EP-4742382-A1 - BATTERY AND ASSEMBLY METHOD THEREFOR

EP4742382A1EP 4742382 A1EP4742382 A1EP 4742382A1EP-4742382-A1

Abstract

The present application relates to the technical field of batteries, and discloses a battery and an assembly method therefor. The battery includes: a shell having a first end and a second end that are arranged opposite, where the first end is configured as a first open end, an edge of the second end extends along a radial direction of the shell towards an axis direction of the shell to form an extension ring, a central area of the extension ring forms a second open end, and the second open end is smaller than the first open end; an electrode assembly mounted in the shell; a positive electrode cover plate arranged at the first end of the shell and fixedly connected to the shell to seal the first open end; a positive electrode column mounted on the positive cover plate in an insulating manner and electrically connected to a positive electrode of the electrode assembly; and a negative electrode cover plate arranged at the second end of the shell and electrically connected to a negative electrode of the electrode assembly, where the negative electrode cover plate is fixedly connected to at least a portion of the extension ring to seal the second open end. The present application changes conventional peripheral welding to top straight welding, achieving easy operation, high welding efficiency, good connection performance, large welding area, and good battery performance.

Inventors

YUAN, Yue

Assignees

SVOLT Energy Technology Co., Ltd.

Dates

Publication Date: 20260513
Application Date: 20240703

Claims (11)

A battery comprising: a shell having a first end and a second end that are arranged opposite, wherein the first end is configured as a first open end, the second end is configured with an extension ring, the extension ring extends from an edge of the second end along a radial direction of the shell towards an axis direction of the shell, a central area of the extension ring forms a second open end, and the second open end is smaller than the first open end; an electrode assembly mounted in the shell; a positive electrode cover plate arranged at the first end of the shell and fixedly connected to the shell to seal the first open end; a positive electrode column mounted on the positive cover plate in an insulating manner and electrically connected to a positive electrode of the electrode assembly; and a negative electrode cover plate arranged at the second end of the shell and electrically connected to a negative electrode of the electrode assembly, wherein the negative electrode cover plate is fixedly connected to at least a portion of the extension ring to seal the second open end.
The battery as claimed in claim 1, wherein the shell is constructed in a cylindrical shape, a diameter of a cross-section of the shell that is perpendicular to an axis of the shell is D, and an extension dimension of the extension ring in the radial direction of the shell is L1, wherein 0.06 ≤ L1/D ≤ 0.12.
The battery as claimed in claim 2, wherein the extension ring comprises a first ring portion and a second ring portion, the second ring portion is located on an inner side of the first ring portion in the radial direction of the shell, the second ring portion is higher than the first ring portion, and the negative electrode cover plate is welded to the second ring portion on a side of the second ring portion that faces an outside of the shell.
The battery as claimed in claim 3, wherein a dimension of the second ring portion in the radial direction of the shell is L2, wherein 0.02 ≤ L2/D ≤ 0.04.
The battery as claimed in claim 3, wherein the electrode assembly comprises: an electrode set; a positive electrode connecting piece arranged between the electrode set and the positive electrode column, wherein one side of the positive electrode connecting piece is electrically connected to a positive electrode of the electrode set and the other side of the positive electrode connecting piece is electrically connected to the positive electrode column; and/or a negative electrode connecting piece arranged between the negative electrode cover plate and the electrode set, wherein one side of the negative electrode connecting piece is electrically connected to the negative electrode cover plate and the other side of the negative electrode connecting piece is electrically connected to a negative electrode of the electrode set.
The battery as claimed in claim 5, wherein the negative electrode connecting piece comprises an electrode set welding area and a cover plate welding area, the cover plate welding area is arranged around the electrode set welding area, the electrode set welding area protrudes upward relative to the cover plate welding area, the electrode set welding area is welded to the electrode set, and the cover plate welding area is welded to the first ring portion.
The battery as claimed in any one of claims 3 to 6, wherein the negative electrode cover plate comprises: an injection area arranged at a central position of the negative electrode cover plate, wherein the injection area is provided with an injection hole; and/or a recessed area arranged around the injection area, wherein the recessed area is lower than the injection area and flush with the first ring portion; and/or a raised area arranged around the recessed area, wherein the raised area is higher than the recessed area and flush with the injection area; and/or an overlap area arranged around the raised area, wherein the overlap area is lower than the raised area and flush with the recessed area, and the overlap area overlaps with the second ring portion.
The battery as claimed in claim 7, wherein a wall thickness of the shell is H, and a lower surface of the injection area is higher than a lower surface of the recessed area by H1, wherein 1.5 ≤ H1/H ≤ 2.5; and/or a connecting portion between the injection area and the recessed area is an inclined annular surface arranged at an angle with the axis of the shell, and an angle between the inclined annular surface and the axis of the shell is θ, wherein 15° ≤ θ ≤ 60°.
The battery as claimed in claim 7, wherein the battery further comprises a sealing cover plate, and the sealing cover plate is arranged in the injection area to seal the injection hole.
The battery as claimed in claim 8, wherein the positive electrode cover plate comprises a cover plate body, a groove ring portion, and an edge ring portion connected in sequence from the inside out along a radial direction of the positive electrode cover plate, the cover plate body is flush with the edge ring portion, the groove ring portion is recessed downward relative to the cover plate body and the edge ring portion, the cover plate body is configured with a mounting hole, the positive electrode column is inserted into the mounting hole, a side wall of the groove ring portion that faces the shell abuts against an inner wall of the shell, and a lower surface of the edge ring portion abuts against an upper end surface of the shell, wherein a dimension of the edge ring portion in the radial direction of the positive electrode cover plate is L3, a lower surface of the groove ring portion is lower than the lower surface of the edge ring portion by H3, L3=H, and 1.2 ≤ H3/H ≤ 2.5.
A battery assembly method, wherein the battery assembly method is used to assemble the battery as claimed in any one of claims 1 to 10, and the battery assembly method comprises: welding the electrode set in the electrode assembly to the negative electrode connecting piece to form a first assembly; mounting the first assembly into the shell from the first open end of the shell; welding the negative electrode connecting piece to the first ring portion of the extension ring from a side of the extension ring that faces the outside of the shell; mounting the positive electrode connecting piece in the electrode assembly from the first open end into the shell and welding the positive electrode connecting piece to the electrode set; mounting the positive electrode cover plate to the first open end and welding the positive electrode cover plate to the shell; mounting the positive electrode column into the mounting hole on the positive electrode cover plate, and welding the positive electrode column to the positive electrode connecting piece; mounting the negative electrode cover plate to the second open end of the shell, and welding the negative electrode cover plate to the second ring portion of the extension ring from a side of the negative electrode cover plate that faces the outside of the shell; and mounting the sealing cover plate to the injection hole on the negative electrode cover plate, and welding the sealing cover plate to the negative electrode cover plate.

Description

CROSS REFERENCE TO RELATED APPLICATION The present application claims priority to Chinese Patent Application No. CN202310810840.3 filed with the China National Intellectual Property Administration on July 3, 2023, and entitled "BATTERY AND ASSEMBLY METHOD THEREFOR", which is incorporated herein by reference in entirety. TECHNICAL FIELD The present application relates to the technical field of batteries, and specifically relates to a battery and an assembly method therefor. BACKGROUND ART Currently, batteries on the market mainly include components such as a shell, an electrode set, an electrode column, and a negative electrode cover plate, where the shell is insulated from and hermetically connected to the electrode column, the electrode column is connected to the electrode set by a positive electrode connecting piece, the negative electrode cover plate is connected to the electrode set by a negative electrode connecting piece, and a sealing cover plate and a sealing nail are further provided at an injection hole on the negative electrode cover plate. In the battery assembly process, the positive/negative electrode connecting piece and the electrode set, the positive electrode connecting piece and the electrode column, the negative electrode connecting piece and the shell, the negative electrode cover plate and the negative electrode connecting piece, the negative electrode cover plate and the shell, are all connected by welding. The negative electrode connecting piece, the negative electrode cover plate, and the shell are usually peripherally welded, that is, a peripheral edge of the negative electrode connecting piece and an inner wall of the shell abut against each other and are welded at the abutting position, and a peripheral edge of the negative electrode cover plate and an edge of the shell abut against each other and are welded at the abutting position. The welding follows the peripheral edge of the negative electrode connecting piece and the peripheral edge of the negative electrode cover plate, to achieve relative fixation of the negative electrode connecting piece and the negative electrode cover plate with the shell. However, the peripheral welding method suffers from low processing efficiency, limited welding area, and poor post-welding connection performance, resulting in poor battery performance and quality problems. SUMMARY In view of this, the present application provides a battery and an assembly method therefor to solve the problems of low efficiency, small welding area, and poor performance of peripheral welding methods for batteries. In a first aspect, the present application provides a battery including: a shell having a first end and a second end that are arranged opposite, where the first end is configured as a first open end, the second end is configured with an extension ring, the extension ring extends from an edge of the second end along a radial direction of the shell towards an axis direction of the shell, a central area of the extension ring forms a second open end, and the second open end is smaller than the first open end; an electrode assembly mounted in the shell; a positive electrode cover plate arranged at the first end of the shell and fixedly connected to the shell to seal the first open end; a positive electrode column mounted on the positive cover plate in an insulating manner and electrically connected to a positive electrode of the electrode assembly; and a negative electrode cover plate arranged at the second end of the shell and electrically connected to a negative electrode of the electrode assembly, where the negative electrode cover plate is fixedly connected to at least a portion of the extension ring to seal the second open end. Beneficial effect: By designing the second end of the shell to form the extension ring, after the electrode assembly is mounted into the shell from the first end, the extension ring not only supports and limits the electrode assembly, but also overlaps with the negative electrode cover plate. The negative electrode cover plate overlaps at least a portion of the extension ring, so compared to the conventional connection method that the edge of the negative electrode cover plate abuts against the shell, the contact area between the negative electrode cover plate and the shell increases, and the negative electrode cover plate can be welded to the extension ring from the outside of the shell. The conventional peripheral welding is changed to top direct welding, achieving easy assembly, high welding efficiency, easy detection and operation, and high connection reliability, increasing the welding area, reducing battery performance problems, improving product yield, and lowering manufacturing costs. In an optional implementation, the shell is constructed in a cylindrical shape, a diameter of a cross-section of the shell that is perpendicular to an axis of the shell is D', and an extension dimension of the extension ring in the radial direct