Morphologically controlled preparation of CoCr2O4 nanomaterials for high-performance asymmetric supercapacitor application

Abstract

CoCr2O4 nanoparticles (NPs) with four different and unique morphologies were synthesized using various surfactants of PVP, PEG, and CTAB and employed as electrodes for high-performance double-layer supercapacitors. The hydrothermal process required to make the CoCr2O4 spinel structure of the nanospheres allows for precise control of particle size, and quick and uniform heating. Electrochemical analysis proves that CoCr2O4 material exhibits EDLC behaviour. In three-electrode cells of cobalt chromite as the electrode material for EDLC and operating in 1 M Na2SO4 electrolyte, CTAB surfactant-induced material exhibits excellent specific capacitance up to 883 F g−1 at a scan rate of 5 mV s−1 and excellent cyclic stability of 92 % of initial capacitance after 5000 cycles. These results are due to the material's increased surface area, surface roughness, and more active sites for ion adsorption. The asymmetric device offers a high energy density of 26.33 W h kg−1 with a power density of 400 W kg−1 and cyclic stability of 91.5 % after 5000 charge/discharge cycles. These outstanding electrochemical properties encourage the development of the possibility of using CoCr2O4 nanoparticles introduced by the CTAB template for advanced energy storage applications.