Patent ID: 9362588
Filing Date: 2016-06-07
CPC Classification: H01M,Y02E,Y02P,Y10T

Claim Text:
1. A lithium-ion secondary battery, comprising: an electricity-generating element including a wound electrode structure that is formed by winding electrodes into a flat form, wherein the electrodes are connected to a pair of electrode terminals; a battery container that includes: a battery casing having an opening, a battery cover configured to cover the opening in the battery casing, and one pair of electrode terminals provided on the battery cover via an electrical insulating member; and an electrical insulating protection film of a sheet-like form that is wrapped around the wound electrode structure and the pair of electrodes in a direction that is orthogonal to an axial direction of the winding of the wound electrode structure, wherein the electrical insulating protection film includes: a protruding end portion on a lateral end of the insulating protection film that extends beyond the wound electrode structure towards a bottom of the battery casing and away from the battery cover, wherein the protruding end portion have opposed portions that are joined together into mutual surface contact, a fold over integral to the protruding end portion that is formed by folding lowermost edges of the opposed portions, and a sealed portion formed by sealing off the lowermost edges of the opposed portions.