Printed Electrodes Based on Vanadium Dioxide and Gold Nanoparticles for Asymmetric Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Printed energy storage components are crucial for flexible and bendable electronics.
• Vanadium dioxide (VO2) is explored as a potential material for energy storage applications.
• Developing stable and homogeneous inks is essential for printable electronic devices.

Purpose of the Study:

• To synthesize a stable, homogeneous vanadium dioxide (VO2) ink using a non-toxic solvent.
• To evaluate the electrochemical performance of VO2, gold (Au), and VO2/Au electrodes for supercapacitor applications.
• To construct and characterize an asymmetric supercapacitor using VO2 and Au electrodes.

Main Methods:

• Hydrothermal synthesis for VO2 nanoparticle preparation.
• Characterization of structural and morphological properties.
• Electrochemical evaluation using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.
• Fabrication and testing of an asymmetric supercapacitor device.

Main Results:

• Well-crystalline monoclinic-phase VO2 nanoparticles were successfully synthesized.
• VO2 electrodes exhibited double-layer capacitance and redox reactions.
• The VO2/Au electrode showed significantly enhanced areal capacitance (16 mF cm-2) compared to VO2 alone (9 mF cm-2).
• The gold (Au) electrode achieved the highest areal capacitance (18 mF cm-2) due to its conductivity.
• An asymmetric supercapacitor (Au positive, VO2 negative) delivered an areal energy density of 0.45 μWh cm-2 at 70 μW cm-2.

Conclusions:

• The synthesized VO2 is a promising material for printed energy storage.
• Combining VO2 with Au enhances electrode performance for supercapacitors.
• The developed asymmetric supercapacitor demonstrates potential for cost-effective, lightweight, and eco-friendly printed energy storage solutions.