Sintering and electrical properties of Ce0.75Sm0.2Li0.05O1.95

Ceria-based electrolytes have been widely investigated in intermediate-temperature solid oxide fuel cell (SOPC), which might be operated at 500-600 degrees C. Samarium doped (20 mol%) ceria (20SDC) one of the most promising material in this class of compounds. In this work we report effect of lattice substitution of 5 mol % Li on Sm in (20SDC). It was prepared by citrate-nitrate auto combustion synthesis having a powder of average particle size similar to 50 nm. The sintered density of more than 98% of the theoretical density at 950 degrees C has been achieved. Increased ionic conductivity (lattice) at 500 degrees C has also been achieved in Ce0.75Sm0.2Li0.05O1.95 compare to that of Ce0.8Sm0.2O1.95. Corresponding activation energy of conduction similar to 0.7 eV has been calculated in the temperature range of 200-600 degrees C. In reducing atmosphere the electrical conductivity has not been altered much. Thus Ce0.75Sm0.2Li0.05O1.95 has been found to be quite promising in terms of reducing the processing temperature as well as operating temperature of SOFC. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.