Secondary battery

Provided is a secondary battery including an electrode assembly and an outer case configured to house the electrode assembly. The secondary battery includes a terminal member provided on the outer case with an insulating material interposed therebetween and connected to a tab of the electrode assembly. The outer case is provided with a cavity through which the tab passes, the terminal member is bonded onto a surface of the outer case with the insulating material interposed therebetween, the surface being positioned around the cavity, and a part of a width dimension of a bonding region provided to surround the cavity for the bonding is reduced.