Frédéric Grasset

Control of water profile and development of dimensionally stable sulfonated polyaromatic PEMFC membranes

Hierarchical organization of sulfonated polymer membranes into multilayers or a porous arrangement has been favored during preparation using solvent casting procedures. Depending on the preparation conditions, different types of membrane morphology are observed, including gas-tight microporous membranes, in which the pores are occluded or coated on their inner surface by a solid inorganic acid. The conduction properties of such filled pore membranes show different temperature and relative humidity dependence from equivalent dense sPEEK-based systems, and essentially no dimensional change between water-soaked and dry states. Multilayer systems associating sulfonated polyetheretherketones of different water uptake characteristics influence the hydration profile across the membrane in an operating fuel cell, and can extend membrane lifetime.