Cap assembly having improved stability and cylindrical secondary battery including the same

Abstract

The present invention relates to a cap assembly formed of a composite of cap assembly ceramic for the cylindrical battery and mounted on a top end portion of the cylindrical secondary battery in which an electrode assembly is placed in a cylindrical can, which includes a safety vent having a predetermined notch configured to be ruptured by high pressure gas generated in the battery, a current interrupt device coupled to a lower end of the safety vent and blocking a current when an internal pressure of the battery rises, and a gasket for the current interrupt device surrounding an outer circumferential surface of the current interrupt device, wherein the gasket for the current interrupt device comprises a polymer resin having a melting point of 250° C. or more and a heat deflection temperature (HDT) of 200° C. or more, and a cylindrical secondary battery including the same.

Dependencies are inferred from the claim text.