Fabrication and performance of Ce0.85Sm0.15O1.925–Fe2O3 electrolytes in IT-SOFCs

The electrolyte materials Ce0.85Sm0.15O1.925–x at.% FeO1.5 (x = 0, 0.5, 1, 2, 3) were synthesized by means of glycine–nitrate process (GNP). Their structures and ionic conductivities were characterized by X-ray diffraction, SEM and AC impedance spectroscopy. All the electrolytes were found to be ceria-based solid solutions of fluorite type structures. Grain size increased with increased Fe2O3 content up to 0.5 at.% and then became almost constant with further addition of Fe2O3. The grain-boundary resistance could be significantly decreased by small addition of Fe2O3. Electrolyte-supported solid oxide fuel cells (SOFC) fabricated with Ce0.85Sm0.15O1.925–x at.% FeO1.5 (x = 0.5, 3) electrolytes were studied and compared with the fuel cell with Ce0.85Sm0.15O1.925 as electrolyte.