Patent ID: 7910238

Claim:
An alkaline battery comprising: a battery case; a power generating element housed in an interior of said battery, an assembled sealing part for closing an opening of said battery case; and an alkaline electrolyte included in said power generating element, said power generating element comprising a positive electrode material mixture brought into close contact with the inner wall of said battery case, a gelled negative electrode disposed in a hollow of said positive electrode material mixture, and a separator disposed between said positive electrode material mixture and said gelled negative electrode, said assembled sealing part including a negative electrode terminal plate, a negative electrode current collector having a head for providing an electrical connection with said negative electrode terminal plate and a shank, and a resin sealing member, said sealing member including a central cylindrical portion having a through-hole for inserting the shank of said negative electrode current collector therethrough, a peripheral cylindrical portion interposed between a periphery of said negative electrode terminal plate and an end portion of the opening of said battery case, and a joint portion for joining said central cylindrical portion and said peripheral cylindrical portion, the shank of said negative electrode current collector being inserted in the center of said gelled negative electrode, the end portion of the opening of said battery case being curved such that an upper portion of the peripheral cylindrical portion of said sealing member is wrapped therein, and the curved portion of said battery case being crimped inward such that the periphery of said negative electrode terminal plate is fixed tightly, wherein said sealing member includes polyamide having an equilibrium moisture content at a relative humidity of 50% of 0.9 to 1.7%, the lower face of said central cylindrical portion of said sealing member is in contact with said gelled negative electrode, and in said assembled sealing part before assembling, a diameter A of the shank of said negative electrode current collector, and a diameter B of said through-hole and an outer diameter C of said central cylindrical portion at a relative humidity of 50% satisfy A/B=1.02 to 1.12 and C/A=1.8 to 3.2.