Asymmetric supercapacitors with high energy densities

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitors (SCs) are limited by low energy densities, primarily due to anode material performance.
• Developing advanced electrode materials is crucial for enhancing SC energy storage capabilities.

Purpose of the Study:

• To synthesize novel anode and cathode materials for high-energy-density asymmetric supercapacitors (ASCs).
• To investigate the electrochemical performance and cycling stability of the fabricated ASCs.

Main Methods:

• Synthesis of Fe3+ modified V2O5@GQDs (m-V2O5@GQDs) as anode material.
• Synthesis of ZIF-67-derived nanoporous carbon loaded with Mn3O4 (C/N-Mn3O4) as cathode material.
• Characterization using electron microscopy, X-ray methods, and electrochemical techniques.
• Fabrication and testing of asymmetric supercapacitors (ASCs).

Main Results:

• The m-V2O5@GQDs anode demonstrated a specific capacitance of 761 F g-1 at 2 A g-1, improving V2O5 conductivity.
• The fabricated ASCs achieved a high energy density of 99.4 W h kg-1 at a power density of 1000 W kg-1 with a 2 V cell voltage.
• ASCs exhibited excellent cycling stability, retaining 95% of initial capacitance after 10,000 cycles.

Conclusions:

• The synthesized m-V2O5@GQDs and C/N-Mn3O4 are effective electrode materials for high-performance ASCs.
• This study presents a viable strategy for designing and constructing supercapacitors with significantly enhanced energy densities.
• The developed ASCs show great potential for advanced energy storage applications.