V2O5/single-walled carbon nanotube hybrid mesoporous films as cathodes with high-rate capacities for rechargeable lithium ion batteries

The hybrid films composed of V2O5 nanoparticles and single-walled carbon nanotubes (V2O5/SWNT) with mesoporous structure are prepared using a simple floating CVD method followed by controllably hydrolytic deposition of V2O5 nanoparticles. The hybrid films as cathodes for lithium ion batteries exhibit a high-rate capacity of 548 mAhg(-1) at the discharge rate of 300 mAg(-1) (similar to 1C); 342 mAhg(-1) and 171 mAhg(-1) at higher discharge rates of 1200 mAg(-1) (similar to 4C) and 2400 mAg(-1) (similar to 8C), which is attributed to the chemical interaction between the V2O5 nanoparticle and the functional groups on the surface of SWNTs evidenced by the HRTEM and XPS results. It is also conclusively elucidated with detailed electrochemicl analysis that SWNTs can improve Li+ diffusivity by 2 to 4 orders of magnitude to significantly facilitate lithium-ion transport, achieving an excellent electrochemical performance of the hybrid cathode system. (c) 2012 Elsevier Ltd. All rights reserved.