Applied Surface Science, Vol.471, 842-851, 2019
Facile synthesis of high-surface vanadium nitride/vanadium sesquioxide/amorphous carbon composite with porous structures as electrode materials for high performance symmetric supercapacitors
Vanadium nitride/vanadium sesquioxide/amorphous carbon (denoted as VN/V2O3/C) composite is successfully synthesized by a facile hydrothermal method using ammonium metavanadate and glucose as the starting materials combined with a calcination process. Results show that VN/V2O3 nanoparticles (main VN and minor V2O3) are highly scattered on the amorphous carbon which is partly graphitized. VN/V2O3/C composite possesses the mesoporous structure with BET specific surface area of 134 m(2).g(-1), and the pore volume of 0.180 cm(3).g(-1). Electrochemical properties of VN/V2O3/C composite are investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (ESI). VN/V2O3/C composite electrode exhibits the satisfied electrochemical properties with the specific capacitance of 169 F.g(-1) at 5 mV.s(-1) (138 F.g(-1) at 0.5 A.g(-1)) and cycling behavior of 99.4% after 4000 cycles. Furthermore, VN/V2O3/C symmetric supercapacitor (denoted as VN/V2O3/C SSC) devices are assembled to assess their practical application. VN/V2O3/C SSC device exhibits the excellent electrochemical performance with the areal capacitance of 129 mF.cm(-2) (16.2 F.g(-1)) at 5 mV.s(-1) and 82 mF.cm(-2) (10.3 F.g(-1)) at 0.5 mA.cm(-2), cycling stability of 87% after 2000 cycles, and the energy density of 92 mWh.m(-2) (1.55 W.h.kg(-1)) at the power density of 2.25 W.m(-2) (14 W.kg(-1)). The impressive finding in this work demonstrates that the VN/V2O3/C composite can be considered as a promising candidate for high-performance energy storage materials.