Synergistic growth of cobalt hydroxide on reduced graphene oxide/nickel foam for supercapacitor application

The electrode material plays a crucial role in achieving the superior performance of supercapacitors. The current study presents a quick and cost-effective method for synthesizing a binder-free Co(OH)2/rGO nanocomposite material decorated over Ni foam, showing promising potential for high-performance supercapacitor applications. The suggested electrode material was extensively characterized using various spectroscopy and electron microscopy techniques to investigate its structural and morphological properties. To assess the electrochemical performance of the Co(OH)2/rGO nanocomposite, cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) experiments were carried out in an appropriate electrolyte of 2 M KOH. Furthermore, electrochemical impedance spectroscopy (EIS) was employed to evaluate the interfacial charge transfer capability. The synthesized nanocomposite exhibited outstanding rate capability, with a maximum specific capacitance of 2688 Fg−1 at a current density of 1Ag−1. Further, a solid-state asymmetric Co(OH)2/rGO/AC supercapacitor coin-devise was fabricated which demonstrated notable energy density and power density of 28.34 Wkg−1 and 1754 WhKg−1, respectively, along with excellent stability. These results highlight the potential of the hybrid material to be utilized as a flexible all-solid-state supercapacitor device in practical applications.