Use of manganese dioxide as oxidant in polymerization of aniline on carbon black for supercapacitor performance

Abstract

α-Manganese dioxide (MnO₂) and β-MnO₂ have been prepared by a simple one-step hydrothermal synthesis method. Polyaniline (PANI)/carbon black composites were synthesized in acidic medium by an in situ polymerization method using α-MnO₂, β-MnO₂, and ammonium peroxydisulfate (APS) as chemical oxidant. The morphology, structure, and electrochemical performances are characterized by X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, cyclic voltammetry, charge–discharge test, and electrochemical impedance measurements. The PANI/carbon black composite (PANI/C-2) prepared using β-MnO₂ as oxidant shows significantly better specific capacity performance compared with those prepared using α-MnO₂ and APS as oxidant. Addition of carbon black into the PANI composites prepared via the conventional polymerization method showed improved specific capacitance.