The synergistic effect of the RuO2 nanoparticle-decorated V2O5 heterostructure for high-performance asymmetric supercapacitors

Two-dimensional RuO2 nanoparticle-decorated V2O5 nanoflakes are successfully synthesized by a simple solvothermal method. The synthesized RuO2-decorated V2O5 nanocomposite electrode exhibited a high charge–discharge capacity with an excellent cyclic retention of 94.6% over 10 000 cycles. Specifically, the 3 wt% RuO2 in V2O5 (R2) nanocomposite electrode showed a high specific capacitance of 421 F g−1 at a current density of 1 A g−1 in a three-electrode system. The specific capacitance of the R2 nanocomposite is almost 3-fold higher than that of pure V2O5 nanosheets in the three-electrode system. An energy density of 29 Wh kg−1 was achieved in a two-electrode system at a power density of 816 W kg−1 in an R2 based asymmetric supercapacitor device. The energy density and power density of the RuO2–V2O5 nanocomposite are higher than those of previously reported V2O5 nanostructured asymmetric supercapacitors.