Patent ID: 8663868

Claim:
An ion conductive membrane composite comprising: a) a shaped article in the form of a network of interconnected micropores, the shaped article comprising: polyvinylidene fluoride or copolymers thereof, a sufficient quantity of nucleating agent to initiate crystallization of the polyvinylidene fluoride or copolymers thereof at a significantly greater number of crystallization sites as compared to crystallization without the nucleating agent, and wherein the shaped article has been oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0 to provide a network of micropores wherein the micropore size is greater than approximately 0.4 micron, and the shaped article has a thickness less than approximately 1.5 mils and a Gurley less than approximately 10 sec/50 cc; and b) a sufficient quantity of ionomer electrolyte filling at least 95% of the pore volume of the micropores of the shaped article to allow the membrane composite to function as an ion conductive membrane.