Low-cost synthesis of cubic spinel structured high efficient NiCo₂O₄/polyaniline nanocomposite for supercapacitor application

In this work, NiCo₂O₄ nanoparticles were synthesized by solution combustion method and NiCo2O4/PANI composite was prepared by physical blending method. The samples were od. The samples were characterized by Fourier transform infrared spectroscopy, x-ray diffraction analysis (XRD), scanning electron microscope (SEM), high- resolution transmission electron microscope (HRTEM) and Electrochemical studies such as Cyclic voltammetry (CV) and galvanostatic charge—discharge analysis. XRD peaks revealed the crystallite size of the NiCo₂O₄ and NiCo₂O₄/PANI composites. The samples were refined using Rietveld refinement method. The values of crystallite size and strain determined by W-H method were in good agreement with the results obtained in the Scherer method. FTIR confirmed the presence of respective functional groups. Morphology was studied by SEM and HRTEM images. The Morphological changes in Composite implied the enhanced electrochemical activity. The crystalline nature of NiCo₂O₄ and NiCo₂O₄/PANI nanoparticles observed by XRD study was further confirmed by SAED pattern of HRTEM images. The specific capacitance of the samples were calculated by CV and CP in three electrode configuration. Specific capacitance obtained for NiCo₂O₄ in 5 mV s⁻¹ was 723 F g⁻¹ and for NiCo₂O₄/PANI was 882 F g⁻¹ from CV study. The maximum specific capacitance obtained for NiCo₂O₄ was 729 F g⁻¹ and for the composite NiCo₂O₄/PANI was 887 F g⁻¹ at the applied current density of 0.5 A g⁻¹ through galvanostatic charge—discharge analysis. NiCo₂O₄/PANI composites showed potential and high performance, in which the maximum specific capacitance was exhibited. (paper)