Polyoxometalate decorated graphene oxide/sulfonated poly(arylene ether ketone) block copolymer composite membrane for proton exchange membrane fuel cell operating under low relative humidity

A phosphotungstic acid (PW) decorated graphene oxide (GO) is explored as a filler for sulfonated poly(arylene ether ketone) (SPAEK) block copolymer. The SPAEK/PW-mGO composite membrane shows higher proton conductivity than a pristine SPAEK membrane. At 80 °C under 25% relative humidity (RH) condition, the fuel cell configured with the SPAEK/PW-mGO composite membrane shows improved fuel cell performance. A maximum power density of 772 mW cm−2 is observed for the SPAEK/PW-mGO composite membrane, whereas the pristine SPAEK membrane exhibits a maximum power density of 10 mW cm−2 operated under 25% RH at 80 °C. Compared with the NRE-212 membrane, the SPAEK/PW-mGO composite membrane exhibits 4.8-times higher maximum power density. Furthermore, the maximum current density of the SPAEK/PW-mGO composite membrane (2271 mA cm−2) is much higher than pristine SPAEK (39 mA cm−2) and NRE-212 (734 mA cm−2) membranes.