Zinc Cobalt Sulfide/Reduced Graphene Oxide Nanocomposite for High-Performance Asymmetric Supercapacitor: A Microwave-Assisted Synthesis

In this work, the microwave-assisted synthesis of ZnxCo1-xS/reduced graphene oxide (rGO) nanocomposite and the evaluation of its electrochemical properties for supercapacitor (SC) application are dealt with. The synergistic effect between ZnxCo1-xS and rGO along with the conducting network provided by rGO facilitates the conducive movement of ions and enhances the electrochemical performance of the nanocomposite. The stoichiometric ratio of Zn:Co:rGO plays a crucial role in the SC behavior of the material. In three electrode systems, a material shows a high specific capacitance of 1094 F g-1 at current density 1 A g-1. The material stores charge both diffusively as well as capacitively. An asymmetric SC with acetylene black as the negative electrode and ZnxCo1-xS/rGO as the positive electrode has a stable potential window 0-1.6 V. For the fabrication of the electrodes, Ni foam is used as the current collector. The energy density and power density of the SC are found to be 32.71 and 431.95 W kg-1, respectively. The Coulombic efficiency of the SC is found to be 107% while its capacitance retention is 86% after 10 000 galvanostatic charge-discharge cycles. The energy and power density of the SC are comparatively higher than many recently reported literature. The material exhibits superior electrochemical stability and reversibility and can be a suitable electrode material for SCs. In this work, a microwave-assisted template synthesis of ZnxCo1-xS/reduced graphene oxide (rGO) for application in asymmetric supercapacitors is described. The Zn to Co and ZnxCo1-xS to rGO ratios play a crucial role in the performance of the electrode material. It retains 83% of its capacitance even after 10 000 repetitive galvanostatic charge-discharge cycles. The material exhibits superior electrochemical stability to find potential end applications.image (c) 2024 WILEY-VCH GmbH