Graphene supercapacitor with both high power and energy density

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitors offer high power and stability but suffer from low energy density.
• Achieving high energy density is critical for expanding supercapacitor applications.

Purpose of the Study:

• To develop supercapacitors with enhanced energy density without compromising power performance.
• To synthesize highly porous graphene electrodes for improved energy storage.

Main Methods:

• A scalable nanoporous graphene synthesis method using annealing in hydrogen.
• Fabrication and testing of supercapacitor devices with the synthesized graphene electrodes.

Main Results:

• Supercapacitors achieved a high energy density of 148.75 Wh kg⁻¹ and power density of 41 kW kg⁻¹.
• Demonstrated high specific gravimetric (306.03 F g⁻¹) and volumetric (64.27 F cm⁻³) capacitance.
• Maintained nearly 100% capacitance after 7000 cycles, indicating excellent stability.

Conclusions:

• The synthesized nanoporous graphene enables supercapacitors with superior energy and power density.
• Ideal pore structure and ion accessibility of graphene contribute to the enhanced performance.
• These findings pave the way for advanced supercapacitors in demanding applications.