Investigation of a direct methanol fuel cell based on a composite Nafion (R)-silica electrolyte for high temperature operation

Operation of a liquid-fed Direct Methanol Fuel Cell (DMFC) working at 145 d egrees C was demonstrated by using a composite membrane made of Nafion(R) i onomer and silica. The enhanced humidification conditions of the membrane-e lectrode (M&E) assembly allowed taking advantage of the high operation temp erature with consequent speeding up of the methanol oxidation kinetics. A p eak power density of 240 mW/cm(-2) for an oxygen-fed cell was reached; the measured methanol cross-over rate was 4 X 10(-6) moles min(-1) cm(-2). A ph ysico-chemical characterization of the cell components is also reported. (C ) 1999 Elsevier Science B.V. All rights reserved.