MEMBRANE ELECTRODE UNITS AND FUEL CELLS WITH AN INCREASED SERVICE LIFE

WIPO Patent Application WO2006008158

A3

The invention relates to a membrane-electrode unit comprising two gas diffusion layers, each layer being in contact with a catalyst layer and said gas diffusion layers being separated by a polymer electrolyte membrane. A polymer frame is provided on at least one of the two surfaces of the polymer electrolyte membrane that are in contact with the catalyst layer. Said polymer frame comprises an inner region that lies on at least one surface of the polymer electrolyte membrane and an outer region that lies outside the gas diffusion layer. The thickness of all components of the outer region is between 50 and 100 % of the thickness of all components of the inner region. The thickness of the outer region is reduced by a maximum 2 % at a temperature of 80 °C and a pressure of 10 N/mm