Facile synthesis of polyaniline/NiCo2O4 nanocomposites with enhanced electrochemical properties for supercapacitors

Polyaniline/NiCo2O4 nanocomposites (PANI/NiCo2O4) with different amounts of NiCo2O4 (5, 8, 10, 15, and 20 wt%) were prepared via in situ chemical oxidation polymerization in the presence of the NiCo2O4 particles, while the NiCo2O4 nanoparticles were synthesized by a modified sol–gel method. The structure and morphology of PANI/NiCo2O4 nanocomposites were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques, respectively. The electrochemical properties of PANI/NiCo2O4 nanocomposites were investigated by cyclic voltammetry, galvanostatic charge–discharge test, and electrochemical impedance spectroscopy (EIS) in 0.5 mol L−1 H2SO4 electrolyte in three-electrode system. The PANI/10 wt% NiCo2O4 nanocomposites show larger specific capacitance of 439.4 F g−1 at a current density of 5 mA cm−2 and lower resistance compared with the pure PANI. The charge–discharge tests showed that the PANI/NiCo2O4 nanocomposites possessed good cycling stability. It maintained about 66.11 % of the initial capacitance after 1000 cycles at a current density of 5 mA cm−2. The results indicated that the PANI/NiCo2O4 nanocomposites are a promising material for supercapacitors.