From natural cotton thread to sewable energy dense supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Cotton thread is a cost-effective and flexible material for wearable electronics.
• Existing cotton thread supercapacitors suffer from low capacitance due to poor active material utilization.

Purpose of the Study:

• To enhance the capacitance and performance of cotton thread-based supercapacitors.
• To develop a lightweight, flexible, and self-powered energy storage solution for wearable devices.

Main Methods:

• Fabrication of a composite thread by coating cotton yarn with ordered mesoporous carbon (OMC) membranes and chemical vapor deposition (CVD) graphene.
• Utilizing OMC as ion reservoirs and CVD graphene for conductivity and mechanical strength.
• Employing a butyl-3-methylimidazolium chloride modified gel electrolyte with MnO2 microparticles.

Main Results:

• Achieved an areal capacitance of 1.1 F cm², a significant improvement over previous designs.
• Demonstrated a volumetric energy density of 2.7 mWh cm³.
• The supercapacitor thread exhibited high conductivity (3.7 Ω cm⁻¹), mechanical durability, and powered a TiO2 nanowire photodetector without external bias.

Conclusions:

• The developed supercapacitor thread offers a promising solution for high-performance, flexible energy storage.
• This technology opens avenues for self-powered wearable nanodevices.
• The facile dip-coating fabrication method is suitable for scalable production.