Patent ID: 8790817

Claim:
A pouch-type lithium secondary battery, comprising: an electrode assembly; and a case comprising, a first case portion having a receiving part that defines side walls to receive the electrode assembly and a wing part having a free end and a first and a second side that extends from the receiving part, and a second case portion folded onto the first case portion so as to close the receiving part of the first case portion so as to retain the electrode assembly therein, the second case portion having an outer part that is sealed to the wing part, and an extension part that extends from the outer part and is folded toward the free end of the wing part and is then folded towards the side walls of the first case portion so as to cover the free end and contact the first and second sides of the win art wherein the extension part comprises a first part that extends away from the receiving part, a second part that is bent from the first part and extends around the free end of the wing part, and a third part that is bent from the second part and extends toward the receiving part, and wherein the third part contacts the receiving part and wing part.