In this article, vanadium nitride quantum dot/nitrogen-doped microporous carbon nanofibers (VNQD/CNF) is developed by a method of combination of electrostatic spinning and high-temperature calcination under the atmosphere of NH3: N-2 = 3: 2 for high performance supercapacitors. VNQD dispersing into CNF, enrichment of N atom doped in carbon bulk, and abundant porous structure not only prevent the growth and aggregation of VN nanoparticles, improve electrical conductivity, wettability, and stability of the electrode materials, but also enhance fast migration of electrolyte ions during the electrochemical process. Thus, VNQD/CNF exhibits a high specific capacitance of 406.5 F g(-1) at 0.5 A g(-1) and a good rate capability with a capacitance retention of 75.1% at 5.0 A g(-1). Additionally, VNQD/CNF as a negative electrode are combined with Ni(OH)(2) as a positive electrode to fabricate the hybrid super capacitor of VNQD/CNF//Ni(OH)(2). Remarkably, at a power density of 774.6 W kg(-1), the supercapacitor device delivers an ultrahigh energy density of 31.2 Wh kg(-1). (C) 2017 Elsevier B.V. All rights reserved.