Synthesis and electrochemical properties of V2O5 intercalated with binary polymers

Abstract We have synthesized a new inorganic/organic hybrid material, which comprises vanadium pentoxide (V2O5) and the binary polymers poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT) and polyaniline (PANI), and have investigated its electrochemical property. Fourier transform infrared spectra (FT-IR) confirms that both 2,5-dimercapto-1,3,4-thiadiazole (DMcT) and aniline molecules are oxidatively intercalated into the interlayer of V2O5 xerogel, and result in a binary polymers/V2O5 hybrid material. X-ray diffraction (XRD) shows that intercalation of polymers expands the V2O5 interlayer distance by 4.8 A. V K-edge X-ray absorption near-edge structure spectroscopic analysis shows no significant change in VO6 octahedral symmetry, but a slight reduction of the V(5+) state. Electrochemical investigations in the 4–2 V range versus Li/Li+ using non-aqueous electrolyte cells show that as-synthesized binary polymers/V2O5 material exhibits an initial discharge capacity of ∼190 mAh g−1 while an oxygen-treated sample exhibits an initial capacity of about 220 mAh g−1 and a better reversibility for lithium insertion/de-insertion.