A new method to prepare vanadium oxide nano-urchins as a cathode for lithium ion batteries

Abstract

Urchin-like vanadium oxide nanotube clusters, abbreviated to VO_x-NUs, were synthesized using a new method. Vanadium pentoxide, having a layered structure, was modified by lithium fluoride (LiF) and transformed into bi-phase lithium vanadate as the inorganic precursor. Then, VO_x-NUs were prepared by hydrothermal reaction with dodecylamine as a template. This is different from other molecular assembly methods reported. VO_x-NUs-350 nano clusters were obtained by annealing VO_x-NUs at a temperature of 350 °C in air. Both samples were identified as three dimensional urchin-like nano clusters. Based on the characterization data obtained, a formation mechanism was established. By simply varying the LiF stoichiometric ratio, the nano tube density of the VO_x-NUs could be controlled. VO_x-NUs presented a higher initial rate capacity of 400 mA h g⁻¹ and VO_x-NUs-350 maintained a better capacity of 150 mA h g⁻¹ after 50 cycles at a 100 mA g⁻¹ current density between 1.5 and 4 V versus Li/Li⁺.