TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The dispersion contains 0.5-15 mass% of fibrilliform fluorocarbon polymer. The fluorocarbon polymer is a polytetrafluoroethylene or a copolymer comprising at least 95 mol.% of polymerization units derived from tetrafluoroethylene. The fluorinated polymer having a sulfonic acid groups is a copolymer comprising polymerization units derived from tetrafluoroethylene and polymerization units derived from CF2CF(OCF2CFX)mOp(CF2)nSO3H.X = F or trifluoromethyl;A = sulfonic acid or its precursor;m = 0-3;n = 0-12;andp = 0-1.When n is 0, p is also 0. EXAMPLE - 9730 g of powdery copolymer consisting of polymerization units derived from tetrafluoroethylene and polymerization units derived from CF2CFOCF2CF(CF3)C(CF2)2SO2F and 270 g of a powdery polytetrafluoroethylene were mixed and extruded to give 9500 g pellets. The pellets were pulverized, hydrolyzed in aqueous solution containing 30% of dimethyl sulfoxide and 15% of potassium hydroxide, immersed in 1 mol/L hydrochloric acid for 16 hours, washed with water, and dried. They were dispersed in ethanol to give an ion exchange polymer dispersion (dispersion A) containing fibrilliform fluorocarbon polymer. An ethanol solution or dispersion containing the above copolymer and platinum-ruthenium alloy-supported carbon was prepared as dispersion for anodic catalyst layer. A dispersion containing 13.7 mass % of the same copolymer and a platinum-supported carbon was prepared as dispersion for cathodic catalyst layer. The anodic and cathodic catalyst layers were respective casted on polypropylene (PP) film, and dried to form respective catalyst layer. Another PP film was coated with dispersion A and dried at 80degreesC for 10 minutes forming an ion exchange membrane. The ion exchange membrane was then interposed between the two PP films. The films were then hot pressed at 130degreesC at 3 MPa for 4 minutes. The anodic and cathodic catalyst layers were then peeled off to provide membrane-electrode assembly. The assembly was then cut and mounted in a cell tester and tested. The results showed output voltages of 0.75 V initially, and became 0.70 V after 1000 hours.