Improved electrochemical performance of hierarchical porous carbon/polyaniline composites

Polyaniline (PANI)-coated hierarchical porous carbon (HPC) composites (HPC/PANI) for use as supercapacitor electrodes were prepared by in situ chemical oxidation polymerization at 273 K of an aniline solution containing well-dispersed HPC particles. After polymerization, a thin layer of PANI was coated on the surface of the HPC particles, which was confirmed by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM) and scanning electron microscopy (SEM). Compared to pure PANI and HPC, the electrochemical capacitance performance of the composites was significantly improved. The highest specific capacitance of the composites obtained is 478 F g−1 at 1 mV s−1, which is more than twice as that of pure PANI and three times as that of pure HPC. Because of the influence from the hierarchical pore structure of the carbon material, the calculated specific capacitance of PANI in the composite (pseudocapacitance contribution from PANI) is almost one magnitude higher than that of pure PANI.

► Polyaniline-coated hierarchical porous carbon (HPC) composites have been synthesized by in situ polymerization.
► The HPC/polyaniline composite has significantly better electrochemical capacitance performance than pure HPC and polyaniline.
► The amount of polyaniline loading has a significant effect on the composites’ electrochemical performances.