Synergistically Active NiCo₂ S₄ Nanoparticles Coupled with Holey Defect Graphene Hydrogel for High-Performance...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors are crucial for energy storage.
• Developing advanced electrode materials with high performance and durability is essential.
• Graphene-based composites offer unique properties for energy applications.

Purpose of the Study:

• To synthesize nickel cobalt sulfide nanoparticles embedded in holey defect graphene hydrogel (NiCo2S4@HGH).
• To evaluate the electrochemical performance of NiCo2S4@HGH as a supercapacitor electrode material.
• To assess the durability and application potential of the developed material in solid-state supercapacitors.

Main Methods:

• Facile solvothermal-hydrothermal synthesis method.
• Characterization of porous structures and nanoparticle sizes.
• Electrochemical testing including specific capacitance and cycling stability measurements.
• Fabrication and testing of symmetric solid-state supercapacitors.

Main Results:

• NiCo2S4@HGH exhibited ultra-high specific capacitances (1000 F/g at 0.5 A/g and 800 F/g at 6 A/g).
• Superb durability was demonstrated with 96.6% capacitance retention after 2100 cycles at 6 A/g.
• Solid-state supercapacitors showed remarkable capacitance (312.6 F/g) and retention (87% after 5000 cycles).

Conclusions:

• The NiCo2S4@HGH composite is a highly promising electrode material for high-performance supercapacitors.
• The solvothermal-hydrothermal method is effective for preparing graphene-coupled binary metal sulfides.
• The developed material demonstrates excellent potential for advanced energy storage applications.