Investigating the synergistic effect of defect rich V2O5/MWCNTs heterostructure for improved electrochemical performance of supercapacitors†
Abstract
The synergistic effect of V2O5 and multiwall carbon nanotubes (MWCNTs) offers a promising strategy to enhance the redox activity of electrode materials for high-performance supercapacitors. In this study, a simple, scalable, and cost-effective hydrothermal approach is employed to synthesize V2O5/MWCNTs heterostructure. The resulting heterostructure exhibits rich oxygen vacancy defects, improved conductivity, favorable structural characteristics, and abundant active sites. DFT study further demonstrate the excellent kinetics of V2O5/MWCNTs as compared to pristine V2O5 structure. Electrochemical analysis reveals that V2O5/MWCNTs electrode achieves good capacitance of 820 F g−1 at 1 A g−1, significantly outperforming pristine V2O5 (463 F g−1) in a 1.0 M neutral Na2SO4 solution. Moreover, the developed supercapacitor (V2O5/MWCNTs//AC) device shows a capacitance of 125 F g−1 at 1 A g−1. The device also delivers an efficient energy density of 39 Wh kg−1 at a power density of 805 W kg−1. Additionally, it exhibits outstanding cycling stability, retaining 93% of its capacity after 8000 cycles at 3 A g−1. These exceptional results highlight the potential of the V2O5/MWCNTs heterostructure as a viable electrode material for future energy devices.