Patent ID: 9028955
Filing Date: 2015-05-12
Classification: C08J,G01N,H01M,Y02E,Y10T

Abstract:
1. An electrochemical cell comprising an ion permeable, liquid and vapor impermeable, membrane made by the method of: a. dissolving high molecular weight polyisobutylene polymer having an average molecular weight of at least about 80,000 in a dry first solvent to produce a first solution; b. dissolving poly(acrylic acid) polymer having a molecular weight of at least about 100,000 in a dry second solvent and neutralizing to form a second solution; c. mixing the first solution with the second solution to form a solution mixture comprising about 4 wt % to about 6 wt poly(acrylic acid) polymer based on polymers in the solution mixture; d. casting a film of the solution mixture on a casting surface and removing the first solvent and second solvent; e. thereby forming an ion permeable, liquid and vapor impermeable, membrane having a thickness of about 0.1 millimeters or greater.