Battery explosion-proof valve manufacturing process, battery cover plate and battery

Abstract

The invention belongs to the technical field of battery manufacturing, and particularly discloses a battery explosion-proof valve manufacturing process, a battery cover plate and a battery. The battery anti-explosion valve manufacturing process comprises the following steps that a metal material plate is selected, a first side face of the metal material plate is punched, a pit is formed in the first side face of the metal material plate, a semi-forming boss protruding out of a second side face is formed in the position, corresponding to the pit, of the second side face of the metal material plate, and therefore a pre-forming material plate is obtained; a first area of the semi-formed boss is punched, so that materials in the first area are transferred towards the radial outer side of the semi-formed boss, a step is formed on the second side face, a thin-wall area is formed in the first area, the formed boss surrounded by the thin-wall area is obtained, and a semi-finished product material plate is obtained; and finally, a nick groove is punched in the thin-wall area of the semi-finished product material plate, and the battery anti-explosion valve is obtained. In the forming process of the battery anti-explosion valve, the thin wall area does not need to be bent and shaped, and the problem that the thin wall is prone to cracking when the anti-explosion valve is machined is fundamentally solved.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and in particular to a battery explosion-proof valve manufacturing process, a battery cover plate, and a battery. Background Technology

[0002] Currently, explosion-proof valves for batteries can be formed by welding thin aluminum sheets or by stamping sheet metal. However, the welding process for explosion-proof valves formed by welding thin aluminum sheets is more demanding, and welding can produce defects such as pinholes and sand holes. Special methods such as helium testing are required to detect these defects, but there is a risk of missed detection, which affects product quality. Explosion-proof valves formed by stamping sheet metal do not require welding and can avoid the defects of the above welding process. However, most explosion-proof valves on the market that are formed by stamping require bending and shaping of the thin wall after stamping. For example, Chinese patent application publication number CN115377574A discloses a process for integrally forming a top cover and an explosion-proof valve. The technical solution is as follows: first, the recess and the convex bulge are stamped and formed, wherein the convex bulge includes the convex bulge wall and the convex bulge bottom. Then, the recess, as well as the convex bulge wall and the convex bulge bottom, are simultaneously shaped and stamped. During stamping, the convex bulge wall (the thin wall after stamping) is bent inward and the convex bulge bottom moves upward to form an explosion-proof valve. However, the convex bulge wall of this explosion-proof valve is prone to cracking when it is bent and shaped inward. Summary of the Invention

[0003] The purpose of this invention is to provide a manufacturing process for a battery explosion-proof valve, a battery cover, and a battery, in order to solve the technical problem in the prior art where the thin-walled structure of the explosion-proof valve needs to be bent and shaped after stamping, and the thin-walled structure is prone to cracking during the bending and shaping process.

[0004] To achieve the above objectives, the first aspect of the present invention provides a manufacturing process for a battery explosion-proof valve, which includes the following steps: A metal sheet is selected and a first side of the metal sheet is stamped to form a recess on the first side of the metal sheet. A semi-formed boss is formed on the second side of the metal sheet by forming the recess, thereby obtaining a preformed sheet; wherein, the radial outer side of the semi-formed boss is unobstructed. A first region located on the outer periphery of the semi-formed boss is stamped, maintaining the contour of the recess, so that the material in the first region is radially outward of the semi-formed boss, thereby forming a step at the second side and forming a thin-walled area in the first region, to obtain a formed boss surrounded by the thin-walled area, thereby obtaining a semi-finished material plate; wherein, the projection of the first region in the thickness direction of the metal material plate at least partially coincides with the bottom of the recess; The battery explosion-proof valve is obtained by stamping grooves in the thin-walled area of ​​the semi-finished material plate.

[0005] In some embodiments, when stamping the first side of the metal sheet, the bottom of the recess is made into a planar structure.

[0006] In some embodiments, while maintaining the contour of the recess, the recess of the preformed material is filled with a fixed mold so that the bottom of the recess maintains its contour.

[0007] In some embodiments, while maintaining the contour of the recess, a stamping die for forming the recess is used as a fixed die to fill the recess.

[0008] In some implementations, the first region is preset to be a ring structure, and the area surrounded by the first region is the second region. When stamping the first region of the semi-formed boss, the outline of the second region is maintained.

[0009] In some embodiments, when the thin-walled area of ​​the semi-finished material plate is stamped with a groove, the thin-walled area on the second side of the semi-finished material plate is stamped with a groove.

[0010] In some embodiments, when stamping grooves into the thin-walled area on the second side of the semi-finished material plate, a stamping die for forming the pit is used as a fixed die to fill the pit.

[0011] In some embodiments, when a groove is stamped in the thin-walled area on the second side of the semi-finished material plate, an annular or ring-shaped groove is stamped in the thin-walled area, and the groove is located in the middle region of the thin-walled area.

[0012] A second aspect of the present invention provides a battery cover plate having an integrally formed explosion-proof valve and a cover plate body. The explosion-proof valve is manufactured using the aforementioned battery explosion-proof valve manufacturing process. The cover plate body has a recess on a first side, and the explosion-proof valve has a formed boss on a second side. The thin-walled region surrounds the outside of the formed boss.

[0013] In some embodiments, the groove is a V-shaped groove.

[0014] In some embodiments, the angle α of the V-shaped included angle of the cross-section of the groove satisfies: 30°≤α≤90°.

[0015] In some embodiments, the outer side of the thin-walled region has a step, and the thin-walled region is connected to the cover plate body by the step.

[0016] In some embodiments, the width of the thin-walled region is W1, where W1 ≥ 0.5 mm.

[0017] In some embodiments, the battery cover is made of aluminum, and the thickness D of the thin-walled area satisfies: 0.2mm≤D≤0.8mm. The etched groove is formed on the thin-walled area on the second side of the semi-finished material plate. The thickness D1 between the etched groove and the bottom surface of the pit satisfies: 0.05mm≤D1≤0.18mm.

[0018] In some implementations, the radial outer side of the step is unobstructed.

[0019] In some embodiments, the relationship between the depth H of the recess and the thickness T of the cover plate body is: 0.75≤H / T≤1.50.

[0020] A third aspect of the present invention provides a battery comprising a housing, a battery cell, and a battery cover as described above; the housing has a receiving cavity for accommodating the battery cell; an opening is provided on one side of the housing, the battery cover seals the opening, and a shaped boss is located on the side of the battery cover facing the battery cell.

[0021] In some embodiments, an insulating element is also included; the insulating element is located between the battery cover and the battery cell, and the insulating element is provided with a receiving groove for accommodating the explosion-proof valve at the position corresponding to the explosion-proof valve, the receiving groove being provided with a hole communicating with the receiving cavity.

[0022] In some embodiments, the aperture is disposed at the bottom of the receiving groove facing the battery cell.

[0023] This invention provides a manufacturing process for a battery explosion-proof valve, a battery cover, and a battery. Its advantages are as follows: During the molding process of the battery explosion-proof valve, the thin-walled area does not need to be bent or shaped, fundamentally solving the problem of cracking of the thin-walled area during processing. Furthermore, since the thin-walled area of ​​the explosion-proof valve does not need to be bent or shaped during molding, creases are reduced in this area, ensuring more uniform stress distribution. This allows for the selection of appropriate locations for grooves to be formed according to different actual application scenarios, accommodating more different types of batteries. Secondly, the explosion-proof valve can be formed in three stamping processes, simplifying the molding steps, thereby reducing the processing time, improving production efficiency, and lowering processing costs. Attached Figure Description

[0024] Figure 1 This is a schematic cross-sectional view of the metal plate in the initial state of the battery explosion-proof valve manufacturing process of the present invention. Figure 2 This is a schematic diagram of the cross-sectional structure of the preformed material plate used in the battery explosion-proof valve manufacturing process of the present invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the semi-formed material plate in the battery explosion-proof valve manufacturing process of the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of the explosion-proof valve formed by the battery explosion-proof valve manufacturing process of the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of the explosion-proof valve when the groove is set in the middle of the thin-walled region according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the cross-sectional structure of the explosion-proof valve when the groove is set at the connection between the thin-walled area and the step according to an embodiment of the present invention; Figure 7 yes Figure 5 Enlarged structural diagram at point A; Figure 8 This is a schematic diagram of the structure of the battery cover plate according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of the battery cover plate with the recess facing upwards according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the battery structure according to an embodiment of the present invention; Figure 11 This is a schematic diagram of the cross-sectional structure of the battery according to an embodiment of the present invention; Figure 12 yes Figure 11 Enlarged structural diagram at point B; Figure 13 This is an exploded structural diagram of the battery according to an embodiment of the present invention; Figure 14 This is a schematic flowchart of the manufacturing process of the battery explosion-proof valve of the present invention; Figure 15 This is a detailed flowchart illustrating the manufacturing process of the battery explosion-proof valve of the present invention.

[0025] In the diagram, 10 is a metal sheet; 11 is a semi-formed boss; 12 is a pre-formed sheet; 13 is an unobstructed area; 14 is the first area; 15 is a semi-finished sheet; 16 is the first side; and 17 is the second side. 100. Housing; 110. Receiving cavity; 120. Opening; 200. Battery cell; 300. Battery cover; 310. Cover body; 311. Recess; 320. Explosion-proof valve; 321. Step; 322. Thin-walled area; 323. Molded boss; 324. Scoring groove; 400. Insulating component; 410. Receiving groove; 420. Hole. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0028] In the description of this invention, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0029] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0030] Please refer to the following: Figures 1 to 14 The manufacturing process of the battery explosion-proof valve provided in the embodiments of the present invention will now be described. For ease of explanation, the X direction in the accompanying drawings is the downward direction, and the Y direction is the opposite direction of the X direction, which is the upward direction. The X direction and the Y direction are different orientations of the metal plate 10 in the thickness direction.

[0031] like Figures 1 to 4 ,as well as Figure 14 As shown, the manufacturing process of the battery explosion-proof valve in this embodiment of the invention includes the following steps: Reference Figure 1 Step one: Select a metal sheet 10 and stamp the first side 16 of the metal sheet 10 to form a recess 311 on the first side 16 of the metal sheet 10. Through the forming of the recess 311, a semi-formed boss 11 is correspondingly formed on the second side 17 of the metal sheet 10, thereby obtaining a preformed sheet 12. The preformed sheet 12 is as follows: Figure 2 As shown; wherein, the radially outer side of the semi-formed boss 11 is such that the radially outer side of the semi-formed boss 11 has an unobstructed area 13; refer to Figure 2 The metal plate 10 is placed on the fixed mold, and the stamping mold presses the metal plate 10 downward to form the corresponding recess 311 and semi-formed boss 11. Reference Figure 2Step two, another stamping die stamps the first region 14 of the semi-formed boss 11 along the Y direction, maintaining the contour of the recess 311, causing the material in the first region 14 to transfer radially outward towards the semi-formed boss 11, thereby forming a step 321 at the second side 17 and a thin-walled region 322 in the first region 14, obtaining a formed boss 323 surrounded by the thin-walled region 322, thus obtaining a semi-finished material plate 15, the semi-finished material plate 15 as shown in the figure. Figure 3 As shown; wherein, the first region 14 is located on the outer periphery of the forming boss 323, and the projection of the first region 14 in the thickness direction of the metal plate 10 at least partially coincides with the bottom of the recess 311, so as to ensure that the thin-walled region 322 is located at the bottom of the recess 311, and to ensure that the thin-walled region 322 has sufficient space. Reference Figure 3 Step three, a groove 324 is punched into the thin-walled area 322 of the semi-finished material plate 15 to obtain the battery explosion-proof valve. The battery explosion-proof valve is as follows: Figure 4 As shown.

[0032] Reference Figure 2 The first side 16 is the upper side of the metal plate 10, and the second side 17 is the lower side of the metal plate 10. The metal plate 10 is a flat plate structure or at least a flat plate in the area where the battery explosion-proof valve is processed. In this way, the semi-formed boss 11 protrudes from the lower side of the metal plate 10, so that the radial outer side of the semi-formed boss 11 is unobstructed. (Refer to...) Figure 5 The relationship between the depth H (mm) of the recess 311 and the thickness T (mm) of the metal plate 10 is: 0.75 ≤ H / T ≤ 1.50. For example, the ratio of H / T can be 0.78, 0.85, 0.95, 1, 1.1, 1.25, 1.3, 1.47, or any value from 0.75 to 1.50. When the ratio of H / T is 1, that is, the depth H (mm) of the recess 311 is the same as the thickness T (mm) of the metal plate 10. For example, the thickness of the metal plate 10 can be set to 1mm, and the depth of the recess is also 1mm.

[0033] Understandably, when H / T is less than 0.75, the depth of the recess 311 is insufficient. When the first region 14 is stamped in step two, the stamping die is prone to impacting other regions of the metal sheet 10, causing deformation of the metal sheet 10. At the same time, the thin-walled region 322 is difficult to achieve the target thickness. When H / T is greater than 1.50, the depth of the recess 311 is too large, which can easily tear the first region of the metal sheet 10 during the stamping of the recess 311, and cause the height of the semi-formed boss 11 to be too large, excessively occupying the space below the metal sheet 10.

[0034] Reference Figure 2 and Figure 3When the first region 14 of the semi-formed boss 11 is stamped, since the radial outer side of the semi-formed boss 11 is an unobstructed area 13, the material in the first region 14 of the semi-formed boss 11 can be transferred towards the unobstructed area 13 without any obstruction. This allows the metal material in the first region 14 to be pushed outward more effectively, thereby reducing the material in the first region 14. Consequently, the thickness between the first region 14 and the bottom surface of the recess 311 can be reduced, facilitating the formation of the thin-walled region 322 and preparing for the fabrication of the scoring groove 324. After the scoring groove 324 is stamped in the thin-walled region 322, the battery explosion-proof valve can be formed.

[0035] Therefore, during the molding process of the battery explosion-proof valve, the thin-walled region 322 does not need to be bent and shaped, fundamentally solving the problem of easy cracking of the thin wall during the processing of the explosion-proof valve 320, and improving the stability of the stamping of the explosion-proof valve 320. Secondly, since the thin-walled region 322 of the explosion-proof valve does not need to be bent and shaped during the molding process in step two, creases are reduced in the thin-walled region 322, which can reduce the stress concentration area on the thin-walled region 322. This ensures that the stress in the thin-walled region 322 of the explosion-proof valve 320 is more uniform, preventing stress concentration in the thin-walled region 322 from causing problems. This prevents the explosion-proof valve 320 from becoming ineffective or damaged, thus improving the reliability of the explosion-proof valve 320. Furthermore, when stamping the first region 14 of the semi-formed boss 11, since the radial outer side of the semi-formed boss 11 is an unobstructed region 13, the material in the first region 14 of the semi-formed boss 11 can be transferred towards the unobstructed region 13 without any other obstruction, avoiding the resistance generated by the metal material during the transfer, so as to better push the metal material in the first region 14 to the outside, thereby reducing the material in the first region 14 and better reducing the thickness of the thin-walled region 322.

[0036] In existing technologies for thinning explosion-proof valves by stamping, most methods rely on stamping and stretching to thin the material plate. For example, Chinese patent application CN115377574A uses a method of stamping a recess into the material plate to form a convex bulge and then thinning the sides of the recess (the bulge wall). However, in order to thin the thickness of the sides of the recess, the recess becomes quite deep. Therefore, the recess, the bulge wall, and the bottom of the bulge need to be stamped and shaped simultaneously to ensure the thickness of the entire explosion-proof valve. As a result, creases will inevitably be generated at the bulge wall, which can easily lead to the bulge wall cracking during processing. In this embodiment, during the molding process of the battery explosion-proof valve, the thin-walled area 322 does not need to be bent and shaped, which fundamentally solves the problem that the thin wall of the explosion-proof valve 320 is prone to cracking during processing, and improves the stability of the stamping of the explosion-proof valve 320. Secondly, since the thin-walled area 322 of the explosion-proof valve does not need to be bent and shaped during the molding process in step two, creases are reduced in the thin-walled area 322, which can reduce the stress concentration area on the thin-walled area 322. This can ensure that the stress in the thin-walled area 322 of the explosion-proof valve 320 is more uniform, and prevent the explosion-proof valve 320 from being ineffectively damaged due to stress concentration in the thin-walled area 322, thereby improving the reliability of the explosion-proof valve 320. In this embodiment, when stamping the first region 14 of the semi-formed boss 11, the radial outer side of the semi-formed boss 11 is an unobstructed region 13. The material in the first region 14 of the semi-formed boss 11 can be transferred towards the unobstructed region 13 without any other obstruction, avoiding the resistance generated by the metal material during the transfer. This allows the metal material in the first region 14 to be pushed outward more effectively, thereby reducing the material in the first region 14 and reducing the thickness of the thin-walled region 322. The thickness of the thin-walled region 322 can then be stamped even smaller, allowing for better processing of the battery explosion-proof valve.

[0037] The groove 324 can be formed on the upper or lower side of the thin-walled region 322, and its position can be arranged according to the actual needs of the battery. The thinnest part of the thin-walled region 322 is located at the groove 324, therefore the structural strength at the groove 324 is the lowest. Compared with other parts of the thin-walled region 322, the groove 324 is more easily burst by the gas inside the battery. When the gas pressure inside the battery rises to a sufficiently high level, it can burst the groove 324 to allow the gas to leak out, thus achieving the purpose of the battery explosion-proof valve 320 in preventing the battery from exploding.

[0038] In some embodiments, refer to Figures 2 to 4In the case of stamping the first side 16 of the metal sheet 10, the bottom of the recess 311 is made into a planar structure. That is, the bottom surface of the recess 311 is flat. Therefore, when stamping the first area 14 of the semi-formed boss 11, the contour of the bottom surface of the recess 311 is maintained, so that the bottom surface of the recess 311 can be the force-bearing surface to better support the entire metal sheet 10. The stamping head of the stamping equipment only stamps and deforms the first area 14 of the semi-formed boss, so as to push the metal material outward to the unobstructed area 13 and form a corresponding step 321. This makes the thickness of the entire thin-walled area 322 formed by stamping more uniform and avoids the failure of the battery explosion-proof valve 320 due to stress concentration. In addition, the contour of the bottom surface of the recess 311 can also be a concave curved surface or other shapes.

[0039] In some embodiments, while maintaining the contour of the recess 311, a fixed mold is used to fill the recess 311 of the preformed plate 12, so that the bottom of the recess 311 maintains its contour. The fixed mold can provide stable support for the recess 311 and the preformed plate 12, so as to better maintain the contour of the preformed plate 12 and avoid other deformations of the preformed plate 12 during the stamping process, which would cause the entire preformed plate 12 to become a scrap. Moreover, using a fixed mold to fill the recess 311 allows the fixed mold to stably support the first region 14. Therefore, when stamping the first region 14 of the semi-formed boss 11, the metal material can be better moved to the outer unobstructed region 13, so as to better form the corresponding thin-walled region 322 on the plate, which facilitates the processing of the explosion-proof valve 320.

[0040] In some embodiments, to better maintain the shape of the recess 311 and make the processing more continuous, while maintaining the contour of the recess 311, a stamping die for forming the recess 311 is used as a fixed die to fill the recess 311. That is, after the recess 311 is stamped, the stamping die is not withdrawn but remains in place, and the position of the stamping die is fixed, so that the stamping die acts as a fixed die to fill the recess 311, so as to better maintain the shape of the recess 311, support the bottom surface of the recess 311, facilitate the stamping of the first region 14 of the semi-formed boss 11, and ensure that the material of the first region 14 of the semi-finished boss can be transferred to the unobstructed region 13 to form a thin-walled region 322, thereby achieving the purpose of thinning the material sheet. The advantage of using a stamping die for forming the recess 311 is that it reduces the number of die replacement steps, thereby reducing the processing steps of the explosion-proof valve, facilitating processing, and improving processing efficiency.

[0041] It is understandable that if the stamping die for the recess 311 is not used as a fixed die to fill the recess 311, other fixed dies with similar shapes can be used to fill the recess 311 to maintain the shape of the recess 311 and provide sufficient support for the first area 14 of the stamping semi-finished product boss, so as to ensure the formation of the thin-walled area 322.

[0042] In some embodiments, refer to Figure 8 and Figure 9 The first region 14 is pre-designed as a ring structure, and the area surrounding the first region 14 is designated as the second region. During the stamping of the first region 14 of the semi-formed boss 11, the outline of the second region is maintained. That is, during the stamping process of the thin-walled region 322, the ring-shaped first region 14 is directly stamped, so that the stamped thin-walled region 322 is also ring-shaped; the corresponding second region maintains its outline to form the formed boss 323 surrounded by the thin-walled region 322.

[0043] It is understandable that stamping only the first region 14 of the semi-formed boss 11 can reduce the area of ​​material that is compressed and thinned, making the forming of the thin-walled region 322 simpler. Moreover, the first region 14 is located on the outer periphery of the second region, and the radial outer side of the first region 14 is the unobstructed region 13. When the first region 14 is stamped, due to maintaining the contour of the second region, the resistance to the material moving to the second region is greater, so the material will not move to the second region, but will be transferred to the unobstructed region 13 with less resistance. This allows the material to be transferred to the unobstructed region 13 more effectively, so that the material can gradually move outward, thereby reducing the thickness of the thin-walled region 322 and forming a thinner thin-walled region 322.

[0044] In this embodiment, the material of the metal plate 10 is primary aluminum, which belongs to the pure aluminum series. Its aluminum content is usually above 99.00%, without the addition of other alloying elements (such as copper, magnesium or silicon). It has better plasticity, so it is easier to perform cold working such as stamping, stretching and bending during the production process.

[0045] When the process of this embodiment is used to stamp the aluminum sheet 10, refer to... Figure 7The thickness D (mm) of the thin-walled region 322 satisfies the condition: 0.2mm ≤ Dmm ≤ 0.8mm. This satisfies the specifications of most explosion-proof valves 320 for production purposes. When the thickness of the thin-walled region 322 is less than 0.2mm, stamping the notched groove 324 in the thin-walled region 322 can easily cause it to crack, rendering the entire sheet scrap. When the thickness of the thin-walled region 322 is greater than 0.8mm, processing the notched groove 324 becomes more difficult, making it hard to control the minimum thickness of the thin-walled region 322 after stamping the notched groove 324 within the desired range. For example, the thickness D of the thin-walled region 322 can be 0.2, 0.5, 0.8, or any value between 0.2 and 0.8.

[0046] In addition, the material of the metal plate 10 can also be other materials such as aluminum alloy.

[0047] In some embodiments, refer to Figures 4 to 7 In the case where the thin-walled area 322 of the semi-finished material plate 15 is stamped with a groove 324, the groove 324 is also stamped on the second side surface 17 of the semi-finished material plate 15. Stamping the groove 324 on the thin-walled area 322 of the second side surface 17 of the semi-finished material plate 15 is easier to achieve and provides better forming stability because the back surface of the thin-walled area 322 is the bottom surface of the recess 311, which is a plane. Therefore, when stamping the groove 324 on the thin-walled area 322 of the second side surface 17 of the semi-finished material plate 15, the mold can better support the thin-walled area, making the stamping support more stable. Alternatively, the groove 324 can also be stamped on the thin-walled area 322 of the first side surface 16 of the semi-finished material plate 15; the location of the groove 324 can be selected according to the actual situation of the battery.

[0048] It is understandable that when the second side 17 of the thin-walled region 322 is stamped with a groove 324, the bottom surface of the pit 311 may have a stamped mark corresponding to the groove 324, so as to form a small annular protrusion on the bottom surface of the pit 311.

[0049] Among them, such as Figure 5 As shown, the groove 324 is generally located in the middle of the thin-walled area 322 to reduce the stress during processing, prevent the thin-walled area 322 from breaking during the stamping process or subsequent use, and ensure the forming and stability of the explosion-proof valve 320.

[0050] In some embodiments, such as Figure 4 As shown, the groove 324 is formed at the edge of the thin-walled area 322 near the forming boss 323. When the groove 324 is stamped, the material in the thin-walled area 322 can move towards the forming boss 323 to reduce burrs.

[0051] In some embodiments, when stamping grooves 324 into the thin-walled area 322 on the second side surface 17 of the semi-finished material plate 15, a stamping die for forming the recess 311 is used as a fixed die to fill the recess 311. After the recess 311 is stamped, the stamping die is not withdrawn but remains in place, and the position of the stamping die is fixed so that the stamping die acts as a fixed die to fill the recess 311, thereby better maintaining the shape of the recess 311 and supporting the bottom surface of the recess 311, which facilitates the stamping of grooves 324 into the thin-walled area 322 on the second side surface 17 of the semi-finished material plate 15.

[0052] Reference Figures 1 to 4 as well as Figure 15 In the stamping process of the metal sheet 10, the following steps can also be followed: Step 1: Select a metal sheet 10 and use a stamping die to stamp the first side 16 of the metal sheet 10 to form a recess 311 on the first side 16 of the metal sheet 10. Through the forming of the recess 311, a semi-formed boss 11 is formed on the second side 17 of the metal sheet 10, thereby obtaining a pre-formed sheet 12. The radial outer side of the semi-formed boss 11 is unobstructed. At this time, the die for stamping the recess 311 stays in the recess 311 and fills the recess 311 to maintain the outline of the recess 311. The lower side of the stamping die is flat, so that the bottom surface of the stamped recess 311 is flat. Step 2: The first region 14 located on the outer periphery of the semi-formed boss 11 is punched from bottom to top, and the contour of the recess 311 is maintained by a die for punching the recess 311, so that the material in the first region 14 is transferred to the radially outer side of the semi-formed boss 11, thereby forming a step 321 at the second side 17 and forming a thin-walled area 322 in the first region 14, obtaining a formed boss 323 surrounded by the thin-walled area 322, thereby obtaining a semi-finished material plate 15; wherein, the projection of the first region 14 in the thickness direction of the metal material plate 10 at least partially coincides with the bottom of the recess 311; Step 3: Continue to maintain the outline of the recess 311 by keeping the mold of the stamping recess 311 in place, and then stamp the thin-walled area 322 on the second side 17 of the semi-finished material plate 15 with a groove 324 to obtain the battery explosion-proof valve 320.

[0053] This embodiment also provides a battery cover 300, which is suitable for square batteries, cylindrical batteries, lithium batteries, etc.; see reference Figures 4 to 9The battery cover 300 has an integrally formed explosion-proof valve 320 and a cover body 310. The explosion-proof valve 320 is manufactured using the battery explosion-proof valve manufacturing process described above. The cover body 310 has a recess 311 on the first side 16. The explosion-proof valve 320 has a formed boss 323 on the second side 17. The thin-walled area 322 surrounds the outside of the formed boss 323.

[0054] The explosion-proof valve 320 is integrally formed with the cover plate body 310. That is, the metal plate 10 can be the blank of the battery cover plate 300. The blank of the battery cover plate 300 is formed by the above-mentioned battery explosion-proof valve manufacturing process. The structure of other areas on the metal plate 10 forms the corresponding cover plate body 310 after processing. The thickness of the formed cover plate body 310 is equal to the thickness of the original metal plate 10. The formed cover plate body 310 has a pit 311 on the first side 16, and a forming boss 323 on the second side 17 of the explosion-proof valve 320. The thin-walled area 322 is formed on the outside of the forming boss 323, and the scoring groove 324 is set on the thin-walled area 322.

[0055] Reference Figure 5 The relationship between the depth H (mm) of the recess 311 and the thickness T (mm) of the cover plate body 310 is 0.75≤H / T≤1.50. After the metal plate 10 is processed and formed, the corresponding cover plate body 310 is formed. In this way, while ensuring the forming of the thin-walled area 322, the thickness of the explosion-proof valve 320 protruding from the cover plate body 310 can be reduced as much as possible, so as to reduce the overall height of the battery cover plate 300, so that the explosion-proof valve 320 extends into the battery receiving cavity 110 to a smaller depth, so that the space inside the receiving cavity 110 is larger, and the energy density of the battery is improved. For example, the H / T ratio can be 0.78, 0.85, 0.95, 1, 1.1, 1.25, 1.3, 1.47, or any value from 0.75 to 1.50. When the H / T ratio is 1, the depth H (mm) of the recess 311 is the same as the thickness T (mm) of the cover plate body 310 (metal plate 10). For example, the thickness of the cover plate body 310 (metal plate 10) can be set to 1mm, and the depth of the recess is also 1mm.

[0056] Therefore, during the molding process of the battery explosion-proof valve 320, the thin-walled area 322 does not need to be bent and shaped, which solves the problem of the thin wall of the explosion-proof valve 320 being prone to cracking during processing from the root. Furthermore, since the thin-walled area 322 of the explosion-proof valve does not need to be bent and shaped during the molding process in step two, creases are reduced in the thin-walled area 322, which can ensure that the stress in the thin-walled area 322 of the explosion-proof valve 320 is more uniform. Therefore, the grooves 324 can be opened at the appropriate positions according to different actual use scenarios to adapt to more different types of batteries. Moreover, the explosion-proof valve 320 can be formed in three stamping processes, which simplifies the forming steps, thereby reducing the time required for processing, improving production efficiency, and reducing processing costs.

[0057] In some embodiments, refer to Figure 7 The notched groove 324 is a V-shaped groove. That is, the cross-section of the notched groove 324 is V-shaped. A V-shaped stamping head can be used to stamp the thin-walled surface, resulting in a V-shaped cross-section for the processed notched groove 324. V-shaped grooves are easier to form and easier to feed material. Furthermore, since the thin-walled area 322 corresponding to the notched groove 324 is a weak point, the location of gas depressurization and explosion-proof valve 320 rupture can be predicted, allowing control over the rupture location of the explosion-proof valve 320, thereby controlling the location of gas discharge from the battery and preventing secondary disasters. To avoid stress concentration, a rounded transition is provided at the V-shaped groove.

[0058] Understandably, referring to Figure 7 The V-angle α of the cross-section of the notched groove 324 satisfies the following condition: 30° ≤ α ≤ 90°. A smaller V-angle makes it easier for the stamping head to press and form the thin-walled area 322, but the stamping head strength will be lower. When the V-angle is less than 30°, the stamping head life is too short, resulting in excessive wear and tear and increased production costs. When the V-angle exceeds 90°, stamping and feeding becomes difficult, making it hard to form the V-groove. For example, the angle α can be 50°, 60°, 70°, or any value between 30° and 90°.

[0059] In addition, the shape of the groove 324 can be trapezoidal, U-shaped, or other common groove shapes.

[0060] In some embodiments, the thin-walled region 322 has a step 321 on its outer side, and the thin-walled region 322 is connected to the cover plate body 310 via the step 321. The step 321 is a region formed during the processing of the thin-walled region 322. The connection between the thin-walled region 322 and the cover plate body 310 via the step 321 can increase the connection strength between the cover plate body 310 and the thin-walled region 322, prevent the connection edge between the thin-walled region 322 and the cover plate body 310 from breaking or cracking, and enhance the reliability of the explosion-proof valve 320.

[0061] In some embodiments, refer to Figure 5To facilitate the creation of the notched groove 324, the width of the thin-walled region 322 is W1 (mm), satisfying: 0.5mm ≤ W1mm ≤ 3mm. This allows the stamping die to easily extend to the thin-walled region 322 for stamping, enabling the notched groove 324 to be machined on the thin-walled region 322. This ensures that the projection of the notched groove 324 in the thickness direction of the metal plate 10 coincides with the bottom projection of the pit 311, guaranteeing that when the thin-walled region 322 breaks at the notched groove 324, the space inside the battery's receiving cavity 110 remains connected to the outside, allowing the gas inside the battery to be released. When the width of the thin-walled region 322 is less than 0.5 mm, it is difficult for the stamping die to align with the thin-walled region 322 for stamping, making it difficult to form the notched groove 324 on the thin-walled region 322. Furthermore, the formed notched groove 324 may be too close to the edge of the thin-walled region 322, easily causing the thin-walled region 322 to break. When the width of the thin-walled region 322 is greater than 3 mm, it is difficult to push the material to both sides, which greatly increases the processing difficulty and processing cost. For example, the width W1 of the thin-walled region 322 can be 0.5, 1.1, 1.7, 2.3, 2.5, or any value from 0.5 to 3.

[0062] In some embodiments, the battery cover 300 is made of primary aluminum, which belongs to the pure aluminum series. Its aluminum content is typically above 99.00%, without the addition of other alloying elements (such as copper, magnesium, or silicon). It has better plasticity, making it easier to perform cold working processes such as stamping, stretching, and bending during production. (Refer to...) Figure 7 The thickness D (mm) of the thin-walled region 322 satisfies: 0.2mm ≤ Dmm ≤ 0.8mm; the thin-walled region 322 is annular, as shown in the reference. Figure 6 The area surrounding the formed boss 323 is a thin-walled region 322. It can be understood that the thickness D here refers to the thickness of the thin-walled region 322 surrounding the formed boss 323. When the thickness of the thin-walled region 322 meets the above range, it facilitates forming while effectively ensuring the structural strength of the explosion-proof valve 320 of the battery cover 300. This allows the explosion-proof valve 320 of the battery cover 300 to effectively withstand normal external forces during battery production and transportation, preventing accidental damage and loss of explosion-proof function. When the thickness of the thin-walled region 322 is less than 0.2 mm, stamping the notched groove 324 in the thin-walled region 322 can easily cause it to crack, rendering the entire material scrap. When the thickness of the thin-walled region 322 is greater than 0.8 mm, processing the notched groove 324 becomes more difficult, making it hard to control the minimum thickness of the thin-walled region 322 after stamping the notched groove 324 within the desired range. For example, the thickness D of the thin-walled region 322 can be 0.2, 0.5, 0.8, or any value from 0.2 to 0.8.

[0063] Among them, reference Figure 8 and Figure 9The notched groove 324 is formed on the thin-walled area 322 on the second side surface 17 of the semi-finished material plate 15. It is easier to stamp the notched groove 324 on the thin-walled area 322 on the second side surface 17 of the semi-finished material plate 15, resulting in better forming stability. This is because the back surface of the thin-walled area 322 is the bottom surface of the recess 311, and the bottom surface of the recess 311 is a plane. Therefore, when stamping the notched groove 324 on the thin-walled area 322 on the second side surface 17 of the semi-finished material plate 15, the mold can better support the thin-walled area, making the stamping support more stable. It is understood that, referring to... Figure 7 The thickness D1 (mm) between the bottom surface of the groove 324 and the pit 311 satisfies: 0.05mm ≤ D1mm ≤ 0.18mm. The range of thickness D1 can be determined according to the battery's chemical system, rated capacity, shell material strength, and the area enclosed by the groove 324. This embodiment provides a commonly used thickness selection, the ultimate goal of which is: to ensure stable sealing during daily use and prevent accidental opening; and to ensure precise rupture and rapid pressure relief before the internal pressure reaches the "danger threshold and the shell's bearing limit" in the event of battery failure. When the thickness D1 is less than 0.05mm, the explosion-proof valve is prone to rupture during processing and transportation, easily leading to scrap and affecting battery use. When the thickness D1 is greater than 0.18mm, the opening pressure threshold of the explosion-proof valve is high, making it difficult to meet design requirements. The opening pressure is too high, making it difficult to open in time when the battery fails, thus compromising safety. For example, the thickness D1 between the bottom surface of the groove 324 and the pit 311 can be 0.05, 0.1, 0.15, 0.18, or any value from 0.05 to 0.18.

[0064] Of course, the thin-walled area 322 on the first side 16 of the semi-finished material plate 15 can also be punched with a groove 324. The position of the groove 324 can be selected according to the actual situation of the battery.

[0065] Among them, such as Figure 5 As shown, the groove 324 is generally located in the middle of the thin-walled area 322 in order to reduce the stress during processing, prevent the thin-walled area 322 from breaking during the stamping of the groove, and ensure the formation of the explosion-proof valve 320.

[0066] In some embodiments, such as Figure 4 As shown, the groove 324 is formed at the edge of the thin-walled area 322 near the forming boss 323. When the groove 324 is stamped, the material in the thin-walled area 322 can move towards the forming boss 323 to reduce burrs.

[0067] In some embodiments, the radial outer side of the step 321 is unobstructed. During the stamping process of the explosion-proof valve 320, the material on both sides of the forming boss 323 will be transferred outward to form the step 321; therefore, the radial outer side of the step 321 is also unobstructed, which not only saves space, but also allows the material to move outward better, so as to better flatten the material, reduce the thickness of the step 321 protruding from the cover plate body 310, and also allows the outwardly moved material to fill the connection between the thin-walled area 322 and the cover plate body 310, improve the connection strength between the thin-walled area 322 and the cover plate body 310, so that the explosion-proof valve 320 of the battery cover plate 300 can more effectively withstand the conventional external forces during battery production and transportation.

[0068] Reference Figures 10 to 13 This embodiment also provides a battery, which includes a housing 100, a battery cell 200 and a battery cover plate 300 as described above; the housing 100 has a receiving cavity 110 for accommodating the battery cell 200; an opening 120 is provided on one side of the housing 100, the battery cover plate 300 covers the opening 120, and the molded boss 323 is located on the side facing the battery cell 200.

[0069] The thin-walled area 322 of the battery cover 300 is located on the side of the battery cover 300 facing the cell 200, so that the thin-walled area 322 is closer to the cell 200 and the receiving cavity 110. Moreover, the inward concavity of the thin-walled area 322 also protects the explosion-proof valve. If the thin-walled area 322 protrudes outward, the explosion-proof valve is more likely to be bumped and damaged, which may lead to failure.

[0070] The battery cover 300 uses an integrated explosion-proof valve 320. The explosion-proof valve 320 of the battery cover 300 can be manufactured with only three stampings, which simplifies the molding process of the battery cover 300, thereby reducing the time required for processing, improving production efficiency, and reducing processing costs. Furthermore, during the molding process of the battery explosion-proof valve 320, the thin-walled area 322 does not need to be bent and shaped, which fundamentally solves the problem of cracking of the thin wall during the processing of the explosion-proof valve 320, ensuring the molding quality of the battery cover 300 and reducing the defect rate.

[0071] In some embodiments, refer to Figures 11 to 13The battery also includes an insulating component 400. The insulating component 400 is located between the battery cover plate 300 and the battery cell 200. The insulating component 400 has a receiving groove 410 corresponding to the position of the explosion-proof valve 320 for accommodating the explosion-proof valve 320. The receiving groove 410 has an opening 420 communicating with the receiving cavity 110. The insulating component 400 provides insulation protection, isolating the battery cell 200 from the battery cover plate 300, effectively blocking the current path between the battery cell 200 and the cover plate, thus achieving insulation. It also provides a buffer for the battery cell 200, reducing damage during transportation and use. The receiving groove 410 of the insulating component 400 accommodates the explosion-proof valve 320, effectively ensuring that the explosion-proof valve 320 does not contact the battery cell 200, thus providing insulation and protection. The receiving tank 410 is connected to the receiving cavity 110 through the hole 420 to ensure that the gas generated inside the battery can enter the receiving tank 410 through the hole 420, so as to open the explosion-proof valve 320 and allow the gas to be transported to the outside of the battery through the hole 420 and the explosion-proof valve 320, thereby achieving the purpose of pressure relief and explosion prevention.

[0072] In some embodiments, refer to Figure 12 and Figure 13 The pore 420 is located at the bottom of the receiving groove 410 facing the cell 200, which makes the gas pressure relief channel smoother, greatly reduces the gas residence time inside, allows the explosion-proof valve 320 to reach the opening threshold more quickly, avoids the pressure from continuously rising during the diffusion process, and further reduces the risk of battery explosion and combustion.

[0073] In addition, the pore 420 can also be provided on the periphery of the receiving groove 410, or in other locations.

[0074] In summary, the explosion-proof valve 320 manufactured by the battery explosion-proof valve manufacturing process of this embodiment, the battery cover plate 300 having the explosion-proof valve 320, and the battery having the explosion-proof valve 320 have at least the following beneficial effects: (1) During the molding process of the battery explosion-proof valve 320, the thin-walled area 322 does not need to be bent and shaped, which solves the problem of the thin wall of the explosion-proof valve 320 being prone to cracking during processing from the root. Furthermore, since the thin-walled area 322 of the explosion-proof valve does not need to be bent and shaped during the molding process of the semi-finished material plate, the creases in the thin-walled area 322 are reduced, which can ensure that the stress in the thin-walled area 322 of the explosion-proof valve 320 is more uniform. Therefore, the groove 324 can be opened at the appropriate position according to different actual use scenarios to adapt to more different types of batteries. (2) The explosion-proof valve 320 can be formed in three stamping processes. The forming steps are simple, thereby reducing the time required for processing, improving production efficiency and reducing processing costs.

[0075] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and substitutions without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A process for manufacturing a battery explosion relief valve, characterized by, The method comprises the following steps, selecting a metal plate, and stamping a first side of the metal plate to form a pit at the first side of the metal plate, and correspondingly forming a semi-formed boss at a second side of the metal plate via the forming of the pit, thereby obtaining a pre-formed plate; wherein the outer side of the semi-formed boss is not shielded; stamping a first area located at the periphery of the semi-formed boss and maintaining the profile of the pit, so that the material of the first area is transferred to the outer side of the semi-formed boss, thereby forming a step at the second side and forming a thin-wall area in the first area, obtaining a formed boss surrounded by the thin-wall area, thereby obtaining a semi-finished plate; wherein the projection of the first area in the thickness direction of the metal plate at least partially coincides with the bottom of the pit; stamping a score groove in the thin-wall area of the semi-finished plate to obtain a battery explosion-proof valve.

2. The battery explosion-proof valve manufacturing process according to claim 1, wherein in the case of stamping the first side of the metal plate, the bottom of the pit is formed as a flat structure.

3. The battery explosion-proof valve manufacturing process according to claim 1, wherein in the case of maintaining the profile of the pit, a fixed die is used to fill the pit of the pre-formed plate, so that the bottom of the pit maintains the profile.

4. The battery explosion vent valve manufacturing process of claim 3, wherein, in the case of maintaining the profile of the pit, the stamping die used to form the pit is used as the fixed die to fill the pit.

5. The battery explosion-proof valve manufacturing process according to claim 1, wherein the first area is in a ring structure, and the area surrounded by the first area is a second area, and in the case of stamping the first area of the semi-formed boss, the profile of the second area is maintained.

6. The battery explosion vent valve manufacturing process of claim 1, wherein, in the case of stamping a score groove in the thin-wall area of the semi-finished plate, a score groove is stamped in the thin-wall area on the second side of the semi-finished plate.

7. The battery explosion vent valve manufacturing process of claim 6, wherein, in the case of stamping a score groove in the thin-wall area on the second side of the semi-finished plate, the stamping die used to form the pit is used as the fixed die to fill the pit.

8. The battery explosion vent valve manufacturing process of claim 7, wherein, in the case of stamping a score groove in the thin-wall area on the second side of the semi-finished plate, a ring-shaped or crescent-shaped score groove is stamped in the thin-wall area, and the score groove is located in the middle region of the thin-wall area.

9. A battery cover plate characterized by, The battery explosion-proof valve is integrally formed by the battery explosion-proof valve manufacturing process according to any one of claims 1 to 8, and the cover plate body is provided with a pit on the first side, the battery explosion-proof valve is provided with a formed boss on the second side, and the thin-wall area surrounds the outer side of the formed boss.

10. The battery cover plate of claim 9, wherein, The score groove is a V-shaped groove.

11. The battery cover plate of claim 10, wherein, The V-shaped included angle of the cross section of the score groove is α, and 30°≤α≤90°.

12. The battery cover plate of claim 9, wherein, The outer side of the thin-wall area has a step, and the thin-wall area is connected to the cover plate body through the step.

13. The battery cover plate of claim 9, wherein, The width of the thin-wall area is W1, and W1≥0.5mm.

14. The battery cover plate of claim 9, wherein, The material of the battery cover plate is aluminum, the thickness D of the thin wall area satisfies 0.2mm≤D≤0.8mm, the notch groove is arranged on the thin wall area on the second side of the semi-finished plate, the thickness D1 between the notch groove and the bottom surface of the pit satisfies 0.05mm≤D1≤0.18mm.

15. The battery cover plate of claim 9, wherein, The radial outer side of the step is not shielded.

16. The battery cover plate of claim 9, wherein, The depth H of the pit and the thickness T of the cover plate body satisfy 0.75≤H / T≤1.

50.

17. A battery, characterized by The battery cover plate comprises a shell, a battery cell and the battery cover plate according to any one of claims 8-14, the shell has a receiving cavity for receiving the battery cell, one side of the shell is provided with an opening, the battery cover plate covers the opening, and the formed boss is located on the side of the battery cover plate facing the battery cell.

18. The battery of claim 17, wherein, Further comprising an insulating member, the insulating member is located between the battery cover plate and the battery cell, and the insulating member is provided with a receiving groove for receiving the explosion-proof valve at the position corresponding to the explosion-proof valve, and the receiving groove is provided with an aperture communicating with the receiving cavity.

19. The battery of claim 18, wherein, The aperture is arranged on the groove bottom of the receiving groove facing the battery cell.

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