EFFECT OF Te AND Sb DOPING ON THE ELECTRICAL PROPERTIES OF Li0.25La0.25NbO₃ CERAMICS

The effects of Te and Sb doping on the structure and conductivity of an Li0.25La0.25NbO₃ (LLNO) solid electrolyte were comparatively studied. Te and Sb doped LLNO with a defect perovskite structure was prepared via a solid-state reaction method. The moderate doping of Te and Sb improves the conductivity of LLNO. The grain conductivity and grain boundary conductivity of the LLNO ceramics was distinguished through the equivalent circuit fitting method. With the same doping amount, the Te doped samples exhibit higher grain and total conductivity than the Sb doped samples. Li0.25La0.25Nb0.95Te0.05O₃ has the highest total conductivity of 4.04×10-5 S.cm-1 at 30 °C, which is two times higher than the pure LLNO solid electrolyte. The DC-polarisation characterisation indicated that Li0.25La0.25Nb0.95Te0.05O₃ and Li0.25La0.25Nb0.95Sb0.05O₃ have an extremely low electronic conductivity. The LLNO ceramics doped with Te and Sb are still solid electrolyte materials with lithium-ion transportation properties.