Investigation of (CeO2)x(Sc2O3)(0.11−x)(ZrO2)0.89 (x = 0.01–0.10) electrolyte materials for intermediate-temperature solid oxide fuel cell

Oxide ionic conductivities of (CeO2)x(Sc2O3)(0.11−x)(ZrO2)0.89 (x = 0.01–0.10) electrolytes were optimized for the application in intermediate-temperature solid oxide fuel cell (IT-SOFC). Powders with different contents of CeO2 and Sc2O3 were prepared via a co-precipitation method. The obtained powders and pellets were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and impedance spectroscopy. Among all the compositions, (CeO2)0.04(Sc2O3)0.07(ZrO2)0.89(4Ce7ScZr) gives the highest ionic conductivity of 0.065 S cm−1 at 800 °C. The effects on densification and electrical properties of different sintering additives, such as SiO2, MgO, Co3O4, MoO3 and Bi2O3, were studied and different conducting behavior with these additives were observed. The densification temperatures of CeO2 and Sc2O3 co-doped electrolytes can be reduced by around 280 °C with the addition of 1 mol% of Bi2O3, while the electrical properties of the electrolytes are not significantly affected by the introduction of Bi2O3 aid.