A dense molybdenum oxide layer was fabricated on nickel foam (MoO2@Ni) and used as the cathode in the 1-ethly-3-methylimidazolium chloride/AlCl3 ionic liquid electrolyte aluminum ion battery. Study on the electrochemical performance demonstrated that the cathode could not only exhibit a discharge potential of 1.9 V which is higher than most of the studied metal oxide cathodes of Al ion battery, but also deliver a specific discharge capacity of 90 mAh g(-1) at a constant current density of 100 mA g(-1). Although the MoO2 was dissolved and transferred to the separator after long cycling, resulting in a rapid capacity decay, we still believe it is an encouraging outcome in terms of these type batteries. (C) The Author(s) 2017. Published by ECS. All rights reserved.