Secondary battery, cap assembly thereof and method of mounting safety valve therefor

摘要

A secondary battery may be manufactured with an electrode assembly having a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. A container encases the electrode assembly. A hole formed on one end of the container with a stepped configuration that opens with different diameters on opposite sides of a cap plate and a safety valve mounted in the stepped surface of the hole, is configured to rupture and tear open upon occurrence of a predetermined internal battery pressure.