Fabrication of porous Co/NiO core/shell nanowire arrays for electrochemical capacitor application

Rational design of asymmetric supercapacitors via a hierarchical core–shell nanocomposite cathode and biochar anode

Hierarchical MnO₂ nanosheets attached on hollow NiO microspheres have been designed by a facile hydrothermal process. The core–shell structure is achieved by decorating an MnO₂ nanosheet shell on a hollow NiO sphere core. The highly hollow and porous structure exhibits a high surface area, shortened ion diffusion length, outstanding electrochemical properties (558 F g⁻¹ at a current density of 5 mA cm⁻²), and excellent cycling stability (83% retention after 5000 cycles). To further evaluate the NiO/MnO₂ core–shell composite electrode for real applications, three asymmetric supercapacitors (NiO/MnO₂//pomelo peel (PPC), NiO/MnO₂//buckwheat hull (BHC), and NiO/MnO₂//activated carbon (AC)) are assembled. The results demonstrated that NiO/MnO₂//BHC delivered a substantial energy density (20.37 W h kg⁻¹ at a power density of 133.3 W kg⁻¹) and high cycling stability (88% retention after 5000 cycles) within a broad operating potential window of 1.6 V.

Hierarchical MnO₂ nanosheets standing on hollow NiO microspheres have been designed by a facile hydrothermal process. Furthermore, asymmetric supercapacitors via core/shell NiO/MnO₂ cathode and biochar anode were assembled.

One-Dimensional Assembly of Conductive and Capacitive Metal Oxide Electrodes for High-Performance Asymmetric Supercapacitors

A one-dimensional morphology comprising nanograins of two metal oxides, one with higher electrical conductivity (CuO) and the other with higher charge storability (Co₃O₄), is developed by electrospinning technique. The CuO-Co₃O₄ nanocomposite nanowires thus formed show high specific capacitance, high rate capability, and high cycling stability compared to their single-component nanowire counterparts when used as a supercapacitor electrode. Practical symmetric (SSCs) and asymmetric (ASCs) supercapacitors are fabricated using commercial activated carbon, CuO, Co₃O₄, and CuO-Co₃O₄ composite nanowires, and their properties are compared. A high energy density of ∼44 Wh kg^-1 at a power density of 14 kW kg^-1 is achieved in CuO-Co₃O₄ ASCs employing aqueous alkaline electrolytes, enabling them to store high energy at a faster rate. The current methodology of hybrid nanowires of various functional materials could be applied to extend the performance limit of diverse electrical and electrochemical devices.

Applications of hierarchically structured porous materials from energy storage and conversion, catalysis, photocatalysis, adsorption, separation, and sensing to biomedicine

A comprehensive review of the recent progress in the applications of hierarchically structured porous materials is given.

Mesoporous Co3O4@carbon composites derived from microporous cobalt-based porous coordination polymers for enhanced electrochemical properties in supercapacitors

In this work, mesoporous Co₃O₄@carbon composites were prepared through a simple, one-step, carbonization of microporous cobalt-based porous coordination polymer ZSA-1.

Hydrothermal growth of MnO2/RGO/Ni(OH)2 on nickel foam with superior supercapacitor performance

A MnO₂/RGO/Ni(OH)₂ composite film with a unique nanoarchitecture was designed and synthesized in situ on nickel foam using a facile one-pot hydrothermal approach, and exhibited superior capacitive performance.

Electrochemical energy-storage performances of nickel oxide films prepared by a sparking method

The sparking method is a practical and effective preparation technique for porous nickel oxide films, suitable for energy-storage applications.

Seaurchin-like hierarchical NiCo2O4@NiMoO4 core–shell nanomaterials for high performance supercapacitors

A seaurchin-like NiCo₂O₄@NiMoO₄ core–shell structure, which exhibits excellent electrochemical performances was first synthesized via a facile two-step hydrothermal method.