Abstract: Disclosed is a non-aqueous electrolyte composition for batteries, which is composed of a mixture of a fluorobenzene component and a carbonic acid ester component in which the volume ratio of the fluorobenzene component to the carbonic acid ester component ranges from 50:50 to 5:95. The non-aqueous electrolyte composition has a significant advantage over electrolyte compositions employing carbonic acid ester solvents only, in terms of low temperature performance, cell life, and high-temperature dischargeability.

Abstract: A sealed battery includes a can for receiving an electric generator, the can having an opened top end, a deformable plate air tightly mounted on the opened top with a gasket disposed between the deformable plate and an inner wall of the opened top end, a terminal cap disposed on the deformable plate, the terminal cap being elevated except for an edge, and a circuit breaker disposed between the deformable plate and the terminal cap to cut-off current flow when the deformable plate is deformed by internal pressure increased above an allowable level.