FLAT SQUARE BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a flat square battery having structure solving a problem of sealing performance drop caused by making a flat battery square. SOLUTION: A power generating element is housed in an inner space formed by facing and assembling a battery case 2 formed in a semi-shell body having a square flat shape and the opening side of a sealing case 3, and a gasket 4 is compressed against a step 35 of the sealing case 3 by calking work of bending the opening end of the battery case 2 via the gasket 4 to seal the battery case 3. A V-shaped notch 36 is formed in a corner 34 where a side circumferential surface 32 on a bottom 31 of the sealing case 3 stands to increase strength, and sealing performance drop caused by bulging outward of the straight part of the side circumferential surface in sealing is prevented.