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[Display omitted] The selection of highly efficient materials and the construction of advantageous structures are essential for realizing high-performance electrode materials. In this paper, electrode material Cu 2 S/C@NiMnCe-LDH/CF with excellent morphology and high performance has been successfully designed and prepared by simple hydrothermal and calcination techniques. First, ZIF-67 is loaded on the outer layer of Cu 2 S rods to obtain core–shell structured Cu 2 S@ZIF-67 rods, whose ZIF-67 MOF shell is carbonized to obtain Cu 2 S@C rods. Then, NiMnCe-LDH are epitaxially loaded on the outer layer of Cu 2 S@C to obtain Cu 2 S/C@NiMnCe-LDH rods. At a current density of 2 mA cm−2, Cu 2 S/C@NiMnCe-LDH/CF exhibits an area capacitance of 5176.4 mF cm−2. The mass capacitance and the energy density of the Cu 2 S/C@NiMnCe-LDH/CF//AC asymmetric supercapacitor (ASC) reach 150.82F g−1 at a sweep rate of 0.8 A/g and 53.62 Wh kg−1 at a power density of 639.99 W kg−1, respectively. Meanwhile, after 8000 electrochemical cycles, the specific capacitance of Cu 2 S/C@NiMnCe-LDH/CF//AC still has a retention rate of 86.32 %, which proves its excellent cycling stability. These results demonstrate a new strategy for the preparation of novel core–shell structured Cu 2 S/C@NiMnCe-LDH/CF nanocomposite material for electrode materials of energy storage devices with superb performance. [ABSTRACT FROM AUTHOR]

A honeycomb-like structure nanocomposite composed of Ag nanoparticles doped NiMn-LDHs nanosheets shell and uniformly arranged Co 2 (OH) 2 CO 3 nanoneedles core shows promising electrochemical storage properties. [Display omitted] • Honeycomb-like CC@Co 2 CH/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@Co 2 CH/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 Co 2 (OH) 2 CO 3 nanoneedle arrays with NiMn-LDH nanosheet arrays and Ag nanoparticles on a carbon cloth (CC) substrate through a hydrothermal strategy (CC@Co 2 CH/NM-LDH-Ag). The fabricated CC@Co 2 CH/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@Co 2 CH/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. [ABSTRACT FROM AUTHOR]

Hierarchical CoSe 2 @NiMn-LDH@Cu 1.8 Se/CF nanosheet arrays with core-shell structure are synthesized via phase pseudomorphic transformation process achieved by selective selenization for Cu and Co elements for green chemistry energy storage. [Display omitted] As an emerging energy storage device, the practical application of supercapacitors (SCs) is currently constrained by their low energy density. Enhancing the capacitance of supercapacitors by leveraging the synergistic effect of multiple components in composite electrodes with well-designed structures can effectively increase their energy density. Here, a wire-sheet-particle hierarchical heterostructured CoSe 2 @NiMn-layered double hydroxide (NiMn-LDH) @Cu 1.8 Se/Copper foam (CF) electrode is synthesized via phase pseudomorphic transformation process achieved by selective selenization for Cu and Co elements. Benefiting from the stable support structure of CuBr 2 , the large specific surface area of NiMn-LDH, and the excellent conductivity of CoSe 2 , the prepared binder-free electrode shows excellent electrochemical properties. The CoSe 2 @NiMn-LDH@Cu 1.8 Se hybrid electrode exhibits a superior specific areal capacitance of 7064 mF cm−2 at 2 mA cm−2 and a stable cyclic performance with 80.11 % capacitance retention after 10,000 cycles. Furthermore, the assembled CoSe 2 @NiMn-LDH@Cu 1.8 Se/CF//AC (activated carbon) asymmetric supercapacitor (ASC) achieves an energy density of 36.6 Wh kg−1 when the power density is 760.6 W Kg−1 and retains 87.35 % of the initial capacitance after 5000 cycles. Overall, this pioneering research provided new insight for preparing supercapacitor electrode materials by selective selenization and ration design of the structures. [ABSTRACT FROM AUTHOR]