Evaluation of a sulfophenylated polysulfone membrane in a fuel cell at 60 to 110 °C
A novel sulfophenylated polysulfone membrane material has been evaluated in a hydrogen/oxygen fuel cell using Nafion-impregnated commercial electrodes. Comparative measurements were performed with Nafion membranes to distinguish between different sources of potential losses. The operational temperatures in the experiments ranged from 60 to 110 °C, and the effect of different humidifying conditions was investigated. Membranes that were operated over 300 h under fully humidified conditions showed a slight increase in the cell resistance. At lower humidification levels the cell resistance increased significantly. No difference in the membrane composition between active areas and areas not subjected to ionic currents could be detected by ATR-IR or Raman spectroscopy after fuel cell testing. The best fuel cell performance for these membranes was found at 90 °C and 100 °C. The current density at a cell voltage of 0.5 V ranged between 100 and 200 mA cm− 2 depending on the operating conditions. The relatively low current densities found when using the new membrane material are explained by high ionic contact resistances between the electrodes and the membrane.