Polyaniline wrapped carbon nanotube/exfoliated MoS2 nanosheet composite as a promising electrode for high power supercapacitors

Abstract

Polyaniline (PANI) wrapped, carbon nanotube (CNT)/and exfoliated MoS2 composite (PANI/CNT/e-MoS2) based electrodes are developed for applications as high-quality supercapacitor electrodes by a facile and effective in-situ oxidative polymerization method. Exfoliation of single/bilayer MoS2 nanosheets via electrochemical method and incorporation of CNT in PANI/e-MoS2 composite are confirmed by scanning and transmission electron microscopy techniques. Electrochemical properties of PANI/CNT/e-MoS2 electrode are evaluated by cyclic voltammetry and galvanostatic charge-discharge techniques. The incorporation of CNT in PANI/e-MoS2 composite provides maximum utilization of PANI nanowires to achieve maximum capacitance. Composite electrode based on PANI/CNT/e-MoS2 shows high specific capacitance of 532 F g−1 at a current density of 1 A g−1 as well as good rate capability from 1 A g−1 to 10 A g−1. Symmetric supercapacitor assembled using PANI/CNT/e-MoS2 composite electrode exhibits good cycling stability and 80% capacity retention after 4000 cycles and gives energy density of 11.8 Wh kg−1 and power density of 3785 W kg−1. Furthermore, electrochemical impedance spectroscopy (EIS) analysis ensures much lower equivalent series resistance of the PANI/CNT/e-MoS2 electrode. Besides, CNT acts as active electrode material in PANI/CNT/e-MoS2 composite and also provides more active sites for insertion and extraction of ions. This electrode design provides a facile and promising approach for improving the electrochemical performance of PANI based electrodes.