Monomers, polymers and cross-linked membranes for membrane fuel cells and electrolysis

Abstract

This contribution comprises an overview about work in the development of ionomers/ionomer (blend) membranes for fuel cells. The topics include the development of novel sulfonated monomers and homo- and copolymers; the preparation of ionically cross-linked membranes prepared by mixing these polymers with different polybenzimidazoles (PBI); the application of these membranes to PEFC and DMFC; development of novel base-excess PBI/sulfonated polymer/H3PO4 blend membranes, and test of these membranes in fuel cells at intermediate fuel cell operation temperatures (170-200°C). These membranes have been tested in a DMFC. The i/U polarization curves of the membranes showed a better performance than Nafion®. Acid-base blend membranes were also applied to the HyS electrolysis process, showing good stability and electrolysis performance. Phosphonated polymers and ternary blend membranes for the application in intermediate T fuel cells have been developed as well. These membranes showed good, their chemical stability being even better than that of pure PBI membranes