Fabrication of dual-hollow heterostructure of Ni2CoS4 sphere and nanotubes as advanced electrode for high-performance flexible all-solid-state supercapacitors

Lu Liu; Anru Liu; Yuhan Xu; Fangqi Yang; Jun Wang; Qiang Deng; Zheling Zeng; Shuguang Deng

doi:10.1016/j.jcis.2019.12.074

Fabrication of dual-hollow heterostructure of Ni₂CoS₄ sphere and nanotubes as advanced electrode for high-performance flexible all-solid-state supercapacitors

J Colloid Interface Sci. 2020 Mar 22:564:313-321. doi: 10.1016/j.jcis.2019.12.074. Epub 2019 Dec 17.

Authors

Lu Liu¹, Anru Liu², Yuhan Xu², Fangqi Yang¹, Jun Wang³, Qiang Deng¹, Zheling Zeng¹, Shuguang Deng⁴

Affiliations

¹ Key Laboratory of Poyang Lake Environment and Resource Utilization (Nanchang University), Ministry of Education, Nanchang 330031, Jiangxi, PR China; School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, PR China.
² School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, PR China.
³ Key Laboratory of Poyang Lake Environment and Resource Utilization (Nanchang University), Ministry of Education, Nanchang 330031, Jiangxi, PR China; School of Resource, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, PR China. Electronic address: jwang7@ncu.edu.cn.
⁴ School for Engineering of Matter, Transport and Energy, Arizona State University, 551 E. Tyler Mall, Tempe, AZ 85287, USA. Electronic address: shuguang.deng@asu.edu.

PMID: 31918199
DOI: 10.1016/j.jcis.2019.12.074

Abstract

High-energy-density and flexible supercapacitors have shown numerous application potential in modern portable electronics. However, the relatively low specific capacity, poor rate retentions, and limited durability have hindered their implement. Herein, a novel hierarchical dual-hollow electrode, composed of a hollow Ni₂CoS₄ sphere and outer hollow Ni₂CoS₄ nanotubes (Ni₂CoS₄HS-HTs), is elaborately constructed. The Ni₂CoS₄HS-HT-5 exhibits a high specific capacity of 817.5 C g^-1 at a current density of 1 A g^-1 with remarkable rate retention of 75.3% at 50 A g^-1. In an all-solid-state asymmetric supercapacitor of Ni₂CoS₄HS-HT-5//CAC, a high capacitance of 1511.5 mF cm^-2 at 5 mA cm^-2 is obtained with an exceptional energy density of 13.6 mWh cm^-3 at a power density of 92.6 mW cm^-3. In addition, the capacity retention reaches 96% over 2000 cycles at 20 mA cm^-3, implying the outstanding durability. The flexibility and mechanical stability are demonstrated by the intact electrochemical performances under different bending angles. As a proof-of-concept, two Ni₂CoS₄HS-HT-5//CACs in series could successfully illuminate 31 LED indicators for more than 8 mins. These fascinating electrochemical performances benefit from the novel electrode structure and depict great potential for modern energy storage applications.

Keywords: All-solid-state supercapacitor; Bimetal sulfide; Dual-hollow heterostructure; Flexible electrode.