| 摘要 |
PROBLEM TO BE SOLVED: To obtain a square secondary battery the productivity of which can be improved by shortening a time required for a liquid injection process since a required amount of an electrolyte can be surely injected into a battery can in a short time.SOLUTION: This square secondary battery C1 includes a wound electrode group 6 having metal foil lamination parts 6F, 6G formed at end parts in the winding axis direction by winding electrode plates 6E, 6D, a bottomed square-shaped battery can 20 for housing the wound electrode group 6 in an attitude state in which the winding axis direction laterally extends, and a battery lid 1 which blocks an opening part 20a opened toward the upper part of the battery can 20 and in which a liquid injection port 22 for injecting an electrolyte is opened and formed. A facing surface part abutting on the metal foil lamination parts 6F, 6G of the wound electrode group 6 and facing the battery lid 1 is deformed, and protrusions 37, 47 forming recessed grooves 6J, 6K continuing toward the outside of the winding axis direction on the facing surface part are thereby provided. |
