Novel octopus shaped organic–inorganic composite membranes for PEMFCs

Phosphoric acid doped polybenzimidazoles are among the most interesting proton exchange membrane materials for high temperature proton exchange membrane fuel cell applications . As a major challenge the proton conducting decline due to free phosphoric acid leaching during the long term fuel cell operation is addressed by fixing overmuch phosphoric acid in the polymer matrix . Novel organic-inorganic composite membranes are prepared via in situ synthesis of poly(2,5-benzimidazole) (ABPBI) and OctaAmmonium POSS (AM-POSS) hybrid composites (ABPBI/AM-POSS) following phosphoric acid doping and membrane casting procedures. Compared with the pristine ABPBI membrane, the introduction of AM-POSS into ABPBI polymer membrane caused water and phosphoric acid absorbilities increasing dramatically, resulting in the significant increase of proton conductivities at whether hydrous or anhydrous condition. ABPBI/3AM composite membranes with phosphoric acid uptake above 250% showed best proton conductivities from room temperature to 160 °C, indicating these composite membranes could be excellent candidates as a polymer electrolyte membrane for low and intermediate temperature applications.