Composite Nafion/Zirconium Phosphate Membranes for Direct Methanol Fuel Cell Operation at High Temperature

Abstract

A direct methanol fuel cell with a composite Nafion-zirconium phosphate electrolyte membrane was investigated and exhibited good performance at operating temperatures up to ∼150°C with dry oxidant, under mild fuel preheating conditions (85°C). Typical cell resistances of 0.08 Ω cm2 were observed under cell operation at 140-150°C. Maximum power densities of 380 and 260 mW cm2 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. © 2001 The Electrochemical Society. All rights reserved.