Nanocrystalline Co3O4 powders were synthesized by aerosol flame synthesis (AFS) method for the anode of lithium ion batteries and the basic electrochemical properties were investigated. The effects of synthesis conditions and heat-treatment temperature on the morphology, crystallite size and electrochemical properties were investigated. As-prepared soot contained Co3O4, CoO and Co(OH)(2), which were eventually converted into cubic spinel Co3O4 by post heat treatment. The as-prepared particle size was in the range of 10-30 nm and grew to 50-85 nm by the heat treatment. With growing particle size and improved crystallinity, charge-discharge capacity and cycle performance were improved and the discharge capacity of the powder heat-treated at 700 degrees C was 571 mAh/g after 30 cycles, which was better than Co3O4 powder reported in the previous literature. (C) 2010 Elsevier B.V. All rights reserved.