Synergistic effect of heterointerface engineering coupled with oxygen vacancies enriched Ag2O-WO2.8-SnO2 anchored carbon nanotubes nanocomposite for high-performance supercapacitor devices and their charge storage mechanism

Abstract

Incorporating oxygen vacancies into metal oxide-based nanocomposites has emerged as a powerful strategy for developing advanced supercapacitors. In this study, Ag₂O-WO_2.8-SnO₂ nanocomposites (AgWSn NCs) and their carbon nanotube-anchored counterpart (AgWSn/CNT NCs) were synthesized via a hydrothermal technique and systematically evaluated for their supercapacitor performance. The introduction of Ag₂O into the WSn matrix and their integration with a CNT scaffold significantly enhanced the conductivity and increased the density of redox-active sites, resulting in a synergistic boost to electrochemical performance. The AgWSn NCs demonstrated a specific capacitance of 791.18 F/g at 2 A/g, which was significantly enhanced to 988.97 F/g upon anchoring onto CNT. This improvement underscores the pivotal role of CNT in improving conductivity and providing structural stability, thereby boosting overall performance. Moreover, AgWSn/CNT NCs based symmetric supercapacitor device (SS-device) unveiled excellent cycling stability, maintaining 94 % of its initial capacitance after 10,000 cycles. The device also attained a high energy density of 86.25 Wh/kg at 1500 W/kg, underscoring the material's potential for practical applications. This research underscores a rational approach to designing high-performance electrode materials by leveraging oxygen vacancies and integrating CNTs into hybrid structures for advanced supercapacitor applications.