A secondary battery includes an electrode assembly, a housing, and an adhesion layer. The housing includes an upper housing body and a lower housing body. The lower housing body is provided with a recess for accommodating the electrode assembly. The upper housing body is configured to cover the recess. The adhesion layer is provided on a bottom surface of the recess opposite to the upper housing body. The housing is a metal housing. The adhesion layer adheres the electrode assembly to the housing.