SOL-GEL SYNTHESIS AND ELECTRICAL PROPERTIES OF LITHIUM IONIC CONDUCTORS Li5La3M2O12 (M=Ta, Bi)

摘要

In this paper, the nanocrystalline Li5La3M2O12 (M=Ta, Bi) powders with average size of about 100nm were synthesized by sol-gel method. The synthesis temperature and reaction time (~5h) of pure garnet-like Li5La3M2O12 (M=Ta, Bi) phase by the sol-gel method are about 150K lower and much shorter than those by the solid state reaction method. The best total lithium ion conductivity of the sample prepared by sol-gel method at room temperature can be as high as 2.4×10-5 S/cm with an activation energy of 0.4 eV in the bulk Li5La3Bi2O12 samples, 25% higher than that of the sample prepared by the solid state reaction.