SQUARE BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a battery the battery can side surface of which expands little at the time of recharging. SOLUTION: This square battery storing battery elements layering a positive electrode and a negative electrode through a separator or flat battery elements winding the positive electrode and the negative electrode around them through the separator has a recessed part connecting an inclined surface with no step difference and a flat part at least one an end part on the bottom surface side of a battery can at least on either one surface of the battery can side surface in parallel with a layered surface or a flat surface of the battery elements.