Silicotungstic Acid Nafion Composite membrane for proton-exchange membrane fuel cell operation at high temperature

摘要

The feasibility of Nafion/Silicotungstic Acid (STA) composite membrane as solid electrolyte for PEMFCs application was shown. Composite Nafion/STA membranes were prepared from solvent evaporation of the mixtures of 5% Nafion solution containing different concentrations of STA and N,N'-dimethylformamide (DMF). From the SEM micrograph, uniform dispersed STA particles of 0.1-0.2 mu m size were observed within the Nafion/STA composite membranes. Front the ionic resistance measurement, it was found that the composite Nafion/STA membrane exhibited good ionic conductivity. Front the excellent thermal stability of the composite Nafion/STA membranes investigated by thermal analysis, it was shown that these composite membranes are more appropriate candidates for high temperatures PEM fuel applications than commercial Nafion family of membranes. The improvement in current density at 0.6 volt of the singlr cell based on the composite membranes when compared to those of the blank Nafion recast membranes was 150 mA.cm(-2) at 110 degrees C.