Lg Chem, Ltd

Geun Ho Seo

Ji Hyun Lee

Sungjong Kim

In Sung Lee

Jaehan Jung

Hokyung Byun

Dongsub Lee

SangMinh Lee

Munsung Kim

Nakjin Kim

Sm Lee

Disclosed herein is a cylindrical secondary battery including a cap assembly constructed in a structure in which a vent, which intercepts electric current and discharges pressurized gas when the interior pressure of the battery is increased due to abnormal operation of the battery, is in contact with a top cap having a protruding central part, wherein the end of the vent is bent to surround the outer circumferential surface of the top cap, and a groove for preventing the leakage of an electrolyte and preventing the occurrence of defectiveness of the battery during the assembly of the battery is formed at interfaces between the vent and the top cap such that the groove is arranged in parallel with the outer circumferential surface of the top cap. The secondary battery according to the present invention has the effect of accomplishing high charging and discharging rate, providing uniform output even when external physical impacts, such as vibration or dropping, are applied to the secondary battery, and preventing the occurrence of defectiveness during the assembly of the secondary battery. Furthermore, the leakage of the electrolyte out of the battery is restrained under these conditions. Consequently, the secondary battery according to the present invention can be preferably used as a high-output power source.

High rate charging and discharging cylindrical secondary battery

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

Busan, South Korea

Geun Ho Seo