Nafion®/clay-SO3H membrane for proton exchange membrane fuel cell application

In this work, Nafion®/Laponite nanocomposite membranes for proton exchange membrane fuel cells (PEMFC) were studied. Nanocomposite membranes were prepared by a recasting procedure using a Nafion® solution mixed with Laponite particles containing sulfonic acid groups bonded to its surface. The surface modification of the clay particles takes place via plasma activation. First, the influence of temperature and relative humidity on the proton conduction of the nanocomposite membranes was studied and compared to the commercial Nafion® reference. It appeared that the proton conductivity of the nanocomposite membrane is higher than that of the commercial Nafion® for all the temperature ranges studied (20–95 °C) with a more significant difference at low relative humidity. Then, the desorption kinetic of the water content was evaluated at different temperature levels for the nanocomposite and commercial membranes. All results show that the addition of the inorganic compounds to Nafion® improves the water retention of the membrane. Finally, the performance of the membrane–electrode assembly (MEA) using the nanocomposite membrane was evaluated by a fuel cell test under different operating conditions. The results obtained show that the performance of the MEA using the nanocomposite membrane is better than the one of a commercial Nafion® membrane, with a more important difference at high operating temperatures.