Secondary battery having cap assembly

摘要

A secondary battery having a cap assembly, including an electrode assembly; a case in which the electrode assembly is located; a cap assembly having a cap plate coupled to and hermetically sealing the case. A terminal member has a head with a stepped protrusion penetrating the cap plate and insulated from the cap plate by an insulating member. The stepped protrusion presses the insulating member in multiple steps. The terminal member is connected to a positive or negative electrode terminal of the electrode assembly.