PEM FUEL CELL CATALYST AND DIFFUSION LAYER STRUCTURE FOR INCREASED WATER STORAGE CAPACITY AND IMPROVED COLD START PERFORMANCE

摘要

Water produced during startup in sub-freezing conditions is accommodated by the various porous structures within the fuel cell. In one example, an interface between a catalyst layer and a gas diffusion layer includes a temperature responsive material that variably absorbs/desorbs water to temporarily increase water storage capacity at low temperatures. In another example, a catalyst layer with porosity of greater than 40% and contains hydrophilic membrane, a perfluorosulfonic acid material, with an equivalent weight of less than 1100 per equivalent weight gram. In yet another example, a gas diffusion layer having a carbon substrate treated with a modifier material to increase fuel cell water storage capacity under sub-freezing conditions.