Carbon nanofiber (CNF)-Co3O4 composites were prepared by the calcination of CNF-Co(OH)(2) composite precursors under argon atmosphere. SEM and TEM observations revealed that Co3O4 particles in the size of ca. 30-50 nm were highly dispersed and attached on the surface of the reticular CNF and all around. As for electrode materials, the CNF-Co3O4 composite demonstrated very high reversible capacity (more than 900 mAh g(-1) in the initial 50 cycles) and excellent electrochemical cycling stability. The improved cycle performance of the CNF-Co3O4 composite can be attributed to its unique reticular and morphology-stable composite texture with high dispersion of Co3O4 nanoparticles on the CNF that provides excellent electronic and ionic conduction pathway for the electrochemical processes. (C) 2007 Elsevier B.V. All rights reserved.