Effect of manganese doping on Li-ion intercalation properties of V2O5 films

Abstract

Mn-doped V2O5 has been prepared by sol–gel processing with H2O2 and V2O5 as precursors with Mn2+ added directly during sol preparation. Stable and homogeneous Mn-doped vanadium oxide sol was obtained and the films were fabricated by dip-coating, drying at ambient, and then annealing at 250 °C in air for 3 h. X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and electrochemical analyses have been employed to characterize and analyze the crystal- and microstructures, surface morphology and Li-ion intercalation properties of both Mn-doped and undoped V2O5 films. Mn-doped V2O5 films exhibit excellent cyclic stability with a fading rate of less than 0.06% per cycle, significantly better than that of the pure V2O5 films (0.8% per cycle). Mn-doped V2O5 films have demonstrated a large discharge capacity of ∼283mAh/g with a current density of 68 mA/g, again much higher than 237 mAh/g of V2O5 films. A possible explanation for such significant enhancement in lithium ion intercalation capacity, cyclic stability, and rate performance of Mn-doped V2O5 films has been discussed.