Fluorocarbon-doped vanadium pentoxide films were produced by dc magnetron sputtering in Ar+O2+CF4 followed by annealing in the same gas. The films served as excellent hosts for galvanostatic and potentiodynamic lithiation. The luminous transmittance was improved by the doping. Lithium intercalation changed the optical band gap and the electrochemical performance in a manner that could be understood from a simple band structure model. © 1994 American Institute of Physics.