Macromolecule sulfonated Poly(ether ether ketone) crosslinked poly(4,4′-diphenylether-5,5′-bibenzimidazole) proton exchange membranes: Broaden the temperature application range and enhanced mechanical properties

Proton exchange membranes with a wide application temperature range were fabricated to start high-temperature fuel cells under room temperature. The volume swelling stability, oxidative stability as well as mechanical properties of crosslinked membranes have been improved for covalently crosslinking poly(4,4'-diphenylether-5,5'-bibenzimidazole) (OPBI) with fluorine-terminated sulfonated poly(ether ether ketone) (F-SPEEK) via N-substitution reactions. High proton conductivity was simultaneously realized at both high (80-160 degrees C) and low (40-80 degrees C) temperatures by crosslinking and jointly constructing hydrophilichydrophobic channels. The crosslinked membranes exhibited the highest proton conductivity of 191 mS cm(-1) at 80 degrees C under 98% relative humidity (RH) and 38 mS cm(-1) at 160 degrees C under anhydrous, respectively. Compared with OPBI membrane, the fuel cell performance of the crosslinked membranes showed higher peak power density at full temperature range (40-160 degrees C). (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.