Emulsion polymerization method for polyaniline-multiwalled carbon nanotube nanocomposites as supercapacitor materials

Nanocomposites consisting of the conducting polymer, polyaniline (PANI), and multiwalled carbon nanotubes (MWNT) were prepared by in situ emulsion polymerization of aniline monomer on the surface of MWNT, using sodium dodecyl sulfate as an emulsifier and by varying the wt% of the MWNT. The morphology, composition, and thermal stability of the PANI-MWNT nanocomposites and pure PANI were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and field emission electron microscopy (FE-SEM). The PANI-MWNT nanocomposites were found to be crystalline in nature, with the PANI corals grown uniformly on the MWNT. Symmetric supercapacitors were constructed using the PANI-MWNT nanocomposites and pure PANI. Electrochemical analysis of the nanocomposites was performed using cyclic voltammetry and the galvanostatic charge-discharge method. The cyclic voltammetry analysis showed a synergistic increase in the specific capacitance of the PANI-MWNT nanocomposites. The unique structure of the PANI-MWNT nanocomposites led to a high specific capacitance of 240 F g(-1) at a current density of 4.0 A g(-1), with good rate performance, and 93 % retention of specific capacitance after 5000 CD cycles, indicating their potential as an electrode material for supercapacitors.