Patent ID: 7993778
Filing Date: 2011-08-09
Classification: H01M,Y02E,Y02P

Abstract:
1. A lithium ion secondary battery comprising: an electrode assembly having a positive electrode plate, a separator, and a negative electrode plate which are simultaneously wound and laminated, a positive electrode lead extending outward from the positive electrode plate and a negative electrode lead extending outward from the negative electrode plate; a can containing the electrode assembly, the can having an opening formed on an end thereof; and a cap plate coupled to the opening of the can, the cap plate having a coupling hole formed through the cap plate and a safety vent plug plugging the coupling hole, the safety vent plug being adapted to soften at a predetermined temperature and open the coupling hole to discharge internal gas; wherein an electrode terminal is extendable through and couplable to a substantially central portion of the cap plate with a gasket interposed therein; wherein the negative electrode lead is connectable to the electrode terminal; wherein the positive electrode lead is connectable to a side of the cap plate; and wherein the safety vent plug comprises a body and a single catching plate, the thickness of the catching plate being between about 0.1-0.9 times that of the body, and the catching plate of the safety vent plug is inside the can containing the electrode assembly.