Next Generation V2O5 Cathode Materials for Li Rechargeable Batteries

We report on investigations of vanadium oxide thin film cathodes prepared by three different synthesis techniques. Our experimental results on PLD-grown, textured V₂O₅ crystalline films concur with reports in the literature that there is a voltage threshold above which, cycling appears to be completely reversible and below which, cycling appears to be irreversible. Crystalline films discharged beyond the threshold to 2.0 V exhibited an immediate and continuous fade in capacity as well as a nearly 90% decrease in XRD peak intensity and a similar decrease in Raman signal intensity in as few as ten cycles. PLD-grown amorphous films show capacity loss of < 2% over 200 cycles. Amorphous plasma-enhanced chemical vapor deposition (PECVD) films have capacities as high as 1.5 Li/V with excellent stability over 3000 cycles. Solution-grown nanoparticles ( < 100 nm) of VO₂ were spray-deposited and sintered at relatively low temperatures to produce nanoporous films. Cycling properties along with structural investigations by XRD and Raman scattering will be presented.