the opening part 101 to the top of the opening part 101 means that the stress acting on each area of the annular notch 103 can be gradually transmitted to the top along the curved surface of the opening part 101, making the pressure borne by each part of the annular notch 103 relatively balanced and avoiding the situation of premature rupture caused by stress concentration in a certain area. In addition, the opening part 101 is in a uniform transition state from the periphery to the top, which can also make the pressure evenly distributed on the opening part 101, prevent excessive local stress from causing excessive deformation, and further avoid premature rupture of the annular notch 103 due to deformation stretching.

[0052] According to an embodiment of the present invention, the opening part 101, the annular notch 103, and the transition part 102 are integrally formed. Using an integral forming process to prepare the opening part 101, the annular notch 103, and the transition part 102 can not only reduce the time cost in the production process, but also improve the overall structural strength of the explosion-proof valve.

[0053] According to an embodiment of the present invention, as Figure 1 and Figure 3As shown, the explosion-proof valve further includes a skirt 2 surrounding the outer periphery of the transition portion 102, and the thickness of the skirt 2 is greater than that of the transition portion 102. By providing the skirt 2 on the outer periphery of the transition portion 102 and making the thickness of the skirt 2 greater than that of the transition portion 102, on the one hand, the structural strength of the explosion-proof valve itself can be improved; on the other hand, when the explosion-proof valve is installed at a preset position on the housing 4 or the cell cover plate 3, the thicker skirt 2 can increase the connection area between the explosion-proof valve and the housing 4 or the cell cover plate 3.

[0054] According to an embodiment of the present invention, as Figure 1 and Figure 3 shown, the upper surface of the skirt 2 is higher than the upper surface of the transition portion 102, the thickness of the skirt 2 is A, and the value range of A is 0.4 mm ≤ A ≤ 0.6 mm. In this embodiment, the skirt 2 is set according to the above parameters. The skirt 2 will neither be too thin to withstand possible external mechanical impacts nor be too thick to increase excessive unnecessary weight and cost.

[0055] According to an embodiment of the present invention, as Figure 3 shown, in the thickness direction of the valve body 1, the thickness of the opening portion 101 is B, and the value range of the thickness B of the opening portion 101 is 0.15 mm ≤ B ≤ 0.32 mm; the relationship between B and H satisfies: 0.05 mm ≤ (B - H) ≤ 0.12 mm; the thickness of the remaining material at the bottom of the second groove 1032 is C, and the relationship between C and H satisfies: C / H ≥ 0.45. In this embodiment, the opening portion 101 is set according to the above parameters, which can ensure that the opening portion 101 has a certain strength. When the cell is operating normally and a pressure difference is generated, the opening portion 101 can withstand a certain pressure by virtue of its own strength and will not be easily deformed due to being too thin. And by setting the thickness H of the bottom of the first groove 1031 according to the above parameters, the opening portion 101 can be stably connected to the transition portion 102 in the open state, preventing the opening portion 101 from completely detaching from the transition portion 102. Further, by setting the difference between B and H according to the above parameters, while ensuring that the opening portion 101 can be stably connected to the transition portion 102 through the bottom of the first groove 1031, the stress at the annular notch 103 can be evenly diffused to the opening portion 101. Secondly, by setting H and C according to the above parameters, when the opening pressure of the explosion-proof valve remains unchanged, the notch thickness at the second groove 1032 of the annular notch 103 (i.e., the thickness C of the remaining material at the bottom of the second groove 1032) can be increased, thereby avoiding the explosion-proof valve from being accidentally opened during the normal operation pressure fluctuation of the cell due to the notch being too thin, and improving the accuracy and stability of the explosion-proof valve.

[0056] In one embodiment, the value range of the thickness C of the remaining material at the bottom of the second groove 1032 is C ≥ 65 μm.

[0057] According to the embodiment of the present invention, on the other hand, asFigure 5 As shown, a cell cover plate 3 is also provided, including: a cover plate body and the above-mentioned explosion-proof valve. Specifically, the cover plate body is provided with a mounting hole; the above-mentioned explosion-proof valve is arranged in the mounting hole. This cell cover plate 3, including the explosion-proof valve as described above, has all the beneficial technical effects of this cell cover plate, which will not be elaborated here. This cell cover plate 3, including the explosion-proof valve as described above, has all the beneficial technical effects of this cell cover, which will not be elaborated here.

[0058] According to an embodiment of the present invention, on the other hand, a cell is also provided, including: a housing 4 and a cell cover plate 3. Specifically, an opening 401 is provided on one side of the housing 4; the above-mentioned cell cover plate 3 covers and seals the opening 401. This cell, including the cell cover plate 3 as described above, has all the beneficial technical effects of this cell, which will not be elaborated here.

[0059] The technical effects of the technical solution of the present invention will be described below in conjunction with specific embodiments and comparative examples.

[0060] Table 1: The designed opening pressure of the explosion-proof valve is 0.9 ± 0.2 Mpa, and the design requirement is C ≥ 65 μm.

[0061] L W H S (S1×L) / S C Opening pressure / Mpa Example 1 5 0.05 0.09 80 <![CDATA[2.81×10 -4 > 65.5 0.921 Example 2 7 0.05 0.09 80 <![CDATA[3.93×10 -4 > 66.8 0.908 Example 3 8 0.06 0.09 80 <![CDATA[5.4×10 -4 > 67.2 0.911 Example 4 9 0.06 0.1 80 <![CDATA[6.75×10 -4 > 66.9 0.889 Example 5 8 0.08 0.13 175 <![CDATA[4.75×10 -4 > 65.3 0.925 Example 6 8.5 0.08 0.13 175 <![CDATA[5.05×10 -4 > 65.1 0.918 Example 7 8 0.08 0.14 175 <![CDATA[5.12×10 -4 > 65.9 0.930 Example 8 9 0.09 0.14 175 <![CDATA[6.48×10 -4 > 66.4 0.923 Example 9 9 0.09 0.15 175 <![CDATA[6.94×10 -4 > 67.2 0.891 Example 10 9.5 0.09 0.15 175 <![CDATA[7.33×10 -4 > 65.8 0.919 Example 11 11 0.1 0.17 350 <![CDATA[5.34×10 -4 > 66.2 0.906 Example 12 12 0.1 0.18 350 <![CDATA[6.17×10 -4 > 69.1 0.895 Example 13 13 0.11 0.18 350 <![CDATA[7.35×10 -4 > 67.8 0.915 Example 14 14 0.11 0.19 350 <![CDATA[8.36×10 -4 > 66.4 0.913 Example 15 13 0.11 0.22 1000 <![CDATA[3.15×10 -4 > 65.7 0.911 Example 16 14 0.12 0.23 1000 <![CDATA[3.86×10 -4 > 66.8 0.921 Example 17 15 0.12 0.23 1000 <![CDATA[4.14×10 -4 > 66.3 0.891 Comparative Example 1 5 0.05 0.08 80 <![CDATA[2.5×10 -4 > 59.4 0.925 Comparative Example 2 10 0.07 0.1 80 <![CDATA[8.75×10 -4 > 52.5 0.903 Comparative Example 3 10.5 0.1 0.15 175 <![CDATA[9.00×10 -4 > 62.1 0.923 Comparative Example 4 11 0.11 0.22 1000 <![CDATA[2.66×10 -4 > 60.7 0.921 Comparative Example 5 18.5 0.18 0.25 1000 <![CDATA[8.33×10 -4 > 54.1 0.935

[0062] It can be seen that when 2.7×10 -4 ≤(L×W×H) / S≤8.0×10 -4 is satisfied, at the same opening pressure, the thickness C of the remaining material at the bottom of the second groove 1032 is basically stable between 65 μm and 70 μm, with good stability and all meeting the design requirements. When the ratio of (L×W×H) / S does not meet the above design requirements, at the same opening pressure, the opening pressure of the explosion-proof valve fluctuates greatly, and the thickness C of the remaining material at the bottom of the second groove 1032 is all below 65 μm, not meeting the design requirement value.

[0063] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An explosion-proof valve, characterized in that: include: A valve body, the valve body comprising an opening portion and a transition portion connected to the periphery of the opening portion; an annular notch surrounding the opening portion is provided between the opening portion and the transition portion; the annular notch comprises a first groove and a second groove communicating with the first groove, and in the thickness direction of the valve body, the groove bottom of the first groove is higher than the groove bottom of the second groove; The projection area of ​​the opening on the horizontal plane is S, and the value range of S is: 80mm 2 ≤S≤1000mm 2 ; The length of the first groove is L, and the value range of L is: 5mm≤L≤15mm; Along the length direction of the first groove, the cross-sectional area of ​​the bottom residual material of the first groove is S1; the relationship between S1, L and S satisfies: 2.7×10 -4 mm≤(L×S1) / S≤8.0×10 -4 mm.

2. The explosion-proof valve according to claim 1, characterized in that: The annular notch includes a straight section and arcuate sections located at two ends of the straight section, and the first groove is located in the straight section.

3. The explosion-proof valve according to claim 2, characterized in that: Along the thickness direction of the valve body, the thickness of the bottom residual material of the first groove is H, and the value range of H is: 0.09mm≤H≤0.23mm; along the width direction of the first groove, the width of the bottom residual material of the first groove is W, and the value range of W is: 0.05mm≤W≤0.12mm; the relationship between W, H and S1 satisfies: S1=W×H.

4. The explosion-proof valve according to claim 1, characterized in that: The opening portion protrudes from the upper surface of the transition portion and has an arc-shaped cross section.

5. The explosion-proof valve according to claim 4, characterized in that: The periphery of the opening portion transitions evenly to the top of the opening portion.

6. The explosion-proof valve according to any one of claims 1 to 5, characterized in that: The opening portion, the annular notch and the transition portion are integrally formed.

7. The explosion-proof valve according to any one of claims 1 to 5, characterized in that: The explosion-proof valve further includes a skirt surrounding the outer periphery of the transition portion, wherein the thickness of the skirt is greater than the thickness of the transition portion.

8. The explosion-proof valve according to claim 3, characterized in that: In the thickness direction of the valve body, the thickness of the opening portion is B, and the value range of the thickness B of the opening portion is 0.15mm≤B≤0.32mm; the relationship between B and H satisfies: 0.05mm≤(BH)≤0.12mm; the thickness of the bottom residual material of the second groove is C, and the relationship between C and H satisfies: C / H≥0.

45.

9. A battery cell cover, characterized in that: include: The cover body is provided with a mounting hole; The explosion-proof valve according to any one of claims 1 to 8 is arranged in the mounting hole.

10. A battery cell, characterized in that: include: A shell having an opening on one side; The cell cover plate of claim 9 covers and seals the opening.

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