BATTERY AND METHOD FOR MANUFACTURING BATTERY

A battery capable of changing its form safely is provided. A bendable battery having a larger thickness is provided. A battery with increased capacity is provided. For an exterior body of the battery, a film in the shape of a periodic wave in one direction is used. A space is provided in an area surrounded by the exterior body and between an end portion of the electrode stack that is not fixed and an interior wall of the exterior body. Furthermore, the phases of waves of a pair of portions of the exterior body between which the electrode stack is located are different from each other. In particular, the phases are different from each other by 180 degrees so that wave crest lines overlap with each other and wave trough lines overlap with each other.