Bowknot-like RuO2 quantum dots@V2O5 nanomaterials have been synthesized by a facile hydrothermal method followed by annealing treatment, which exhibit largely enhanced electrochemical performance. Especially, the RuO2 quantum dots@V2O5 cathode delivers 160 mA h g(-1) at 1000 mA g(-1) after 100 cycles, which is much higher than 86 mA h g(-1) of the pure V2O5 cathode.