This presentation will describe the latest research at the University of Surrey on the development of high-performance anion-exchange membranes (AEM) and ionomers (AEI) for use in alkaline membrane fuel cells (AEMFC). These anion-exchange polymer electrolyte matreials are produced using the peroxidation pre-irradiation grafting method (RG).

Recent achievements that will be discussed in this presentation include:

• Synthesis of RG-AEMs with new chemistries that are more stable to alkali than those containing the benzyltrimethylammonium benchmark;
• The ability to produce RG-AEMs based on low density polyethylene (LDPE) as well as poly(ethylene-co-tetrafluoroethylene) (ETFE);
• Synthesis of thinner AEMs (< 30 μm thickness);
• Synthesis of an interesting class of RG-based solid-state AEI powders;
• AEMs with high hydroxide conductivities and high performances in hydrogen-fuelled AEMFC;
• Advanced use of Raman micro-spectroscopy for studying radiation-grafted anion-exchange polymer electrolytes.

We will demonstrate that changes in head-group chemistry can switch off several alkali degradation mechanisms for RG-AEMs. We will also show that 2 W cm^-2 peak power densities can be achieved in H₂/O₂ AEMFCs containing Pt cathodes and > 1 W cm^-2 can be achieved with non-platinum-group-metal cathodes. The figure below shows the performance of a thin ETFE-based RG-AEM in H₂/O₂ and H2/air(CO₂-free) AEMFCs when Ag/C cathode is used as a cathode electrocatalyst.