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EP-4738586-A1 - EXPLOSION-PROOF VALVE, BATTERY AND PROCESSING METHOD FOR EXPLOSION-PROOF VALVE

EP4738586A1EP 4738586 A1EP4738586 A1EP 4738586A1EP-4738586-A1

Abstract

The present application relates to the technical field of batteries, and discloses an explosion-proof valve, a battery, and a processing method for an explosion-proof valve. The explosion-proof valve includes: an explosion-proof valve body suitable for being arranged on a housing of a battery; a thinned area surrounding the circumference of the explosion-proof valve body, where the thickness of the thinned area is less than that of the explosion-proof valve body; an explosion rib arranged in the thinned area, where the thickness of the explosion rib is less than the thickness of the thinned area, and the explosion rib is suitable for breaking at a preset pressure value; and a plurality of pits spaced apart from each other in the thinned area and spaced apart from the explosion rib to reduce stress in the thinned area. When the gas pressure value inside the battery reaches the preset pressure value, the explosion rib first breaks to form an exhaust channel, facilitating the discharge of high-pressure gas inside the battery. The pits in the thinned area can destroy the crystal structure on the surface of the thinned area, thereby relieving some stress, solving the problem of high stress in the forming process of the explosion-proof valve, and preventing structural deformation or break.

Inventors

  • MA, Yonggui

Assignees

  • SVOLT Energy Technology Co., Ltd.

Dates

Publication Date
20260506
Application Date
20240628

Claims (10)

  1. An explosion-proof valve, comprising: an explosion-proof valve body suitable for being arranged on a housing of a battery; a thinned area surrounding a circumference of the explosion-proof valve body, wherein a thickness of the thinned area is less than a thickness of the explosion-proof valve body; an explosion rib arranged in the thinned area, wherein a thickness of the explosion rib is less than the thickness of the thinned area, and the explosion rib is suitable for breaking at a preset pressure value; and a plurality of pits spaced apart from each other in the thinned area and spaced apart from the explosion rib to reduce stress in the thinned area.
  2. The explosion-proof valve as claimed in claim 1, wherein the thickness of the thinned area is H1, and a depth of the pit is H2, wherein H2≥1/2*H1.
  3. The explosion-proof valve as claimed in claim 2, wherein the thickness H1 of the thinned area ranges from 0.2 mm to 0.5 mm.
  4. The explosion-proof valve as claimed in claim 1, wherein the plurality of pits are symmetrically distributed on both sides of the explosion rib; and/or a distance L1 between the two adjacent pits along the circumference of the explosion-proof valve body is 0.2 mm to 1 mm.
  5. The explosion-proof valve as claimed in claim 1, wherein a circumferential surface of the explosion-proof valve body is an inclined surface at an angle to an axis of the explosion-proof valve; and/or a width L2 of the thinned area ranges from 0.5 mm to 5 mm.
  6. The explosion-proof valve as claimed in claim 1, wherein the thinned area further comprises a connecting portion, the connecting portion and the explosion rib are connected end to end, and the connecting portion surrounds the explosion-proof valve body, and a dimension L3 of the connecting portion along the circumference of the explosion-proof valve body is 2 mm to 20 mm.
  7. The explosion-proof valve as claimed in any one of claims 1 to 6, wherein the explosion-proof valve further comprises a boss surrounding the circumference of the thinned area, and an upper surface of the boss is higher than an upper surface of the explosion-proof valve body and an upper surface of the thinned area.
  8. A battery, comprising: a housing with an open end; an electrode set mounted in the housing; and a cover plate arranged at the open end of the housing to close the housing, wherein the explosion-proof valve according to any one of claims 1 to 7 is configured on the cover plate.
  9. A processing method for an explosion-proof valve, wherein the processing method is used to process the explosion-proof valve as claimed in any one of claims 1 to 7, and the processing method comprises: selecting a first area on the housing, and shaping the first area upwards so that the first area protrudes upwards relative to other areas of the housing, to form a raised area; pressing a ring-shaped area downwards along a circumference of the raised area to form the thinned area, wherein the ring-shaped area is spaced with a first preset distance from the edge of the raised area; processing the plurality of spaced pits in the thinned area to destroy a crystal structure inside a material of the thinned area; and pressing an indentation of a preset width along the circumference of the thinned area to form the explosion rib, wherein in the pressing process, the excess material flows freely towards both sides of the explosion rib.
  10. The processing method for the explosion-proof valve as claimed in claim 9, wherein a distance of upward movement of the raised area relative to other areas on the housing is H3, wherein H3 ranges from 0.3 mm to 2 mm.

Description

CROSS REFERENCE TO RELATED APPLICATION The present application claims priority to Chinese Patent Application No. 202310783400.3 filed with the China National Intellectual Property Administration on June 28, 2023, and entitled "EXPLOSION-PROOF VALVE, BATTERY, AND PROCESSING METHOD FOR EXPLOSION-PROOF VALVE", which is incorporated herein by reference in entirety. TECHNICAL FIELD The present application relates to the technical field of batteries, and specifically relates to an explosion-proof valve, a battery, and a processing method for an explosion-proof valve. BACKGROUND ART To ensure battery safety, most batteries currently on the market are provided with an explosion-proof valve on their housing. When the gas pressure inside the battery is excessively high, the explosion-proof valve opens to prevent battery explosion. Commonly, the explosion-proof valve is formed separately and laser-welded to a through hole formed on a cover plate to form a whole. However, such a structural form decreases local strength of the cover plate, thereby affecting the explosion value of the explosion-proof valve of the entire battery, making it difficult to ensure battery safety. To solve the above problem, an integral explosion-proof valve technology is employed in the prior art to form an explosion-proof valve on a bare aluminum sheet through stretching and thinning. However, high stress is generated in the integral forming process, resulting in structural deformation and even a risk of structural break, which will affect the safety of the explosion-proof valve. SUMMARY In view of this, the present application provides an explosion-proof valve, a battery, and a processing method for an explosion-proof valve to solve the problem of high stress in the forming process of explosion-proof valves. In a first aspect, the present application provides an explosion-proof valve, including: an explosion-proof valve body suitable for being arranged on a housing of a battery; a thinned area surrounding the circumference of the explosion-proof valve body, where the thickness of the thinned area is less than that of the explosion-proof valve body; an explosion rib arranged in the thinned area, where the thickness of the explosion rib is less than that of the thinned area, and the explosion rib is suitable for breaking at a preset pressure value; and a plurality of pits spaced apart from each other in the thinned area and spaced apart from the explosion rib to reduce stress in the thinned area. Beneficial effect: The housing is pressed to form the thinned area on the circumference of the explosion-proof valve body, the thickness of the thinned area is less than that of other areas on the housing, and the strength of the thinned area is less than that of other areas on the housing, so the thinned area with lower strength forms an explosion area of the explosion-proof valve. In addition, the thickness of the explosion rib arranged in the thinned area is less than the overall thickness of the thinned area, so the thickness of a solid portion corresponding to the explosion rib is minimum, and the strength at the explosion rib is minimum. When the gas pressure value inside the battery reaches the preset pressure value, the explosion rib first breaks, so that the explosion-proof valve body surrounded by the explosion rib can be opened to form an exhaust channel, facilitating the discharge of high-pressure gas inside the battery, preventing battery explosion, and reducing losses. Meanwhile, the plurality of spaced pits in the thinned area can destroy the crystal structure on the surface of the thinned area, thereby relieving some stress, solving the problem of high stress in the forming process of the explosion-proof valve, preventing a risk of structural deformation or break, and thus improving the safety of the explosion-proof valve. In an optional implementation, the thickness of the thinned area is H1, and the depth of the pit is H2, where H2≥1/2*H1. Beneficial effect: Designing the depth H2 of the pit to be greater than or equal to half of the thickness H1 of the thinned area can ensure that the pits are sufficient to destroy the crystal structure inside the material of the thinned area, thereby reducing stress, reducing the processing difficulty in the thinned area, and ensuring the structural stability. In an optional implementation, the thickness H1 of the thinned area ranges from 0.2 mm to 0.5 mm. Beneficial effect: Designing the thickness H1 of the thinned area within the range 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 lower processing costs. In an optional implementation, the plurality of pits are symmetrically distributed on both sides of the explosion rib; and/or the distance L1 between the two adjacent pits along the circumference of the explosion-proof valve body is 0.2 mm to 1 mm. Beneficial effect: The symmetrical distribu