Superionic conductivity of glass-ceramics in the system Li 2 O- Al 2 O 3 -TiO 2 -P 2 O 5

A Li 2O-Al 2O 3-TiO 2-P 2O 5 glass was prepared and converted into glass-ceramics through heat-treatment at 700–1000 °C for 12 h. X-ray analysis indicated that the resultant glass-ceramics were mainly composed of Li 1 + xAl xTi 2 − x(PO 4) 3 phases. The lithium ion conductivity of the glass-ceramics increased with the growth of the Li 1 + xAl xTi 2 − x(PO 4) 3 phase and a extremely high value, 1.3 × 10 −3 Scm −1, was obtained at room temperature. This value is as large as that of Li 3N which is well known to exhibit the highest lithium ion conductivity for a solid electrolyte.