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

Vanadium pentoxide (V₂O₅) is proposed and investigated as a cathode material for lithium-ion (Li-ion) batteries. However, the dissolution of V₂O₅ during the charge/discharge remains as an issue at the V₂O₅-electrolyte interface. In this work, we present a heterogeneous nanostructure with carbon nanotubes supported V₂O₅/titanium dioxide (TiO₂) multilayers as electrodes for thin-film Li-ion batteries. Atomic layer deposition of V₂O₅ 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 V₂O₅/carbon nanotubes. The physical and chemical properties of TiO₂/V₂O₅/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 V₂O₅ is unveiled.