Hybrid Materials for Electrochemical Energy Conversion

Abstract

Electrodes in electrochemical reactors – in particular batteries, electrolyzers and fuel cells -for energy conversion need to fulfill several functionalities that often lead to materials problems. In general, a combined electronic and ionic conductivity is needed with adequate gas or mass transport (porosity) properties as well as chemical and mechanical stability in aggressive environments. These conflicting properties are rarely achieved with homogeneous materials and therefore a hybrid material approach is quite common in electrochemical energy conversion. Hybrid materials are often a nanometer dispersed combination of metal or metal oxides with polymeric materials, e.g. ionomers with ionic conductivity or polymeric binders. This contribution will present selected examples for electrolyzers, fuel cells and lithium batteries and discuss how technological driven approaches can help to design electrodes with superior performance and stability. Characterization to evaluate performance structure relationships will be discussed with respect to the following hybrid configurations: • Electrodes for oxygen evolution reaction with amorphous IrOx and electroceramic supports with ionomer • Ceramic perovskites/Ni anode materials as alternative solid oxide fuel cell anodes • Cathode composites with sulfur, carbon and polymer • Gas diffusion electrodes for metal air and polymer electrolyte fuel cells