Preparation and characterization zirconium and samarium co-doped ceria solid electrolytes for IT-SOFC applications

Abstract

Zirconium and Samarium co-doped ceria solid electrolyte materials Ce0.8–xSm0.2ZrxO2-δ (x=0, 0.05, 0.10, 0.15 and 0.20) for intermediate temperature-solid oxide fuel cells were synthesized by citrate-nitrate auto combustion synthesis technique. Powder x-ray diffraction results reveal that all the synthesized samples show a single-phase with cubic fluorite structure. The lattice parameter values were calculated from the powder x-ray diffraction data. Samples with high density were obtained by sintering the samples at 1300°C for 4h. The average crystallite sizes were calculated from the Scherer formula. Surface morphologies of all the samples were obtained by using the scanning electron microscope. The total ionic conductivity of all the samples was carried out from impedance analysis in the temperature range RT – 500°C. The highest total ionic-conductivity with lowest activation energy values were observed for Ce0.65Sm0.2Zr0.15O2-δ at 500°C makes it as a useful solid electrolyte material for intermediate temperature-solid oxide fuel cells (IT-SOFCs) applications.