Modifications of Sulfonic Acid Based Membranes
Aiming at intermediate temperature operation (100 150 degC) composite polymer electrolyte membranes consisting of perfluorosulfonic acid (PFSA) ionomer and inorganic fillers, particularly short side chain perfluorosulfonic membranes, e.g. Aquivion(r) membranes with an equivalent weight of 790 850 g eq 1 and their composites with inorganic fillers represent a practical approach to advanced membrane materials. This chapter is devoted to an updated review of the methodologies and materials including their practical applications in direct alcohol fuel cells, water electrolysers, and automotive hydrogen fuel cells. An analysis of the basic operation mechanism of such materials is provided and the characteristic performances achieved under intermediate temperature operation are reviewed. The influence of the surface chemistry and acid base characteristics of the inorganic fillers is also discussed.