Gd3+ and Sm3+ co-doped ceria based electrolytes for intermediate temperature solid oxide fuel

Co-doped ceria of Ce1-aGda-ySmyYO2-0.5a, wherein a = 0.15 or 0.2, 0 less than or equal to y less than or equal to a, were prepared for intermediate temperature solid oxide fuel cells (ITSOFCs). Their structures and ionic conductivities were characterized by X-ray diffraction and AC impedance spectroscopy. All the electrolytes were found to be ceria based solid solutions of fluorite type structures. However, co-doping effect was observed more apparent for the electrolytes with a = 0.15 than for those with a = 0.2. In comparison to the singly doped ceria, the co-doped ceria Of Ce0.85Gd0.15-ySmyO1.925, wherein 0.05 less than or equal to y less than or equal to 0.1, showed much higher ionic conductivities at 773-973 K. These co-doped ceria are more ideal electrolyte materials of ITSOFCs. (C) 2004 Elsevier B.V. All rights reserved.