Patent ID: 8247111

Claim:
An alkaline battery, comprising a battery casing and a sealing unit sealing an opening part of the battery casing, wherein the sealing unit includes a negative electrode terminal plate, a negative electrode current collector joined to the negative electrode terminal plate, and a gasket, the gasket includes a boss part through which the negative electrode current collector passes, an outer peripheral part in contact with the opening part of the battery casing, and an annular part arranged between the boss part and the outer peripheral part, a part of the annular part being formed into a thin part serving as a safety valve, the negative electrode current collector has a body diameter of 1.8 mm or smaller and includes at an end part thereof a collar part, and a ratio of an outer diameter of the boss part to an outer diameter of the collar part is 3.1 or larger and 4.0 or smaller.