Interfacial Electronic Engineering in NiCo₂S₄@NiAl‑LDH Core-Shell Nanoarrays for Advanced Supercapacitor Electrodes

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitor performance relies on electrode materials with efficient charge transport and reaction kinetics.
• Heterostructured materials offer tunable properties for enhanced electrochemical energy storage.

Purpose of the Study:

• To design and synthesize a hierarchical core-shell nanoarray for high-performance supercapacitors.
• To investigate the interfacial effects on charge transport and redox kinetics in heterostructured electrodes.

Main Methods:

• Fabrication of NiCo2S4 nanoneedles coated with NiAl-layered double hydroxide nanosheets on nickel foam.
• Electrochemical characterization including specific capacity, rate capability, and cycling stability tests.
• In-situ experimental and theoretical calculations to elucidate interfacial electronic structure and charge transfer mechanisms.

Main Results:

• The NiCo2S4@NiAl-LDH electrode exhibited a high specific capacity (244.8 mAh g-1 at 2 A g-1) and excellent cycling stability (91.4% retention after 5000 cycles).
• Surface-dominated charge storage mechanism with enhanced capacitive contribution was identified.
• Interfacial electronic engineering via heterostructure formation facilitated electron transfer and optimized OH- adsorption, boosting redox kinetics.

Conclusions:

• The hierarchical NiCo2S4@NiAl-LDH core-shell structure provides an effective strategy for interfacial electronic engineering in supercapacitor electrodes.
• Optimized interfacial coupling and electronic structure modulation are key to enhancing electrochemical performance.
• This approach offers a pathway for developing next-generation high-performance energy storage materials.