Embedding of conductive Ag nanoparticles among honeycomb-like NiMn layered double hydroxide nanosheet arrays for ultra-high performance flexible supercapacitors

• Published in: Journal of colloid and interface science 2023-01, Vol.629, p.938-949
• Main Authors: Fu, Hucheng, Zhang, Aitang, Zong, Hanwen, Jin, Fuhao, Guo, Hanwen, Liu, Jingquan
• Format: Article
• Language: English
• Subjects: Ag nanoparticles; Flexible electrodes; Honeycomb-like structure; Supercapacitors; Ultra-high capacitance
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2022.08.175

A honeycomb-like structure nanocomposite composed of Ag nanoparticles doped NiMn-LDHs nanosheets shell and uniformly arranged Co2(OH)2CO3 nanoneedles core shows promising electrochemical storage properties. [Display omitted] •Honeycomb-like CC@Co2CH/NM-LDH-Ag nanosheet arrays are synthesized on carbon cloth.•The hybrid of various active components provides abundant active sites and fast ion diffusion.•CC@Co2CH/NM-LDH-Ag is used to prepare binder-free electrodes and exhibits excellent electrochemical properties.•The assembled all-solid-state asymmetric supercapacitor shows high energy density and power density. Layered double hydroxides are considered promising electrode materials for the preparation of high-energy–density supercapacitors owing to their suitable microstructure and significant electrochemical properties. In this study, honeycomb-like NiMn-layered double-hydroxide (NiMn-LDH) nanosheet arrays with numerous electron/ion channels, a large number of active sites, considerable redox reversibility, and significant electrical conductivity were synthesized by combining Co2(OH)2CO3 nanoneedle arrays with NiMn-LDH nanosheet arrays and Ag nanoparticles on a carbon cloth (CC) substrate through a hydrothermal strategy (CC@Co2CH/NM-LDH-Ag). The fabricated CC@Co2CH/NM-LDH-Ag binder-free electrode exhibited a high specific capacitance of 10,976 mF cm−2 (3092F/g, 1391.4C g−1) at 2 mA cm−2 (1 A/g), and a high capacitance retention of 93.2 % after 10,000 cycles at a current density of 20 mA cm−2. In addition, a solid-state asymmetric supercapacitor (ASC) device assembled using CC@Co2CH/NM-LDH-Ag as the cathode possessed an ultrahigh energy density of 68.85 Wh kg−1 at a power density of 722.6 W kg−1, and two fabricated ASC units in series were able to power a multifunctional display for more than 30 min. Therefore, this study provides a new approach for the design and synthesis of high-performance flexible electrodes.