Benefiting from good ion accessibility and high electrical conductivity, graphene-based material as electrodes show promising electrochemical performance in energy storage systems. In this study, a novel strategy is devised to prepare binder-free Mn₃O₄-reduced graphene oxide (Mn₃O₄/rGO) electrodes. Well-dispersed and homogeneous Mn₃O₄ nanosheets are grown on graphene layers through a facile chemical co-precipitation process and subsequent flame procedure. This obtained Mn₃O₄/rGO nanostructures exhibit excellent gravimetric specific capacitance of 342.5 F g-1 at current density of 1 A g-1 and remarkable cycling stability of 85.47% capacitance retention under 10,000 extreme charge/discharge cycles at large current density. Furthermore, an asymmetric supercapacitor assembled using Mn₃O₄/rGO and activated graphene (AG) delivers a high energy density of 27.41 Wh kg-1 and a maximum power density of 8 kW kg-1. The material synthesis strategy presented in this study is facile, rapid and simple, which would give an insight into potential strategies for large-scale applications of metal oxide/graphene and hold tremendous promise for power storage applications.
Keywords: Mn3O4; flame plasma; reduced graphene oxide; supercapacitors.