A battery includes a conductive substrate, the conductive substrate including a first resin layer, a barrier layer, a second resin layer, a first electrode current collector layer, and a first electrode coating layer that are sequentially stacked inward from an outermost side of the battery, an exterior member disposed to face the conductive substrate, a sealing portion formed at edges of the conductive substrate and the exterior member, and at least one second inner electrode positioned between the conductive substrate and the exterior member and stacked using a separator as a border.