Carbon-carbon nanocomposites were prepared by the chemical reduction of strongly oxidized multi-walled carbon nanotubes (O-MWNTs) and acid-treated carbon blacks (A-CBs). To apply the electrode materials, the electrochemical performance of the MWNTs-CBs was examined as a function of the CB content. The chemically converted MWNTs-CBs were formed successfully by physical interaction during the reduction of the functional groups of O-MWNTs and A-CBs, resulting in the conjugation of CBs onto the MWNT surface with a high aspect ratio. The electrical properties of the MWNTs increased with increasing CB content, resulting from the condensed MWNT networks by the CBs deposited on the MWNTs. In addition, MWNTs-CBs showed higher current density than the pristine MWNT alone. This suggests that the incorporation of CBs onto MWNTs could have a compacting effect on the empty pores in MWNT networks, leading to MWNTs-based electrodes with enhanced electrochemical performance. (C) 2012 Elsevier Ltd. All rights reserved.