Facile synthesis of PANI-MWCNT-Ni(OH)2 ternary composites and study of their performance as electrode material for supercapacitors

Abstract This work explores the synergetic effect of three electrochemically important materials, polyaniline (PANI), multiwalled carbon nanotubes (MWCNT) and nickel hydroxide (Ni(OH)2), when used in ternary composites and their application as positive electrode in supercapacitors. The composite material was prepared by a two-step process involving interfacial polymerization and hydrothermal method at two different temperatures, 120 °C and 180 °C, and were abbreviated as PCN1 and PCN2, respectively. X-ray diffraction studies confirmed the presence of β-Ni(OH)2 in the composites. Absorption frequencies characteristic of PANI-MWCNT and Ni(OH)2 were observed in the FTIR and Raman spectra of the composites. BET surface area analysis indicated a slightly higher surface area for PCN1 compared to PCN2. Electrochemical studies of the composites were carried out using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). In comparison, PCN1 exhibited a higher specific capacitance, percentage retention, cycle stability and coulombic efficiency than PCN2. PCN1 exhibited a specific capacitance of 1917 Fg−1 at a scan rate of 2.5 mV/s by CV and 1013 Fg−1 by GCD at a current density of 1.0 Ag−1 in 1 M KOH.