Patent ID: 8852774

Claim:
A method of producing a battery, comprising: a winding step of winding an electrode assembly around the circumference of a winding core; and a flattening step of pressing the electrode assembly wound in the winding step, in a direction orthogonal to an axial direction thereof to form a flattened shape in which the wound electrode assembly is flattened in a direction that is orthogonal to the pressing direction and the axial direction, wherein: at least one rod-shaped spacer is inserted, in parallel to the axial direction, into the electrode assembly wound during the course of winding the electrode assembly around the winding core in the winding step, and the spacer is pulled out from the wound electrode assembly between the winding step and the flattening step; and the at least one spacer is positioned in the winding step on a plane that passes through the shaft center of the electrode assembly and that is perpendicular to the flattening direction.