Fabrication and Fuel Cells Performance of Lanthanum-Doped Cerium Diphosphate Electrolyte

Abstract

Proton conductivity of indium-doped cerium diphosphate (CeP2O7) was investigated to explore its potential for application as an electrolyte in intermediate temperature fuel cells. The La3+-doped CeP2O7 powder was synthesized by the digestion of metal oxide in a phosphoric acid solution. The structure and ion conductivity of La3+ doped CeP2O7 were analysed using X-ray diffraction, scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Under humidified conditions, the La3+-doped CeP2O7 exhibited sufficient conductivity in the intermediate temperature range. The maximum ionic conductivity of Ce0.95La0.05P2O7 was 2.00 × 10-2 Scm-1 at 180 °C. The maximum power density of the fabricated H2/air fuel cells using the Ce0.95La0.05P2O7 as electrolyte (0.44 mm thickness) was 49.0 mW cm-2 at 240 °C. The results indicate that Ce0.95In0.05P2O7 is a promising material for the fabrication of intermediate temperature fuel cells.