Polyaniline/carbon nanotube composite supercapacitor electrodes synthesized by a microwave-plasma polymerization

Polyaniline/carbon nanotube (PANI/CNT) nanocomposite electrodes were fabricated by the microwave-plasma polymerization of the aniline monomer in the existence of the chemically functionalized f-MWCNTs or f-SWCNTs. The performance of both composites as supercapacitor electrodes was evaluated and compared. FE-SEM images of the electrodes showed the development of the core-shell CNTs-PANI structure, which improved the electrical conductivity and the porosity structure of the composite. The electrochemical behavior of the composite electrode was inspected, and the specific capacitance was calculated using the cyclic voltammetry and the galvanostatic charge/discharge at a constant current. Furthermore, the cyclic stability of the composite capacitance and its energy and power density was examined. The maximum achieved specific capacitance for PANI/f-SWCNT composite was 139 F/g at a 1.6 A/g charging current density, which delivers a 43 Wh/Kg energy density. While the maximum achieved capacitance for PANI/f-MWCNT composite was 112 F/g at the same charging current density, which delivers a 34.8 Wh/Kg energy density. Whereas the maximum attained power density was 10104 W/Kg, and 8381 W/Kg for the f-SWCNTs and f-MWCNTs composites, respectively. The attained energy density of both composites was promising to approach the supercapacitor from being an independent source of energy.