Facile synthesis of functionalized carbon nanotube integrated V₂O₅ nanocomposites (f-CNT/V₂O₅) for supercapacitor application

The development of renewable energy technologies requires effective energy storage devices. Supercapacitors are promising energy storage devices that have attracted considerable attention from researchers due to their fast charging and discharging rates. In this study, V₂O₅and functionalized carbon nanotubes (f-CNT) integrated V₂O₅composites (f-CNT/V₂O₅) were synthesized and utilized for supercapacitor application. While the V₂O₅was synthesized using a hydrothermal process. The f-CNT integrated V₂O₅(f-CNT/V₂O₅) composites at various percentages of f-CNT were synthesized using a wet impregnation process. The specific capacitance obtained for V₂O₅nanoparticles was 20.78 F.g^-1at 0.1 A.g^-1, but f-CNT integrated V₂O₅composites showed enhanced specific capacitance of 66.58, 140.94, and 73.15 F.g^-1at 0.1 A.g^-1for f-CNT/V₂O₅(10:90), f-CNT/V₂O₅(20:80), and f-CNT/V₂O₅(30:70) composites, respectively. These results confirmed the enhancement in the supercapacitive performance of V₂O₅due to the integration of f-CNT. The f-CNTs facilitate electron transfer through enhanced conductivity and promote redox reactions through an increased electrode surface area. The best-performing f-CNT/V₂O₅composite (f-CNT/V₂O₅(20:80)) electrode was used to assemble an asymmetric supercapacitor device. The f-CNT/V₂O₅//AC device shows a specific capacitance of 261.1 F.g^-1at 1 A.g^-1, and 81.8% of coulombic efficiency for 5000 cycles at 4 A.g^-1. Additionally, the assembled coin cell supercapacitor device shows a characteristic energy density (52.2 Wh.kg^-1) and power density (2400 W.kg^-1), which is better than many similar devices.