CAP ASSEMBLY WITH IMPROVED STABILITY AND CYLINDRICAL SECONDARY BATTERY INCLUDING THE SAME

摘要

The present invention relates to a cap assembly which is mounted on the opened upper part of a can in a battery with a structure where an electrode assembly is built into a cylindrical can. The cap assembly comprises: a safety vent with a certain notch to be disconnected by high pressure gas from a battery; a current blocking member which is welded with the lower end of the safety vent and blocks the current when the inner pressure of the battery increases; and a gasket for the current blocking member which surrounds the outer peripheral surface thereof. The current blocking member includes two or more through-holes for gas discharge. The total area of the through-holes is 20% - 50% based on the total area of the current blocking member.