Synthesis and Characterization Studies of Ca2+ and Y3+ Co-Doped Ceria-Na2CO3 Nanocomposite Electrolytes for Low Temperature SOFCs

Abstract

Doped ceria-carbonate composites have been developed for low temperature (300-600 °C) solid oxide fuel cells (SOFCs) due to its enhanced performance compared to single phase doped ceria electrolytes and the possibility to avoid the Ce4+ reduction. In this study, Y3+ and Ca2+ doped and co-doped ceria Ce0.8Y0.2-xCaxO2-δ (x = 0 and 0.1) samples were synthesized through a simple and cost-effective molten salt method. Nanocomposites based on doped and co-doped ceria-Na2CO3 were then synthesized through mechanical milling. The prepared materials were characterized by X-ray diffraction, thermal analysis, scanning electron microscopy and electrochemical impedance spectroscopy. XRD result shows a single cubic fluorite phase of ceria with carbonate exist as amorphous phase. SEM micrographs also exhibited the homogeneous distribution of ceria and amorphous carbonate phase. Electrical conductivity analysis at different sintering temperatures shows high conductivity value is obtained for co-doped ceria-carbonate nanocomposite sample sintered at 700°C.