LI+ -ION CONDUCTIVITY OF LI1+XMXTI2-X(PO4)3 (M-SC(3+),Y(3+))

In Li1+xScxTi2-x(PO4)3 (0 < x < 0.3), both the conductivity and size of the crystal lattice increase with x, suggesting that Sc3+ ions substitute for Ti4+ ions. In the Li1+xYxTi2-x (PO4)3 system, the ionic conductivity increased with x up to x = 0.3, but the crystal lattice did not change with x. EDX analysis of the reaction products prepared by hydrothermal synthesis showed that the y3+ ions do not substitute for Ti4+ ions. The extra Li+ ions and/or doped Y3+ ions may segregate in the grain-boundary regions, and result in a conductivity enhancement.