Patent ID: 6685806
Filing Date: 2004-02-03
Classification: C08J,C25B,H01B,H01M,Y02E,Y02P

Abstract:
Membrane-electrode assembly that consists of a fluorocontaining cation-exchange membrane having two surfaces, wherein the membrane is made of a hydrolyzed copolymer of tetrafluoroethylene and a perfluorsulfur-contaning vinyl ether having a value of EW=equal to 900-1300 and porous electrode material layers made of an electrocatalyst, an electroconductive inactive material and fluoropolymeric binder situated on both surfaces of the cation exchange membrane, wherein the fluorocontaining cation exchange membrane is produced from a hydrolyzed copolymer of tetrafluoroethylene with a perfluorsulfur-containing vinyl ether having a degree of crystallinity of 2-8%, and wherein the porous electrode material layers are each produced with porosity 40-70%, wherein the porosity of each layer decreases in the direction of the respective cation exchange membrane surface with a gradient of 5-15% per 1&mgr;.