Imidazolium Trifluoromethanesulfonate sPEEK Composites for Anhydrous High Temperature Proton Exchange Membrane Fuel Cells

Imidazolium Trifluoromethanesulfonate (IFMS) was inserted into a sPEEK host, and a systematic evaluation of the pristine sPEEK, and reference composites was performed. With electrochemical impedance spectroscopy (EIS) data from the series of polymer, solid-acid, and composites, it was shown that both the anion and cation are involved in proton conduction as well as the sulfonate group on the polymer. EIS also depicted the maximum salt content for highest proton conductivity, collected in anhydrous conditions at 120°C, of 1.1*10-3 S/cm with the least amount of salt, which was 37%. These dynamics were observed in 1H solid state NMR.