Garnet-type solid electrolytes Li7La3Zr2 - xMg(2x)O(12), Li7La3Zr2 - 0.75xScxO12 and Li-7 (-) 2xZnxLa3Zr2O12 with x = 0, 0.025, 0.05 and 0.1 were synthesized at 1075 degrees C by using the traditional solid-state reaction method. It is found that substitution of Mg2+ and Sc3+ for Zr4+ is more effective in improving the Li7La3Zr2O12 (LLZ)'s densification and ionic conductivity than the substitution of Zn2+ for Li+. As a result, the highest room-temperature total conductivity and the lowest activation energy are obtained in LIZ-Mg-2x with x = 0.05, being 0.291 mS/cm at 293 K and 0254 eV, respectively. (C) 2016 Elsevier B.V. All rights reserved.