Hydrothermal synthesis of coralloid-like vanadium nitride/carbon nanocomposites for high-performance and long-life supercapacitors

Vanadium nitride is highly desirable for their good electrochemical performance and wide work potential window, but they are cramped practical applications in supercapacitors due to poor cycling stability. Herein a combined strategy is exploited to fabricate coralloid-like nanostructure vanadium nitride/carbon (VN/C) via a facile hydrothermal method. The structural characterization displayed that nano-VN was uniformly distributed in the carbon scaffold materials to improve the electrode behavior. Those composites exhibited a wide voltage window of -1.1 to 0 V with a specific capacitance of 385 F g(-1) at 1 A g(-1), and exceptional cycling stability (88.9% retention after 10000 cycles). The two-electrode system based on VN/C electrodes obtains a high energy density of 24.2 Wh kg(-1) at a power density of 1050 W kg(-1). The device also shows perfect cycling stability with 93.3% capacitance retention after 10000 cycles. The coralloid-like VN/C electrode materials can be used in practical applications of the high-performance energy storage device. (C) 2019 Elsevier B.V. All rights reserved.