Synthesis and characterization of a new organo-inorganic poly(3,4-ethylene dioxythiophene) PEDOT/V₂O₅ nanocomposite by intercalation

Abstract

We have developed a novel nanocomposite material, PEDOT/V₂O₅ by inserting poly(3,4-ethylene dioxythiophene) PEDOT in V₂O₅ layers using oxidative polymerization/intercalation in air. A systematic study of the synthesis of the nanocomposites by direct in situ reaction of 3,4-ethylene dioxythiophene (EDOT) with V₂O₅ fine powder shows that upon intercalation, the interlayer spacing of V2O5 expands in two stages, i.e., first from 4.32 to 13.84 Å and further to 19.04 Å. The interlayer separation is consistent with the existence of two phases in the PEDOT/V₂O₅ system corresponding to the intercalation of one and two monolayers of PEDOT, respectively, in the V₂O₅ framework. The unique properties of the organo-inorganic composites are investigated by electronic conductivity measurements, X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis and SEM. The application potential of these composites as cathode materials in rechargeable lithium batteries is also demonstrated by the electrochemical intercalation of lithium into the PEDOT/V₂O₅ nanocomposites, where an enhancement in the discharge capacity (240 mA h g^-1) is observed compared to that (140 mA h g^-1) observed for V₂O₅.