LiAlO2-coated LiNi1/3Mn1/3Co1/3O2 powders were prepared by a sol-gel method associated with ultra-sonication, and the obtained LiAlO2-coated LiNi1/3Mn1/3Co1/3O2 was investigated as positive electrode materials for all-solid-state batteries with sulfide-based solid electrolytes. All-solid-state lithium batteries were assembled with the obtained LiAlO2-coated LiNi1/3Mn1/3Co1/3O2 powders and with amorphous Li3PS4 as solid electrolytes. The charge-discharge cycle performance of the all-solid-state cells was improved by the LiAlO2-coating on LiNi1/3Mn1/3Co1/3O2 powders. The LiAlO2 coating was effective in suppressing an increasing of the interfacial resistance between the LiNi1/3Mn1/3Co1/3O2 electrode material and the sulfide based solid electrolyte, Li3PS4, during charge-discharge cycling. The battery with the 1.0 mol% LiAlO2-coated LiNi1/3Mn1/3Co1/3O2 showed an initial discharge capacity of 134 mAhg(-1) and the battery retained the capacity more than 124 mAhg(-1) even after 400 charge-discharge cycles at a current density of 11 mAg(-1) at room temperature. (C) 2014 Elsevier B.V. All rights reserved.