Copolymer synergistic coupling for chemical stability and improved gas barrier properties of a polymer electrolyte membrane for fuel cell applications. (28th February 2020) - Ben youcef, Hicham
Abstract: A novel radiation grafted ETFE based proton conducting membrane was prepared by double irradiation grafting of two different monomers. The intrinsic oxidative stability of the ETFE-g-poly(styrene sulfonic acid-co-divinylbenzene) membrane was improved by reducing the gas crossover through incorporation of polymethacrylonitrile (PMAN) containing the strong polar nitrile group. A fuel cell test was carried out at 80 °C under constant current density of 500 mA cm −2 for a time exceeding 1′900 h. The incorporation of PMAN considerably improves the interfacial properties of the membrane-electrode assembly. No significant change in the membrane hydrogen crossover and performance over the testing time was observed, except for a measured decrease in the membrane ohmic resistance after 1′000 h. The combination of the double irradiation induced grafting with the use of the PMAN as gas barrier in addition to its chelating abilities (e. g. Ce 3+ ) offers a promising strategy to develop more durable membranes for fuel cells. Graphical abstract: Image 1 Highlights: Double irradiation grafting of two different monomers was performed for the first time in literature. Methacrylonitrile re-grafted membranes were, for the first time, prepared for PEM fuel cells. Dimensional stability was improved by the methacrylonitrile re-grafted membranes. The Nitrile groups enhance the gas barrier properties of the tested membranes. Promising PEM Fuel cell durability results were obtained with the re-grafted membranes.