SECONDARY BATTERY AND SECONDARY BATTERY CASE

A secondary battery includes a case with at least one opening, the at least one opening having a long side portion and a short side portion, a stepped portion at the short side portion and the long side portion of the opening along an inner surface of the case, an electrode assembly accommodated in the case, and at least one cap plate joined to the at least one opening, the at least one cap plate being positioned on the stepped portion.