Nanostructured Co3O4 fibers were prepared by a sol-electrospinning technique. The Co3O4 fibers from 600 nm to 1.0 mu m in diameter were composed of polycrystalline nanoparticles in sizes of 15-30 nm. The nanostructured Co3O4 fibers used as anode materials for lithium-ion batteries displayed excellent electrochemical properties, including a high initial discharge capacity of 816 mAh/g and good cycle stability. (C) 2008 Elsevier B.V. All rights reserved.