Explosion-proof valve, battery cover plate and battery

Abstract

An explosion-proof valve, a battery cover plate and a battery. The explosion-proof valve (10) comprises a valve body (100), a buffer part (200) and a welding part (300), which are arranged in sequence. The valve body (100) comprises an opening part (110), a burst section (122), and a transition part (130). When the pressure on one side of the explosion-proof valve (10) exceeds a valve-opening pressure, the burst section (122) at least partially breaks, such that the opening part (110) is separated from the transition part (130), thereby forming at the opening part (110) a flow channel for a gas to pass therethrough. The buffer part (200) is arranged circumferentially around the transition part (130), and the welding part (300) is arranged circumferentially around the buffer part (200).

Description

Explosion-proof valve, battery cover plate and battery

[0001] This application claims priority to the Chinese patent application No. 202411087911.2 filed on August 9, 2024 with the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, for example to an explosion-proof valve, a battery cover plate and a battery. BACKGROUND

[0003] In order to ensure the safety of the battery, an explosion-proof valve is generally arranged on the light aluminum sheet of the battery cover plate, and the installation mode of the explosion-proof valve is generally that the circumferential side of the explosion-proof valve is welded with the inner wall of the mounting hole on the light aluminum sheet. However, when this installation mode is adopted, due to thermal expansion and contraction during the welding process, the explosion-proof valve may be stretched and deformed during welding, the score on the explosion-proof valve is thinned, the opening pressure of the explosion-proof valve is reduced, and more seriously, the explosion-proof valve may be directly cracked, resulting in the product being scrapped. In addition, the explosion-proof valve in the related art may also have the problem of deformation of the score during welding, resulting in that the explosion-proof valve fails the breathing test and the reliability is reduced. SUMMARY

[0004] The present application provides an explosion-proof valve, a battery cover plate and a battery, which improve the structure of the explosion-proof valve, avoid the cracking and deformation of the explosion-proof valve during the welding process as much as possible, stabilize the opening pressure, have high reliability and good safety performance.

[0005] In a first aspect, the present application provides an explosion-proof valve, comprising:

[0006] a valve body, comprising an opening part, a burst segment and a transition part, the burst segment is arranged around the opening part, and the transition part is arranged around the burst segment, when the pressure on one side of the explosion-proof valve exceeds the opening pressure, the burst segment is at least partially disconnected to separate the opening part from the transition part;

[0007] a buffer part, which is arranged around the circumference of the transition part;

[0008] a welding part, which is arranged around the circumference of the buffer part, and the outer circumferential surface of the welding part is arranged to be connected with the light aluminum sheet of the battery cover plate;

[0009] wherein the thickness of the welding part along the first direction is C, and the value range of C is 0.4 millimeters≤C≤1 millimeter; the width of the projection of the welding part on the light aluminum sheet along the first direction is C1, and the value range of C1 is 0.4 millimeters≤C1≤3 millimeters, and the first direction is perpendicular to the plane where the light aluminum sheet is located.

[0010] In some embodiments, a distance between a projection of the buffer portion on the light aluminum sheet in the first direction near a side of the burst segment and a projection of the burst segment on the light aluminum sheet in the first direction near a side of the buffer portion is C2, and C2 is in a range of 0.1 mm to 3 mm.

[0011] In some embodiments, a thickness of at least one of the opening portion and the transition portion in the first direction is A, and A is in a range of 0.2C≤A≤0.5C.

[0012] In some embodiments, the explosion-proof valve further comprises a connecting segment, the connecting segment and the burst segment are connected in a head-to-tail manner to form an annular structure, and the annular structure is arranged around a circumference of the opening portion.

[0013] A residual thickness of the connecting segment in the first direction is A1, and A1 is in a range of 0.5A≤A1≤A.

[0014] In the first direction, a residual thickness of the burst segment is A2, and A2 is in a range of 0.25A≤A2≤0.75A, and A1>A2.

[0015] In some embodiments, a transition wall surface is formed between the connecting segment and the burst segment, the transition wall surface and the first wall surface of the burst segment have an included angle K, and K is in a range of 90 degrees≤K≤160 degrees.

[0016] In some embodiments, the buffer portion comprises a horizontal segment and an inclined segment, the inclined segment is arranged at an included angle with the horizontal segment, the horizontal segment is connected with the welding portion, and the inclined segment is connected with the valve body.

[0017] The size information of the explosion-proof valve comprises at least one of the following:

[0018] The horizontal segment is perpendicular to the first direction, a thickness of the horizontal segment is B1, and B1 is in a range of 0.6A≤B1≤1.5A; a thickness of the inclined segment is B2, and B2 is in a range of 0.6A≤B2≤1.5A.

[0019] Or, a width of a projection of the horizontal segment on the light aluminum sheet in the first direction is F, and the width F of the horizontal segment is in a range of 1 mm to 10 mm.

[0020] Or, the horizontal segment and an inner side of the inclined segment are connected through a first circular arc R1, and R1 is in a range of 0.05 mm≤R1≤F / 2.

[0021] Or, the horizontal segment and an inner side of the welding portion are connected through a second circular arc R2, and R2 is in a range of 0.05 mm≤R2≤F / 2.

[0022] Or, the horizontal section and the outer side of the inclined section are connected by a third circular arc R3, and the value range of R3 is 0.05 millimeter≤R3≤F / 2+B1;

[0023] Or, the horizontal section and the outer side of the welding part are connected by a fourth circular arc R4 and a circumferential circular arc R, the value range of R4 is 0.05 millimeter≤R4≤F / 2+B1, and the value range of R is 0.1 millimeter-2 millimeter;

[0024] Or, the inclined section and the outer side of the valve body are connected by a fifth circular arc R5, and the value range of R5 is 0.1 millimeter-3 millimeter;

[0025] Or, the inclined section and the inner side of the valve body are connected by a sixth circular arc R6, and the value range of R6 is R5+0.5B2≤R6≤R5+2B2;

[0026] Or, the included angle between the inclined section and the horizontal section is A3, and the value range of A3 is 25 degrees≤A3≤85 degrees.

[0027] In some embodiments, the projection area of the opening part on the light aluminum sheet in the first direction is S1, the total projection area of the explosion-proof valve on the light aluminum sheet in the first direction is S2, the proportion of the projection area S1 of the opening part in the total projection area S2 of the explosion-proof valve is k, k=S1 / S2, and the value range of k is 0.45≤k≤0.9.

[0028] In some embodiments, the size information of the explosion-proof valve includes at least one of the following:

[0029] In the first direction, the distance between the end face of the valve body away from the buffer part and the end face of the welding part away from the buffer part is D1, and the value range of D1 is 0≤D1≤0.9C.

[0030] In the first direction, the distance between the end face of the buffer part away from the valve body and the end face of the welding part away from the valve body is D2, and the value range of D2 is 0.2C≤D2≤C.

[0031] In a second aspect, the application provides a battery cover plate, which comprises a light aluminum sheet and an explosion-proof valve in any of the above embodiments, and the light aluminum sheet is provided with a mounting hole, and the explosion-proof valve is arranged in the mounting hole.

[0032] In a third aspect, the application provides a battery comprising a shell and a battery cover plate in any of the above embodiments, and the shell and the battery cover plate are connected. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 is a structural schematic diagram of an explosion-proof valve in the embodiment of the present application;

[0034] Fig. 2 is a sectional view of A-A in Fig. 1;

[0035] Fig. 3 is an enlarged view of B in Fig. 2;

[0036] Fig. 4 is an enlarged view of C in Fig. 2;

[0037] Fig. 5 is a sectional view of D-D in Fig. 1;

[0038] Fig. 6 is an enlarged view of E in Fig. 5;

[0039] Fig. 7 is an enlarged view of F in Fig. 5;

[0040] Fig. 8 is a sectional view of G-G in Fig. 1;

[0041] Fig. 9 is an enlarged view of H in Fig. 8;

[0042] Fig. 10 is a structural schematic diagram of a battery cover plate in the embodiment of the present application;

[0043] Fig. 11 is a sectional view of I-I in Fig. 10;

[0044] Fig. 12 is a structural schematic diagram of a battery in the embodiment of the present application.

[0045] In the drawings: 10, explosion-proof valve; 20, battery cover plate; 21, light aluminum sheet; 22, mounting hole; 30, shell; 40, battery; 100, valve body; 110, opening part; 120, annular structure; 121, connecting section; 1211, transition wall surface; 122, blasting section; 1221, first wall surface 1221; 130, transition part; 200, buffer part; 210, horizontal section; 220, inclined section; 300, welding part. DETAILED DESCRIPTION

[0046] The embodiments of the present application will be described below with reference to the drawings, and the described embodiments are some embodiments related to the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0047] In the description of the present application, the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation. In addition, the terms "first", "second", are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and moreover, the "above", "over" and "on" of the first feature to the second feature include the first feature above and obliquely above the second feature, or indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "under" and "under" of the first feature to the second feature include the first feature below and obliquely below the second feature, or indicate that the horizontal height of the first feature is less than that of the second feature.

[0048] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the meaning of the above terms in the present application can be understood as appropriate.

[0049] The embodiments of the present application are described below, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application.

[0050] As shown in FIGS. 1-4, the present embodiment provides an explosion-proof valve 10 arranged in a mounting hole 22 on an aluminum sheet 21. The explosion-proof valve 10 includes a valve body 100, a buffer portion 200, and a welding portion 300. The valve body 100 lies in an X-Y plane shown in FIG. 1, and includes an opening portion 110, a burst section 122 arranged partially around the opening portion 110, and a transition portion 130 arranged around the burst section 122. When the pressure on one side of the explosion-proof valve 10 exceeds the valve opening pressure, the burst section 122 at least partially breaks to separate the opening portion 110 from the transition portion 130, thereby forming a flow passage at the opening portion 110 for gas to pass through, and the gas on one side of the explosion-proof valve 10 can be discharged to the other side of the explosion-proof valve 10 through the flow passage. The buffer portion 200 is arranged around the transition portion 130 in the circumferential direction. The welding portion 300 is arranged around the buffer portion 200 in the circumferential direction, and the outer circumferential surface of the welding portion 300 is connected to the aluminum sheet 21. Exemplarily, the outer circumferential surface of the welding portion 300 is a circumferential side surface perpendicular to the plane in which the aluminum sheet 21 lies, and the outer circumferential surface of the welding portion 300 is perpendicular to the X-Y plane. By arranging the buffer portion 200, the problem of cracking or deformation of the burst section 122 of the valve body 100 when the welding portion 300 is welded to the aluminum sheet 21 can be alleviated, thereby ensuring that the valve opening pressure of the explosion-proof valve 10 is stable and the valve opening reliability is high.

[0051] In some embodiments, the outer circumferential surface of the welding portion 300 can also be arranged at an angle to the plane in which the aluminum sheet 21 lies, as long as the outer circumferential surface of the welding portion 300 is fitted to the inner wall of the mounting hole 22 on the aluminum sheet 21 or has a small gap.

[0052] In some embodiments, the thickness of the welding portion 300 in a first direction is C. The first direction is the negative direction of the Z axis shown in FIG. 2, and is parallel to the outer circumferential surface of the welding portion 300, i.e., the first direction is perpendicular to the X-Y plane. The value of C is in the range of 0.4 millimeters (mm) to 1 mm. For example, the value of the thickness C of the welding portion 300 in the first direction can be 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, etc. By controlling the thickness C of the welding portion 300 in the first direction to be within the above range, the welding portion 300 can have sufficient mechanical strength, the welding strength between the welding portion 300 and the aluminum sheet 21 can be improved, and the material used can be minimized to reduce costs.

[0053] In some embodiments, the projection of the welding portion 300 on the light aluminum sheet 21 along the first direction has a width C1, and C1 is in a range of 0.4 mm to 3 mm. For example, C1 can be 0.4 mm, 0.8 mm, 1.2 mm, 1.6 mm, 2.0 mm, 2.4 mm, 2.8 mm, 3.0 mm, or the like. By controlling C1 in the above range, deformation of the buffer portion 200 or the burst section 122 during welding can be avoided as much as possible, which helps to improve the reliability of the opening of the explosion-proof valve 10 and ensure the stability of the opening pressure of the explosion-proof valve 10.

[0054] Optionally, the distance between the projection of the buffer portion 200 on the light aluminum sheet 21 along the first direction near the burst section 122 and the projection of the burst section 122 on the light aluminum sheet 21 along the first direction near the buffer portion 200 is C2, and C2 is in a range of 0.1 mm to 3 mm. For example, C2 can be 0.1 mm, 0.5 mm, 1.0 mm, 2.0 mm, or 3.0 mm. It should be noted that C2 cannot be too small, otherwise the distance between the buffer portion 200 and the burst section 122 is too close, and the burst section 122 is prone to deformation during welding of the explosion-proof valve 10 and the light aluminum sheet 21, which leads to unstable opening pressure and reduced reliability. C2 also cannot be too large, otherwise it will increase the material cost and waste space.

[0055] Continuing to refer to FIGS. 5-7, in the present embodiment, the thickness of the opening portion 110 and the transition portion 130 along the first direction is A, and A is in a range of 0.2C≤A≤0.5C. By controlling the thickness A of the opening portion 110 and the transition portion 130 in the above range, the stability of the opening pressure of the explosion-proof valve 10 can be ensured as much as possible. For example, when A<0.2C, the thickness A of the opening portion 110 and the transition portion 130 is too small, which leads to low strength of the valve body 100 and unstable opening pressure; when A>0.5C, the thickness A of the opening portion 110 and the transition portion 130 is too large, which leads to high strength of the valve body 100 and unstable opening pressure. The thickness of the opening portion 110 and the transition portion 130 along the first direction can be equal or not equal, as long as the thickness is in the above range.

[0056] In some embodiments, the explosion-proof valve 10 in the present embodiment further comprises a connecting section 121, the connecting section 121 and the burst section 122 are connected end to end to form an annular structure 120, the annular structure 120 is arranged around the circumference of the opening part 110. The connecting section 121 can be formed by machining a first notch on the valve body 100, and the burst section 122 can be formed by machining a second notch on the valve body 100, the depth of the second notch is greater than the depth of the first notch. When the pressure on one side of the explosion-proof valve 10 exceeds the valve opening pressure, the residual thickness at the burst section 122 is smaller due to the greater depth of the second notch, and the burst section 122 will break first, causing the opening part 110 and the transition part 130 to separate, and then the opening part 110 flips to one side with the connecting section 121 as the axis, thereby forming a flow passage for gas to pass through. In the present embodiment, the first notch and the second notch are arranged on the end face of the valve body 100 away from the buffer part 200, so that when the explosion-proof valve 10 is opened, the opening part 110 is more likely to flip away from the buffer part 200. In other embodiments, the first notch and the second notch can also be arranged on the end face of the valve body 100 close to the buffer part 200.

[0057] Optionally, the annular structure 120 formed by the connecting section 121 and the burst section 122 in the present embodiment is in the shape of a racetrack, the annular structure 120 comprises two arc-shaped sides and two straight sides arranged opposite to each other, and the two arc-shaped sides and the two straight sides are connected end to end. The connecting section 121 is arranged on one of the straight sides of the annular structure 120, and the length of the connecting section 121 is less than the length of the straight side, and the remaining positions of the annular structure 120 are all burst sections 122. The residual thickness of the connecting section 121 in the first direction is A1, and the value of A1 is in the range of 0.5A≤A1≤A. That is, when A1 is the maximum, the first notch can not be machined; when A1 is the minimum, the depth of the first notch is half of the thickness A of the opening part 110. The residual thickness of the burst section 122 in the first direction is A2, and the value of A2 is in the range of 0.25A≤A2≤0.75A, and it is necessary to ensure that A1>A2, so that the burst section 122 will crack first when the pressure on one side of the explosion-proof valve 10 exceeds the valve opening pressure; otherwise, if the connecting section 121 cracks first, the opening part 110 will not be able to complete the flip, the area of the flow passage will be very small, and the explosion-proof valve 10 cannot play a good pressure relief role, and the battery is at risk of explosion.

[0058] The residual thickness A1 of the connecting section 121 in the first direction should not be set too small, otherwise when the explosion-proof valve 10 is opened, the connecting section 121 will break at the same time as the bursting section 122, causing the opening part 110 to fly out as a whole. On the one hand, the flying opening part 110 may injure people, and on the other hand, the flying opening part 110 is also easy to cause short circuit between the battery cells. In addition, the residual thickness A2 of the bursting section 122 in the first direction should not be set too small, otherwise the bursting section 122 is prone to breakage, damage, deformation, and reliability is reduced; the residual thickness A2 of the bursting section 122 in the first direction should not be set too large, otherwise the opening pressure of the explosion-proof valve 10 is unstable, and the consistency is low.

[0059] Referring to FIGS. 8 and 9, due to the height difference between the connecting section 121 and the bursting section 122, a transition wall surface 1211 is formed between the connecting section 121 and the bursting section 122, and the transition wall surface 1211 and the first wall surface 1221 of the bursting section 122 have an included angle K, wherein the first wall surface 1221 refers to the bottom wall of the second score. The value of K is in the range of 90°≤K≤160°. In some embodiments, the value of K is in the range of 120°≤K≤150°. Exemplarily, K can be 90°, 100°, 120°, 135°, 140°, 150° or 160°, etc., for example, K is 135°.

[0060] Continuing to refer to FIGS. 3, 4 and 6, the buffer part 200 in the embodiment includes a horizontal section 210 and an inclined section 220, the horizontal section 210 is connected with the welding part 300, the inclined section 220 is connected with the valve body 100, the inclined section 220 is arranged at an included angle with the horizontal section 210, and the horizontal section 210 is perpendicular to the first direction. The thickness of the horizontal section 210 is B1, and the value of B1 is in the range of 0.6A≤B1≤1.5A. By controlling B1 in the above range, it is ensured that the buffer part 200 is easy to process and is not easy to crack or break. For example, if B1<0.6A, the mechanical strength of the buffer part 200 is insufficient, it is easy to break, and the reliability of the explosion-proof valve 10 is reduced; if B1 is greater than 1.5A, due to the thickness of the buffer part 200 being relatively thick, the mechanical strength is relatively high, it is relatively difficult to stamp form during processing, the processing difficulty is relatively large, and material cost is wasted. In some embodiments, the thickness of the inclined section 220 is B2, and the value of B2 is in the range of 0.6A≤B2≤1.5A. By controlling B2 in the above range, it is ensured that the buffer part 200 is easy to process and is not easy to crack or break. It should be noted that the thickness B1 of the horizontal section 210 and the thickness B2 of the inclined section 220 can be the same or different.

[0061] In some embodiments, in the present embodiment, the inner side between the horizontal section 210 and the inclined section 220 is transitioned by the first circular arc R1, the inner side between the horizontal section 210 and the welding portion 300 is transitioned by the second circular arc R2, the outer side between the horizontal section 210 and the inclined section 220 is transitioned by the third circular arc R3, the outer side between the horizontal section 210 and the welding portion 300 is transitioned by the fourth circular arc R4 and the circumferential circular arc R, the outer side between the inclined section 220 and the valve body 100 is transitioned by the fifth circular arc R5, and the inner side between the inclined section 220 and the valve body 100 is transitioned by the sixth circular arc R6. Wherein, the above-mentioned inner side refers to the side of the welding portion 300 surrounding the buffer portion 200, and the side of the buffer portion 200 surrounding the valve body 100. The buffer portion 200 and the welding portion 300 form a avoiding space therebetween, and the side of the valve body 100, the horizontal section 210, the inclined section 220 and the welding portion 300 close to the avoiding space is the inner side, that is, the side of the valve body 100, the horizontal section 210, the inclined section 220 and the welding portion 300 facing the positive direction of the Z axis (as shown in FIG. 2 and FIG. 5), and the first notch and the second notch are also arranged on the inner side of the valve body. The outer side refers to the side opposite to the inner side, and the side of the valve body 100, the horizontal section 210, the inclined section 220 and the welding portion 300 far away from the avoiding space is the outer side, that is, the side of the valve body 100, the horizontal section 210, the inclined section 220 and the welding portion 300 facing the negative direction of the Z axis (as shown in FIG. 2 and FIG. 5). By using the first circular arc R1, the second circular arc R2, the third circular arc R3, the fourth circular arc R4, the circumferential circular arc R, the fifth circular arc R5 and the sixth circular arc R6 to transition the horizontal section 210, the inclined section 220 and the welding portion 300, the stress state of the blasting section 122 of the explosion-proof valve 10 is improved, which is conducive to improving the process yield.

[0062] Optionally, in the present embodiment, the width of the projection of the horizontal section 210 on the light aluminum sheet 21 along the first direction is F, and the value range of F is 1mm-10mm. The value range of the first circular arc R1 is 0.05mm≤R1≤F / 2. The value range of the second circular arc R2 is 0.05mm≤R2≤F / 2. The value range of the third circular arc R3 is 0.05mm≤R3≤F / 2+B1. The value range of the fourth circular arc R4 is 0.05≤R4≤F / 2+B1. The value range of the circumferential circular arc R is 0.1mm-2mm. The value range of the fifth circular arc R5 is 0.1mm-3mm. The value range of the sixth circular arc R6 is R5+0.5B2≤R6≤R5+2B2. The values of F, R1, R2, R3, R4, R, R5 and R6 can be adjusted as appropriate, as long as they are within the above-mentioned ranges, which can ensure the good process of the explosion-proof valve 10, and the finished product of the explosion-proof valve 10 meets the use requirements.

[0063] In some embodiments, the buffer portion 200 comprises a horizontal segment 210 and an inclined segment 220, the inclined segment 220 is arranged at an angle with the horizontal segment 210, the horizontal segment 210 is connected with the welding portion 300, and the inclined segment 220 is connected with the valve body 100;

[0064] The size information of the explosion-proof valve comprises at least one of the following:

[0065] The horizontal segment 210 is perpendicular to the first direction, the thickness of the horizontal segment 210 is B1, and the value range of B1 is 0.6A≤B1≤1.5A; the thickness of the inclined segment 220 is B2, and the value range of B2 is 0.6A≤B2≤1.5A;

[0066] Or, the width of the projection of the horizontal segment 210 on the light aluminum sheet along the first direction is F, and the value range of the width F of the horizontal segment 210 is 1 millimeter to 10 millimeters;

[0067] Or, the inner side between the horizontal segment 210 and the inclined segment 220 is transitioned through a first circular arc R1, and the value range of R1 is 0.05 millimeter≤R1≤F / 2;

[0068] Or, the inner side between the horizontal segment 210 and the welding portion 300 is transitioned through a second circular arc R2, and the value range of R2 is 0.05 millimeter≤R2≤F / 2;

[0069] Or, the outer side between the horizontal segment 210 and the inclined segment 220 is transitioned through a third circular arc R3, and the value range of R3 is 0.05 millimeter≤R3≤F / 2+B1;

[0070] Or, the outer side between the horizontal segment 210 and the welding portion 300 is transitioned through a fourth circular arc R4 and a circumferential circular arc R, the value range of R4 is 0.05 millimeter≤R4≤F / 2+B1, and the value range of R is 0.1 millimeter to 2 millimeters;

[0071] Or, the outer side between the inclined segment 220 and the valve body 100 is transitioned through a fifth circular arc R5, and the value range of R5 is 0.1 millimeter to 3 millimeters;

[0072] Or, the inner side between the inclined segment 220 and the valve body 100 is transitioned through a sixth circular arc R6, and the value range of R6 is R5+0.5B2≤R6≤R5+2B2;

[0073] Or, the angle between the inclined segment 220 and the horizontal segment 210 is A3, and the value range of A3 is 25 degrees≤A3≤85 degrees.

[0074] In some embodiments, the projection area of the opening part 110 on the light aluminum sheet 21 in the first direction is S1, the total projection area of the explosion-proof valve 10 on the light aluminum sheet 21 in the first direction is S2, the proportion of the projection area S1 of the opening part 110 in the total projection area S2 of the explosion-proof valve 10 is k, k = S1 / S2, 0.45≤k≤0.9. When the projection area S1 of the opening part 110 meets the above requirement range, it can be ensured that the area of the flow passage is large enough when the explosion-proof valve 10 is opened, which is beneficial to realize rapid pressure relief.

[0075] The projection area S1 of the opening part 110 in the first direction is related to the structural size of the buffer part 200. For example, referring to FIG. 7, the included angle between the inclined segment 220 and the horizontal segment 210 is A3, and the value of the included angle A3 is in the range of 25°≤A3≤85°. For example, the included angle A3 can be 25°, 35°, 45°, 55°, 65°, 75° or 85°, etc. In the case that the total projection area S2 of the explosion-proof valve 10 is unchanged, the greater the value of the included angle A3, the greater the projection area S1 of the opening part 110; on the contrary, the smaller the value of the included angle A3, the smaller the projection area S1 of the opening part 110. In addition, the projection area S1 of the opening part 110 is also related to the setting position of the burst segment 122 on the valve body 100. Referring to FIG. 3, the greater the value of C2, the smaller the projection area S1 of the opening part 110, and the smaller the value of C2, the greater the projection area S1 of the opening part 110, thereby enabling the explosion-proof valve 10 to achieve rapid pressure relief.

[0076] Continuing to refer to FIGS. 3 and 4, in the first direction, the distance between the end face of the valve body 100 away from the buffer part 200 and the end face of the welding part 300 away from the buffer part 200 is D1, and the value of the distance D1 is in the range of 0≤D1≤0.9C. In the first direction, the distance between the end face of the buffer part 200 away from the valve body 100 and the end face of the welding part 300 away from the valve body 100 is D2, and the value of the distance D2 is in the range of 0.2C≤D2≤C. By controlling the distance D1 and the distance D2 in the above range, the stress concentration of the burst segment 122 on the valve body 100 is improved, which is beneficial to improve the reliability of the explosion-proof valve 10, and at the same time ensures the stability of the opening pressure.

[0077] The embodiment provides a battery cover plate 20, as shown in FIG. 10 and FIG. 11, which comprises an aluminum sheet 21 and the above-mentioned explosion-proof valve 10, the aluminum sheet 21 is provided with a mounting hole 22, and the explosion-proof valve 10 is arranged in the mounting hole 22. A limiting step is arranged in the mounting hole 22, the explosion-proof valve 10 is arranged in the mounting hole 22 from one side of the mounting hole 22 along the positive direction of the Z axis shown in FIG. 11 and abuts against the bottom wall of the limiting step, and the welding part 300 of the explosion-proof valve 10 is welded and connected with the side wall of the limiting step, so that the assembly process of the explosion-proof valve 10 on the aluminum sheet 21 is realized. By adopting the explosion-proof valve 10 in the embodiment, the safety performance of the battery cover plate 20 can be improved, the opening pressure of the explosion-proof valve 10 is stable, and the reliability is high.

[0078] The embodiment also provides a battery comprising a shell and the above-mentioned battery cover plate 20. The shell and the battery cover plate 20 are buckled and welded and connected, the battery cover plate 20 and the shell enclose a containing space, and the containing space is used for placing battery cells. By adopting the battery cover plate 20, the safety performance of the battery is good, when the pressure in the containing space exceeds the opening pressure of the explosion-proof valve 10, the explosion-proof valve 10 can be opened and pressure relief, the opening pressure of the explosion-proof valve 10 is stable, and the reliability is high.

[0079] In some embodiments, as shown in FIG. 12, the embodiment provides a battery 40 comprising a shell 30 and the battery cover plate 20 in any of the embodiments.

[0080] In some embodiments, when the explosion-proof valve 10 is assembled with the aluminum sheet 21, the end face provided with the first notch and the second notch of the explosion-proof valve 10 can be arranged away from the side where the battery cell is located, at this time, the buffer part 200 protrudes towards the side where the battery cell is located, that is, the buffer part 200 protrudes towards the negative direction of the Z axis shown in FIG. 11. In other embodiments, the end face provided with the first notch and the second notch of the explosion-proof valve 10 can be arranged towards the side where the battery cell is located, at this time, the buffer part 200 protrudes towards the positive direction of the Z axis shown in FIG. 11.

[0081] The opening pressure test and the breathing test of explosion-proof valves 10 of different size specifications are performed.

[0082] As shown in Table 1, the variables of the plurality of samples are the thickness C of the welding part 300 along the first direction and the distance C2 between the projection of the buffer part 200 along the first direction on the aluminum sheet 21 and the projection of the burst segment 122 along the first direction on the aluminum sheet 21.

[0083] Table 1

[0084] Referring to Table 1, the thickness C of the weld 300 of the sample 1 along the first direction is lower than the minimum value of the range 0.4mm≤C≤1mm, and the width C1 of the projection of the weld 300 on the light aluminum sheet 21 along the first direction satisfies the range 0.4mm≤C1≤3mm. At this time, the opening pressure of the explosion valve 10 is not a problem, but after the breathing test, the CT detection shows that the burst section 122 of the explosion valve 10 is deformed obviously, the reliability of the explosion valve 10 is low, and the sample 1 is not good.

[0085] Continuing to refer to Table 1, the thickness C of the weld 300 of the sample 11 along the first direction is higher than the maximum value of the range 0.4mm≤C≤1mm, and the width C1 of the projection of the weld 300 on the light aluminum sheet 21 along the first direction satisfies the range 0.4mm≤C1≤3mm. At this time, the opening pressure of the explosion valve 10 is not a problem, and after the breathing test, the CT detection shows that the burst section 122 of the explosion valve 10 is not deformed obviously, the reliability of the explosion valve 10 is higher, but the material cost of the explosion valve 10 is higher at this time, the economy is not good, and the sample 11 is not good.

[0086] Continuing to refer to Table 1, the thickness C of the weld 300 of the sample 2 along the first direction satisfies the range 0.4mm≤C≤1mm, and the width C1 of the projection of the weld 300 on the light aluminum sheet 21 along the first direction is lower than the minimum value of the range 0.4mm≤C1≤3mm. At this time, the opening pressure of the explosion valve 10 is not a problem, but the weld seam of the explosion valve 10 and the light aluminum sheet 21 falls into the buffer 200, and after the breathing test, the CT detection shows that the burst section 122 is deformed obviously, the reliability of the explosion valve 10 is low, and the sample 2 is not good.

[0087] Continuing to refer to Table 1, the thickness C of the weld 300 of the sample 10 along the first direction satisfies the range 0.4mm≤C≤1mm, and the width C1 of the projection of the weld 300 on the light aluminum sheet 21 along the first direction is higher than the maximum value of the range 0.4mm≤C1≤3mm. At this time, the opening pressure of the explosion valve 10 is not a problem, and after the breathing test, the CT detection shows that the burst section 122 is not deformed obviously, but the projection area S1 of the opening part 110 of the explosion valve 10 along the first direction is too small at this time, the flow passage is small, and the pressure relief requirement cannot be met, and the sample 10 is not good.

[0088] Continuing to refer to Table 1, the thickness C of the weld 300 of the sample 3, the sample 4, the sample 5, the sample 6, the sample 7, the sample 8, and the sample 9 along the first direction satisfies the range 0.4mm≤C≤1mm, and the width C1 of the projection of the weld 300 on the light aluminum sheet 21 along the first direction satisfies the range 0.4mm≤C1≤3mm. At this time, the opening pressure of the explosion-proof valve 10 is stable, and after the breathing test, the CT detection shows that the explosion section 122 does not have obvious deformation, the projected area S1 of the opening part 110 along the first direction is sufficient, and the pressure relief requirement is met, the sample 3, the sample 4, the sample 5, the sample 6, the sample 7, the sample 8, and the sample 9 are good and meet the requirements.

[0089] As shown in Table 2, the variable of the plurality of samples is the included angle K between the transition wall surface 1211 and the first wall surface 1221 of the explosion section 122.

[0090] Table 2

[0091] Referring to Table 2, the included angle K between the transition wall surface 1211 and the first wall surface 1221 of the explosion section 122 in the sample 1 is too small, far less than the required range of the K value 90°≤K≤160°, and the explosion section 122 cannot be formed, so the sample 1 is not good.

[0092] Continuing to refer to Table 2, the included angle K between the transition wall surface 1211 and the first wall surface 1221 of the explosion section 122 in the sample 10 is relatively large, greater than the maximum boundary of the required range of the K value 90°≤K≤160°, at this time, the forming rate of the explosion section 122 of the explosion-proof valve 10 is relatively low, and the processing has difficulty, so the sample 10 is not good.

[0093] Continuing to refer to Table 2, the included angle K between the transition wall surface 1211 and the first wall surface 1221 of the explosion section 122 in the sample 2 is relatively small, located at the minimum boundary of the required range of the K value 90°≤K≤160°, and can be normally formed during processing, and the sample 2 can ensure normal use when the number of weldings is small. After the welding part 300 of the explosion-proof valve 10 is welded for 3 times, the explosion section 122 on the side opposite to the connecting section 121 of the explosion-proof valve 10 has obvious abnormal deformation, at this time, the opening pressure and the breathing test can pass, meeting the use requirements, and the sample 2 is good.

[0094] Continuing to refer to Table 2, the included angle K between the transition wall surface 1211 and the first wall surface 1221 of the burst section 122 of sample 3, sample 4, sample 5, sample 6, sample 7, sample 8, and sample 9 satisfies the required range 90°≤K≤160°, at this time, the forming rate of the burst section 122 of the explosion-proof valve 10 is relatively high, easy to process, and the welding part 300 of the explosion-proof valve 10 does not have obvious abnormal deformation on the relative side of the connection section 121 after 5 times of welding, the opening valve pressure is stable, the breathing test is passed, and the reliability is high, and sample 3, sample 4, sample 5, sample 6, sample 7, sample 8, and sample 9 are good.

[0095] As shown in Table 3, the variable of the plurality of samples is the proportion k of the projection area S1 of the opening part 110 along the first direction in the total projection area S2 of the explosion-proof valve 10 along the first direction.

[0096] Table 3

[0097] Referring to Table 3, the proportion k of the projection area S1 of the opening part 110 along the first direction in the total projection area S2 of the explosion-proof valve 10 along the first direction of sample 1 is relatively small, lower than the minimum value of the range 0.45≤k≤0.9, the projection area S1 of the opening part 110 along the first direction is relatively small, and the forming rate of the processing at the burst section 122 is low. The proportion k of the projection area S1 of the opening part 110 along the first direction in the total projection area S2 of the explosion-proof valve 10 along the first direction of sample 12 is relatively large, higher than the maximum value of the range 0.45≤k≤0.9, the projection area S1 of the opening part 110 along the first direction is relatively large, and the forming of the buffer part 200 is relatively difficult during processing, and the processing yield is low. Sample 1 and sample 12 are not good.

[0098] Continuing to refer to Table 3, the proportion k of the projection area S1 of the opening part 110 along the first direction in the total projection area S2 of the explosion-proof valve 10 along the first direction of sample 2, sample 3, sample 4, sample 5, sample 6, sample 7, sample 8, sample 9, sample 10, and sample 11 satisfies the range 0.45≤k≤0.9, at this time, the flow channel of the explosion-proof valve 10 is large enough to meet the pressure relief needs, and the forming yield of the burst section 122 and the buffer part 200 is also relatively high, easy to process and manufacture, and the good product rate of the explosion-proof valve 10 is more than 99%. And the opening valve pressure of the explosion-proof valve 10 is stable, the breathing test is passed, and the reliability is high, and sample 2, sample 3, sample 4, sample 5, sample 6, sample 7, sample 8, sample 9, sample 10, and sample 11 are good.

Claims

1. An explosion-proof valve, comprising: a valve body comprising an opening part, a burst section and a transition part, the burst section being arranged around the opening part, the transition part being arranged around the burst section, the burst section being at least partially broken to separate the opening part from the transition part when the pressure on one side of the explosion-proof valve exceeds the opening pressure; a buffer part arranged around the circumference of the transition part; a welding part arranged around the circumference of the buffer part, an outer circumferential surface of the welding part being arranged to connect with an aluminum sheet of a battery cover plate; wherein a thickness of the welding part in a first direction is C, C being in a range of 0.4 mm≤C≤1 mm; a width of a projection of the welding part on the aluminum sheet in the first direction is C1, C1 being in a range of 0.4 mm≤C1≤3 mm, the first direction being parallel to the outer circumferential surface of the welding part.

2. The explosion relief valve of claim 1, wherein, A distance between a projection of the buffer part on the aluminum sheet in the first direction close to the burst section and a projection of the burst section on the aluminum sheet in the first direction close to the buffer part is C2, C2 being in a range of 0.1 mm≤C2≤3 mm.

3. The explosion relief valve of claim 2, wherein, A thickness of at least one of the opening part and the transition part in the first direction is A, A being in a range of 0.2C≤A≤0.5C.

4. The explosion-proof valve according to claim 3, further comprising a connecting section, the connecting section and the burst section being connected end to end to form an annular structure, the annular structure being arranged around the circumference of the opening part; a residual thickness of the connecting section in the first direction is A1, A1 being in a range of 0.5A≤A1≤A; a residual thickness of the burst section in the first direction is A2, A2 being in a range of 0.25A≤A2≤0.75A, A1>A2.

5. The explosion relief valve of claim 4, wherein, A transition wall surface is formed between the connecting section and the burst section, the transition wall surface and a first wall surface of the burst section having an included angle K, K being in a range of 90°≤K≤160°.

6. The explosion relief valve of claim 3, wherein, The buffer part comprises a horizontal section and an inclined section, the inclined section being arranged at an included angle with the horizontal section, the horizontal section being connected with the welding part, and the inclined section being connected with the valve body.

7. The explosion relief valve of claim 6, wherein, The horizontal section is perpendicular to the first direction, a thickness of the horizontal section is B1, B1 being in a range of 0.6A≤B1≤1.5A; a thickness of the inclined section is B2, B2 being in a range of 0.6A≤B2≤1.5A.

8. The explosion relief valve of claim 6, wherein, A width of a projection of the horizontal section on the aluminum sheet in the first direction is F, F being in a range of 1 mm≤F≤10 mm.

9. The explosion relief valve of claim 8, wherein, A first circular arc R1 is arranged between the horizontal section and an inner side of the inclined section, R1 being in a range of 0.05 mm≤R1≤F / 2.

10. The explosion relief valve of claim 8, wherein, A second circular arc R2 is arranged between the horizontal section and an inner side of the welding part, R2 being in a range of 0.05 mm≤R2≤F / 2.

11. The explosion relief valve of claim 7, wherein, A projection of the horizontal section on the aluminum sheet in the first direction has a width F, F is in a range of 1mm to 10mm; the horizontal section and the outer side of the inclined section are connected by a third circular arc R3, R3 is in a range of 0.05mm≤R3≤F / 2+B1.

12. The explosion relief valve of claim 7, wherein, A projection of the horizontal section on the aluminum sheet in the first direction has a width F, F is in a range of 1mm to 10mm; the horizontal section and the outer side of the welding part are connected by a fourth circular arc R4 and a circumferential circular arc R, R4 is in a range of 0.05mm≤R4≤F / 2+B1, R is in a range of 0.1mm to 2mm.

13. The explosion relief valve of claim 6, wherein, The inclined section and the outer side of the valve body are connected by a fifth circular arc R5, R5 is in a range of 0.1mm to 3mm.

14. The explosion relief valve of claim 7, wherein, The inclined section and the outer side of the valve body are connected by a fifth circular arc R5, R5 is in a range of 0.1mm to 3mm; the inclined section and the inner side of the valve body are connected by a sixth circular arc R6, R6 is in a range of R5+0.5B2≤R6≤R5+2B2.

15. The explosion relief valve of claim 6, wherein, An angle between the inclined section and the horizontal section is A3, A3 is in a range of 25 degrees≤A3≤85 degrees.

16. The explosion relief valve of claim 1, wherein, A projection area of the opening part on the aluminum sheet in the first direction is S1, a total projection area of the explosion-proof valve on the aluminum sheet in the first direction is S2, a proportion of the projection area S1 of the opening part in the total projection area S2 of the explosion-proof valve is k, k=S1 / S2, k is in a range of 0.45≤k≤0.

9.

17. The explosion relief valve of claim 1, wherein, The size information of the explosion-proof valve comprises at least one of the following: In the first direction, a distance between an end face of the valve body away from the buffer part and an end face of the welding part away from the buffer part is D1, D1 is in a range of 0≤D1≤0.9C; In the first direction, a distance between an end face of the buffer part away from the valve body and an end face of the welding part away from the valve body is D2, D2 is in a range of 0.2C≤D2≤C. 18.A battery cover plate comprising an aluminum sheet and the explosion-proof valve in any one of claims 1 to 17, the aluminum sheet being provided with a mounting hole, and the explosion-proof valve being arranged in the mounting hole. 19.A battery comprising a shell and the battery cover plate in claim 18, the shell and the battery cover plate being connected.

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