Orthorhombic niobium oxide nanowires for next generation hybrid supercapacitor device

Energy storage device with high energy density at high power density is of particular importance for various applications, such as hybrid vehicles. Next generation high performance hybrid supercapacitor using organic electrolyte is able to provide high operation voltage as well as enhanced energy density. However, the energy density at high power density is usually low, partly due to the slow electrode kinetics at high current densities. In this contribution, we report a facile preparation method for orthorhombic phase niobium oxide (T-Nb₂O₅) nanowire structure with ultra-thin carbon coating, which shows stable high rate Li⁺ storage ability. A prototype of 3V hybrid supercapacitor is fabricated using carbon coated T-Nb₂O₅ as anode and commercially available activated carbon as cathode. This hybrid device shows high energy density of 43.4Whkg^-1 and a high power density of 7.5kWkg^-1 with excellent stability.