CN-121983721-A - Cover plate assembly, safety device and cylindrical battery

CN121983721ACN 121983721 ACN121983721 ACN 121983721ACN-121983721-A

Abstract

The invention provides a cover plate assembly, a safety device and a cylindrical battery, wherein the cover plate assembly comprises a base plate, a explosion-proof piece and a through hole, wherein the base plate is provided with a mounting hole and is used for being connected with a shell of the cylindrical battery, the outer end of the explosion-proof piece is connected with the inner wall of the mounting hole in the radial direction of the explosion-proof piece, the middle part of the explosion-proof piece is provided with the through hole for being used for mounting a pole column, when the internal pressure of the cylindrical battery does not reach a preset value, the middle part of the explosion-proof piece is close to the inner side of the cylindrical battery, and when the internal pressure of the cylindrical battery reaches the preset value, the middle part of the explosion-proof piece drives the pole column to move towards one side far away from the inner side of the cylindrical battery so as to separate the pole column and a current collecting disc. In the invention, the base plate and the explosion-proof piece are combined, so that the current cutting-off protection function can be realized when the cylindrical battery is applied to the cylindrical battery, the cylindrical battery deforms after the internal air pressure exceeds a critical value, the polar post is driven to separate from the current collecting disc, the current of the battery is cut off, and the safety protection function of the cylindrical battery is improved.

Inventors

XU YAN
HE JIEQING
FAN WENGUANG
LI LI
XU QIANG

Assignees

常州长晟创新科技有限公司

Dates

Publication Date: 20260505
Application Date: 20260120

Claims (10)

1. A cover plate assembly for a cylindrical battery, the cover plate assembly comprising: The base plate is provided with a mounting hole along the thickness direction of the base plate and is used for being connected with the shell of the cylindrical battery; The explosion-proof plate is an annular part, the outer end of the explosion-proof plate is connected with the inner wall of the mounting hole in the radial direction of the explosion-proof plate, a through hole is formed in the middle of the explosion-proof plate and used for mounting the pole, the explosion-proof plate is a deformable part, when the internal pressure of the cylindrical battery does not reach a preset value, the middle of the explosion-proof plate is close to the inner side of the cylindrical battery, and when the internal pressure of the cylindrical battery reaches the preset value, the middle of the explosion-proof plate drives the pole to move towards one side far away from the inner side of the cylindrical battery so that the pole and the current collecting disc are separated.
2. The cover assembly of claim 1, wherein the explosion proof sheet has a height difference between a location on the explosion proof sheet near the outer edge and a middle portion of the explosion proof sheet, the middle portion of the explosion proof sheet being closer to the interior of the cylindrical battery, and/or wherein the explosion proof sheet has an explosion proof score line thereon.
3. The cover plate assembly of claim 1, wherein the base plate and the rupture disc are one piece.
4. A security device, comprising: A cover plate assembly according to any one of claims 1-3; a pole mounted in the through hole, an insulating seal being provided between an outer peripheral surface of the pole and an inner wall surface of the through hole; The current collecting disc is arranged at the end part, close to the inside of the cylindrical battery, of the pole column, the current collecting disc is welded with the pole column, an insulating layer is arranged between the current collecting disc and the base plate, and the outer end of the explosion-proof piece of the cover plate assembly is positioned between the insulating layer and the base plate.
5. The safety device according to claim 4, wherein the pole has a welding groove on a side thereof axially away from the inside of the cylindrical battery, and the current collecting plate is welded to the pole at the welding groove.
6. The safety device according to claim 4, wherein the outer peripheral surface of the pole has an annular first groove, the inner edge of the rupture disc extends into the first groove, and the insulating seal is provided between the inner wall of the first groove and the surface of the rupture disc.
7. The safety device according to claim 6, wherein the insulating seal member is a split structure or an integral structure, a part of the insulating seal member is located on one side of the middle portion of the explosion proof sheet in the self thickness direction, a further part of the insulating seal member is located on the other side of the middle portion of the explosion proof sheet in the self thickness direction, and a further part of the insulating seal member is located between the inner wall of the through hole and the inner wall of the first groove.
8. The safety device according to claim 5, wherein one of an end portion of the post near the inside of the cylindrical battery and an end portion of the current collecting plate near the post has a boss, the welding groove corresponds to a position of the boss in an axial direction of the mounting hole, and a surface of the other of the end portion of the post near the inside of the cylindrical battery and the end portion of the current collecting plate near the post is a plane or has a second groove, the boss protruding into the second groove.
9. The safety device according to claim 8, wherein the second groove is provided at an end portion of the pole near the inside of the cylindrical battery, the boss is provided at an end portion of the current collecting plate near the pole, the boss protrudes into the second groove, and a third groove or a flat surface is provided at a surface of the current collecting plate on a side away from the pole, the third groove being aligned with the boss in the axial direction of the mounting hole.
10. A cylindrical battery comprising a safety device according to any one of claims 4 to 9.

Description

Cover plate assembly, safety device and cylindrical battery Technical Field The invention relates to the technical field of batteries, in particular to a cover plate assembly, a safety device and a cylindrical battery. Background With the continuous development of new energy automobiles, energy storage systems, consumer electronics and other applications, the requirements on battery technology are also higher and higher, and the requirements on high energy density, high power density, high safety and the like become the main targets of battery technology development. And currently, large-sized cylindrical batteries (e.g., 46mm diameter or 32mm diameter) are an important direction for the development of secondary batteries due to their high energy/power density, good uniformity, and higher production efficiency. In order to meet the safety requirements of high-voltage systems such as automobile battery modules, energy storage systems and the like, the conventional full-tab large-cylindrical battery is not provided with a current cut-off protection device (CID, current Interrupting Device). However, the lack of CID results in a reduced safety protection function for large cylindrical batteries in other applications, such as 3C consumer electronics applications. Disclosure of Invention An object of the present invention is to provide a cap plate assembly, a safety device, and a cylindrical battery, which can improve the safety protection function of the cylindrical battery. In order to achieve the above object, the present invention provides the following technical solutions. According to the cover plate assembly, the cover plate assembly is used for a cylindrical battery and comprises a base plate, the base plate is provided with a mounting hole in the thickness direction of the base plate and is used for being connected with a shell of the cylindrical battery, the explosion-proof piece is an annular piece, the outer end of the explosion-proof piece is connected with the inner wall of the mounting hole in the radial direction of the explosion-proof piece, the middle of the explosion-proof piece is provided with a through hole and is used for mounting a pole, the explosion-proof piece is a deformable piece, when the internal pressure of the cylindrical battery does not reach a preset value, the middle of the explosion-proof piece is close to the inner side of the cylindrical battery, and when the internal pressure of the cylindrical battery reaches the preset value, the middle of the explosion-proof piece drives the pole to move towards one side far away from the inner side of the cylindrical battery, so that the pole and the current collecting disc are separated. Optionally, the part of the explosion-proof sheet close to the outer edge and the middle part of the explosion-proof sheet have a height difference, the middle part of the explosion-proof sheet is closer to the inner part of the cylindrical battery, and/or the explosion-proof sheet is provided with explosion-proof score lines. Optionally, the base plate and the rupture disc are one piece. The safety device comprises a cover plate assembly, a pole column and a current collecting disc, wherein the cover plate assembly is arranged in any one of the cover plate assemblies, an insulating sealing piece is arranged between the outer peripheral surface of the pole column and the inner wall surface of the through hole, the current collecting disc is arranged at the end part, close to the inside of a cylindrical battery, of the pole column, the current collecting disc is welded with the pole column, an insulating layer is arranged between the current collecting disc and the base plate, and the outer end of an explosion-proof piece of the cover plate assembly is arranged between the insulating layer and the base plate. Optionally, a side of the pole column, which is far away from the interior of the cylindrical battery in the axial direction of the pole column, is provided with a welding groove, and the current collecting disc and the pole column are welded at the position of the welding groove. Optionally, the outer peripheral surface of the pole is provided with an annular first groove, the inner edge of the explosion-proof piece stretches into the first groove, and the insulating sealing piece is arranged between the inner wall of the first groove and the surface of the explosion-proof piece. Optionally, the insulating sealing member is a split structure or an integral structural member, a part of the insulating sealing member is located at one side of the middle part of the explosion-proof sheet in the thickness direction of the insulating sealing member, another part of the insulating sealing member is located at the other side of the middle part of the explosion-proof sheet in the thickness direction of the insulating sealing member, and another part of the insulating sealing member is located between the inner wall of the through hole and the inner wall