Electrochemical studies of poly (3,4-ethylenedioxythiophene) PEDOT/VS₂ nanocomposite as a cathode material for rechargeable lithium batteries

Abstract

Here, we demonstrate the electrochemical characterization of a new type of layered poly (3,4-ethylenedioxythiophene) PEDOT/ VS₂ nanocomposite. It has been prepared via flocculation of delaminated VS₂ with subsequent in situ oxidative polymerization of 3,4-ethylenedioxythiophene (EDOT) with VS₂ as a host material in the presence of an external oxidizing agent. The interlayer spacing of VS₂ expands from 5.71 to 14.01 Å and this interlayer separation is consistent with the existence of a monolayer of PEDOT in the VS₂ framework. X-ray diffraction, XPS and TEM studies have been shown the change in interlayer separation is consistent with the existence of two phases of organic and inorganic species in the nanocomposites corresponding to the intercalation of PEDOT in the VS₂ framework. The application potential of the nanocomposite as a cathode material for rechargeable lithium batteries is also demonstrated by the electrochemical intercalation of lithium into the PEDOT/VS₂ nanocomposite, where a significant enhancement in the discharge capacity is observed (~130 mAh/g) compared to that (80 mAh/g) for pristine VS₂.