Enhanced Conductivity in Polyanion-Containing Polybenzimidazoles. Improved materials for proton-exchange membranes and PEM Fuel Cells

摘要

In an effort to develop improved Proton Exchange Membranes for Polymeric Fuel cells two different forms of polyanion inclusionudin poly(2,5-benzimidazole) (ABPBI) have been carried out. Namely by (i) sulfonation of pre-formed polymer membranesudand (ii) by addition of inorganic phosphomolybdic acid to form hybrid ABPBI–PMo12 membranes. In both cases we have detectedudan increased proton conductivity of the resulting membranes, associated to an enhanced capacity of the polyanion-modified materialsudto uptake phosphoric acid (in comparison with previously known ABPBI or even commercial PBI membranes). These newudmembranes are stable up to 200 C and feature high conductivities at these temperatures, which makes them promising candidatesudfor higher-temperature PEM Fuel Cells.