Patent ID: 8470057

Claim:
A method for producing an alkaline primary battery, comprising the steps of: (1) inserting at least one hollow cylindrical positive electrode pellet into a cylindrical battery case with a bottom and pressing the at least one positive electrode pellet to form a cylindrical positive electrode having a hollow and adhering closely to an inner face of the battery case; (2) inserting a cylindrical separator with a bottom into the hollow of the positive electrode inside the battery case, the separator including: a wound cylindrical portion; and a bottom portion that is substantially U-shaped in cross-section, the bottom portion covering an opening of the cylindrical portion at a lower end of the cylindrical portion and having an upstanding portion that extends along a lower outer face of the cylindrical portion; (3) injecting an electrolyte into the separator to impregnate the positive electrode and the separator with the electrolyte; (4) filling a gelled negative electrode into the separator; (5) inserting a negative electrode current collector into the negative electrode; and (6) sealing an opening of the battery case, wherein the amount of the electrolyte injected into the separator in the step (3) is sufficient so as to impregnate the positive electrode and the separator and immerse a lower end of the cylindrical portion of the separator in the electrolyte remaining in the separator without being absorbed by the positive electrode and the separator, thereby bringing the lower end of the cylindrical portion into contact with the upstanding portion of the bottom portion.