Battery and device

The present application provides a battery including an electrode tab assembly that including an electrode tab and a protective layer arranged on the electrode tab including a first connecting layer arranged outside the protective layer, and a package film including a second connecting layer arranged outside the first connecting layer; after the electrode tab assembly is packaged, a first step and a second step are formed outside the package film, and the first step and the second step have a first thickness h and a second thickness j in a first direction of the battery. An object of the present application is to provide a battery capable of ensuring high sealing strength without leakage and penetration.