EP-4738585-A1 - CASE OF BATTERY, AND BATTERY

EP4738585A1EP 4738585 A1EP4738585 A1EP 4738585A1EP-4738585-A1

Abstract

The present application relates to the technical field of lithium-ion batteries, and more particularly to a case (100) of battery and a battery. A sidewall perpendicular to the width direction (Y) is defined as a first sidewall (101), and a sidewall perpendicular to the thickness direction (Z) is defined as a second sidewall (102). The first sidewall is provided with a mounting hole (105) for mounting an explosion-proof valve (104). In the thickness direction, the mounting hole (105) is located at the center of the first sidewall (101). The first sidewall is connected to two adjacent second sidewalls via rounded corner walls (103). Each rounded corner wall (103) includes a first side and a second side. The distance from the first side of the mounting hole (105) to the corresponding first side of the rounded corner wall (103), and the distance from the second side of the mounting hole (105) to the corresponding first side of the rounded corner wall (103), are both defined as "C". The dimension of the case in the thickness direction is "B", and the dimension of the mounting hole in the thickness direction is "E", wherein 0.05B≤C≤0.20B, and 0.35B≤E≤0.70B. The case (100) of battery and battery of the present application solve the problem of inappropriate distance between the edge of the explosion-proof valve and the rounded corner wall after adjusting the pressure relief mechanism to the sidewall of the case body.

Inventors

LI, LONG

Assignees

SVOLT Energy Technology Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240628

Claims (10)

A case of battery, characterized in that , the case has a length direction, a width direction, and a thickness direction, a sidewall perpendicular to the width direction is defined as a first sidewall, a sidewall perpendicular to the thickness direction is defined as a second sidewall, the first sidewall is provided with a mounting hole for mounting an explosion-proof valve, in the thickness direction, the mounting hole is located at the center of the first sidewall, the first sidewall is connected to two adjacent second sidewalls via rounded corner walls, each rounded corner wall comprises a first side and a second side, the first side of the rounded corner wall is connected to the first sidewall, and the second side of the rounded corner wall is connected to the second sidewall, the mounting hole comprises a first side and a second side opposite to each other in the thickness direction, the distance from the first side of the mounting hole to the corresponding first side of the rounded corner wall, and the distance from the second side of the mounting hole to the corresponding first side of the rounded corner wall, are both defined as "C", the dimension of the case in the thickness direction is "B", and the dimension of the mounting hole in the thickness direction is "E", wherein 0.05B≤C≤0.20B, and 0.35B≤E≤0.70B.
The case of battery according to claim 1, characterized in that , C≥2 mm.
The case of battery according to claim 1, characterized in that , the radius of the cross-section of the cylindrical surface containing the outer circular surface of the rounded corner wall is "R", wherein E=B-2R-2C.
The case of battery according to claim 1, characterized in that , the mounting hole comprises a stepped portion and a through-hole, and the stepped portion is arranged circumferentially along the through-hole, the stepped portion divides the through-hole into a first oblong-hole and a second oblong-hole, wherein the first oblong-hole is located on the outer side of the first sidewall, and the second oblong-hole is located on the inner side of the first sidewall, the cross-sectional area of the first oblong-hole is larger than the cross-sectional area of the second oblong-hole, and the explosion-proof valve is installed in the first oblong-hole.
The case of battery according to claim 4, characterized in that , the dimension of the first oblong-hole in the width direction is "f", and the dimension of the explosion-proof valve in the width direction is "e", wherein f≥e+0.1mm.
The case of battery according to claim 4, characterized in that , a thinning zone is provided in the middle of the explosion-proof valve, the distance from the outer edge of the thinning zone to the outer edge of the explosion-proof valve is "F", and the distance from the inner edge of the stepped portion to the outer edge of the stepped portion is "D", wherein D≤F.
The case of battery according to claim 6, characterized in that , 0.5mm≤D.
A battery, characterized in that , it comprises a case of battery according to any one of claims 1-7.
The battery according to claim 8, characterized in that , the battery further comprises an explosion-proof valve installed in the mounting hole, and the dimension of the explosion-proof valve in the length direction is "L", wherein L/E≤10.
The battery according to claim 8, characterized in that , the battery further comprises a positive electrode cap plate, a negative electrode cap plate, a cell, a side plate, and an insulating protective film, the insulating protective film is sleeved on the cell, the side plate is installed on the sidewall of the battery cell for fixing the insulating protective film, the case is sleeved on the insulating protective film, two openings are respectively provided at both ends of the case, and the positive electrode cap plate and the negative electrode cap plate are respectively installed in the two openings.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to Chinese Patent Application No.2023107767009, filed on June 28, 2023, entitled "Case of battery and battery", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present application relates to the technical field of lithium-ion batteries, and in particular, to a case of battery and a battery. BACKGROUND With continuous technological advancements, users have increasingly higher demands for new energy batteries. To improve the safety performance of an individual battery cell, a pressure relief mechanism is typically installed on the battery cell. When the battery cell malfunctions and generates internal gas, the pressure relief mechanism releases the gas, in order to prevent major safety incidents. In the existing technology, as shown in Figure 11, an explosion-proof valve is located on the cap plate. During the assembly of a battery pack, vents are pre-installed at both ends of the cell to release gas generated when the explosion-proof valve is opened in the event of thermal runaway. However, the presence of these vents at both ends of the cell significantly occupies space of the battery pack, hindering further improvements in the energy density of the battery pack. By moving the explosion-proof valve from the cap plate to the sidewall of the case body, gas is directly discharged downwards. During cell-to-pack assembly, vents at both ends of the cell are no longer necessary. This allows for increasing the cell length or maintaining the same cell dimension while reducing the dimension of the battery pack, thereby significantly improving the energy density or the volume utilization of the battery pack. Therefore, moving the pressure relief structure from the cap plate to the sidewall of the case body is a highly effective method for improving the energy density of the battery pack. In view of this, after adjusting the pressure relief mechanism to the sidewall of the case body, the pressure relief mechanism needs to be reliably fixed to the case body to prevent leakage. Specifically, as shown in Figures 2 and 8, if the distance "C" between the edge of the explosion-proof valve and the rounded corner wall is too small (or the width of the explosion-proof valve is too large) in the thickness direction of the case body, the heat generated during welding will deform the outer walls on both sides of the case body. This also hinders the airtightness test after welding, potentially leading to products that fail the airtightness test being incorrectly identified as normal (because a sealing ring needs to be installed at position "C" during the airtightness test). If the distance "C" between the edge of the explosion-proof valve and the rounded corner wall is too large (or the width of the explosion-proof valve is too small), the effective exhaust area will be small when the explosion-proof valve is opened, failing to promptly remove gas from inside the case body, resulting in high internal pressure inside the case body and posing a safety risk. SUMMARY OF INVENTION The objective of the present application is to provide a case of battery and a battery that can solve a series of problems caused by the inappropriate distance between the edge of the explosion-proof valve and the rounded corner wall after adjusting the pressure relief mechanism to the sidewall of the case body. According to a first aspect of the present application, a case of battery is provided. The case has a length direction, a width direction, and a thickness direction. A sidewall perpendicular to the width direction is defined as a first sidewall, and a sidewall perpendicular to the thickness direction is defined as a second sidewall. The first sidewall is provided with a mounting hole for mounting an explosion-proof valve. In the thickness direction, the mounting hole is located at the center of the first sidewall. The first sidewall is connected to two adjacent second sidewalls via rounded corner walls. Each rounded corner wall includes a first side and a second side. The first side of the rounded corner wall is connected to the first sidewall, and the second side of the rounded corner wall is connected to the second sidewall. The mounting hole includes a first side and a second side opposite to each other in the thickness direction. The distance from the first side of the mounting hole to the corresponding first side of the rounded corner wall, and the distance from the second side of the mounting hole to the corresponding first side of the rounded corner wall, are both defined as "C". The dimension of the case in the thickness direction is "B", and the dimension of the mounting hole in the thickness direction is "E", wherein 0.05B≤C≤ 0.20B, and 0.35B≤E≤0.70B. In any of the above technical solutions, optionally, C≥2mm. In any of the above technical solutions, optionally, the radius of the cross-section of the cylindrical surface conta