Proton conducting phosphated zirconia–sulfonated polyether sulfone nanohybrid electrolyte for low humidity, wide-temperature PEMFC operation

Fully re-dispersible nanozirconia precursor powder in polar organic solvents was prepared using sol–gel technique. This was blended with sulfonated poly ether sulfone (SPES) to get the nanohybrid electrolyte. In situ generation of zirconium hydrogen phosphate (ZrP) in the SPES matrix was carried out by treating with H3PO4. The proton conductivity values of the hybrid electrolytes were measured under various humidity conditions at different temperatures. The SPES hybrid electrolyte containing phosphated zirconia showed high conductivity even at low humidity conditions. At 90 °C, ZrP–SPES hybrid electrolyte showed proton conductivity value of the order of 10−2 S/cm at a relative humidity (RH) of 50%. At a high relative humidity (90% RH) the ZrP–SPES showed the highest conductivity value of 0.19 S/cm.