Heterogeneous TiO/VO/Carbon Nanotube Electrodes for Lithium-Ion Batteries.

Vanadium pentoxide (VO) is proposed and investigated as a cathode material for lithium-ion (Li-ion) batteries. However, the dissolution of VO during the charge/discharge remains as an issue at the VO-electrolyte interface. In this work, we present a heterogeneous nanostructure with carbon nanotubes supported VO/titanium dioxide (TiO) multilayers as electrodes for thin-film Li-ion batteries. Atomic layer deposition of VO on carbon nanotubes provides enhanced Li storage capacity and high rate performance. An additional TiO layer leads to increased morphological stability and in return higher electrochemical cycling performance of VO/carbon nanotubes. The physical and chemical properties of TiO/VO/carbon nanotubes are characterized by cyclic voltammetry and charge/discharge measurements as well as electron microscopy. The detailed mechanism of the protective TiO layer to improve the electrochemical cycling stability of the VO is unveiled.