Low-temperature processing of Garnet-type ion conductive cubic Li7La3Zr2O12 powders for high performance all solid-type Li-ion batteries

Synthesis of lithium stuffed cubic Li2La3Zr2O12 (c-LLZO) garnet at low-processing temperatures is hampered by the lack of deep understanding on powder processing technology. The present article proposes a hybrid solid-state approach to accomplish controllable synthesis of Al doped LLZO cubic garnet oxide nanoparticles at low-processing temperatures. In this procedure, powders of ZrO2 and La(OH)(3) in ethanol based suspension were mechanochemically (MC) treated along with 1 wt.% of AlOOH in a planetary ball mill with increasing milling time to increase the homogeneity of the precursor. Lithium acetate in the form of an ethanolic solution was subsequently added for the solid-state synthesis of single phase LLZO. Cubic LLZO phases were obtained at temperatures i.e. 700 degrees C within 3 h. The ease of lithium diffusion in these MC activated La-Zr precursor materials is attributed to the formation of single phase LLZO with the lowest Al3+ doping content. The sintered pellets (94% relative density at 1100 degrees C for 3h in air) of the newly obtained Li6.61La3Zr2Al0.13O11.98 deliver high bulk Li-ion conductivity of 1.35 x 10(-4) Scm(-1). The new low-temperature processing of typical garnet and the use of c-Li6.61La3Zr2Al0.13O11.98 nanoparticles could open pathways toward future solid electrolyte-electrode assembly options for all-solid state Li-ion batteries. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.