Construction of new transport channels by blending POM-based inorganic-organic complex into sulfonated poly(ether ketone sulfone) for proton exchange membrane fuel cells

A series of novel hybrid membranes consisted of sulfonated poly(ether ketone sulfone) with carboxyl groups (C-SPAEKS) and POM-based inorganic-organic complex were prepared. The C-SPAEKS was synthesized by polycondensation. The POM-based organic-inorganic complex with proton-conducting ability was constructed by the self-assembly method. The FT-IR, PXRD and 1H NMR were used to verify the structure of POM-based organic-inorganic complex, C-SPAEKS and the hybrid membranes. The hybrid membranes showed good mechanical properties, excellent folding character and long-term stability. Moreover, the hybrid membranes had low swelling ratio (≤13%) even at 80 °C. In addition, C-SPAEKS-P15% exhibited the highest proton conductivities (0.048 S cm-1 at 30 °C, 0.099 S cm-1 at 90 °C) and low methanol crossover (5.02 × 10-7 cm2 s-1). Compared to pure C-SPAEKS, the overall performance of the POM-based-doped hybrid membranes has been improved. The results indicate that the POM-based organic-inorganic complex has great potential to be used as proton-conducting filler in the field of proton exchange membrane.