A battery includes a first current collector, a laminate disposed on a first region of a surface of the first current collector, a thermal-expandable layer disposed on a second region of the surface of the first current collector, and a second current collector disposed on both of the laminate and the thermal-expandable layer. The laminate includes a first active material layer disposed on the first region, an electrolyte layer disposed on the first active material layer, and a second active material layer disposed on the electrolyte layer. A thermal expansion ratio of the thermal-expandable layer is greater than a thermal expansion ratio of the laminate.