Formation and Characterization of Li0.24 ＋ 2x La0.59-x Mx TiO3-LaPO4 （M = K, Na） System

Ionic conductingsolid materials has received con-siderable attention in the last few years due to theirpotential utilityin high energy batteries and other elec-trochemical devices . Several systems of lithium fastion conductors ,such as γ-Li3PO4-type sol…

Formation and Characterization of Li0.24+2xLa0.59-xMxTiO3-LaPO4 (M=K, Na) System

Li0.24 2xLa0.59-xMxTiO3-LaPO4 (M=K, Na) fast ionic conductor was synthesized by high temperature solid state reaction. A.C. Impedance measurements show that the compositions of system have better conductivities in low doping content of Na and K , as the doping content increases, the conductivity goes down in Na doping system. But in doping K system, the conductivity goes down and then goes up with the increasing content of K . The activation energies of different doped ions are about 20 kJ·mol-1 in the temperature range of 25～400 ℃. X-ray powder diffraction shows that the doped Na and K would not affect the structure of compositions in the system. The main phase is Li0.24 2xLa0.59-xMxTiO3 perovskite solid solution, LaPO4 as a second phase also can be found. With increasing the content of M (x＞0.04), unknown phase appears. IR measurement also indicates that the structure of compositions in the system would not be affected by doping alkali ion.