A flexible wearable self-supporting hybrid supercapacitor device based on hierarchical nickel cobalt sulfide@C electrode

Xin Chen; Ming Sun; Fadi Jaber; Erfan Zal Nezhad; K S Hui; Zhenwu Li; Sungchul Bae; Muge Ding

doi:10.1038/s41598-023-42278-9

A flexible wearable self-supporting hybrid supercapacitor device based on hierarchical nickel cobalt sulfide@C electrode

Sci Rep. 2023 Sep 20;13(1):15555. doi: 10.1038/s41598-023-42278-9.

Authors

Xin Chen¹, Ming Sun¹, Fadi Jaber^{2

3}, Erfan Zal Nezhad⁴, K S Hui⁵, Zhenwu Li¹, Sungchul Bae⁶, Muge Ding⁷

Affiliations

¹ Department of Mechanical Engineering, Heze University, Heze, Shandong, China.
² Department of Biomedical Engineering, Ajman University, Ajman, United Arab Emirates.
³ Center of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates.
⁴ Department of Biomedical Engineering and Chemical Engineering, University of Texas at San Antonio, San Antonio, TX, USA. e.zalnezhad@gmail.com.
⁵ School of Mathematics, University of East Anglia, Norwich, NR4 7TJ, UK.
⁶ Department of Architectural Engineering, Hanyang University, Seoul, South Korea. sbae@hanyang.ac.kr.
⁷ Engineering Faculty, Auckland University, Auckland, New Zealand.

Abstract

A flexible wearable electrode consisting of nickel-cobalt sulfide (NCS) nanowires was fabricated in this study. Self-supporting NCS was grown in situ on porous carbon nanofibers without a binder as a novel material for supercapacitor electrodes. The NCS nanowires were grown using cyclic voltammetry electrodeposition, which proved to be a fast and environmentally friendly method with good controllability of the material structure. One-dimensional carbon nanofibers (C) have high surface-area-to-volume ratios, short ion transmission distances, excellent mechanical strengths, and remarkable flexibilities. Moreover, the NCS@C flexible electrode exhibited a synergetic effect with the active compounds, and the dense active sites were uniformly distributed across the entire surface of the carbon fibers, enabling rapid electron transport and enhancing the electrochemical properties of the NCS@C nanowires. The NCS@C achieved specific capacitances of 334.7 and 242.0 mAh g^-1 at a current density of 2 A g^-1 and high current densities (up to 40 A g^-1), respectively, corresponding to a 72.3% retention rate. An NCS@C-nanofilm-based cathode and an activated-carbon-based anode were used to fabricate a flexible asymmetric supercapacitor. The device exhibited high energy and power densities of 12.91 Wh kg^-1 and 358 W kg^-1, respectively.