Sulfonated poly (arylene ether ketone sulfone)/ZrP composite membranes for medium-high temperature operation of PEMFC

Sulfonated poly (arylene ether ketone sulfone)(SPAEKS)/Zirconium hydrogen phosphate (ZrP) composite membranes with various ZrOCl₂ contents were prepared by in situ precipitation. The SPAEKS/ZrP composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo gravimetric analyzer (TGA) and differential scanning calorimetry (DSC). The performance of SPAEKS/ZrP composite membranes was investigated in detail. They exhibited good thermal stability, excellent water retention and low swelling ratio. The extremely low swelling ratio (15.9–11.3 % at 80 °C) of the composite membranes is desirable to reduce the dimensional change at high temperature. The methanol permeability of the composite membranes decreased to 2.12 × 10⁻⁷ cm/s at 25 °C, which is lower than that of SPAEKS and Nafion-117 membranes. Although the composite membrane exhibited lower water uptake, the presence of ZrP led to an improvement in conductivity (0.093S/cm for SPAEKS/ZrP-20 %) at Medium-high temperature (120 °C). These composite membranes are promising candidates for application as proton exchange membrane fuel cells at medium-high temperature.