Metal-free supercapacitor with aqueous electrolyte and low-cost carbon materials

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitors (SCs) offer rapid energy storage with high efficiency and cyclability.
• Aqueous SCs are eco-friendly but require expensive materials due to corrosive electrolytes.
• High material costs limit the widespread adoption of conventional aqueous SCs.

Purpose of the Study:

• To develop a novel, low-cost aqueous supercapacitor (SC).
• To address the high material costs associated with traditional aqueous SCs.
• To demonstrate an environmentally friendly and economical alternative for energy storage.

Main Methods:

• Utilized graphite foil as a current collector.
• Employed a composite electrode material including graphene, nanographite, water-purification carbons, and nanocellulose.
• Developed a direct electrode coating method onto graphite foil using casting frames.
• Assembled the supercapacitors in a pouch cell configuration.

Main Results:

• Achieved a material cost reduction exceeding 90%.
• Maintained approximately 50% of the specific capacitance compared to commercial units.
• Demonstrated the feasibility of using low-cost materials in aqueous SCs.

Conclusions:

• The developed aqueous SC presents a viable, low-cost, and environmentally friendly alternative to conventional SCs.
• The use of inexpensive materials like graphite foil and nanocellulose significantly reduces manufacturing costs.
• This approach enables broader applications of supercapacitor technology in energy storage.