Synthesis and characterisation of alkaline anionic-exchange membranes for direct alcohol fuel cells

Materials Science and Manufacturing, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001, South Africa *snonjola@csir.co.za INTRODUCTION Great effort in research and development has been made over the years to improve and commercialize new systems (e.g. Fuel Cells) of generating electricity. The use of polymer electrolytes represents an interesting path to pursue for these systems, the most important being proton exchange membrane fuel cell (PEMFC), which uses an acidic membrane like Nafion (sulfonated fluorocarbon polymers) as an electrolyte [1]. However, when Nafion membranes are applied to direct alcohol fuel cells (DAFCs), several obstacles emerge, i.e. methanol crossover and relative low activity [2]. Therefore, there is a need for the development of novel anion exchange membranes (AEMs) that can be applied in these systems. In alkaline fuel cells, the OH anions are produced at the cathode and then transported through the membrane to the anode where they are consumed (opposite to the movement of protons in acidic membranes). The pathway of the OH anions opposes the direction of methanol flux through the membrane leading to an intrinsic reduction in methanol crossover (Figure 1) [3].