Urchin-like NiCo2S4 structures synthesized through a one-step solvothermal process for high-performance supercapacitors--颗粒学报PARTICUOLOGY

Hu, Y., Zhang, J., Wang, D., Sun, J., Zhang, L., Liu, Y., . . . Cui, Y. (2019). Urchin-like NiCo2S4 structures synthesized through a one-step solvothermal process for high-performance supercapacitors. Particuology, 45, 66-73. https://doi.org/10.1016/j.partic.2018.07.008

Urchin-like NiCo₂S₄ structures synthesized through a one-step solvothermal process for high-performance supercapacitors

Yan Hu ^{a b 1}, Jie Zhang ^{a b 1}, Di Wang ^a, Jiangbo Sun ^a, Li Zhang ^a, Yanjie Liu ^a, Shiqiu Gao^a, Yanbin Cui ^a *

a State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
b University of Chinese Academy of Sciences, Beijing 100049, China

10.1016/j.partic.2018.07.008

August 2019, Volume 45, Pages 66-73

Received 2 April 2018, Revised 13 July 2018, Accepted 19 July 2018, Available online 3 January 2019, Version of Record 10 June 2019.

E-mail: ybcui@ipe.ac.cn

Highlights

• Urchin-like NiCo₂S₄ was synthesized through a one-step solvothermal process.

• PEG 200 was used as a solvent and shape-control agent.

• A NiCo₂S₄//AC asymmetric supercapacitor was fabricated.

• An energy density of 37.32 Wh/kg was obtained at a power density of 317.8 W/kg.

Abstract

Nickel cobalt sulfides (NiCo₂S₄) have attracted considerable attention as electrode materials for supercapacitors. Herein, a sea-urchin-like NiCo₂S₄ material was synthesized through a one-step solvothermal process. Polyethylene glycol (PEG) 200 and thiourea were used as a shape-control agent and sulfur source for in-situ sulfuration, respectively. The urchin-like NiCo₂S₄ was characterized by X-ray powder diffraction, scanning electron microscopy, Brunauer–Emmett–Teller surface area, and electrochemical measurements. The resulting NiCo₂S₄ with ion diffusion-favored structure demonstrated remarkable electrochemical characteristics for supercapacitor with a high specific capacitance (1334 F/g at 0.5 A/g) and superior rate capability (78.1% of the original capacity from 0.5 to 20 A/g) in 6 M KOH aqueous solution. Furthermore, an asymmetric supercapacitor was assembled using NiCo₂S₄ as a positive electrode and activated carbon (AC) as a negative electrode. A NiCo₂S₄//AC device exhibited a high energy density of 37.32 Wh/kg at a power density of 317.8 W/kg with capacity retention of 91.9% and up to 2000 charge/discharge cycles at 3 A/g. The results demonstrate that the sea-urchin-like NiCo₂S₄ has potential applications in supercapacitors.

Graphical abstract

Keywords

NiCo₂S₄; PEG; Asymmetric supercapacitor; Urchin-like structure; High specific capacitance

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