Template-free synthesis of vanadium oxides nanobelt arrays as high-rate cathode materials for lithium ion batteries

A facile hydrothermal route has been developed to fabricate the metastable VO2 (B) ultra-thin nanobelt arrays, which can be converted into V2O5 porous nanobelt arrays after calcinating VO2 (B) in air at 400 degrees C for 1 h. The influence of hydrothermal time to the crystallinity and morphology of the VO2 phase has been studied. A possible mechanism for the formation of VO2 nanobelt arrays has been proposed in this paper. As a cathode material for lithium ion batteries, the V2O5 nanobelt arrays show excellent rate capability and cycling stability. An initial discharge capacity of 142 mA h g(-1) can be delivered at a current density of 50 mA g(-1) with almost no capacity fading after 100 cycles. Even at a current density of 1000 mA g(-1), they still exhibit the capacity of 130 mA h g(-1) and superior capacity retention capability. The excellent electrochemical properties are attributed to the ultra-thin thickness and the porous structures of the nanobelts. (C) 2014 Elsevier B.V. All rights reserved.