Anti-explosion valve, battery cover plate and battery

Abstract

The invention belongs to the technical field of batteries, and discloses an anti-explosion valve, a battery cover plate and a battery, the anti-explosion valve comprises a base body provided with an anti-explosion nick, the anti-explosion nick comprises a weakening part, the thickness size of the base body is T, the residual thickness size of the area, provided with the weakening part, of the base body is t1, t1 is smaller than T, the length size of the base body in the first direction is A, and t1 is smaller than T; the length of the base body in the second direction is B, and B / A is larger than or equal to 0.35 and smaller than or equal to 0.8. By limiting the width-to-length ratio, on one hand, the situation that the explosion-proof valve is too long and narrow due to the too small width-to-length ratio, the contact area of pressure gas and the explosion-proof valve is too dispersed, and the difficulty of breaking through the explosion-proof valve is increased is avoided, and therefore it is not needed to reduce the opening difficulty by reducing the residual thickness in order to guarantee the opening pressure requirement of the explosion-proof valve; according to the explosion-proof valve, the opening pressure is guaranteed, meanwhile, enough residual thickness is reserved for the performance of high structural strength, and on the other hand, the situation that the explosion-proof valve cannot adapt to a narrow installation area due to the fact that the width-length ratio is too large is avoided.

Description

Technical Field

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

[0002] The structure of lithium-ion batteries generally includes a cover plate, a shell, an electrode group, an electrolyte, an insulating protective sheet, etc. The cover plate and the shell are fixed by welding to form a closed space to protect the electrode group; the electrode group is covered with a bare cell insulating sheet to protect the electrode group from contacting the shell and causing an internal short circuit in the battery cell. The cover plate is usually integrated with structures such as poles, explosion-proof valves, and injection holes. The main function of the explosion-proof valve is to release pressure and exhaust gas. It is used for the directional release of internal high-temperature and high-pressure gas when the battery cell experiences thermal runaway due to mechanical impact, abnormal internal lap short circuit, etc., thereby improving safety performance.

[0003] Explosion-proof valves are usually provided with explosion-proof notches to weaken the structural strength of the explosion-proof valve itself, so that when thermal runaway occurs inside the battery, the pressurized gas generated by the thermal runaway can be discharged into the external environment by breaking through the explosion-proof valve, thus achieving the effect of pressure relief protection. In order to ensure the smooth discharge of pressurized gas, the explosion-proof valve needs to reduce the residual thickness after the explosion-proof notch is opened. However, when the residual thickness is reduced, the structural strength of the explosion-proof valve itself will be reduced, causing the explosion-proof valve to deform when subjected to external impact and other factors, reducing the opening pressure of the explosion-proof valve, thereby causing the explosion-proof valve to open prematurely. If the structural strength of the explosion-proof valve itself is to be ensured, the residual thickness of the explosion-proof valve after the explosion-proof notch is opened will increase, which will increase the difficulty of opening the explosion-proof valve. Therefore, it is impossible to ensure a high structural strength while also having the opening pressure of the explosion-proof valve. Summary of the invention

[0004] The object of the present invention is to provide an explosion-proof valve, a battery cover and a battery, which can ensure the opening pressure of the explosion-proof valve and have high structural strength.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] On the one hand, an explosion-proof valve is provided, which includes a substrate, on which explosion-proof notches are provided, and the explosion-proof notches include a weakened portion. The thickness dimension of the substrate is T, and the residual thickness dimension of the substrate in the area where the weakened portion is provided is t1, and t1<T is satisfied. The length dimension of the substrate along the first direction is A, and the length dimension of the substrate along the second direction is B, and 0.35≤B / A≤0.8 is satisfied.

[0007] Optionally, the explosion-proof notch further includes a connecting portion, and the residual thickness dimension of the substrate in the area of ​​the connecting portion is t2, and t1<t2<T is satisfied.

[0008] Optionally, the length dimension of the connecting portion along the first direction is C, and satisfies 5mm≤C≤10mm. Optionally, the explosion-proof valve further comprises a protective boss, and the protective boss is continuously arranged around the circumferential edge of the base.

[0009] Optionally, a width dimension of the protective boss along the first direction is D, and satisfies 0.75 mm ≤ D ≤ 1 mm.

[0010] Optionally, the groove width of the weakened portion along the second direction decreases as the depth of the weakened portion increases.

[0011] Optionally, the projection of the explosion-proof notch on the substrate is rectangular, circular or racetrack-shaped.

[0012] On the other hand, a battery cover is provided, which includes a cover body and an explosion-proof valve as described in any one of the above items, wherein a mounting hole is provided on the cover body, the explosion-proof valve is arranged in the mounting hole, the width dimension of the cover body along the second direction is W, and satisfies 45%≤B / W≤75%.

[0013] Optionally, a length dimension B of the explosion-proof valve along the second direction and a width dimension W of the cover plate body along the second direction satisfy (WB) / 2≥3 mm.

[0014] On the other hand, a battery is provided, comprising a battery shell, a pole group and a battery cover as described in any one of the above items, wherein the battery shell is a hollow shell structure with an opening, and the battery cover is used to close the opening of the battery shell to form a chamber for accommodating the pole group.

[0015] Beneficial effects of the present invention:

[0016] The present invention provides an explosion-proof valve, which includes a substrate provided with explosion-proof notches. By limiting the relationship between a length dimension A of the substrate along a first direction and a dimension B of the substrate along a second direction, the two satisfy 0.35≤B / A≤0.8. On the one hand, it is avoided that the width-to-length ratio is too small, which makes the explosion-proof valve too narrow and long, resulting in excessive dispersion of the contact area between the pressurized gas and the explosion-proof valve, and increasing the difficulty of the pressurized gas breaking through the explosion-proof valve. Therefore, there is no need to reduce the residual thickness to reduce the opening difficulty in order to ensure the opening pressure requirement of the explosion-proof valve. While ensuring the opening pressure of the explosion-proof valve, sufficient residual thickness is retained for performance with higher structural strength. On the other hand, it is avoided that the width-to-length ratio is too large, which makes the explosion-proof valve unable to adapt to a narrow installation area.

[0017] The present invention also provides a battery cover plate, which limits the relationship between the width dimension W of the cover plate body along the second direction and the dimension B of the explosion-proof valve base along the second direction, so that the two satisfy 45%≤B / W≤75%. On the one hand, this avoids the width occupied by the explosion-proof valve on the cover plate body along the second direction being too large, which causes the cover plate body to be easily deformed when welding the explosion-proof valve and the cover plate body. On the other hand, it avoids the width occupied by the explosion-proof valve on the cover plate body along the second direction being too small, which causes the shape of the explosion-proof valve to be too narrow and long under the premise that the area of ​​the explosion-proof valve remains unchanged, resulting in the area where the pressure gas contacts the explosion-proof valve to be too dispersed, thereby increasing the difficulty of the pressure gas to break through the explosion-proof valve.

[0018] The present invention also provides a battery, which, by applying the above-mentioned battery cover, ensures the opening pressure of the battery during thermal runaway and improves safety, and has high structural strength, thereby avoiding the problem of premature opening of the explosion-proof valve due to external force factors or reducing the opening pressure, thereby improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a plan view of the explosion-proof valve provided by the present invention;

[0020] Figure 2 It is a three-dimensional isometric view of the explosion-proof valve provided by the present invention;

[0021] Figure 3 It is a three-dimensional isometric side cross-sectional view of the explosion-proof valve provided by the present invention;

[0022] Figure 4 yes Figure 3 The structure of part I is enlarged;

[0023] Figure 5 It is a structural schematic diagram of a battery cover plate using an explosion-proof valve provided by the present invention;

[0024] Figure 6 It is a schematic structural diagram of a battery using a battery cover provided by the present invention.

[0025] In the figure:

[0026] 100, cover body; 200, battery housing; 300, electrode group;

[0027] 1. Base; 11. Explosion-proof notch; 111. Weakened portion; 112. Connecting portion;

[0028] 2. Protective boss. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0030] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0032] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0033] Since the current explosion-proof valves with explosion-proof notches cannot ensure high structural strength while also meeting the explosion-proof valve opening pressure, this embodiment provides an explosion-proof valve to solve the above problem.

[0034] like Figures 1 to 4 As shown, the explosion-proof valve includes a substrate 1, on which an explosion-proof notch 11 is provided, the explosion-proof notch 11 includes a weakened portion 111, the thickness dimension of the substrate 1 is T, the residual thickness dimension of the substrate 1 in the area where the weakened portion 111 is provided is t1, and t1<T is satisfied, the length dimension of the substrate 1 along the first direction is A, the length dimension of the substrate 1 along the second direction is B, and 0.35≤B / A≤0.8 is satisfied.

[0035] The explosion-proof valve includes a substrate 1 provided with an explosion-proof notch 11. The relationship between a length dimension A of the substrate 1 along a first direction and a dimension B of the substrate 1 along a second direction is limited so that the two satisfy 0.35≤B / A≤0.8. On the one hand, the aspect ratio is prevented from being too small, which makes the explosion-proof valve too narrow and long, resulting in the area where the pressurized gas contacts the explosion-proof valve being too dispersed, thereby increasing the difficulty of the pressurized gas breaking through the explosion-proof valve. Therefore, there is no need to reduce the residual thickness to reduce the opening difficulty in order to ensure the opening pressure requirement of the explosion-proof valve. While ensuring the opening pressure of the explosion-proof valve, sufficient residual thickness is retained for performance with higher structural strength. On the other hand, the aspect ratio is prevented from being too large, which makes the explosion-proof valve unable to adapt to a narrow installation area.

[0036] Among them, the explosion-proof valve can be adapted to different types of batteries, such as blade batteries or square shell batteries, and can also be set on the battery cover or the battery housing 200 according to location requirements.

[0037] The projection of the explosion-proof notch 11 on the substrate 1 is rectangular, circular or track-shaped. In this embodiment, the shape of the explosion-proof notch 11 matches the shape of the explosion-proof valve, both of which are track-shaped structures.

[0038] Alternatively, if Figure 1 As shown, the explosion-proof notch 11 further includes a connecting portion 112, and the residual thickness dimension of the area where the base 1 is provided with the connecting portion 112 is t2, and t1<t2<T is satisfied. By making the residual thickness dimension t2 of the area where the base 1 is provided with the connecting portion 112 of the explosion-proof notch 11 greater than the residual thickness dimension t1 of the area where the weakened portion 111 of the explosion-proof notch 11 is provided on the base 1, when thermal runaway occurs and the area surrounded by the explosion-proof notch 11 on the explosion-proof valve is opened, the connecting portion 112 prevents the part of the explosion-proof valve surrounded by the explosion-proof notch 11 from flying out, thereby improving safety.

[0039] Furthermore, if Figure 1 As shown, the length dimension C of the connection portion 112 along the first direction satisfies 5mm≤C≤10mm. By limiting the length dimension C of the connection portion 112 along the first direction to satisfy 5mm≤C≤10mm, on the one hand, it is prevented that the length of the connection portion 112 is too small, resulting in weak connection strength, causing the connection portion 112 to break during thermal runaway, causing the part of the explosion-proof valve surrounded by the explosion-proof notch 11 to fly out, and on the other hand, it is prevented that the length of the connection portion 112 is too large, reducing the length of the weakened portion 111, resulting in increased difficulty in the pressure gas to break the explosion-proof valve.

[0040] The length dimension C of the connecting portion 112 along the first direction may be any value between 5 mm and 10 mm or a range between any two values, such as 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc.

[0041] Alternatively, if Figure 2 As shown, the explosion-proof valve further includes a protective boss 2, which is continuously arranged around the circumferential edge of the base 1. By arranging the protective boss 2 on the explosion-proof valve, on the one hand, a sufficient welding area is provided for welding the explosion-proof valve, and on the other hand, the protective boss 2 protects the inner explosion-proof notch 11 to prevent damage to the explosion-proof notch 11, thereby affecting the pressure at which the explosion-proof valve is opened.

[0042] Furthermore, if Figure 1 As shown, the thickness dimension D of the protective boss 2 along the first direction satisfies 0.75 mm ≤ D ≤ 1 mm. By limiting the width dimension D of the protective boss 2 along the first direction to satisfy 0.75 mm ≤ D ≤ 1 mm, on the one hand, the width of the protective boss 2 is prevented from being too narrow, thereby affecting the subsequent welding operation of the explosion-proof valve, and on the other hand, the width of the protective protrusion is prevented from being too large, resulting in occupying more area, thereby affecting the pressure of opening the explosion-proof valve.

[0043] The width dimension D of the protective boss 2 along the first direction may be any value between 0.75 mm and 1 mm or a range between any two values, such as 0.75 mm, 0.85 mm, 0.95 mm, 1 mm, etc.

[0044] Alternatively, if Figure 4 As shown, the groove width of the weakened portion 111 along the second direction decreases as the depth of the weakened portion 111 increases. By making the groove width of the weakened portion 111 along the second direction decrease as the depth of the weakened portion 111 increases, the weakened portion 111 forms a trumpet-shaped structure with a larger top and a smaller bottom, thereby retaining more material for the explosion-proof valve while maintaining the same depth, thereby increasing the structural strength of the explosion-proof valve itself.

[0045] The cross-sectional shape of the weakened portion 111 may be U-shaped, V-shaped or inverted trapezoidal. In the present embodiment, the cross-sectional shape of the weakened portion 111 is an inverted trapezoidal.

[0046] In this embodiment, in order to determine the influence of the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction on the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 under the premise of having the same effective area and opening pressure of the explosion-proof valve, as shown in Table 1, ten experimental groups are provided for verification, wherein in order to avoid the influence of other factors on the experiment, the length dimension C of the connecting portion 112 along the first direction and the width dimension D of the protective boss 2 along the first direction are set as constant values, and the pressure of the opening pressure of the explosion-proof valve is about 0.9 MPa, wherein 32 explosion-proof valves are taken for testing in each experimental group, and the average value of the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 is obtained and recorded.

[0047] Table 1

[0048]

[0049] In Experimental Group 1, the effective area of ​​the explosion-proof disk was set to 85 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction is set to 0.45. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 73.8 μm.

[0050] In Experimental Group 2, the effective area of ​​the explosion-proof disk was set to 85 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction to the dimension B of the substrate 1 along the second direction is set to 0.40. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 75.2 μm.

[0051] In Experimental Group 3, the effective area of ​​the explosion-proof disk was set to 85 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction is set to 0.35. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 76.3 μm.

[0052] In Experimental Group 4, the effective area of ​​the explosion-proof disk was set to 85 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction is set to 0.25. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 65.9 μm.

[0053] In Experimental Group 5, the effective area of ​​the explosion-proof disk was set to 85 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction to the dimension B of the substrate 1 along the second direction is set to 0.20. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 61.4 μm.

[0054] It can be seen from experimental groups 1 to 5 that when having the same effective area of ​​the explosion-proof valve and an approximate opening pressure, since the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction of experimental groups 1 to 3 satisfies the range of 0.35≤B / A≤0.8, and the ratio of the length dimension A along the first direction and the dimension B of the substrate 1 along the second direction of experimental groups 4 to 5 is less than the minimum value of 0.35≤B / A≤0.8, the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 obtained by experimental groups 1 to 3 is greater than the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 obtained by experimental groups 4 to 5. Therefore, compared with experimental groups 4 to 5, experimental groups 1 to 3 have higher structural strength at approximate opening pressures.

[0055] In Experimental Group 6, the effective area of ​​the explosion-proof disk was set to 110 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction to the dimension B of the substrate 1 along the second direction is set to 0.45. At this time, the average value of the residual thickness dimension t1 of the substrate 1 having the weakened portion 111 is obtained by experiment to be 89.2 μm.

[0056] In Experimental Group 7, the effective area of ​​the explosion-proof disk was set to 110 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction to the dimension B of the substrate 1 along the second direction is set to 0.40. At this time, the average value of the residual thickness dimension t1 of the substrate 1 having the weakened portion 111 is obtained by experiment to be 88.7 μm.

[0057] In Experimental Group 8, the effective area of ​​the explosion-proof disk was set to 110 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction is set to 0.35. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 86.2 μm.

[0058] In Experimental Group 9, the effective area of ​​the explosion-proof disk was set to 110 mm 2, the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction is set to 0.25. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 78.2 μm.

[0059] In Experimental Group 10, the effective area of ​​the explosion-proof disk was set to 110 mm 2 , the length dimension C of the connecting portion 112 along the first direction is set to 5 mm, the width dimension D of the protective boss 2 along the first direction is set to 1 mm, and the ratio of the length dimension A of the substrate 1 along the first direction to the dimension B of the substrate 1 along the second direction is set to 0.20. At this time, the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is obtained through experiments is 75.9 μm.

[0060] It can be seen from experimental groups 6 to 10 that when having the same effective area of ​​the explosion-proof valve and an approximate opening pressure, since the ratio of the length dimension A of the substrate 1 along the first direction and the dimension B of the substrate 1 along the second direction of experimental groups 6 to 8 satisfies the range of 0.35≤B / A≤0.8, and the ratio of the length dimension A along the first direction and the dimension B of the substrate 1 along the second direction of experimental groups 9 to 10 is less than the minimum value of 0.35≤B / A≤0.8, the residual thickness dimension t1 of the substrate 1 with the weakened portion 111 obtained by experimental groups 6 to 8 is greater than the residual thickness dimension t1 of the substrate 1 with the weakened portion 111 obtained by experimental groups 9 to 10. Therefore, compared with experimental groups 9 to 10, experimental groups 6 to 8 have higher structural strength at approximate opening pressures.

[0061] In this embodiment, if Figure 1 , Figure 5 As shown, a battery cover is also provided, which includes a cover body 100 and the above-mentioned explosion-proof valve. A mounting hole is opened on the cover body 100, and the explosion-proof valve is arranged in the mounting hole. The width dimension of the cover body 100 along the second direction is W, and satisfies 45%≤B / W≤75%.

[0062] The battery cover plate limits the relationship between the width dimension W of the cover plate body 100 along the second direction and the dimension B of the explosion-proof valve substrate 1 along the second direction, so that the two satisfy 45%≤B / W≤75%. This, on the one hand, avoids the width of the explosion-proof valve on the cover plate body 100 along the second direction being too large, resulting in the cover plate body 100 being easily deformed when welding the explosion-proof valve and the cover plate body 100, affecting the opening pressure of the explosion-proof valve and requiring adjustment of the residual thickness. On the other hand, it avoids the width of the explosion-proof valve on the cover plate body 100 along the second direction being too small, resulting in the shape of the explosion-proof valve being too narrow and long under the premise that the area of ​​the explosion-proof valve remains unchanged, resulting in the area where the pressure gas contacts the explosion-proof valve being too dispersed, increasing the difficulty of the pressure gas breaking through the explosion-proof valve.

[0063] In this embodiment, in order to determine the influence of the ratio of the width dimension W of the cover body 100 along the second direction and the dimension B of the substrate 1 along the second direction on the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 under the premise of having the same effective area and opening pressure of the explosion-proof valve, as shown in Table 2, ten experimental groups are provided for verification. When conducting the test, the same explosion-proof valve is welded to the cover bodies 100 of different widths respectively, and the pressure for opening the explosion-proof valve is set to be approximately 0.9 MPa, so as to conduct the test, thereby realizing the change of the ratio of the width dimension W of the cover body 100 along the second direction and the dimension B of the substrate 1 along the second direction, and obtaining the average value of the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 for recording.

[0064] Table 2

[0065] <![CDATA[Explosion-proof film effective area / mm 2 > Opening pressure / Mpa B / W Mean residual thickness of notch / μm Experimental Group 11 85 0.92 0.35 65.2 Experimental Group 12 85 0.91 0.45 75.2 Experimental Group 13 85 0.90 0.55 75.8 Experimental Group 14 85 0.91 0.75 76.5 Experimental Group 15 85 0.92 0.80 66.5 Experimental Group 16 110 0.93 0.35 78.2 Experimental Group 17 110 0.90 0.45 88.7 Experimental Group 18 110 0.91 0.55 89.3 Experimental Group 19 110 0.93 0.75 88.9 Experimental Group 20 110 0.90 0.80 71.9

[0066] In Experimental Group 11, the effective area of ​​the explosion-proof disk was set to 85 mm 2 The opening pressure is set to 0.92 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.35, and the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is provided is 65.2 μm.

[0067] In Experimental Group 12, the effective area of ​​the explosion-proof disk was set to 85 mm 2 The opening pressure is set to 0.91 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.45, and the average value of the residual thickness dimension t1 of the substrate 1 having the weakened portion 111 is 75.2 μm.

[0068] In Experimental Group 13, the effective area of ​​the explosion-proof disk was set to 85 mm 2The opening pressure is set to 0.90 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.55, and the average value of the residual thickness dimension t1 of the substrate 1 with the weakened portion 111 is 75.8 μm.

[0069] In Experimental Group 14, the effective area of ​​the explosion-proof disk was set to 85 mm 2 The opening pressure is set to 0.91 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.75, and the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is provided is 76.5 μm.

[0070] In Experimental Group 15, the effective area of ​​the explosion-proof disk was set to 85 mm 2 The opening pressure is set to 0.92 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.80, and the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is provided is 66.5 μm.

[0071] It can be seen from experimental groups 11 to 15 that when having the same effective area of ​​the explosion-proof valve and an approximate opening pressure, since the ratio of the width dimension W of the cover plate body 100 along the second direction and the dimension B of the substrate 1 along the second direction of experimental groups 12 to 14 satisfies the range of 45%≤B / W≤75%, while experimental groups 11 and 15 do not meet the range of 45%≤B / W≤75%, the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 obtained by experimental groups 12 to 14 is greater than the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 obtained by experimental groups 11 and 15. Therefore, compared with experimental groups 11 and 15, experimental groups 12 to 14 have higher opening pressures at approximate opening pressures. The structural strength of experimental group 11 is that the width occupied by the explosion-proof valve along the second direction on the cover body 100 is too small, resulting in the shape of the explosion-proof valve being too narrow and long under the premise that the area of ​​the explosion-proof valve remains unchanged, resulting in the contact area between the pressure gas and the explosion-proof valve being too dispersed, increasing the difficulty of the pressure gas breaking through the explosion-proof valve, and therefore it is necessary to deepen the depth of the explosion-proof notch 11, resulting in a reduction in residual thickness, while the width occupied by the explosion-proof valve along the second direction on the cover body 100 is too large in experimental group 15, resulting in the cover body 100 being easily deformed when welding the explosion-proof valve and the cover body 100, affecting the opening pressure of the explosion-proof valve, resulting in an increase in the difficulty of the pressure gas breaking through the explosion-proof valve, and therefore it is necessary to deepen the depth of the explosion-proof notch 11, resulting in a reduction in residual thickness.

[0072] In Experimental Group 16, the effective area of ​​the explosion-proof disk was set to 110 mm 2The opening pressure is set to 0.93 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.35, and the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is provided is 78.2 μm.

[0073] In Experimental Group 17, the effective area of ​​the explosion-proof disk was set to 110 mm 2 The opening pressure is set to 0.90 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.45, and the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is provided is 88.7 μm.

[0074] In Experimental Group 18, the effective area of ​​the explosion-proof disk was set to 110 mm 2 The opening pressure is set to 0.91 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.55, and the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is provided is 89.3 μm.

[0075] In Experimental Group 19, the effective area of ​​the explosion-proof disk was set to 110 mm 2 The opening pressure is set to 0.93 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.75, and the average value of the residual thickness dimension t1 of the substrate 1 in the area where the weakened portion 111 is provided is 88.9 μm.

[0076] In Experimental Group 20, the effective area of ​​the explosion-proof disk was set to 110 mm 2 The opening pressure is set to 0.90 MPa, the ratio of the width dimension W of the cover body 100 along the second direction to the dimension B of the substrate 1 along the second direction is 0.80, and the average value of the residual thickness dimension t1 of the substrate 1 having the weakened portion 111 is 71.9 μm.

[0077] It can be seen from experimental groups 16 to 20 that when having the same effective area of ​​the explosion-proof valve and an approximate opening pressure, since the ratio of the width dimension W of the cover plate body 100 along the second direction and the dimension B of the substrate 1 along the second direction in experimental groups 17 to 19 satisfies the range of 45%≤B / W≤75%, while experimental groups 16 and 20 do not meet the range of 45%≤B / W≤75%, the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 in experimental groups 17 to 19 is greater than the residual thickness dimension t1 of the substrate 1 provided with the weakened portion 111 in experimental groups 16 and 20. Therefore, compared with experimental groups 16 and 20, experimental groups 17 to 19 have higher opening pressures at approximate opening pressures. The structural strength of experimental group 16 is that the width occupied by the explosion-proof valve on the cover body 100 along the second direction is too small, resulting in the shape of the explosion-proof valve being too narrow and long under the premise that the area of ​​the explosion-proof valve remains unchanged, resulting in the contact area between the pressure gas and the explosion-proof valve being too dispersed, increasing the difficulty of the pressure gas breaking through the explosion-proof valve, and therefore it is necessary to deepen the depth of the explosion-proof notch 11, resulting in a reduction in residual thickness, while the width occupied by the explosion-proof valve on the cover body 100 along the second direction is too large in experimental group 20, resulting in the cover body 100 being easily deformed when welding the explosion-proof valve and the cover body 100, affecting the opening pressure of the explosion-proof valve, resulting in an increase in the difficulty of the pressure gas breaking through the explosion-proof valve, and therefore it is necessary to deepen the depth of the explosion-proof notch 11, resulting in a reduction in residual thickness.

[0078] Alternatively, if Figure 1 , Figure 5 As shown, the length dimension B of the explosion-proof valve along the second direction and the width dimension W of the cover body 100 along the second direction satisfy (WB) / 2≥3mm. By making the length dimension B of the explosion-proof valve along the second direction and the width dimension W of the cover body 100 along the second direction satisfy (WB) / 2≥3mm, the minimum width value of the region where the mounting hole of the cover body 100 is provided along the second direction is determined, so as to avoid the width of the region where the mounting hole of the cover body 100 is provided along the second direction being too small, resulting in poor structural strength and deformation when welding the explosion-proof valve.

[0079] In this embodiment, if Figure 6 As shown, a battery is also provided, the battery comprising a battery housing 200, an electrode group 300 and the above-mentioned battery cover, the battery housing 200 is a hollow housing structure with an opening, and the battery cover is used to close the opening of the battery housing 200 to form a chamber for accommodating the electrode group 300. By applying the above-mentioned battery cover, the battery not only ensures the opening pressure of the battery in thermal runaway, improves safety, but also has a high structural strength, avoids the problem of premature opening of the explosion-proof valve due to external factors, or reduces the opening pressure, and improves product quality.

[0080] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Explosion-proof valve, characterized in that: The explosion-proof valve includes a substrate, on which an explosion-proof notch is provided, wherein the explosion-proof notch includes a weakened portion, the thickness dimension of the substrate is T, the residual thickness dimension of the substrate in the area where the weakened portion is provided is t1, and t1<T is satisfied, the length dimension of the substrate along the first direction is A, the length dimension of the substrate along the second direction is B, and 0.35≤B / A≤0.8 is satisfied.

2. The explosion-proof valve according to claim 1, characterized in that: The explosion-proof notch further includes a connecting portion, and the residual thickness dimension of the substrate in the area where the connecting portion is provided is t2, and t1<t2<T is satisfied.

3. The explosion-proof valve according to claim 2, characterized in that: The length dimension of the connecting portion along the first direction is C, and satisfies 5mm≤C≤10mm.

4. The explosion-proof valve according to claim 1, characterized in that: The explosion-proof valve further comprises a protection boss which is continuously arranged around the circumferential edge of the base.

5. The explosion-proof valve according to claim 4, characterized in that: The width dimension of the protective boss along the first direction is D, and satisfies 0.75mm≤D≤1mm.

6. The explosion-proof valve according to claim 1, characterized in that: The groove width of the weakened portion along the second direction decreases as the depth of the weakened portion increases.

7. The explosion-proof valve according to claim 1, characterized in that: The projection of the explosion-proof notch on the substrate is in the shape of a rectangle, a circle or a racetrack.

8. A battery cover, characterized in that: The battery cover includes a cover body and an explosion-proof valve as described in any one of claims 1-7, a mounting hole is opened on the cover body, the explosion-proof valve is arranged in the mounting hole, the width dimension of the cover body along the second direction is W, and satisfies 45%≤B / W≤75%.

9. The battery cover according to claim 8, characterized in that: A length dimension B of the explosion-proof valve along the second direction and a width dimension W of the cover plate body along the second direction satisfy (WB) / 2≥3 mm.

10. A battery, characterized in that The battery comprises a battery shell, a pole group and a battery cover as described in any one of claims 8 to 9, wherein the battery shell is a hollow shell structure with an opening, and the battery cover is used to close the opening of the battery shell to form a chamber for accommodating the pole group.

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