Polybenzimidazoles for High Temperature Fuel Cell Applications

Fuel cells were designed for high temperature operations. Poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI) was synthesized in a solution of P 2 O 5 , CH 3 SO 3 H, and CF 3 SO 3 H. The PBI was dissolved in a mixture of CF 3 CO 2 H and H 3 PO 4 and the solution was used for the preparation of Pt catalyst slurry for membrane electrode assembly. The single cell showed a current density of 280 mA.cm -2 at a cell voltage of 0.5 V with feeds of H 2 and O 2 at 160 °C and without external humidification.