High-performance VO₂/CNT@PANI with core-shell construction enable printable in-planar symmetric supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Flexible supercapacitors are crucial for portable electronics.
• Vanadium dioxide (VO2) offers high theoretical capacitance but suffers from poor cycling life and low energy density.
• Developing advanced electrode materials is essential for high-performance energy storage.

Purpose of the Study:

• To enhance the electrochemical performance of vanadium dioxide (VO2) for flexible supercapacitors.
• To address the limitations of cycling life and energy density in VO2-based pseudocapacitors.
• To develop a scalable manufacturing method for flexible supercapacitor devices.

Main Methods:

• Synthesis of VO2 nanorods integrated with carbon nanotubes (CNT) via a solvothermal method.
• In situ polymerization of a polyaniline (PANI) shell onto VO2/CNT nanostructures.
• Screen printing of VO2/CNT@PANI inks to fabricate in-planar symmetric supercapacitor devices.

Main Results:

• The VO2/CNT@PANI composite achieved a specific capacitance of 354.2 F/g at 0.5 A/g with 88.2% capacitance retention over 5000 cycles.
• The symmetric supercapacitor device exhibited an areal energy density of 99.57 μWh/cm² at 387.5 μW/cm².
• The device maintained approximately 87.6% of its initial capacitance after prolonged use and powered a portable game machine.

Conclusions:

• The synergistic combination of VO2, CNT, and PANI significantly boosts supercapacitor performance.
• The developed screen-printing technique enables the fabrication of high-performance, flexible supercapacitors.
• This work presents a viable strategy for creating advanced energy storage solutions for wearable electronics.