Tailoring cobalt oxide nanostructures for stable and high-performance energy storage applications

Different micro- and nanostructures of cobalt oxide are grown on Ni foam using surface-modifying agents via a simple one-pot hydrothermal synthesis process with the help of surface modifying agents. The structural, chemical, morphological, and electrochemical properties are systematically investigated using a potentiostat, X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis. The pristine Co3O4, cetyltrimethyl ammonium bromide (CTAB) mediated Co3O4, and Triton X-100 mediated Co3O4 form the chestnut bur flower, dandelion flower, and star anise-like morphology, respectively. The electrochemical measurements demonstrate that interconnected nanonetwork of dandelion flower-like morphology obtained via CTAB delivers the highest specific capacitance of 521.63 F g−1. Since an interconnected network provides the channel path for high electronic conductivity and low diffusion resistance, the fabricated electrode provides excellent electrochemical stability over the 3000 charge-discharge cycles. It retains 95.29% of the initial capacitance after 3000 charge-discharge cycles. The result proved that surface modification of Co3O4 material improved the charge storage performance of electrodes for supercapacitor applications.