Polydopamine and MnO2 core-shell composites for high-performance supercapacitors

Polydopamine and MnO2 core-shell composites (PDA@MnO2) for high-performance supercapacitors had been successfully synthesized by a facile and fast method. The morphology, crystalline phase and chemical composition of PDA@MnO2 composites are characterized using SEM, TEM, XRD, EDS and XPS. The performance of PDA@MnO2 composites are further investigated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy in 1 M Na2SO4 electrolyte. The PDA@MnO2 core-shell nanostructure composites exhibit a high capacitance of 193 F g−1 at the current density of 1A g−1 and retained over 81.2% of its initial capacitance after 2500 cycles of charge-discharge at 2 A g−1. The results manifest that the PDA@MnO2 composites can be potentially applied in supercapacitors.