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The use of high electrochemical active binary nickel−cobalt sulfides/ phosphides/selenides (Ni−Co−X, X = S, P, Se) as electrochemical energy storage materials still has a space for improvement because they become electrochemically unstable during long-term use. Herein, a facile and cost-effective dual-ligand synergistic modulation tactic is described to substantially improve the durability of Ni−Co−X (X = S, P, Se) at the atomic level by partially substituting S, P, and Se ligands into the nickel−cobalt hydroxide precursor, respectively. Remarkably, the dual-ligand electrodes on Ni-foam achieve superior durability and high electrochemical activity when used as positive electrodes in supercapacitors. Impressively, the density functional theory calculations demonstrate that the OH ligand in NiCo 2 (MOH) x (M = S, P, Se) could attract electrons from metal−S/metal−P/metal−Se bonds to the metal−O bond, enhancing the binding energy of metal−S/metal−P/metal−Se bonds and improving the long-term durability of Ni−Co−X (X = S, P, Se) in alkaline electrolytes. Moreover, OH and S/P/Se ligands could effectively alter the electron structure and result in favorable electrochemical activity. Overall, this tactic could offer an exciting avenue to achieve long-term durability and electrochemical activity of supercapacitor electrodes simultaneously.

A three-dimensional (3D) hollow CoWO 4 composite grown on Ni-foam (3DÀ H CoWO 4 /NF) based on a flower-like metal-organic framework (MOF) is designed by utilizing a facile dipping and hydrothermal approach. The 3DÀ H CoWO 4 /NF not only possesses large specific areas and rich active sites, but also accommodates volume expansion/ contraction during charge/discharge processes. In addition, the unique structure facilitates fast electron/ion transport of 3DÀ H CoWO 4 /NF. Meanwhile, a series of characterization measurements demonstrate the appropriate morphology and excellent electrochemical performance of the material. The 3DÀ H CoWO 4 /NF possesses a high specific capacitance of 1395 F g À 1 , an excellent cycle stability with 89% retention after 3000 cycles and superior rate property. Furthermore, the 3DÀ H CoWO 4 /NF can be used as a cathode to configurate an asymmetric supercapacitor (ASC), and 3DÀ H CoWO 4 /NF//AC shows a good energy density (29.0 W h kg À 1 ). This work provides a facile method for the preparation of 3D-hollow electrode materials with high electrochemical capability for advanced energy storage devices. cell (F g À 1 ) is the specific capacitance of the asymmetric supercapacitor, ΔV (V) stands for the potential change. E is the energy density (Wh kg À 1 ), and then t denotes the discharge time (s).

In this work, for the first time, we managed to derive the hierarchical porous carbon (HPC) at a large scale from the carbonization of franchet groundcherry fruit peels. With the interconnected porous characteristics and high specific surface area, the environmentally friendly HPC demonstrates a favorable specific capacity of 335 F/g. Moreover, the HPC-based symmetrical device demonstrates a superior energy density of 22.3 Wh/kg. This study not only paves an economical and practical way to recycle the franchet groundcherry fruit peels, but also develops an eco-friendly approach to obtain hierarchical porous carbon for enhanced capacitive electrochemical energy storage.