Using a sequential synthesis approach to fabricate (Ni,Co)Se₂ electrodes for high-performance supercapacitors.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Bimetallic selenides are promising for supercapacitors.
• Optimizing selenization degree from bimetallic oxides is challenging.
• Improving electrochemical performance requires advanced synthesis strategies.

Purpose of the Study:

• Fabricate (Ni,Co)Se2 electrode materials with specific morphology.
• Evaluate the supercapacitive performance of the synthesized materials.
• Investigate the impact of synthesis strategy on electrochemical properties.

Main Methods:

• Sequential synthesis of (Ni,Co)Se2 from NiCo-LDH precursor.
• Fabrication of rose-petal-like morphology.
• Systematic evaluation of supercapacitive performance, rate capability, and cycling stability.

Main Results:

• Achieved a specific capacitance of 1565 F g-1 at 1 A g-1.
• Demonstrated excellent rate capability (97.7% retention at 10 A g-1).
• Showcased high cycling stability (87.8% capacity retention after 5000 cycles at 20 A g-1).
• Constructed a supercapacitor with high energy density (44.44 Wh kg-1) and power density (867.78 W kg-1).

Conclusions:

• The sequential synthesis strategy significantly enhances selenization degree and electrochemical properties.
• The rose-petal-like morphology ensures efficient mass transport.
• The developed (Ni,Co)Se2 materials offer superior performance for supercapacitor applications.