Composition Nafion/zirconium phosphate membranes for direct methanol fuel cell operation at high temperature

A direct methanol fuel cell with a composite Nafion-zirconium phosphate electrolyte membrane was investigated and exhibited good performance at operating temperatures up to similar to 150 degreesC with dry oxidant, under mild fuel preheating conditions (85 degreesC). Typical cell resistances of 0.08 Ohm cm(2) were observed under cell operation at 140-150 degreesC. Maximum power densities of 380 and 260 mW cm(2) were achieved under oxygen and air feed, respectively. The distribution of zirconium phosphate inside the membrane was quite uniform, as shown by scanning electron microscopy energy dispersive analysis by X-ray. X-ray diffraction spectra showed modifications in the crystallographic structure of zirconium phosphate entrapped in the membrane upon hydration. (C) 2001 The Electrochemical Society.