Study of the Li+ insertion into V2O5 films deposited by CVD onto various substrates

Vanadium oxide films were synthesised by chemical vapour deposition (CVD) from pure of triisopropoxyvanadium oxide (VO(OC3H7)3) and oxygen as precursors. The influence of the substrate on the crystallinity of the vanadium oxide films was studied before and after annealing at 500 °C. On mica substrates, as-deposited film was composed of crystalline V2O5 as revealed by XRD. On Pt, Ti, stainless steel, glass and F-doped SnO2 substrates, an annealing procedure was required to get V2O5. SEM investigations have clearly evidence V2O5 plates but the kinetics growth seems to be strongly dependent on the nature of the substrate. The insertion/extraction of Li+ into the host structure was investigated in 1 M LiClO4-PC with annealed V2O5 films deposited on Ti, Pt and stainless steel substrates. The best electrochemical performances were obtained in the potential range 3.8–2.8 V versus Li/Li+ with V2O5 films deposited onto stainless steel substrate: the reversible capacity reaches after subsequent cycles was about 115 mAh g−1 (rate C/23). In a wider potential range (between 3.8 and 2.2 V versus Li/Li+), V2O5 deposited onto Ti substrate exhibited the higher electrochemical performances (220 mAh g−1 for a rate of C/23).