Synthesis and properties of ceramics-polymer composite membranes as high temperature proton conducting electrolytes

Abstract

Proton-conducting inorganic/organic composite membranes, which were mechanically flexible, were fabricated, and their conduction properties were characterised for use as polymer electrolyte fuel cells (PEFCs) operating at relatively higher temperatures (100 similar to 150 degrees C). SiO2/PEO (polyethylene oxide) membranes doped with acidic molecules (monododecylphosphate) were fabricated by using the sol-gel route, and the proton conductivities were measured using impedance spectroscopy. The composite electrolytes showed reasonable electrical-conductivity values (10(-3)similar to 10(-4) S/cm) up to 150 degrees C and differential thermal analysis and thermogravimetric analysis (DTA/TG) data showed that the membranes were thermally stable up to 350 degrees C, possibly due to the SiO2 backbone framework.