Synthesis and Li-insertion properties of poly(ethylene-oxide)/V2O5 nanocomposite films

V2O5 xerogel films modified by poly(ethylene-oxide) (PEO) were synthesized via sol-gel method. Investigations were conducted by X-ray diffraction (XRD), Fourier transformation infrared spectrometry (FT-IR), cyclic voltammetry and-optical spectra transmittance. The results show that when V2O5 xerogel is modified by the intercalation of PEO, the H atoms in PEO are bound with the O atoms in the V=O bonds of V2O5 xerogel in H-bonding form, which effectively shields the electrostatic interaction between V2O5 interlayer and Li+ ions. Because of the modification of PEO in V2O5 xerogel, the reversibility of insertion/extraction of Li+ ions is greatly improved and the transmittance in the visible and near infrared region is enhanced. Moreover, the cathodic electrochromic property is weakened and the anodic electrochromic property is improved after the intercalation of PEO into V2O5 interlayer.