Li-intercalation behaviour of vanadium oxide thin film prepared by thermal oxidation of vanadium metal

摘要: Abstract In order to produce thin films of crystalline V 2 O 5 , vanadium metal was thermally oxidised at 500 °C under oxygen pressures between 250 and 1000 mbar for 1–5 min. The oxide were characterised by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), diffraction (XRD) Rutherford backscattering spectrometry (RBS). lithium intercalation performance the investigated cyclic voltammetry (CV), chronopotentiometry electrochemical impedance (EIS). It shown that composition, crystallinity related properties critically dependent on oxidation conditions. formation stimulated higher pressure longer time. Exposure 5 min 750 mbar resulted in a surface film composed 5, consisting crystallites up 200 nm lateral size. thickness layer about 100 nm. This found have good cycling potential window 3.8 2.8 V, with stable capacity 117 ± 10 mAh/g an applied current density 3.4 μA/cm . diffusion coefficients corresponding two plateaus 3.4 3.2 V determined from measurements (5.2 3.0) × 10 −13  cm  s −1 respectively. Beneath layer, lower oxides (mainly VO ) close metal. At shorter exposure times, less amount 4+ increased film, as revealed XPS. intermediate times mixture 6 13 film.