Heterogeneous TiO 2 /V 2 O 5 /Carbon Nanotube Electrodes for Lithium-Ion Batteries.

Vanadium pentoxide (V2 O5 ) is proposed and investigated as a cathode material for lithium-ion (Li-ion) batteries. However, the dissolution of V2 O5 during the charge/discharge remains as an issue at the V2 O5 -electrolyte interface. In this work, we present a heterogeneous nanostructure with carbon nanotubes supported V2 O5 /titanium dioxide (TiO2 ) multilayers as electrodes for thin-film Li-ion batteries. Atomic layer deposition of V2 O5 on carbon nanotubes provides enhanced Li storage capacity and high rate performance. An additional TiO2 layer leads to increased morphological stability and in return higher electrochemical cycling performance of V2 O5 /carbon nanotubes. The physical and chemical properties of TiO2 /V2 O5 /carbon nanotubes are characterized by cyclic voltammetry and charge/discharge measurements as well as electron microscopy. The detailed mechanism of the protective TiO2 layer to improve the electrochemical cycling stability of the V2 O5 is unveiled.