SQUARE BATTERY AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a square battery in which sealing reliability between a body member and a lid member constituting a battery case can also be enhanced between the R part of opening and the R part of a lid.SOLUTION: The battery case 110 of a square battery 100 includes a bottomed square cylindrical body member 111 having a rectangular aperture 111h consisting of an aperture long side 111a, an aperture short side 111b and an aperture R part 111r, and a rectangular lid member 113 for sealing the aperture 111h. The aperture 111h has a wall thickness t3 at the aperture R part 111r set thicker than the wall thickness t1 of the aperture long sides 111a. The aperture 111h and the lid peripheral part 113f are welded airtightly over the whole circumference with an energy beam LS irradiated from the outside of the lid member 113 in the thickness direction.