| 摘要 |
PURPOSE: A secondary battery and its preparation method are provided, to improve the structure of a safety vent and a gasket for obtaining sufficiently stable sealing property of the inside of a battery. CONSTITUTION: The secondary battery(30) comprises a battery part comprising an anode plate(31a), a cathode plate(31b) and a separator(31c) positioned between the two electrode plates; a can(32) receiving the battery part; and a cap assembly(35) which is combined with the upper part of the can and comprises a cap cover(36), a safety vent(39) set in the lower part of the cap cover, and a gasket(310) positioned along the safety vent, wherein the short part of the safety vent is folded to the inside and the gasket is fixed to the safety vent by filling the folded short part with the gasket. The safety vent is exploded by the certain pressure of the inside of a battery. The short part of the safety vent is bent toward the inside from the edge of the based where a notch part(39a) is formed, and is positioned at the bottom of the gasket. |
