Sustainable design of NiWO₄@Chitosan-derived N, O doped carbon hybrid architecture for high-performance supercapacitor electrode applications
摘要
The rapid development of energy storage devices demands sustainable and high-performance electrode materials that integrate high capacitance, long durability, and eco-friendly design. In this work, we report the synthesis of a NiWO4@chitosan-derived N, O-doped carbon composite via a green hydrothermal–carbonization strategy. The formation of NiWO4@ N, O doped carbon hybrid was confirmed by various characterization techniques. The formation of single-phase monoclinic NiWO4 with a reduced crystallite size (~ 18–25 nm) was confirmed by XRD analysis. BET investigations revealed a hierarchical porous structure with a surface area of ~ 210 m² g⁻¹ and a pore volume of 0.39 cm³ g⁻¹. The behavior of the supercapacitor was examined by cyclic voltammetry, galvanostatic charge-discharge, and impedance analysis. Electrochemical assessments in a three-electrode configuration revealed a specific capacitance of approximately 910 F g⁻¹ at 1 A g⁻¹, remarkable rate retention of 72% at 10 A g⁻¹, and exceptional stability with around 92% retention after 5000 cycles. The synergistic impacts of abundant redox-active Ni sites, conductive carbon routes, and rapid ion transport channels were further validated using CV, GCD, and EIS investigations. Upon assembly into an asymmetric supercapacitor (NiWO4@CS-S // CS-S), the device exhibited a specific capacitance of 165 F g⁻¹ at 1 A g⁻¹, an energy density of 42 Wh kg⁻¹ at about 0.9 kW kg⁻¹, and exceptional cycling stability with approximately 91% retention after 5000 cycles. These results not only exceed numerous previously documented NiWO₄-based systems but also underscore the potential of biopolymer-derived carbons as sustainable substrates for next-generation high-performance supercapacitors.