Utility of Ce0.8M0.2O1.9, Ce0.8M0.15Y0.05O1.9, M = Gd, Sm powders synthesized by aerosol decomposition method in solid oxide fuel cell technology

Singly-doped and co-doped ceria powders with the formula Ce0.8Sm0.2O1.9 or Ce0.8Sm0.15Y0.05O1.9, M=Gd, Sm were synthesized using the spray pyrolysis method at 700 degrees C. X-ray diffraction analysis showed that all obtained powders were pure cubic CeO2-based solid solutions. Scanning and transmission electron microscopy were used to characterize the morphology of CeO2-based powders. It was found that the prepared powders were composed of fully spherical particles ranging in size from similar to 0.1 to 1.3 mu m. Additional heat treatment of these powders in the-temperature range of 700-1000 degrees C resulted only in small increased particle size. The particles lost their spherical shape at temperatures above 1200 degrees C. A study of sintering activity of powders prepared in this way was also performed, using the dilatometric method. Finally, CeO2-based samples were sintered at 1500 degrees C in air for 2 h. The ionic conductivity of Ce0.8Sm0.2O1.9 and Ce0.8Sm0.15Y0.05O1.9 M = Gd, Sm sintered samples were studied by AC impedance spectroscopy. It was found that the partial substitution of Y3+ for Gd3+ resulted in increased ionic conductivity of Ce0.8Sm0.15Y0.05O1.9, M = Gd, Sm compared to Ce0.8Sm0.2O1.9, M= Gd, Sm. The possibility of using spherical CeO2-based powders for the preparation of screen-printable paste (to be used in turn for the deposition of gas-tight electrolyte films for anode-supported solid oxide fuel cells) was also investigated. The performance of single anode supported solid oxide fuel cells, involving singly doped ceria as Ce0.8Sm0.2O1.9 or Ce0.8Sm0.15Y0.05O1.9 as oxide electrolytes fueled with gaseous hydrogen, was presented and analyzed. The authors also pointed out that the co-doped ceria electrolytes Ce0.8Sm0.15Y0.05O1.9, M = Gd, Sm seem to be also promising oxide electrolytes for construction solid oxide fuel cells, which utilized solid carbon as fuel. (C) 2013 Elsevier Ltd. All rights reserved.