Three-Dimensional NiCo₂O₄@MnMoO₄ Core-Shell Nanoarrays for High-Performance Asymmetric Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Designing materials with advanced nanostructures is key to enhancing properties for various applications.
• Combining electron-conductive (NiCo2O4) and high-capacitance (MnMoO4) materials can lead to superior electrochemical performance.

Purpose of the Study:

• To synthesize and characterize NiCo2O4@MnMoO4 core-shell nanoarrays (CSNAs) for supercapacitor electrodes.
• To evaluate the electrochemical performance of these CSNAs in asymmetric supercapacitors (ASCs).

Main Methods:

• Fabrication of NiCo2O4@MnMoO4 CSNAs.
• Electrochemical testing of CSNAs as electrodes in ASCs assembled with active carbon (AC).
• Analysis of capacitance, energy density, power density, and cycle stability.

Main Results:

• The NiCo2O4@MnMoO4 CSNAs electrode exhibited a high capacitance of 1169 F g-1.
• The assembled ASCs demonstrated high energy density (15 Wh kg-1) and power density (6734 W kg-1).
• The ASCs maintained 96.45% of their initial capacitance after 10,000 cycles, indicating excellent stability.

Conclusions:

• The NiCo2O4@MnMoO4 CSNAs show great promise as high-performance electrode materials for supercapacitors.
• The core-shell nanostructure facilitates enhanced surface area, electroactive sites, and ion/electron transport.
• Dominance of capacitive charge storage contributes to the ultra-long cycle stability of the supercapacitors.