Simultaneous in-situ conductivity and cyclic voltammetry characterization of Li-ion intercalation into thin V2O5 films

Cyclic voltammetry (CV) and in-situ electronic conductivity curves have bee n simultaneously measured during Li-ion Insertion de-insertion Into from th in, partially crystallized. Li8V2O5 film in 1 M LiBF4+ propylene carbonate solution. A similarity has been observed between the CV curves and the plot s of the derivative of conductivity, d sigma/dE, versus potential. A semi-m etal-to-insulator transition. and vice versa, has been observed (in interca lation and de-intercalation, respectively), ascribed to the epsilon- to del ta-phase transition of LixV2O5. This transition Is accompanied by an increa se in the V-V distance between adjacent VO8; layers. and is probably respon sible for the decrease in the film conductivity, realized via electron hopp ing between the high and low-valence vanadium sites. (C) 1999 Elsevier Scie nce S.A. All rights reserved.