Membranes were prepared by casting a solution of a polymer and 1-butyl-3-methylimidazolium trifluoromethanesulfonate or 1-ethylimidazolium trifluoromethanesulfonate as typical representatives of aprotic and protic ionic liquids and then evaporating the solvent. The following two polymers were used: poly(vinylidene fluoride-co-hexafluoropropene) and Nafion. The prepared membranes were tested with respect to their ionic conductivity in dependence on temperature under dry conditions and under humidification. Subsequently, selected membranes were tested in a laboratory fuel cell. Whereas satisfactory ionic conductivity was observed for the prepared membranes, temperatures above 100 degrees C resulted in a low output performance of the fuel cell for all membrane materials under study. The main reason proposed for this is the low MEA conductivity for hydrogen ions. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.