All-solid-state lithium batteries were fabricated by use of LiNi1/3Mn1/3Co1/3O2 powders coated with ZrO2 as positive electrode materials and amorphous Li3PS4 as solid electrolytes. The ZrO2-coated powders were prepared by a sol-gel method associated with ultrasonic irradiation. The charge-discharge cycle performance of the all-solid-state cells was improved by use of the ZrO2-coated LiNi1/3Mn1/3Co1/3O2 powders. The ZrO2 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, a-Li3PS4, during charge-discharge cycling. The battery with the ZrO2-coated LiNi1/3Mn1/3Co1/3O2 showed an initial discharge capacity of 115 mAh g(-1) and good capacity retention even after 50 cycles at a current density 01 0.1 mA cm(-2) at room temperature. (C) 2011 Elsevier B.V. All rights reserved.