Effect of Li_2O additions on properties of gadolinia-doped ceria ceramics

Li2O doped Ce0.8Gd0.2O1.9 ceramic samples were prepared by solid state reaction.Effect of Li2O additive on phase structure,density and electric properties of Ce0.8Gd0.2O1.9 were investigated by XRD,SEM and EIS.The results show that addition of 3 mol% Li can reduce sintering temperature to 1450℃,reaching 98 % of theoretical density.The results of XRD indicate that no new phase appears and Ce0.8Gd0.2O1.9 is still fluorite structure.AC impedance spectroscopy shows that addition of 3 mol% Li enhances the bulk conductivities and lowers the activation energy compared to the pure Ce0.8Gd0.2O1.9 sintered at 1600℃.Li2O doping is very effective in promoting the densification of CGO when a dopant Li2O concentration is more than 1.5mol%.