Synthesis and characterization of nanocomposites of polyaniline and polyindole with multiwalled carbon nanotubes for high performance supercapacitor electrodes

In this study, the preparation and characterization of Polyaniline (PANI) and Polyindole (PI) composite materials prepared through a chemical oxidation polymerization method is presented. A novel class of nanocomposites, namely PANI-PI/MWCNT, has been developed and explored for their potential as supercapacitor electrodes. The primary aim of this research is to elucidate the effect of PANI and PI blending on the electrochemical attributes of the resulting composites. This study pioneers the investigation of the electrochemical characteristics of these composite materials. The electrochemical performances of blended PANI-PI and PANI-PI/MWCNT nanocomposites were evaluated in a 1.0 M H2SO4 electrolyte using various techniques, including galvanostatic charge/discharge (GCD), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The PANI-PI composite (2:1 ratio) showed specific capacitance values of 682.4 F/g at 0.5 A/g and 705.2 F/g at 5.0 mV/s. Incorporating 3 % MWCNT into PANI-PI led to enhanced performance figures: 895 F/g at 0.5 A/g and 930 F/g at 5.0 mV/s. Both materials exhibited high energy/power densities: PANI-PI - 136.5 W h/kg and 300 W/kg; PANI-PI (2–1)/3 %MWCNT - 179 W h/kg and 300 W/kg. Remarkably, cyclic stability analysis showed 97.8 % retention after 1000 galvanostatic charge/discharge cycles. Subsequently, the synergistic combination of the optimized PANI-PI composite with multiwalled carbon nanotubes (MWCNT) led to the creation of high-performing supercapacitor electrodes. The synthesis process of PANI, PI, and MWCNT via chemical oxidation-polymerization demonstrated efficacy in producing nanostructured materials, characterized by remarkable efficiency and tailored properties conducive to the targeted application.