Sol-gel synthesis and electrical properties of ceria-based solid electrolytes

A series of solid electrolytes (Ce0.8RE0.2)(1-x)MxO2-delta(RE: Rare earth, M: Alkali earth) were prepared by sol-gel methods. XRD indicated that a pur e fluorite phase was formed at 800 degrees C. The synthesis temperature by the sol-gel methods was about 700 degrees C lower than by the traditional c eramic method. The electrical conductivity and impedance spectra were measu red. XPS showed that the oxygen vacancy increased obviously by doping MO, t hus, resulting in the increase of the oxygen ionic transport number and con ductivity. The performance of ceria-based solid electrolyte was improved. T he effects of RE2O3 and MO on the electrical properties were discussed. The conductivity and the oxygen ionic transport number of (Ce0.8Sm0.2)(1-0.05) Ca0.05O2-delta is 0.126 S.cm(-1) and 0.99 at 800 degrees C, respectively.