“Hybrid” Anion-Exchange-Membranes for Direct Ethanol Fuel Cells

Abstract

In the past few years, we have developed novel anion-exchange-membranes (AEMs) based on block copolymers for H2/O2 fuel cell applications [1-2] and discovered that dimensional stability of an AEM is very critical for achieving optimal performance in the fuel cells. Since ethanol is a non-toxic bio-fuel with a rather high energy density, it has attracted great attentions to be fed directly into polymeric electrolyte fuel cells. Ethanol oxidation reaction (EOR) in an alkaline media is much faster than that in an acid media and can be catalyzed on non-Pt catalysts. In this work, we aim to develop AEMs suitable for direct ethanol fuel cell (DEFC) applications.Four types of AEMs were prepared by varying "hybrid" SEBS-based copolymers. The swelling, water uptake, ionic conductivity, thermal stability and ion exchange capacity of the membranes were measured using the methods described in our previous work [1]. The impacts of ionic exchange capacity in the membranes on the performance of DEFCs were studied and compared with the commercial membrane (Tokuyama’s A201).DEFCs performances of various "hybrid" types of QSEBS membranes (Type I, II, III and IV) and commercial membrane (A201) will be presented. The correlations of the swelling, water uptake, ionic conductivity, thermal stability and ion exchange capacity of the membranes with the performance of DEFCs will be established and discussed. The key factors for developing AEMs for DEFC applications will be identified.