Heterogeneous TiO₂/V₂O₅/Carbon Nanotube Electrodes for Lithium-Ion Batteries

Vanadium pentoxide (V 2 O 5 ) is proposed and investigated as a cathode material for lithium-ion (Li-ion) batteries. However, the dissolution of V 2 O 5 during the charge/discharge remains as an issue at the V 2 O 5 –electrolyte interface. In this work, we present a heterogeneous nanostructure with carbon nanotubes supported V 2 O 5 /titanium dioxide (TiO 2 ) multilayers as electrodes for thin-film Li-ion batteries. Atomic layer deposition of V 2 O 5 on carbon nanotubes provides enhanced Li storage capacity and high rate performance. An additional TiO 2 layer leads to increased morphological stability and in return higher electrochemical cycling performance of V 2 O 5 /carbon nanotubes. The physical and chemical properties of TiO 2 /V 2 O 5 /carbon nanotubes are characterized by cyclic voltammetry and charge/discharge measurements as well as electron microscopy. The detailed mechanism of the protective TiO 2 layer to improve the electrochemical cycling stability of the V 2 O 5 is unveiled.