| 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.SOLUTION: This square secondary 1 has a wound electrode group 4 having electrode foil lamination parts 11d, 12d formed by flatly winding electrode plates 11, 12 at the end portion in the winding axis direction, a battery can 2 for housing the wound electrode group 4 in an attitude state in which the winding axis direction of the wound electrode group 4 laterally extends and having an opening part in the upper part thereof, and a battery lid 3 which blocks the opening part of the battery can 2 and in which a liquid injection port 42 for injecting an electrolyte into the battery can 2 is provided. The battery can 2 has swollen parts 2A swelling so as to part from the electrode foil lamination parts 11d, 12d continuously from the upper part of the battery can 2 to the lower part thereof at a position facing the electrode foil lamination parts 11d, 12d of the longitudinal wall part PW of the battery can 2. |
