A coralliform-structured γ-MnO2/polyaniline nanocomposite for high-performance supercapacitors

The different crystallographic structures of manganese dioxide (α-MnO 2 , β-MnO 2 , γ-MnO 2 and δ-MnO 2 ) were prepared via simple and feasible methods. Among four crystallographic structures, γ-MnO 2 exhibited the best electrochemical property and was chosen to compound γ-MnO 2 /polyaniline (PANI) composite electrode through in situ synthesis techniques. The as-prepared samples were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). The electrochemical properties of as-prepared samples influenced by the different mass ratios, scan rates, and current densities were mainly investigated by cyclic voltammetry (CV), galvanostatic charge-discharge, electrochemical impedance spectroscopy (EIS), and cycle life, respectively. The results showed that the specific capacitance can be up to 493   F   g −   1 as mass ratio of γ-MnO 2 /PANI was 1:5 at current density of 0.5   A   g −   1 , suggesting the γ-MnO 2 /PANI (1:5) composite as an electrode material for super capacitors has great development prospects.