Patent ID: 8597824

Claim:
A lithium secondary battery comprising: an electrode assembly; a can to receive the electrode assembly; a cap assembly including: a safety vent to close an opening of the can, the safety vent having a central region that protrudes inward and is deformable outward by an internal pressure of the battery, the safety vent comprising a top surface, a bottom surface and a thin side surface, a current isolation member having an upper side, and a cap up connected to the upper side of the current isolation member; a gasket disposed between the cap assembly and the can to maintain an airtight seal, the gasket having horizontal and vertical surfaces; and a first supporting sealing member formed between the safety vent and the gasket, wherein the first supporting sealing member forms a seal between the safety vent and the gasket and a first surface of the first supporting sealing member contacts only the bottom surface of the safety vent and a second surface of the first supporting sealing member contacts a horizontal surface of the gasket.