Vanadium Sesquioxide/Nitride Nanostructures in Electrospun Carbon Fibers for High Energy Density Supercapacitors

Vanadium sesquioxide/vanadium nitride nanoparticles were prepared in carbon fibers by electrospinning, followed by carbonization. Polyacrylonitrile was used as the carbon precursor, poly(methyl methacrylate) as the porogen, and V₂O₅ nanowires as the vanadium source. During the high temperature carbonization, V₂O₅ was reduced in situ by carbon and converted into V₂O₃ and further transformed into VN by NH₃ released from polyacrylonitrile. The composite was used as electrodes and fabricated into a symmetric coin cell-type supercapacitor using 1 M lithium bis(trifluoromethanesulfonyl)imide in propylene carbonate as the electrolyte. The resulting supercapacitor showed a specific capacitance of 369 F g^–1 at 5 mV/s, an energy density of 107 Wh kg^–1 at 0.05 A g^–1, and a high power density of 5154 W kg^–1 at 5 A g^–1.