ACF/NiCo2S4 honeycomb-like heterostructure material: Room-temperature sulfurization and its performance in asymmetric supercapacitors. (20th February 2019)

• Record Type: Journal Article
• Authors: Zhao, Shihuai; Yang, Zibo; Xu, Wenwen; Zhang, Qingyin; Zhao, Xiaoming; Wen, Xin
• Is Part Of: Electrochimica acta. Volume 297(2019)
• Page Start: 334
• Page End: 343
• Publication Date: 2019-02-20
• Subjects: Room-temperature sulfurization -- NiCo2S4 -- ACF -- High energy density -- Asymmetric supercapacitor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.11.211
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Transition metal sulfide, especially NiCo2 S4, is of great interest as the promising battery-type electrode material for asymmetric supercapacitor (ASC). However, such material has its own disadvantages of energy waste of preparation and poor electrical conductivity. In this work, we adopted a green and environmentally friendly room-temperature sulfurization method to successfully prepare the electrode material (ACF/NCS-HL) with activated carbon fiber (ACF) as the core and honeycomb-like NiCo2 S4 as the shell (NCS-HL). This material has porous structure with heterogeneous redox electron pairs and shows excellent electrochemical performance. The optimized ACF/NCS-HL exhibits remarkable specific capacitance of 1682 F g −1 at 1 A g −1 in 2 M KOH aqueous electrolyte in the three-electrode system. The asymmetric supercapacitor device with ACF/NCS-HL as positive electrode and ACF as negative electrode shows the high energy density of 49.38 W h kg −1 at the power density of 800 W kg −1 and the preeminent cycle stability up to 82.88% after 5000 cycles, indicating its promising potential application in the future as high-performance supercapacitors. Graphical abstract: Image 1 Highlights: A novel sulfurization method of NiCo2 S4 at room-temperature(25 °C) based on solubility difference between nickel-cobalt sulfide and nickel-cobalt hydroxide is proposed. A high energy density of 49.38 W h kg –1 at a power density of 800 W kg –1 is achieved. A durable cyclic stability of ACF/NiCo2 S4 with high retention ratio of 82.88% after 5000 cycles is obtained.