Scalable fabrication of high-performance micro-supercapacitors by embedding thick interdigital microelectrodes into...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Micro-supercapacitors (MSCs) are crucial for microscale energy storage.
• Thick interdigital microelectrodes are key to enhancing MSC performance.
• Carbon-based materials offer promising properties for electrode fabrication.

Purpose of the Study:

• To develop a scalable method for fabricating thick, embedded multiwalled carbon nanotube (MWCNT) microelectrodes for MSCs.
• To investigate the electrochemical performance of MSCs utilizing these novel microelectrodes.
• To demonstrate the practical applicability of the fabricated MSCs in powering electronic devices.

Main Methods:

• Casting sufficient MWCNT inks onto pre-patterned microcavity surfaces.
• Embedding MWCNT materials into microcavities via rapid solvent evaporation.
• Utilizing a doctor-blading process to obtain thick interdigital MWCNT microelectrodes (up to 190 μm).

Main Results:

• Fabricated MSCs with 250 μm width and 50 μm interspace microelectrodes achieved a capacitance of 19.5 mF cm⁻² and energy density of 2.48 μW h cm⁻² at 24.7 μW cm⁻² power density.
• The embedded microelectrodes simplified device structure and enhanced mechanical flexibility.
• Three series of MSCs successfully powered four light-emitting diodes (LEDs).

Conclusions:

• The developed scalable strategy enables the fabrication of high-performance MSCs with thick, embedded MWCNT microelectrodes.
• These MSCs offer excellent electrochemical performance and mechanical flexibility, suitable for microscale energy storage.
• The results indicate the potential for practical applications by connecting MSCs in series or parallel for desired operating voltages and currents.