Hierarchically hollow structured NiCo2S4@NiS for high-performance flexible hybrid supercapacitors

• Published in: Nanoscale 2020-02, Vol.12 (7), p.4686-4694
• Main Authors: Qu, Guangmeng, Li, Chuanlin, Hou, Peiyu, Zhao, Gang, Wang, Xiao, Zhang, Xiaoli, Xu, Xijin
• Format: Article
• Language: English
• Subjects: Capacitance; Electrochemical analysis; Energy storage; Flexibility; Flux density; Hydroxides; Intermetallic compounds; Nanostructure; Nickel compounds; Nickel sulfide; Stability; Supercapacitors
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c9nr09991c

Hierarchical nanostructures with outstanding electrochemical properties and mechanical stability are ideal for constructing flexible hybrid supercapacitors. Herein, hierarchically hollow NiCo2S4@NiS nanostructures were designed and synthesized by sulfurizing the hierarchical NiCo double hydroxides (DHs) coated with nickel hydroxide nanostructures on carbon fabrics (NiCo-DHs@Ni(OH)2/CF), which trigger excellent electrochemical performances. The NiCo2S4@NiS/CF exhibits a high specific capacity of 1314.0 C g−1 at a current density of 1 A g−1, and maintains the rate performance at about 79.2% of the initial capacity at 30 A g−1. The hybrid supercapacitors of NiCo2S4@NiS//AC display a high energy density of 62.4 W h kg−1 at a power density of 800 W kg−1 with a remarkable cycling stability (96.2% of initial capacitance after 5000 cycles) and robust mechanical flexibility (no obvious decay of specific capacitance during various deformations). Consequently, NiCo2S4@NiS electrodes are expected to be a promising candidate for new smart energy storage devices with high security, stability and flexibility.