Hierarchically self-assembled NiCo2O4 nanopins as a high-performance supercapacitor cathodic material: a morphology controlled study

Abstract

In this study, 3D hierarchically self-assembled NiCo₂O₄ nanopins were synthesized by a morphology controlled hydrothermal method. Structure, morphology, and composition of the samples were investigated using FT-IR, XRD, EDS, and SEM methods. Electrochemical tests such as cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) studies were done in a three-electrode system with 1.0 M Na₂SO₄ solution as the electrolyte for the supercapacitive study of the samples on a carbon paste electrode for the first time. The results confirmed the high-performance supercapacitive behavior of the dense nanostructure and acceptable stability during the charge–discharge cycle. The specific capacitance for the dense self-organized nanopins was calculated using a galvanostatic charge/discharge experiment which gave 2168 F g⁻¹ at a current density of 5 A g⁻¹.