Rare Earth Ion Doped Ceria As Electrolytes For Solid Oxide Fuel Cell

We report the nature of rare earth ion doped ceria (REC), Ce0.8Ln0.2O2−δ, (Ln = Y 3+ , Gd 3+ , Sm 3+ , Nd 3+ and La 3+ ) as oxide ion conductors for their plausible application as electrolytes in intermediate temperature solid oxide fuel cell (SOFC). The samples were prepared by citrate-complexation method and characterized by XRD, SEM/ EDX and UV-Visible spectra. The cubic fluorite-type crystal structure is confirmed from XRD patterns, and the observed lattice parameters are in agreement with calculated values. The UV-Vis spectra of the particles dispersed in aqueous medium showed absorption in the UV region which is ascribed to charge-transfer transition. The dc conductivities at 673 K are in the order of Ce0.8Sm0.2O2−δ > Ce0.8Gd0.2O2−δ > Ce0.8Y0.2O2−δ > Ce0.8Nd0.2O2−δ > Ce0.8La0.2O2−δ and their corresponding activation energies are 0.85, 0.87, 0.87, 0.88 and 0.95 eV. Based on ionic and electronic transference numbers, electrical conductivity obtained here is purely ionic, i.e., oxid