SULFONATED POLYSULFONE MEMBRANES FOR HIGH TEMPERATURE IN POLYMER ELECTROLYTE FUEL CELLS (PEFC)

In this work the synthesis of sulfonated polysulfone (PSF) with three different sulfonation levels was carried out and several membranes were developed with the corresponding polymers. The membranes were characterised in terms of ion-exchange capacity (IEC) and water up-take. Electrochemical tests in a single cell fed with H2/air were also carried out on the Membrane-Electrodes Assemblies (MEAs) prepared with the developed membranes in a temperature range of 80-120°C and compared to commercial Nafion 112 (N112). Chemical-physical properties of the tested membranes have got a good reproducibility and comparable values with commercial Nafion. A maximum power density of about 360 mW/cm2 for PSF (at 0.6 V) was obtained and the measured OCV value for PSF membrane is higher than the perfluorinated membrane (0.943 V for PSF and 0.862 for N112) indicating a lower gas permeability of polysulfone polymer.