Electrochemical fabrication of polyaniline/MnO₂/graphite felt as free‐standing, flexible electrode for supercapacitors

Polyaniline/MnO₂/graphite felt (PMGF) composite, which can be used as a novel free‐standing, flexible electrode for supercapacitors, was fabricated via a facile electrochemical method. Polyaniline/graphite felt (PANI/GF) electrode was prepared by electropolymerization of PANI onto the GF. Subsequently, manganese dioxide (MnO₂) was electrodeposited on the surface of the PANI/GF electrode to prepare PMGF electrode. The microstructure and morphology of the as‐prepared samples were characterized by Fourier transform infrared spectra, X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. Specific surface area was examined using N₂ adsorption/desorption test. Cyclic voltammogram, chronopotentiometry techniques and electrochemical impedance spectroscopy were introduced to investigate the electrochemical performance of the composites. The PMGF electrode exhibited specific capacitance as high as about 630 F g⁻¹ at the current density of 0.5 A g⁻¹, which is much higher than that of PANI/MnO₂ composites reported previously. The high specific capacitance of PMGF may be attributed to the fact that the porous GF is a good conductive matrix for the dispersion of PANI/MnO₂ and it can facilitate easy access of electrolytes to the electrode, which results in enhancement of the electrochemical performance of the composite. Moreover, the specific capacitance of PMGF is much larger than that of MnO₂/GF (MGF), which may be ascribed to the participant of PANI, which contributes additional pseudocapacitance and electron transport path. POLYM. COMPOS., 34:819–824, 2013. © 2013 Society of Plastics Engineers