Comparative effect of REO co-dopant (La, Y, Nd) on ionic conductivity of Gd-doped CeO2 solid electrolyte for IT-SOFC

Abstract

The intermediate temperature solid oxide fuel cell (IT-SOFC) is to be realized in shortcoming with the progressing of higher ionic conductivity for electrolyte materials. The CeO2-based electrolyte is known to have a high ionic conductivity and is suitable as a solid electrolyte of IT-SOFC with an operation temperature below 700 °C. CeO2 co-doped with rare earth oxides (REOs) La and Gd (LGDC), Y and Gd (YGDC), and also Nd and Gd (NGDC) were evaluated in this study. Samples were sintered at 1200 °C, 1300 °C, and 1400 °C for 3, 4, and 5 h. The results show that the increased sintering temperature, sintering time, and value of mole % dopant can increase the value of the ionic conductivity. The highest ionic conductivity number of 8.61 × 10−2 S cm−1 was obtained in the NGDC samples with the composition of 20 mol% of dopant at 600 °C.