Secondary battery

Abstract

A secondary battery includes an electrode assembly having a first electrode plate, a second electrode plate and a separator interposed between the first and second electrode plates; a lower case accommodating the electrode assembly therein; and a cap assembly sealing the lower case. In the secondary battery, the lower case has the electrode assembly and a vent portion, and includes a surface facing the cap assembly. The vent portion includes an intersecting portion formed inside the surface, first and second curved portions curved to extend from the intersecting portion, and an extending portion extended in a straight line from the intersecting portion. The thickness of the intersecting portion includes the minimum thickness of the surface.

Dependencies are inferred from the claim text.