A core–shell structured nanocomposite of NiO with carbon nanotubes as positive electrode material of high capacitance for supercapacitors. (February 2016)

• Record Type: Journal Article
• Authors: Wen, Z.B.; Yu, F.; You, T.; Zhu, L.; Zhang, L.; Wu, Y.P.
• Is Part Of: Materials research bulletin. Volume 74(2016)
• Page Start: 241
• Page End: 247
• Publication Date: 2016-02
• Subjects: Nanocomposite -- Nanostructures -- Solvothermal -- Electrochemical properties -- Energy storage; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2015.10.035
• Languages: English
• ISSNs: 0025-5408

Abstract

Graphical abstract: Highlights: A core–shell structured NiO@CNTs nanocomposite is synthesized by a simple hydrothermal method. The CNTs core effectively improves the capacitance, rate and cycling performance of NiO. A supercapacitor is assembled when activated carbon is used as the negative electrode. The supercapacitor presents an energy density up to 52.6 Wh kg −1 . Abstract: A nanocomposite of carbon nanotubes coated with nickel oxide was prepared by a simple hydrothermal method. The structure, morphology and electrochemical performance of the nanocomposite were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, electrochemical tests including cyclic voltammogram, galvanostatic charge–discharge and electrochemical impedance spectroscopy, respectively. It presents the highest specific capacitance of 1844 F g −1 at 1 A g −1 and 1145 F g −1 at current density of 10 A g −1 with 88.9% (at 1 A g −1 ) capacitance retention after 1000 cycles. The specific capacitance of the nanocomposite is almost double of that of the virginal NiO (972 F g −1 at 1 A g −1 ). Its cycling behavior is also very good. When combined with activated carbon as the negative electrode, the energy density can be up to 52.6 Wh kg −1 . Such good electrochemical behavior indicates that the nanocomposite is a promising electrode material for supercapacitors.