IMPROVED MEMBRANE-ELECTRODE UNITS AND FUEL CELLS HAVING A LONG SERVICE LIFE

摘要

The invention relates to a membrane-electrode unit comprising two gas diffusion layers each in contact with a catalyst layer, separated by a polymer- electrolyte membrane. The polymer-electrolyte membrane comprises an inner region which is in contact with a catalyst layer, and an outer layer which is not provided on the surface of a gas diffusion layer. The inventive membrane- electrode unit is characterised in that the thickness of the inner region of the membrane decreases by at least 5 % at a pressure of 5 N/mm2 over a period of 10 minutes, and the thickness of the outer region of the membrane is greater than the thickness of the inner region of the membrane.