Sol−Gel Synthesis of Vanadium Oxide within a Block Copolymer Matrix

Films consisting of a vanadium pentoxide (i.e., V 2 O 5 ) phase formed within a rubbery block copolymer were developed for their potential use as nanocomposite cathodes in lithium rechargeable batteries. Nanocomposite films were prepared by sol−gel synthesis from vanadyl triisopropoxide precursor in poly(oligooxyethylene methacrylate)- block -poly(butyl methacrylate), POEM- b -PBMA. The in situ growth of amorphous V 2 O 5 was confirmed by wide-angle X-ray scattering (WAXS), X-ray photoelectron spectroscopy (XPS), and small-angle X-ray scattering (SAXS). Scanning transmission electron microscopy (STEM) and differential scanning calorimetry (DSC) demonstrated the selective incorporation of vanadium oxide within the ion-conducting POEM domains, while the oxide morphology was revealed by TEM to be a filamentous network. Cyclic voltammetry and impedance spectroscopy confirmed the preservation of the redox properties of the vanadium oxide and the ion-conductive properties of the polymer in hybrid films. Co-assembled nanocomposite films incorporating up to 34 wt % (13 vol %) vanadium oxide were flexible and semi-transparent.