Electrolyte Materials for Alkaline Membrane Fuel Cells (AMFC) and Their Cell Performances

Abstract

Abstract: Recently the alkaline membrane fuel cells (AMFCs) enhance their presence because of the possibility of non-precious-metal catalyst and low overpotential at cathodic reaction. The anion exchange membrane (AEM) and ionomer for AMFCs should be key materials in order to achieve the practical performance as fuel cells. We are developing anion exchange membranes and anion-conducting ionomers for AMFCs, which have hydrocarbon type main chain and quaternary ammonium unit. The optimized AMFC shows better performance in H₂/O₂ system. The cell performance strongly depends on CO₂ gas. Carbonation of the alkaline membrane easily occurred in ambient air. The absorbed CO₂ gas in alkaline membrane should be released through power generation of AMFC. This phenomenon was called “self-purging” and it will prevent from lower ion conductivity of alkaline membrane during power generation of AMFC.