KR-20260063716-A - SECONDARY BATTERY

KR20260063716AKR 20260063716 AKR20260063716 AKR 20260063716AKR-20260063716-A

Abstract

The present application relates to a secondary battery comprising an electrode assembly having a positive plate, a separator, and a negative plate wound thereon, an opening in which the electrode assembly is housed, a bottom portion located on the opposite side of the opening, and a side surface connecting the opening and the bottom portion, wherein the maximum thickness of the side surface of the battery can is 1.5 times or more and 3 times or less the minimum thickness of the side surface of the battery can.

Inventors

김민규

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260507
Application Date: 20241031

Claims (13)

an electrode assembly wound with an anode plate, a separator, and a cathode plate, and A battery can comprising an opening in which the electrode assembly is housed, a bottom portion located on the opposite side of the opening, and a side surface connecting the opening and the bottom portion, A secondary battery characterized in that the maximum thickness of the side surface of the battery can is 1.5 times or more and 3 times or less the minimum thickness of the side surface of the battery can.
In claim 1, A secondary battery characterized in that the thickness (Tb) of the side surface of the battery can in contact with the bottom portion of the battery can is 1.5 times or more and 3 times or less the thickness (To) of the side surface of the battery can in contact with the opening portion of the battery can.
In claim 1, A secondary battery characterized in that the thickness at a point halfway between the side surface (H B ) of the battery can in contact with the bottom portion of the battery can and the side surface (H O ) of the battery can in contact with the opening portion of the battery can is thicker than the thickness of the side surface of the battery can in contact with the opening portion of the battery can.
In claim 1, A secondary battery characterized in that the side surface of the battery can has an inclined surface that becomes thicker from the opening to the bottom.
In claim 1, A secondary battery characterized by having an inclined surface that becomes thicker towards the bottom of the battery can from a point halfway between the distance between the side surface (H B ) of the battery can in contact with the bottom of the battery can and the side surface (H O ) of the battery can in contact with the opening of the battery can.
In claim 1, A secondary battery characterized in that the angle of the inner side surface of the battery can is 90.1° to 91° with respect to the bottom portion.
In claim 1, A secondary battery characterized in that the above battery can includes a beading portion formed by being pressed into the inside of the battery can in an area adjacent to the opening.
In claim 1, A secondary battery characterized by including a cap assembly located at the opening of the battery can.
In claim 8, A secondary battery characterized in that the above-described cap assembly includes a top cap; a safety vent provided on the lower surface of the top cap; and a current interruption portion.
In claim 1, A secondary battery characterized in that the side surface adjacent to the bottom of the battery can includes a curved portion, starting from a point corresponding to half the distance between the side surface (H B ) of the battery can in contact with the bottom of the battery can and the side surface (H O ) of the battery can in contact with the opening of the battery can.
A battery module comprising a secondary battery according to any one of claims 1 to 10.
A battery pack comprising a secondary battery according to any one of claims 1 to 10.
A battery pack comprising a battery module according to claim 11.

Description

Secondary battery The present application relates to a secondary battery, and more specifically, to a secondary battery having a structure capable of solving the problem of the lower compression ratio of the battery can increasing during a crush test in a safety test of the secondary battery, and solving the problem that the increased lower compression ratio of the battery can can lead to a short circuit and ignition due to electrode rupture. Due to the rapid increase in the use of fossil fuels, there is a growing demand for alternative or clean energy. As part of this effort, the fields of power generation and energy storage utilizing electrochemical reactions are the most actively researched. Currently, a representative example of an electrochemical device utilizing such electrochemical energy is the secondary battery, and its scope of application is steadily expanding. With the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly rising. Among these secondary batteries, lithium-ion batteries, which possess high energy density and voltage, long cycle life, and low self-discharge rates, have been commercialized and are widely used. Furthermore, active research is being conducted on methods to manufacture high-density electrodes with higher energy density per unit volume for use in such high-capacity lithium-ion batteries. Meanwhile, if a secondary battery is damaged by pressure, there may be a risk of internal short circuits, fire, or explosion. To prevent such risks, a compression test is performed to verify that the design is properly implemented. In this case, the compression test may involve pressing a steel plate while the battery cell is lying flat. Figure 1 is a cross-sectional view of a conventional secondary battery. Referring to Figure 1, the battery can used in the conventional secondary battery has the same outer wall thickness in the upper, middle, and lower outer diameters, and when the outer diameters of the upper, middle, and lower parts of the battery cell are measured after a compression test, a problem arises in that the outer diameter of the lower part is compressed more severely. In particular, if the pressure on the battery cell is more severe, it may lead to a short circuit and ignition due to electrode rupture. Therefore, research is needed on secondary batteries that prevent the outer diameter of the lower part of the battery cell from being compressed during a compression test. Figure 1 is a cross-sectional view of a conventional secondary battery. FIG. 2 is a cross-sectional view of a secondary battery according to one embodiment of the present invention. FIG. 3 is a cross-sectional view of a secondary battery according to another embodiment of the present invention. FIG. 4 is a drawing illustrating the inclination of the side surface of a battery can formed with an inclination in a secondary battery according to one embodiment of the present invention. FIG. 5 is a drawing showing a curved side surface adjacent to the bottom of a battery can in a secondary battery according to one embodiment of the present invention. FIG. 6 is a drawing showing a curved side surface adjacent to the bottom of a battery can (100) in a secondary battery according to another embodiment of the present invention. FIG. 7 is a schematic diagram showing the configuration of a battery pack including a secondary battery cell according to one embodiment of the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely one preferred embodiment of the present invention and do not represent all aspects of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application. In the drawings, the size of each component or specific part constituting the component is exaggerated, omitted, or schematically depicted for convenience and clarity of explanation. Accordingly, the size of each component does not entirely reflect its actual size. If it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such description shall be omitted. In this specification and claims, when a part is described as "comprising" a certain component, this means that