Properties and Application of Double Alkali Earth Doped Ce0.9Ca0. 1 - xSrxO1.90

A series of solid solution material based on ceria, Ce0.9Ca0.1-xSrxO1.90 (x=0, 0.04, 0.05， 0.06), were synthesized by a solid reaction method. Ceria doped with two alkali earth elements has cubic fluorite structure. The ionic conductivity of these materials at high temperature was studied by impedance spectra, and an increasing effect of ionic conductivity was found. A maximum conductivity is achieved when the effective ionic radius is near to the critical radius (0.1106 nm). Some fuel cells were made using these materials as electrolyte. The output power and current of the SOFC with the electrolyte of double doped ceria are better than those of YSZ and single doped ceria, and the open-circuit-voltage of the double doped ceria is also higher than that of the single doped ones.