Micromachined Planar Supercapacitor with Interdigital Buckypaper Electrodes

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Flexible electronics require advanced energy storage solutions.
• Micro-supercapacitors offer compact and efficient power options.
• Buckypaper electrodes provide unique electrochemical properties.

Purpose of the Study:

• To develop a flexible micro-supercapacitor with interdigital planar buckypaper electrodes.
• To investigate a simple fabrication process for these devices.
• To evaluate the electrochemical performance and stability of the flexible micro-supercapacitors.

Main Methods:

• Fabrication of in-plane interdigital buckypaper electrodes using vacuum filtration and SU-8 molding.
• Cyclic voltammetry to measure specific capacitance.
• Charge-discharge tests to assess electrochemical stability and cycle life.
• Electrochemical impedance spectroscopy (Nyquist plot) to determine equivalent series resistance.

Main Results:

• Achieved a maximum specific capacitance of 107.27 mF/cm² at 20 mV/s.
• Demonstrated linear increase in specific capacitance with buckypaper electrode thickness.
• Exhibited high cycle stability with 96.59% retention after 1000 cycles.
• Measured a low leakage current of approximately 9.95 µA after 3600 s.
• Obtained an equivalent series resistance of approximately 18 Ω.

Conclusions:

• The proposed fabrication method yields flexible micro-supercapacitors with excellent performance.
• The devices are suitable for integration into flexible electronic systems.
• Buckypaper electrodes offer a promising material for advanced energy storage applications.