Flexible High-Performance and Screen-Printed Symmetric Supercapacitor Using Hierarchical Rodlike V₃O₇ Inks

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• The Internet of Things (IoT) drives demand for flexible, miniaturized energy storage devices like supercapacitors.
• Screen printing offers a promising fabrication technique for supercapacitors, but high-performance inks remain a challenge.

Purpose of the Study:

• To develop a high-performance screen-printable ink for flexible supercapacitors.
• To synthesize and characterize hierarchical V3O7 with rodlike texture for supercapacitor electrodes.
• To evaluate the electrochemical performance and durability of screen-printed V3O7-based supercapacitors.

Main Methods:

• Hierarchical V3O7 with rodlike texture was synthesized using a facile template-solvothermal route.
• Screen-printable inks were formulated using V3O7, acetylene black, and PVDF, with rheological properties studied.
• Flexible V3O7 symmetrical supercapacitors (SSCs) were screen-printed and assembled on Ag current collectors.

Main Results:

• The optimal screen-printed electrode achieved a specific capacitance of 274.5 F/g with 81.9% retention after 5000 cycles.
• The flexible SSC demonstrated an areal specific capacitance of 322.5 mF/cm², 90.8% cycling stability after 5000 cycles, and a maximum energy density of 129.45 μWh/cm².
• The SSC exhibited remarkable flexibility, durability, a charged voltage of 1.70 V, and no significant self-discharge.

Conclusions:

• The developed V3O7-based screen-printed ink facilitates the large-scale fabrication of high-performance flexible supercapacitors.
• The study provides a facile and low-cost reference for creating advanced energy storage solutions for flexible electronics and IoT applications.
• The V3O7 SSC shows significant potential for practical power supply applications due to its stability and energy density.