Hierarchical Co3O4@multiwalled carbon nanotube nanocable films with superior cyclability and high lithium storage capacity

Hierarchical Co3O4@multiwalled carbon nanotube (MWCNT) nanocable films are deposited on copper foils via a facile one-step electrophoretic deposition (EPD) from MWCNT suspension containing Co(NO3)(2)center dot 6H(2)O and the subsequent heat treatment. The obtained films show network morphologies, with micro-/mesoporous Co3O4 sheath uniformly coated on the interconnected MWCNT core. By varying the mass ratios of Co(NO3)(2)center dot 6H(2)O to MWCNTs in the suspension, a series of nanocable films are obtained with different Co3O4 sheath thickness, morphology, and mass content. Among them, the Co3O4@MWCNT-4 nanocable film, with a high surface area of 156 m(2) g(-1) and optimally hierarchical pore size distribution, proves to be a qualified candidate anode for lithium-ion batteries. The reversible capacity can reach as high as 1109 mAh g(-1) at a relatively high current of 0.2 C (1 C = 890 mA g(-1)). At a higher current of 1 C, the reversible capacity can retain as high as 860 mAh g(-1) and shows no obvious decay after 250 cycles. (C) 2013 Elsevier Ltd. All rights reserved.