Patent ID: 7943251

Claim:
A rechargeable battery, comprising: a cap assembly comprising, a safety vent that comprises a protrusion that bends in response to an increase in the internal pressure of the battery, and a current interrupt device arranged on an upper portion of the safety vent, wherein the current interrupt device comprises, an outer ring, an upper conductive thin film arranged on an upper surface of the outer ring, a lower conductive thin film arranged on a lower surface of the outer ring, a cross bar that extends across a center portion of the outer ring and is coupled with inside edges of the outer ring, wherein the cross bar comprises, a central breakage part formed by weakening the cross bar at a center portion of the cross bar, at least one first via hole arranged between the central breakage part and an end of the cross bar, the upper conductive thin film arranged on an upper portion of the cross bar, the upper portion of the cross bar comprising at least an area from an end of the cross bar at the outer ring to the first via hole, the lower conductive thin film arranged on a lower portion of the cross bar, the lower portion of the cross bar comprising at least an area from an end of the cross bar at the outer ring to the first via hole, an upper uncovered portion where the upper conductive thin film is not formed on an upper portion of the cross bar between the first via hole and one end of the crossbar at the outer ring, a lower uncovered portion where the lower conductive thin film is not formed on a lower portion of the cross bar between the first via hole and the other end of the crossbar at the outer ring, and a first conductive layer arranged on an inner wall of the first via hole and electrically connected with the upper conductive thin film and the lower conductive thin film.