Electrochemical characterization of vanadium oxide nanostructured electrode

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. Films were prepared by sol-gel synthesis from vanadyl triisopropoxide precursor in poly (oligooxyethylene methacrylate)-block-poly(butylmethacrylate), incorporating LiCF(3)SO(3) and carbon black as conductivity additives. The morphology of the films was examined using electron microscopy, and their electrochemical performance was assessed by galvanostatic cycling. An all-solid-state battery comprising a polymer-based cathode and a block copolymer electrolyte was cycled repeatedly. The capacity was measured to be 40 mAh/g and found to be limited by the conductivity of the polymer electrolyte. A comparison between a nanocomposite cathode and a control cathode with the same carbon: vanadium oxide ratio demonstrated higher rate capability for the nanocomposite sample when paired with a liquid electrolyte. This study demonstrates the potential utility of block copolymers in the fabrication of high-surface-area cathodes for lithium batteries. (c) 2008 The Electrochemical Society.