Electrochemical performance enhancement of MnO2 nanowires through silver incorporation for next-generation supercapacitors

Abstract

Increased demand for effective energy storage systems emphasizes the urgency to overcome the bottlenecks of existing technology. Supercapacitors (SCs), owing to their high specific power and fast charging/discharging capabilities, are perfect candidates for future energy applications but their low energy density makes them impractical for commercial applications. Because of their high energy density and variable oxidation states, transition metal oxides (TMOs) have great potential as supercapacitor electrode materials. But for practical applications, their poor intrinsic conductivity needs to be improved. Noble metal doping offers a compelling method to raise the conductivity and structural stability of TMOs. Herein, we have prepared Ag_xMnO₂ (x = 0.05, 0.10, and 0.15) to improve the conductivity and structural stability of the electro-active material. FESEM micrographs exhibit cracks on the nanowire (NW) surface by Ag doping, proposing less dead volume. Ag doping also fortified electrode pulverization during charging/discharging cycles by imparting structural stability. These properties enabled Ag_0.05MnO₂ NWs to demonstrate a specific capacitance of 1027 F g⁻¹ at a current density of 1 A g⁻¹. The electrode also retained a capacitance of 93.16% after 10 000 GCD cycles@12 A g⁻¹ along with 86% rate capability at 9 A g⁻¹. By tackling critical difficulties such as poor conductivity and structural stability, this study advances energy storage technologies and lays the groundwork for the creation of high-performance supercapacitors for future energy applications.