Producing method of power storage device

A producing method of a power storage device, including:

• roll pressing a mixture laminated portion of a wide strip-shaped electrode plate which includes the mixture laminated portion of a strip shape in which an electrode mixture layer is laminated on a surface of a strip-shaped current collecting foil extending in a longitudinal direction and a pair of mixture non-laminated portions of the current collecting foil in which no electrode mixture layer is laminated, the mixture non-laminated portions extending in the longitudinal direction on both sides of the mixture laminated portion in a width direction orthogonal to the longitudinal direction,
• non-laminated-portion stretching of stretching the pair of the mixture non-laminated portions of the wide strip-shaped electrode plate in the longitudinal direction, and
• laminated-portion stretching of stretching a pair of mixture non-laminated-portion-side sections of the mixture laminated portion placed on sides close to the mixture non-laminated portion, wherein
• the roll pressing, the non-laminated portion extending, and the laminated portion extending are allowed to be performed in any order,
• the producing method includes:
• cutting the wide strip-shaped electrode plate, which has been finished with the roll pressing, the non-laminated-portion extending, and the laminated-portion extending, in the longitudinal direction at a center in the width direction to divide the wide strip-shaped electrode plate into two strip-shaped electrode plates,
• winding up each of the two strip-shaped electrode plates in a roll-like shape around a winding core with applying a tensile force in the longitudinal direction to form two electrode rolls,
• storing each of the two electrode rolls, and
• electrode plate producing of cutting the strip-shaped electrode plates configuring the electrode rolls, which have been through with the storing, by a predetermined length to produce a plurality of electrode plates.