Effect of Ca on the Properties of Gd-Doped Ceria for IT-SOFC

Abstract

Ceria based electrolyte materials are very useful in intermediate - temperature solid oxide fuel cell (IT-SOFC). The compositions Ce 0.85 Gd 0.15 - x Ca x O 2 - δ ( x = 0.0 - 0.075) were prepared through sol-gel method. Their structure was stud ied by X-ray diffraction. Dense ceramic Ce 0.85 Gd 0.15 - x Ca x O 2 - δ samples were prepared by sintering the pellets at 1300°C. The lattice parameter was calculated by Rietveld refin e me n t of XRD patterns. Four probe A.C. impedance spectroscopy was used to study the total ionic conductivity of doped and co-doped ceria ceramics in the temperature range 200°C - 700°C. The Ce 0.85 Gd 0.15 - x Ca x O 2 - δ composition showed maximum ionic conductivity with less activation energy.