Lg Chem, Ltd

Jaehan Jung

Sungjong Kim

BongTae Kim

Hong-Jeong Kim

Ji Hyun Lee

In Sung Lee

Geun Ho Seo

Dongsub Lee

Munsung Kim

Nakjin Kim

A cylindrical battery has a crimp region is formed at the upper end of the container. The upper end of the crimp region is gently bent to surround a gasket located at the inside of the crimp region. A bent front end is continuously bent twice to press the gasket, while the bent front end extends inward, such that a radius of curvature (R1) of the first bent area is less than a radius of curvature (R2) of the second bent area. The upper end of the crimp region of the cylindrical container is continuously bent twice in a predetermined condition. Consequently, when external physical impacts are applied to the battery, and when the internal pressure of the battery increases, the sealed portions are restrained from being separated from each other, thereby preventing the leakage of an electrolyte and thus greatly improving the safety of the battery.

Lithium ion battery of crimping shape of increased safety

A cylindrical battery constructed in a structure in which a crimp region is gently bent, such that the crimp region surrounds a gasket located at the inside of the crimp region, a bent front end is continuously bent twice to press the gasket, to be in the form of a compound curve. Under external physical impacts, such as vibration or dropping, applied to the battery, and when the internal pressure of the battery increases, the sealed portions are restrained from being separated from each other, thereby preventing the leakage of an electrolyte and thus greatly improving the safety of the battery. Furthermore, it is possible to minimize the deformation of the container, such as wrinkles, which may be formed due to failure to form the bent area gently when bending the front end of the crimp region with a small radius of curvature.

Disclosed herein is a cylindrical secondary battery constructed in a structure in which a crimping region, at which a cap assembly is mounted to the open upper end of a cylindrical container having an electrode assembly mounted therein, is formed at the upper end of the container, wherein the crimping region is constructed in a structure in which the upper end of the crimping region is gently bent at a predetermined radius of curvature (R), such that the crimping region surrounds a gasket located at the inside of the crimping region, the bent front end extends inward, such that the bent end presses the gasket, and an inclination of a predetermined angle is formed at the sidewall of the crimping region, such that the upper part of the crimping region is directed inward. According to the secondary battery of the present invention, the sealability of the gasket is improved, and external impacts are partially absorbed by the inclination formed at the crimping region. Consequently, the deformation of the crimping region is minimized, whereby the leakage of the electrolyte is prevented, and the safety of the battery is greatly improved.

Cylindrical secondary battery of improved safety

Growing community of inventors

Daejeon, South Korea

Jaehan Jung