Synthesis, characterization and thermal expansion of Ce0.8-xSm0.2ZrxO2-δ Solid electrolytes for IT-SOFC applications

The solid electrolyte materials Ce0.8-xSm0.2ZrxO2-delta (CSZ) (x=0, 0.05, 0.10 and 0.15) for intermediate temperature-solid oxide fuel cells (IT-SOFCs) are prepared by citrate-nitrate auto combustion (CNAC) method. The x-ray diffraction studies of the prepared samples confirm the presence of single phase-cubic fluorite structure with the space group Fm (3) over barm. The calculated average crystallite sizes are found to be in the range of 14 nm to 19 nm. The lattice parameter values are calculated from the XRD patterns. Microstructure analysis and elemental distributions of the composition of the sintered samples are obtained by using the scanning electron microscope (SEM) and energy dispersive spectrum (EDS). The measurements of coefficients of thermal expansion (TECs) are determined from thermal expansion of the CSZ system. The observed TEC values are found to increase with the increase of the doping content of Zr4+. It is found that the thermal expansion coefficients of Zr4+ and Sm3+ co-doped ceria samples match with commonly used electrode materials for IT-SOFCs. (C) 2016 Elsevier Ltd. All rights reserved.