(Invited) Reaction Kinetics and Gas Permeability Properties of Thin Film Ionomers for High-Temperature Polymer Electrolyte Membrane Systems

Abstract

Polymer electrolyte membranes and binders are important materials to the performance and efficiency of numerous electrochemical processes such as electrolyzers and fuel cells. This talk presents the impetus behind the re-emergence of high-temperature polymer electrolyte membrane (HT-PEM) fuel cells. New polymer architectures based upon polycation-acid anion interactions have resulted in superior HT-PEMs in terms of ionic conductivity and stability over the classic phosphoric acid imbibed polybenzimidazole (PBI). Despite the advent of more functional membranes, gas reactant transport and reaction kinetic limitations in electrode layers still stymie the power density of HT-PEM fuel cells. To address these problems, our lab has leveraged high-throughput experimental methods to study the electrochemical properties of thin film high-temperature polymer electrolytes. These methods include a new class of interdigitated electrodes featuring nanoscale electrocatalysts from block copolymer templating. Furthermore, the new HT-PEMs and binders developed in our lab are effective for carrying out challenging hydrogen separations from reforming effluents.