A battery and battery package is disclosed which improves a battery's heat dissipation capability by using an aluminum material and a phase change material capable of maintaining a suitable temperature through phase change according to a temperature in order to prevent a battery from being deteriorated in terms of performance. More specifically, battery package has a top case and a bottom case as a battery cell case for housing a battery cell. The top and bottom cases are adhered to each other, and either or both the top and bottom cases includes: a top sheet plate repeatedly undulated at predetermined intervals to form a plurality of unidirectionally extended convex parts to be filled with a phase change material; a bottom sheet plate formed in a flat shape and adhered to the top sheet plate; and a phase change material filled in between the convex parts and the bottom sheet plate.