Lithium ion transport properties of high conductive tellurium substituted Li7La3Zr2O12 cubic lithium garnets

In this paper synthesis, structure and Li+ transport process of Li(7-2)xLa(3)Zr(2-x)Te(x)O(12) (x = 0.125 and 0.25) lithium garnets are reported. Preparation of high Li(+)k conductive Li7La3Zr2O12 (LLZ) in cubic phase by conventional solid state method demands sintering it around 1200 degrees C for 36 h in Al2O3 crucible. Cubic phase lithium garnet is successfully obtained at lower sintering temperature around 750 degrees C with the substitution of Zr4+ by Te6+ in the garnet lattice over the investigated composition range. Among the investigated compounds Li65La3Zr1.75Te0.25O12 sintered at 1100 degrees C exhibits a maximum room temperature total (bulk grain boundary) ionic conductivity of 1.02 x 10(-3) S cm(-1). The present studies reveal the stabilization of the cubic garnet phase relatively at lower sintering temperature along with an enhancement in Li+ conductivity with lithium content lesser than 7 by suitable doping in Li7La3Zr2O12. (C) 2013 Elsevier B.V. All rights reserved.