US Patent 10217971 Power storage unit and electronic device

A power storage unit or the like which has flexibility is achieved. An exterior body has projections and depressions. For example, part of the exterior body has projections and depressions in a wave cross-sectional shape. The shape of the projections and depressions is not limited to a shape with a curve and may be a shape with a straight line, such as a rectangle wave shape or a triangle wave shape. The projections and depressions allows the exterior body to be easily shrunk on the inner side of a bend portion and easily stretched on the outer side of the bend portion.