Varying thicknesses of ethylene-co-tetrafluoroethylene (ETFE) Alkaline Anion Exchange Membranes (AAEMs) with quaternary ammonium functional groups were prepared using e-beam irradiation. The performances in H-2/O-2 single cell fuel cells were tested at 50 degrees C with the thinnest AAEM (S2O) achieving the highest peak power density of 230 mW cm(-2). The ability to use non-Pt electrocatalysts for the oxygen reduction reaction (ORR) at the cathode was also investigated. (C) 2009 Elsevier B.V. All rights reserved.