Three-dimensionally networked RGO-MoO₃-MoS₂/polyindole nanocomposite on woven carbon fiber for supercapacitor device and their improved charge storage mechanism

Energy storage devices, particularly supercapacitors, are integral to modern technological advancements, with hybrid systems gaining significant attention for superior performance. This study investigates the synthesis and comparative evaluation of nanocomposites, namely RGO-MoO₃-MoS₂/PIn nanocomposites (NCs), MoO₃-MoS₂/PIn NCs, and PIn, for supercapacitor applications. The RGO-MoO₃-MoS₂/PIn NCs integrate reduced graphene oxide (RGO), MoO₃ (molybdenum trioxide), and MoS₂ (molybdenum disulphide), nanoparticles into a polyindole (PIn) matrix, leveraging the unique properties of each component. RGO forms a highly conductive network while providing mechanical strength, while MoO₃ and MoS₂ introduce redox-active sites with multiple oxidation states, significantly improving charge storage and ion transport efficiency. Electrochemical studies revealed that the RGO-MoO₃-MoS₂/PIn NCs achieved an impressive specific capacitance of 1189.79 F/g at 2 A/g, outperforming MoO₃-MoS₂/PIn NCs and PIn by factors of 1.26 and 5.32, respectively, underscoring the remarkable enhancement in performance. Further analysis of the charge storage mechanism offers valuable insights into the individual contributions of the composite's components. In a symmetric supercapacitor configuration, RGO-MoO₃-MoS₂/PIn NCs demonstrated a specific capacitance of 303 F/g at 2 A/g, accompanied by an energy density of 67.34 Wh/kg at a power density of 1000 W/kg, while retaining 81 % of its capacitance after 20,000 cycles, highlighting exceptional durability. This work underscores the potential of advanced nanocomposites to address critical challenges in energy storage, providing robust performance and long-term stability for practical applications.