Characterization of niobium and vanadium oxide nanocomposites with improved rate performance and cycling stability

•Niobium and vanadium oxides nanocomposites were synthesized using a facile sol–gel process.•Such nanocomposites exhibit both significantly improved rate and cycling stability.•Possible synergistic mechanism between the constituent components of the nanocomposites was proposed.

Niobium and vanadium oxides nanocomposites are synthesized using a facile sol–gel process, and characterized by scanning and transmission electron microscopy. X-ray diffraction results show that the nanocomposites are composed of Nb2O5 and its solid solutions. Such nanocomposites exhibit both significantly improved rate and cycling stability. At a current density of 1 A g−1, the nanocomposites deliver more than three times of capacity than pure Nb2O5, and remain ~95% of its initial capacity after 50 cycles. Possible synergistic mechanism between the constituent components of the nanocomposites is also proposed.