High-Activity 2D/2D Core-Shell Structure to NiMoO₄-Based Electrodes for Electrochemical Energy Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Limited reactive sites on NiMoO4 electrodes hinder supercapacitor (SC) performance.
• Improving redox site utilization in NiMoO4 electrodes is challenging.

Purpose of the Study:

• To develop a novel 2D/2D core-shell electrode structure for enhanced SC performance.
• To investigate the effect of the core-shell interface on electrochemical properties.

Main Methods:

• Fabrication of a 2D/2D core-shell electrode (NiFeZn-LDH nanosheets grown on NiMoO4 nanosheets) on carbon cloth (NFZ@NMO/CC).
• Characterization of the electrode's interface properties, including OH- adsorption and diffusion.
• Assembly and testing of an asymmetric SC using the novel electrode.

Main Results:

• The NFZ@NMO/CC electrode demonstrated significantly improved OH- adsorption and diffusion (1.47 × 10-7 cm2 s-1) and ECSA (737.5 mF cm-2) compared to pure NiMoO4.
• NFZ@NMO/CC achieved a capacitance of 2864.4 F g-1 at 1 A g-1 with 92% rate performance.
• The asymmetric SC exhibited superior energy (70 Wh kg-1) and power densities (709 W kg-1) with good cycling stability.

Conclusions:

• The 2D/2D core-shell structure effectively enhances the utilization of active sites and ion transport in NiMoO4-based electrodes.
• The developed NFZ@NMO/CC electrode offers a promising pathway for high-performance supercapacitors.
• The asymmetric SC demonstrates potential for practical energy storage applications.