Explosion-proof valve, battery and processing method for explosion-proof valve

Abstract

An explosion-proof valve (1), a battery and a processing method for the explosion-proof valve (1). The explosion-proof valve (1) comprises: an explosion-proof valve body (101), adapted to be provided on a casing of a battery; a thinned region (102), surrounding the explosion-proof valve body (101) in the circumferential direction, the thickness of the thinned region (102) being less than the thickness of the explosion-proof valve body (101); a blasting rib (103), arranged in the thinned region (102), the thickness of the blasting rib (103) being less than the thickness of the thinned region (102), and the blasting rib (103) being adapted to break at a preset pressure value; and a plurality of pits (104), provided at intervals in the thinned region (102) and being spaced apart from the blasting rib (103), so as to reduce the stress of the thinned region (102). When the value of the gas pressure in the battery reaches the preset pressure value, the blasting rib (103) first breaks to form an exhaust channel, thus facilitating discharge of high-pressure gas inside the battery; and the pits (104) in the thinned region (102) can damage crystalline-phase structures on the surface of the thinned region (102), so as to eliminate some stress, thus solving the problem of relatively great stress during the process of forming the explosion-proof valve (1), and preventing structure deformation or breakage.

Description

Explosion-proof valve, battery, and explosion-proof valve processing method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the Patent Office of China on June 28, 2023, with application number 202310783400.3 and invention name “Explosion-proof valve, battery and processing method of explosion-proof valve”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to an explosion-proof valve, a battery, and a processing method for the explosion-proof valve. Background Art

[0004] To ensure battery safety, batteries currently on the market typically feature explosion-proof valves on their casings. These valves open when excessive internal pressure occurs, preventing explosion. A common explosion-proof valve structure involves separately molded valves that are laser-welded to a through-hole in a cover plate, forming a single unit. However, welding a separately molded valve to the cover plate weakens the strength of localized areas of the cover plate, affecting the burst value of the entire battery explosion-proof valve and making it difficult to guarantee battery safety.

[0005] To address these issues, existing technologies utilize integrated explosion-proof valve technology. These valves are integrally molded onto a plain aluminum sheet through a stretching and extrusion process. However, this integral molding process generates significant stress, which can cause structural deformation and even the risk of fracture, compromising the safety of the valve.

[0006] Summary of the Invention

[0007] In view of this, the present application provides an explosion-proof valve, a battery, and a method for processing the explosion-proof valve to solve the problem of high stress during the molding process of the explosion-proof valve.

[0008] In a first aspect, the present application provides an explosion-proof valve, comprising: an explosion-proof valve body, suitable for being arranged on the outer shell of a battery; a thinning area, surrounding the circumference of the explosion-proof valve body, the thickness of the thinning area being less than the thickness of the explosion-proof valve body; a bursting rib, arranged in the thinning area, the thickness of the bursting rib being less than the thickness of the thinning area, the bursting rib being suitable for breaking at a preset pressure value; a plurality of pits, spaced apart from each other in the thinning area and spaced apart from the bursting rib, so as to reduce the stress in the thinning area.

[0009] Beneficial effect: A thinning area is formed in the circumferential direction of the explosion-proof valve body by extruding the shell, and the thickness of the thinning area is less than the thickness of other areas on the shell. The strength of the thinning area is less than the strength of other areas on the shell, so that the thinning area with smaller strength forms the explosion-proof valve explosion area, and the thickness of the bursting ribs arranged in the thinning area is less than the overall thickness of the thinning area. Therefore, the thickness of the solid part corresponding to the bursting rib is the smallest, and the strength at the bursting rib is the smallest. When the gas pressure value in the battery reaches the preset pressure value, the bursting rib is disconnected first, so that the explosion-proof valve body surrounded by the bursting rib can be opened to form an exhaust channel, which is convenient for the discharge of high-pressure gas inside the battery, prevents the battery from exploding, and reduces losses; at the same time, a number of pits arranged at intervals in the thinning area can destroy the crystal phase structure on the surface of the thinning area, thereby eliminating part of the stress, solving the problem of high stress during the formation of the explosion-proof valve, and preventing the risk of deformation or fracture of the structure, thereby improving the safety of the explosion-proof valve.

[0010] In an optional embodiment, the thickness of the thinned area is H1, and the depth of the pit is H2, wherein H2≥1 / 2*H1.

[0011] Beneficial effect: Setting the depth H2 of the pit to be greater than or equal to half the thickness H1 of the thinning area can ensure that the pit is sufficient to destroy the crystal structure inside the material of the thinning area, thereby reducing stress, reducing the processing difficulty of the thinning area, and ensuring the stability of the structure.

[0012] In an optional embodiment, the thickness H1 of the thinned area ranges from 0.2 mm to 0.5 mm.

[0013] Beneficial effect: Setting the thickness H1 of the thinned area to a value of 0.2 mm to 0.5 mm can not only ensure the structural strength of the thinned area, but also ensure the timely opening of the explosion-proof valve and reduce processing costs.

[0014] In an optional embodiment, a plurality of the pits are symmetrically distributed on both sides of the blasting bar;

[0015] And / or, a distance L1 between two adjacent recesses along the circumference of the explosion-proof valve body is 0.2 mm to 1 mm.

[0016] Beneficial effects: By symmetrically arranging a number of pits on both sides of the bursting bar, the number of pits is increased, thereby increasing the stress elimination effect, and the symmetrically distributed layout is simple and beautiful, which is also conducive to increasing the stability of the overall structure and facilitating processing; setting the distance L1 between two adjacent pits between 0.2mm-1mm is not only convenient for processing, but also can ensure the complete release of stress.

[0017] In an optional embodiment, the circumferential surface of the explosion-proof valve body is an inclined surface arranged at an angle to the axis thereof;

[0018] And / or, the width L2 of the thinned area is in the range of 0.5 mm to 5 mm.

[0019] Beneficial effect: The inclined surface is inclined in the direction away from the thinning area, so that the corresponding part of the thinning area is similar to a trumpet-shaped opening outward, which is convenient for processing and forming on the one hand, and on the other hand, it plays a role in controlling the direction of material running during the extrusion processing of the thinning area, so that the extruded material flows toward the side of the oblique edge, thereby preventing material accumulation and achieving the purpose of eliminating stress; the width L2 of the thinning area is set to a value within the range of 0.5mm-5mm, which is convenient for the subsequent processing of blasting ribs and pits and can reduce costs.

[0020] In an optional embodiment, the thinned area further includes a connecting portion, which is connected end to end with the bursting rib and surrounds the explosion-proof valve body. The dimension L3 of the connecting portion along the circumference of the explosion-proof valve body is 2 mm-20 mm.

[0021] Beneficial effect: The strength of the connection part is greater than that of the bursting rib. When the bursting rib breaks when the air pressure in the battery reaches the preset pressure value, the connection part will not break, which can prevent the explosion-proof valve body from exploding and causing secondary damage to the surrounding batteries or other structures, thereby reducing the danger; setting L3 to a value between 2mm and 20mm can not only ensure that the explosion-proof valve body will not pop out as a whole, but also ensure that the explosion-proof valve can be opened in time.

[0022] In an optional embodiment, the explosion-proof valve further comprises: a boss surrounding the circumference of the thinned area, wherein the upper surface of the boss is higher than the upper surface of the explosion-proof valve body and the upper surface of the thinned area.

[0023] Beneficial effect: By arranging a boss circumferentially on one side of the thinned area away from the explosion-proof valve body, the strength of the shell in which the explosion-proof valve is arranged is increased, and the stability of the overall structure is increased.

[0024] In a second aspect, the present application further provides a battery, comprising: a shell having an open end; an electrode group installed in the shell; a cover plate arranged at the open end of the shell to close the shell, and the cover plate is constructed with the above-mentioned explosion-proof valve.

[0025] Beneficial effects: The explosion-proof valve is integrally formed on the cover plate, the product structure is simple, the molding method is simple, and it is easy to process. Compared with the traditional welding method, the integral molding method can improve the strength of the cover plate and reduce the impact on the burst value of the explosion-proof valve caused by the weak strength of the cover plate. In addition, the design of the pit on the explosion-proof valve and the blank area in the middle area and bottom of the explosion-proof valve increase the product feeding space, thereby achieving the purpose of eliminating stress and increasing the reliability of the structure. At the same time, the boss on the explosion-proof valve is higher than the upper surface of the cover plate, which can reduce the risk of residual electrolyte entering the explosion-proof valve during liquid injection and increase the safety of the battery.

[0026] In the third aspect, the present application also provides a method for processing an explosion-proof valve, which is used to process the above-mentioned explosion-proof valve, and the method for processing the explosion-proof valve includes: selecting a first area on the outer shell, and forming the first area upward so that the first area protrudes upward relative to other areas of the outer shell to form a raised area; extruding an annular area downward along the circumference of the raised area to form a thinning area, wherein the annular area is reserved with a first preset distance from the edge of the raised area; processing a number of pits arranged at intervals in the thinning area to destroy the crystal structure inside the material of the thinning area; extruding a groove of a preset width along its circumference in the thinning area to form a bursting rib, and during the extrusion process, excess material flows freely to both sides of the bursting rib.

[0027] Beneficial effect: By executing the above-mentioned method steps, an explosion-proof valve can be processed. Compared with the traditional method that requires stamping, cleaning, annealing, welding and other processes, the explosion-proof valve processing method of this embodiment can form the explosion-proof valve only by stamping, reducing the product molding process and thus reducing costs; and in the explosion-proof valve molding process, not only are pits that destroy the material's crystal phase structure set, but also sufficient material flow space is provided for excess material, which is conducive to eliminating stress, preventing the thinning area from breaking due to excessive stress, and improving the strength and stability of the explosion-proof valve.

[0028] In an optional embodiment, the distance that the raised area moves upward relative to other areas on the housing is H3, wherein the value range of H3 is: 0.3mm-2mm.

[0029] Beneficial effect: Setting the upward movement distance H3 of the raised area relative to other areas on the shell to a value between 0.3mm and 2mm can ensure that there is sufficient space for material flow and that the boss has sufficient strength, thereby increasing the stability of the overall structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] FIG1 is a schematic structural diagram of a cover plate according to an embodiment of the present application;

[0032] FIG2 is a partial enlarged schematic diagram of the explosion-proof valve area of ​​the cover plate shown in FIG1 ;

[0033] FIG3 is a partial enlarged schematic diagram of A in FIG2 ;

[0034] FIG4 is a schematic diagram of the structure of an explosion-proof valve of another shape according to an embodiment of the present application;

[0035] FIG5 is a schematic diagram of the structure of an explosion-proof valve in another shape according to an embodiment of the present application;

[0036] FIG6 is a schematic structural diagram of the cover plate according to an embodiment of the present application after the first step of the explosion-proof valve processing method;

[0037] FIG7 is a schematic structural diagram of the cover plate of FIG6 after undergoing the second step of the explosion-proof valve processing method;

[0038] FIG8 is a partial enlarged schematic diagram of B in FIG7;

[0039] FIG9 is a schematic structural diagram of the cover plate of FIG7 after the third step of the explosion-proof valve processing method;

[0040] FIG10 is a partial enlarged schematic diagram of C in FIG9 ;

[0041] FIG11 is a schematic structural diagram of the cover plate of FIG9 after the fourth step of the explosion-proof valve processing method;

[0042] FIG12 is a partial enlarged schematic diagram of D in FIG11 .

[0043] Explanation of the accompanying reference numerals: 1. explosion-proof valve; 101. explosion-proof valve body; 102. thinning area; 1021. connection part; 103. bursting rib; 104. pit; 105. boss; 201. positive pole; 202. negative pole; 3. liquid injection hole; 4. cover plate; 401. raised area. DETAILED DESCRIPTION

[0044] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present application.

[0045] The following describes an embodiment of the present application with reference to FIG. 1 to FIG. 12 .

[0046] According to an embodiment of the present application, on the one hand, an explosion-proof valve is provided, which mainly includes: an explosion-proof valve body 101, a thinned area 102, a bursting rib 103 and a plurality of pits 104.

[0047] Specifically, the explosion-proof valve body 101 is suitable for being arranged on the outer shell of the battery; the thinned area 102 surrounds the circumference of the explosion-proof valve body 101, and the thickness of the thinned area 102 is less than the thickness of the explosion-proof valve body 101; the thinned area 102 is arranged in the thinned area 102, the thickness of the bursting rib 103 is less than the thickness of the thinned area 102, and the bursting rib 103 is suitable for breaking at a preset pressure value; a plurality of pits 104 are arranged at intervals from each other in the thinned area 102 and at intervals from the bursting rib 103 to reduce the stress in the thinned area 102.

[0048] The explosion-proof valve of this embodiment is applied, and a thinned area 102 is formed in the circumferential direction of the explosion-proof valve body 101 by squeezing the shell. The thickness of the thinned area 102 is less than the thickness of other areas on the shell, and the strength of the thinned area 102 is less than the strength of other areas on the shell. Therefore, the thinned area 102 with smaller strength forms the explosion-proof valve explosion area, and the thickness of the bursting rib 103 provided in the thinned area 102 is less than the thickness of the entire thinned area 102. Therefore, the thickness of the solid part corresponding to the bursting rib 103 is the smallest, and the strength at the bursting rib 103 is the smallest. When the battery is When the gas pressure reaches the preset pressure value, the bursting rib 103 is disconnected first, so that the explosion-proof valve body 101 surrounded by the bursting rib 103 can be opened to form an exhaust channel, which is convenient for the discharge of high-pressure gas inside the battery, prevents the battery from exploding, and reduces losses; at the same time, the pits 104 arranged at intervals in the thinning area 102 can destroy the crystalline structure on the surface of the thinning area 102, thereby eliminating part of the stress, solving the problem of high stress during the molding process of the explosion-proof valve 1, and preventing the risk of deformation or fracture of the structure, thereby improving the safety of the explosion-proof valve 1.

[0049] It should be noted that the explosion-proof valve 1 is applied to the battery. By arranging the explosion-proof valve 1 on the surface of the battery, the explosion-proof valve 1 can be used to discharge the gas inside the battery when the air pressure inside the battery reaches a certain value, thereby preventing the battery from exploding due to excessive internal air pressure. The outer shell of the battery can be the cover plate 4 that constitutes the battery, or it can be the shell of the battery. The thickness refers to the dimension in the direction perpendicular to the surface of the outer shell, specifically the dimension in the "up and down" direction indicated by the arrows in Figures 6 to 12. The thinned area 102 is formed by thinning a part of the outer shell, and can be thinned by extrusion. Optionally, the thinned area 102 is extruded on the cover plate 4, that is, the thinned area 102 is integrally formed with the cover plate 4, which is simple to form and easy to process, and can also improve the strength of the cover plate 4. The thinned area 102 surrounds the circumference of the explosion-proof valve body 101. When the bursting rib 103 in the thinned area 102 breaks, the explosion-proof valve body 101 opens relative to the shell, wherein the thinned area 102 can be a closed ring surrounding the explosion-proof valve body 101, or it can be a part of the ring; the preset pressure value is the bursting value of the explosion-proof valve 1, and when the gas pressure value inside the battery reaches the preset pressure value, the bursting rib 103 breaks; the pit 104 is a small depression smaller than the thinned area 102. The pit 104 is arranged on the upper surface of the thinned area 102, which can eliminate a certain stress on the thinned area 102, wherein the upper surface refers to the surface of the side of the shell facing the outside of the battery, and also refers to the surface in the direction of "up" indicated by the arrow in Figures 6 to 12.

[0050] Specifically, the shape of the pit 104 is not fixed, and can be one or more of the shapes of circle, square, rectangle, trapezoid, etc., with a simple structure and easy processing.

[0051] In one embodiment, the thickness of the thinning region 102 is H1, and the depth of the pit 104 is H2, where H2 ≥ 1 / 2 * H1. Further in conjunction with Figures 7 to 10, the thickness of the thinning region 102 and the depth of the pit 104 refer to their respective dimensions along the "up and down" direction. If the depth of the pit 104 is less than half the thickness of the thinning region 102, the depth of the pit 104 is too small to destroy the crystal structure inside the material of the thinning region 102 and the processing difficulty is greater, affecting the stability of the structure. Therefore, setting the depth H2 of the pit 104 to be greater than or equal to half the thickness H1 of the thinning region 102 can ensure that the pit 104 is sufficient to destroy the crystal structure inside the material of the thinning region 102, thereby reducing stress, reducing the processing difficulty of the thinning region, and ensuring the stability of the structure.

[0052] In one embodiment, the thickness H1 of the thinned region 102 is in the range of 0.2 mm to 0.5 mm. If the thickness H1 of the thinned region 102 is less than 0.2 mm, the thickness of the thinned region 102 is too thin, making it difficult to ensure the structural strength of the thinned region 102, and making processing difficult, thereby increasing processing costs. If the thickness H1 of the thinned region 102 is greater than 0.5 mm, the thickness of the thinned region 102 is too thick, and the strength of the thinned region 102 is correspondingly increased, increasing the gas pressure required for the explosion-proof valve 1 to blast, affecting the timely opening of the explosion-proof valve 1, thereby affecting the safety of the battery. In addition, the excessive thickness of the thinned region 102 increases the difficulty of processing the subsequent blasting rib 103, resulting in increased processing costs. Therefore, setting the thickness H1 of the thinned region 102 to a value of 0.2 mm to 0.5 mm can ensure the structural strength of the thinned region 102, ensure the timely opening of the explosion-proof valve 1, and reduce processing costs. Optionally, the thickness H1 of the thinned region 102 is 0.3 mm.

[0053] In one embodiment, a plurality of dimples 104 are symmetrically distributed on either side of the bursting rib 103. The term "on either side of the bursting rib 103" refers to the width of the bursting rib 103 within the plane of the outer shell surface, i.e., the radial direction of the annular shape formed by the thinned region 102. Specifically, multiple dimples 104 are distributed on both sides of the bursting rib 103. The dimples 104 on the same side of the bursting rib 103 are evenly spaced around the circumference of the explosion-proof valve body 101. In other words, the line connecting the dimples 104 on the same side of the bursting rib 103 forms a concentric ring with the bursting rib 103, resulting in a neat structure and ease of processing. By symmetrically distributing the dimples 104 on either side of the bursting rib 103, the number of dimples 104 is increased, thereby enhancing the stress-relieving effect. Furthermore, the symmetrical layout is simple and aesthetically pleasing, and also enhances the stability of the overall structure and facilitates processing. Specifically, the number of dimples 104 on either side of the bursting rib 103 is equal.

[0054] In one embodiment, the distance L1 between two adjacent dimples 104 along the circumference of the explosion-proof valve body 101 is 0.2 mm to 1 mm. Further referring to FIG3 , the plurality of dimples 104 in the same circle along the circumference of the explosion-proof valve body 101 are evenly spaced. If the distance L1 between two adjacent dimples 104 is less than 0.2 mm, that is, the distance between the two adjacent dimples 104 is too small, the density of the dimples 104 on the thinning area 102 is too high, and the molding process cannot be performed. If the distance L1 between two adjacent dimples 104 is greater than 1 mm, that is, the distance between the two adjacent dimples 104 is too large, the density of the dimples 104 on the thinning area 102 is too low, and the effect of complete stress release cannot be achieved. Therefore, setting the distance L1 between two adjacent dimples 104 between 0.2 mm and 1 mm facilitates processing while ensuring the effect of complete stress release.

[0055] In one embodiment, the circumferential surface of the explosion-proof valve body 101 is an inclined surface arranged at an angle to its axis. Further referring to Figures 7 to 12 , the circumferential surface of the explosion-proof valve body 101 is connected to the thinned region 102. By setting the connecting surface as an inclined surface, and the inclined surface tilting away from the thinned region 102, the corresponding portion of the thinned region 102 is shaped like a trumpet opening outward. This not only facilitates processing and molding, but also serves to control the direction of material flow during the extrusion process of the thinned region 102, causing the extruded material to flow toward the inclined side, thereby preventing material accumulation and achieving the purpose of eliminating stress. Specifically, the upper surface of the thinned area 102 is lower than the upper surface of the explosion-proof valve body 101, and the lower surface of the thinned area 102 is higher than the lower surface of the explosion-proof valve body 101, that is, the upper surface of the thinned area 102 is located relatively below the upper surface of the explosion-proof valve body 101, and the lower surface of the thinned area 102 is located relatively above the lower surface of the explosion-proof valve body 101. The connecting surfaces of the thinned area 102 on both sides along the up and down directions with the explosion-proof valve body 101 are both inclined surfaces, wherein the upper direction refers to the direction of the "upper" indicated by the arrows in Figures 7 to 12, and the lower direction refers to the direction of the "lower" indicated by the arrows in Figures 7 to 12.

[0056] In one embodiment, the width L2 of the thinning region 102 is 0.5 mm to 5 mm. Further referring to FIG12 , the width of the thinning region 102 refers to the size of the thinning region 102 along the radial direction of the ring in which it is located. If the width L2 of the thinning region 102 is less than 0.5 mm, the size of the thinning region 102 is too small, and it is not convenient for the subsequent processing of the bursting ribs 103 and the pits 104, resulting in insufficient strength of the post-process forming punch, affecting normal production. If the width L2 of the thinning region 102 is greater than 5 mm, the size of the thinning region 102 is too large, the pressure required for extrusion molding is relatively large, the processing mold requirements are high, and the cost is high. Therefore, setting the width L2 of the thinning region 102 to a value within the range of 0.5 mm to 5 mm is convenient for the subsequent processing of the bursting ribs 103 and the pits 104, and can reduce costs.

[0057] In one embodiment, the thinned region 102 further includes a connection portion 1021. The connection portion 1021 is connected end to end with the bursting rib 103 and surrounds the explosion-proof valve body 101. The circumferential dimension L3 of the connection portion 1021 along the explosion-proof valve body 101 is 2 mm to 20 mm. Further referring to FIG2 , the connection portion 1021 and the bursting rib 103 are connected end to end to form a closed ring. The connection portion 1021 is the portion of the thinned region 102 where the bursting rib 103 is not provided. Therefore, the strength of the connection portion 1021 is greater than the strength of the bursting rib 103. When the bursting rib 103 breaks when the air pressure in the battery reaches a preset pressure value, the connection portion 1021 will not break, thereby preventing the explosion-proof valve body 101 from exploding and causing secondary damage to the surrounding batteries or other structures, thereby reducing the risk. The circumferential dimension L3 of the connection portion 1021 along the explosion-proof valve body 101 is the dimension L3 of the ring where the thinned region 102 is located where the bursting rib is not provided. If L3 is less than 2mm, the size of the connection part 1021 is too small, and the connection strength cannot be guaranteed. When the bursting rib 103 breaks, the connection part 1021 may also break due to the impact of the high-pressure gas, increasing the risk. If L3 is greater than 20mm, the size of the connection part 1021 is too large, and the size of the bursting rib 103 is too small. When the bursting rib 103 breaks, the explosion-proof valve body 101 cannot be opened, affecting the exhaust effect and increasing the risk of battery explosion. Therefore, setting L3 to a value between 2mm and 20mm can ensure that the explosion-proof valve body 101 will not pop out as a whole and that the explosion-proof valve 1 can be opened in time. Specifically, the size of the connection part 1021 is specifically formulated according to the size of the explosion-proof valve 1.

[0058] In one embodiment, the explosion-proof valve further comprises a boss 105 circumferentially surrounding the thinned region 102. The upper surface of the boss 105 is higher than both the upper surface of the explosion-proof valve body 101 and the upper surface of the thinned region 102. Specifically, the boss 105 is located on the upper surface of the housing, on the side of the thinned region 102 facing away from the explosion-proof valve body 101. The provision of the boss 105 circumferentially on the side of the thinned region 102 facing away from the explosion-proof valve body 101 increases the strength of the housing housing of the explosion-proof valve 1 and enhances the stability of the overall structure.

[0059] According to an embodiment of the present application, on the other hand, a battery is also provided, comprising: a shell, an electrode group, and a cover plate 4. The shell has an open end; the electrode group is installed in the shell; the cover plate 4 is arranged at the open end of the shell to close the shell, and the above-mentioned explosion-proof valve 1 is constructed on the cover plate 4. Specifically, the explosion-proof valve 1 is integrally formed on the cover plate 4, which has a simple product structure and a simple molding method, and is easy to process. In addition, compared with the traditional welding method, the integral molding method can improve the strength of the cover plate 4 and reduce the impact of the weak strength of the cover plate 4 on the explosion value of the explosion-proof valve 1. In addition, the design of the pit 104 on the explosion-proof valve 1 and the blank area in the middle area and bottom of the explosion-proof valve 1 increase the product feeding space, thereby achieving the purpose of eliminating stress and increasing the reliability of the structure. At the same time, the boss 105 on the explosion-proof valve 1 is higher than the upper surface of the cover plate 4, which can reduce the risk of residual electrolyte entering the explosion-proof valve 1 during injection, thereby increasing the safety of the battery.

[0060] Optionally, the cover plate 4 is further provided with a positive electrode column 201 and a negative electrode column 202 spaced apart from each other, the positive electrode column 201 is electrically connected to the positive electrode of the electrode group, and the negative electrode column 202 is electrically connected to the negative electrode of the electrode group.

[0061] Optionally, the cover plate 4 is further provided with a liquid injection hole 3 , which passes through the cover plate 4 so as to inject electrolyte into the battery.

[0062] Optionally, the cover plate 4 is made of imported or domestically produced 3-series aluminum, which has good quality and high strength, and is beneficial to improving the overall safety of the battery.

[0063] In one embodiment, the explosion-proof valve 1 is shaped like a waist as shown in FIG. 1 to FIG. 2 , and the connecting portion 1021 is provided in a local area of ​​the straight portion of the waist, which has a reasonable structure and is easy to process.

[0064] In addition, in other embodiments, the explosion-proof valve 1 may also be circular as shown in FIG. 4 . In this case, the connecting portion 1021 is located in a partial area on the circumference, which is also convenient for processing and the explosion-proof valve 1 is easy to open.

[0065] In addition, in other embodiments, the explosion-proof valve 1 may also be semicircular as shown in FIG. 5 . In this case, the connecting portion 1021 is a diameter portion of the semicircle.

[0066] It's important to note that the traditional method of welding explosion-proof discs to bare aluminum sheets to create explosion-proof valves typically involves the following steps: stamping, cleaning, annealing, and welding. Problems in any of these steps can cause the valve to fail. Furthermore, the numerous steps involved in the production process increase manufacturing costs, further impacting product competitiveness.

[0067] According to an embodiment of the present application, on the other hand, a method for processing an explosion-proof valve is provided. The method for processing the explosion-proof valve is used to process the above-mentioned explosion-proof valve 1. The method for processing the explosion-proof valve specifically includes the following steps:

[0068] Step S101: A first area is selected on the housing, and the first area is molded upward so that the first area protrudes upward relative to other areas of the housing to form a protruding area 401.

[0069] Among them, the outer shell is preferably a cover plate 4, and the first area is the area used to process the explosion-proof valve 1. Further combined with Figure 6, the upward molding of the first area means that the first area forms a convex bulge relative to the body of the cover plate 4 along the "up" direction indicated by the arrow in Figure 6, in order to increase the strength of the cover plate 4 and the material feeding space of the subsequent processing steps.

[0070] Specifically, the raised area 401 is formed by punching the first area, and the punching operation is simple, the technology is mature, and the reliability is high.

[0071] Step S102: Extruding the annular area downward along the circumference of the raised area 401 to form a thinned area 102, wherein a first preset distance is reserved between the annular area and the edge of the raised area 401.

[0072] As shown in Figures 7 and 8, the thinning area 102 is in the shape of a ring, and the outer diameter of the ring is a first preset distance away from the edge of the raised area 401. By downwardly squeezing the annular area close to the edge of the raised area 401, the annular area is thinned to form the thinning area 102; the excess material extruded flows to the middle area of ​​the raised area 401 surrounded by the annular area to reduce the stress of the product. After the thinning area 102 is formed downward, the part of the raised area 401 surrounded by the annular area forms the explosion-proof valve body 101; the area reserved for the first preset distance forms the boss 105, which can increase the strength of the cover plate 4. Here, down refers to the direction of "down" indicated by the arrow in Figures 7 and 8. Specifically, the thinning area 102 is stamped using a stamping die.

[0073] Step S103: machining a plurality of pits 104 spaced apart in the thinned region 102 to destroy the crystal structure inside the material of the thinned region 102.

[0074] 9 and 10 , the depth H2 of the dimples 104 is less than the thickness H1 of the thinned region 102. By forming the dimples 104 in the thinned region 102 to disrupt the crystal structure within the material, stress relief can be achieved. Furthermore, the dimples 104 can be formed by simply stamping with a suitable die head, resulting in a simple, controllable, and efficient molding process. Optionally, two circles of dimples 104 are formed along the width of the thinned region 102, each circle containing a plurality of dimples 104 spaced apart.

[0075] Step S104: Extruding a dent of a preset width in the thinning area 102 along its circumference to form a bursting rib 103, and during the extrusion process, excess material flows freely to both sides of the bursting rib 103.

[0076] The preset width of the indentation is smaller than the width of the thinned region 102, and the indentation does not interfere with the already formed pits 104. Optionally, the indentation is located between two circles of pits 104. The two sides of the bursting rib 103 refer to the two sides along the width direction of the bursting rib 103, specifically the area where the explosion-proof valve body 101 is located and the area on the lower surface of the cover plate 4 away from the explosion-proof valve body 101. The bursting rib 103 is formed by thinning the indentation area. The strength of the bursting rib 103 is lower than that of other parts of the cover plate 4. The bursting rib 103 breaks when the pressure reaches the bursting value, achieving the purpose of bursting the explosion-proof valve 1 at the preset pressure value. During the extrusion molding process of the bursting rib 103, excess material freely flows to the sides of the bursting rib 103, which can reduce the molding pressure of the material. Specifically, the bursting rib 103 is stamped.

[0077] By executing the above-mentioned method steps, an explosion-proof valve 1 can be processed. Compared with the traditional method which requires stamping, cleaning, annealing, welding and other processes, the explosion-proof valve processing method of this embodiment can form the explosion-proof valve 1 only by stamping, which reduces the product molding process and thus reduces the cost. In addition, during the molding process of the explosion-proof valve, not only are pits 104 provided to destroy the crystal structure of the material, but also sufficient space for excess material to move is provided, which is conducive to eliminating stress, preventing the thinned area 102 from breaking due to excessive stress, and improving the strength and stability of the explosion-proof valve 1.

[0078] In one embodiment, the distance that the raised area 401 moves upward relative to other areas on the shell is H3, wherein the value range of H3 is: 0.3mm-2mm. Further in conjunction with FIG6 , the distance H3 is the height by which the first area is squeezed upward in step S101. If H3 is less than 0.3mm, the height by which the first area moves upward is too small. When the thinning area 102, the pit 104, and the bursting rib 103 are subsequently punched, there is insufficient space for the excess material to flow, which is not conducive to stress elimination. If H3 is greater than 2mm, the height by which the first area moves upward is too large, resulting in insufficient step strength and insufficient strength of the boss 105, which is not conducive to improving the strength of the cover plate 4. Therefore, setting the distance H3 by which the raised area 401 moves upward relative to other areas on the shell to a value between 0.3mm and 2mm can ensure both sufficient material flow space and sufficient strength of the boss 105, thereby increasing the stability of the overall structure.

[0079] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. An explosion-proof valve, characterized in that: include: The explosion-proof valve body is suitable for being arranged on the outer shell of the battery; A thinned area surrounding the explosion-proof valve body in a circumferential direction, wherein the thickness of the thinned area is less than the thickness of the explosion-proof valve body; a bursting rib, arranged in the thinned area, the thickness of the bursting rib being less than the thickness of the thinned area, the bursting rib being adapted to break at a preset pressure value; A plurality of pits are arranged in the thinning area at intervals from each other and from the bursting ribs to reduce the stress in the thinning area.

2. The explosion-proof valve according to claim 1, characterized in that: The thickness of the thinned area is H1, and the depth of the pit is H2, wherein H2≥1 / 2*H1.

3. The explosion-proof valve according to claim 2, characterized in that: The thickness H1 of the thinned area ranges from 0.2 mm to 0.5 mm.

4. The explosion-proof valve according to claim 1, characterized in that: A plurality of the pits are symmetrically distributed on both sides of the blasting rib; And / or, a distance L1 between two adjacent pits along the circumference of the explosion-proof valve body is 0.2 mm-1 mm.

5. The explosion-proof valve according to claim 1, characterized in that: The circumferential surface of the explosion-proof valve body is an inclined surface arranged at an angle to the axis thereof; And / or, the width L2 of the thinned area is within a range of 0.5 mm to 5 mm.

6. The explosion-proof valve according to claim 1, characterized in that: The thinned area also includes a connecting portion, which is connected end to end with the bursting rib and surrounds the explosion-proof valve body. The dimension L3 of the connecting portion along the circumferential direction of the explosion-proof valve body is 2mm-20mm.

7. The explosion-proof valve according to any one of claims 1 to 6, characterized in that: The explosion-proof valve further comprises: a boss surrounding the circumference of the thinned area, wherein the upper surface of the boss is higher than the upper surface of the explosion-proof valve body and the upper surface of the thinned area.

8. A battery, characterized in that: include: a housing having an open end; A pole group, mounted in the housing; A cover plate is arranged at the open end of the shell to close the shell, and the explosion-proof valve according to any one of claims 1 to 7 is constructed on the cover plate.

9. A method for processing an explosion-proof valve, characterized in that: The method for processing the explosion-proof valve is used for processing the explosion-proof valve according to any one of claims 1 to 7, and the method for processing the explosion-proof valve comprises: A first area is selected on the housing, and the first area is molded upward so that the first area protrudes upward relative to other areas of the housing to form a protruding area; Extruding the annular area downward along the circumference of the raised area to form a thinned area, wherein a first preset distance is reserved between the annular area and the edge of the raised area; Processing a plurality of pits arranged at intervals in the thinning region to destroy the crystal structure inside the material of the thinning region; A dent of a preset width is extruded in the thinned area along its circumference to form a bursting rib, and during the extrusion process, excess material flows freely to both sides of the bursting rib.

10. The method for processing an explosion-proof valve according to claim 9, characterized in that: The distance that the raised area moves upward relative to other areas on the housing is H3, wherein the value range of H3 is: 0.3mm-2mm.

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