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, V2O5 and functionalized carbon nanotubes (f-CNT) integrated V2O5 composites (f-CNT/V2O5) were synthesized and utilized for supercapacitor application. While the V2O5 was 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 V2O5 nanoparticles was 20.78 F.g-1 at 0.1 A.g-1, but f-CNT integrated V2O5 composites showed enhanced specific capacitance of 66.58, 140.94, and 73.15 F.g-1 at 0.1 A.g-1 for 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 V2O5 due 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/V2O5 composite (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-1 at 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.