An H3PO4-doped polybenzimidazole/Sn0.95Al0.05P2O7 composite membrane for high-temperature proton exchange membrane fuel cells

► A composite membrane comprising Sn0.95Al0.05P2O7 (SAPO) and polybenzimidazole (PBI) is developed for high-temperature proton exchange membrane fuel cells. ► Homogenous dispersion of the SAPO particles is obtained in the composite membrane. ► The interaction between protons in the SAPO and H3PO4 provides high proton conductivities. ► The composite membrane yields a good cell performance at high temperatures.