Secondary battery

Abstract

A secondary battery includes: a battery element; a casing which accommodates the battery element; a positive electrode terminal and a negative electrode terminal provided to the casing and electrically connected to the battery element; and a cut-off portion which switches from a grounded state in which the casing and one terminal of the positive electrode terminal and the negative electrode terminal have an identical potential, to a cut-off state in which the casing and the one terminal are electrically cut off. The one terminal has a facing portion which faces the casing, and the cut-off portion is arranged between the facing portion and the casing. When the casing is externally short-circuited, the cut-off portion switches from the grounded state to the cut-off state by being deformed by heat generated as a short-circuit current flows.

Dependencies are inferred from the claim text.