High power density supercapacitor devices based on nickel foam-coated rGO/MnCo2O4 nanocomposites

Abstract

New nanocomposite electrode material of rGO/MnCo2O4 was freely loaded on flexible substrate on nickel foam and prepared by a simple, cost-effective, and eco-friendly pathway. The results show that the spinel manganese cobaltite (MnCo2O4) with reduced graphene oxide (rGO) nanocomposite forms a uniform deposit and densely covers on the nickel foam (NF). The electrochemical measurements were investigated in three methods, such as cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS). The synergistic effects from rGO and MnCo2O4 deliver outstanding an excellent electrochemical performance that was not realized by any of these components alone. The electroactive material exhibits a high specific capacitance of Csp = 808 F/g at 2 mV/s in 1 M KOH solution. Furthermore, this device delivers an excellent power density of P = 7658 W/kg and a high energy density of E = 15.2 Wh/kg. More importantly, cycling retention is 135% after 1000 charge/discharge cycles. This study proposes that the as-prepared (rGO/MnCo2O4)/nickel foam has a potential application and a promising candidate for energy storage devices. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.