Microcrack Arrays in Dense Graphene Films for Fast-Ion-Diffusion Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Laminated graphene films offer potential for compact, high-power capacitive energy storage due to high bulk density and open architecture.
• However, ion diffusion limitations in graphene films hinder high-power capabilities in energy storage applications.

Purpose of the Study:

• To engineer microcrack arrays in graphene films to serve as rapid ion diffusion channels.
• To enhance ion diffusion, improve volumetric capacitance, and enable efficient alternating current (AC) filtering.
• To demonstrate the practical application of microcracked graphene supercapacitors in renewable energy systems.

Main Methods:

• Fabrication of microcrack arrays within laminated graphene films.
• Characterization of ion diffusion coefficients and volumetric capacitance.
• Fabrication and testing of microcracked graphene-based supercapacitors for AC filtering and integration into a renewable energy system.

Main Results:

• Optimized microcrack arrays improved ion diffusion sixfold, maintaining high bulk density (0.92 g cm⁻³).
• Achieved high volumetric capacitance of 221 F cm⁻³ (240 F g⁻¹).
• Demonstrated a supercapacitor with 200 Hz characteristic frequency and 4 V voltage window for AC filtering, and successfully powered 74 LEDs in a renewable energy system.

Conclusions:

• Microcracked graphene films represent a significant advancement in optimizing ion diffusion for compact energy storage and AC filtering.
• The microcracking approach is roll-to-roll producible, offering a cost-effective and scalable solution for large-scale manufacturing.
• Microcracked graphene supercapacitors show high promise for practical applications in renewable energy systems and advanced filtering.