A Ternary Composite Electrode Material of MnO 2 /PDA/rGO for High Performance Supercapacitors

Abstract Dopamine‐polymerized MnO 2 and graphene were designed as electrode materials for supercapacitors. The MnO 2 /PDA/rGO composite was synthesized by optimizing the mass fraction of dopamine and hydrothermal reaction temperature, using MnO 2 and graphene oxide (GO) as the fundamental components. The electrode materials were characterized by SEM, TEM, EDS, XRD, FTIR, and XPS for structural and compositional analysis, and evaluated by cyclic voltammetry (CV), galvanostatic charge‐discharge (GCD), electrochemical impedance spectroscopy (EIS), and cycling tests for electrochemical performance. The MnO 2 /PDA/rGO electrode exhibits a specific capacitance of 202.44 F/g at 0.5 A/g and maintains 167.95 F/g at a high current density of 10 A/g (83% retention), demonstrating excellent rate capability and structural stability.