Core-shell structured Ni3S2@VO2 nanorods grown on nickel foam as battery-type materials for supercapacitors
By Du, Hongmei; Ding, Feifei; Zhao, Jinsheng; Zhang, Xianxi; Li, Yunwu; Zhang, Yan; Li, Jin; Yang, Xiaofan; Li, Kun; Yang, Yaqing
Published in Applied Surface Science
2019
Abstract
Rational design of composite with other electroactive materials can effectively improve the supercapacitive performances through the modulation of electronic structure and conductivity of the hybrid material. In this work, core-shell structured Ni3S2@VO2 nanorods on the nickel foam are prepared through a one-pot hydrothermal method. The addition of VO2 effectively reduces the charge transfer resistance and thus enhances the electrochemical conductivity. The nickel foam provides a platform for the in situ dispersive growth of Ni3S2@VO2 as well as a “superhighway” for the transformation of electrons. The Ni3S2@VO2 shows a high areal specific capacity of 1.09 C cm-2 at 1 mA cm-2. After a slight decrease in the initial 200 cycles, the discharge capacity remains almost constant at about 1.00 C cm-2 during the following cycles. At a high current of 50 mA cm-2, the areal specific capacitance is 0.09 C cm-2. A symmetric supercapacitor is assembled using Ni3S2@VO2 as both the anode and cathode. The specific capacity of it is 0.864 C cm-2 at a current of 1mA cm-2. Good cycling stability and rate capability are also obtained. All these features promise it a high performance supercapacitor electrode.