• Doped SnP2O7;
  • Intermediate Temperature Fuel Cells;
  • PBI;
  • PEMFC;
  • Phosphoric Acid


Fine particles of a solid proton conductor Sb0.2Sn0.8P2O7 were incorporated in PBI-H3PO4 membranes with 20 wt.%. In SEM figures, the Sb0.2Sn0.8P2O7 particles exhibited even and uniform distribution in the PBI-Sb0.2Sn0.8P2O7 membrane. Influences of the immersing time and the concentration of H3PO4 solution for immersion on H3PO4 loading level were investigated. H3PO4 loading level was found an important factor on membrane conductivity. Incorporation of Sb0.2Sn0.8P2O7 in the PBI-H3PO4 membrane resulted in greater membrane conductivities. In the single cell tests, the peak power density of the membrane electrode assembly (MEA) with the PBI-Sb0.2Sn0.8P2O7-H3PO4 membrane was also greater than that of a MEA with PBI-H3PO4 membrane. One MEA using PBI-Sb0.2Sn0.8P2O7-H3PO4 membrane achieved a peak power density of 0.67 W cm–2 at 175 °C with H2/O2 and exhibited satisfactory stability.