Lithium secondary battery

摘要

A lithium secondary battery having a cap assembly including a cap plate, an insulation plate and a terminal plate. The insulation plate and the terminal plate each have a predetermined vent hole corresponding to a safety vent formed on the cap plate so that if the secondary battery is dropped, an electrolyte passes through the vent-holes and undergoes a pressure reduction, thereby preventing fracture of a safety vent by the electrolyte while allowing gas to be exhausted upon battery overcharge, full discharge or by overheating.