SQUARE-SHAPE CLOSED BATTERY

摘要

A rectangular and sealed battery incorporating an outer can for accommodating a power generation element and a cover for closing an opening of the outer can such that the outer can and the cover are welded to each other. The thickness of a body portion of the outer can is smaller than the thickness of the opening. A flange formed into a stepped portion is provided for the outer end of the cover, and the end of the opening of the outer can is made contact with the outer surface of a projection of the cover formed by the stepped portion so as to be joined to the outer surface of the projection and butt-welded to the flange. In the foregoing case, the cover and the end of the opening of the outer can are welded to each other from a side direction.