Patent attributes
Provided is a secondary battery which can more securely suppress vibrations applied to a current interrupting mechanism. A secondary battery including: a current interrupting mechanism that interrupts a current path between an external terminal and an electrode in a battery container. The current interrupting mechanism includes a collector plate that is connected to the electrode, a diaphragm that is connected to a base portion of the collector plate and disconnected from the base portion by being deformed when a pressure in the battery container is increased, and an insulating member that fixes the diaphragm and the base portion of the collector plate on the inside of the battery container. The insulating member includes a plurality of projections that protrude in a thickness direction of the base portion, and the base portion includes a plurality of notches through which the projection passes in the thickness direction. The projection includes an engaging member that is engaged with an end surface of the base portion on a side opposite to the insulating member and a side surface of the base portion along the thickness direction.