LITHIUM ION BATTERY OF CRIMPING SHAPE OF INCREASED SAFETY

摘要

Disclosed herein is a cylindrical battery constructed in a structure in which a crimp region, at which a cap assembly is mounted to an open upper end of a cylindrical container having an electrode assembly mounted therein, is formed at the upper end of the container, wherein the crimp region is constructed in a structure in which the upper end of the 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, 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 cylindrical battery according to the present invention is constructed such that the upper end of the crimp region of the cylindrical container is continuously bent twice in a predetermined condition. Consequently, when external physical impacts, such as vibration or dropping, 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. 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.