Hierarchical Nanosheet-Built CoNi

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitors are crucial for energy storage, demanding materials with high energy/power density and long cycle life.
• Developing efficient electrode materials is key to advancing supercapacitor technology.

Purpose of the Study:

• To design and fabricate a hybrid supercapacitor with superior electrochemical performance.
• To utilize novel ternary nickel-cobalt sulfides (CoNi2S4) as cathode materials and iron-based composites (CNTs@Fe2O3@C) as anode materials.

Main Methods:

• Hierarchical CoNi2S4 nanotubes synthesized via solvothermal and sulfidation routes.
• CNTs@Fe2O3@C anode materials prepared using atomic layer deposition and acetylene thermal decomposition.
• Fabrication of an aqueous hybrid supercapacitor device integrating the developed electrodes.

Main Results:

• CoNi2S4 nanotubes cathode: 2552 F g⁻¹ at 1 A g⁻¹, 81% retention at 25 A g⁻¹.
• CNTs@Fe2O3@C anode: 678 F g⁻¹ at 1 A g⁻¹, 82% retention at 25 A g⁻¹.
• Hybrid device: 90.5 Wh kg⁻¹ energy density at 1.84 kW kg⁻¹, 73.1 Wh kg⁻¹ at 26.9 kW kg⁻¹, 82.1% retention over 5000 cycles.

Conclusions:

• The hybrid supercapacitor demonstrates excellent electrochemical performance, high energy/power density, and long cycle life.
• The coordinative design strategy offers a novel approach for manufacturing high-performance, safe energy storage devices.
• This work paves the way for next-generation energy storage solutions.