Defect induced RGO-MnOx hybrid electrodes for supercapacitor applications

Abstract

Developing a high specific-capacitance, quick charging and long cycle supercapacitor electrodes are essential for the future energy storage devices. In this paper, we report defect induced reduced graphene oxide (dRGO)-MnOx composites, which were prepared through redox reaction of KMnO4 and graphene oxide. The deformation/increasing defects in graphene sheets confirmed through micro-Raman studies. The dRGO-MnOx composite exhibit a high specific-capacitance, 264 Fg−1 at 0.2 Ag−1 in 1 M Na2SO4 neutral electrolyte. Most importantly, the dRGO-MnOx electrode was able to inhibit the outstanding cyclic performance of 153% capacitance retention and 100% Coulombic efficiency after 10,000 cycles at a high current density of 10 Ag−1. It also had 85% capacitance at a very short time (1/10 charging time of 0.2 Ag−1) with a charging current density at 1 Ag−1 and discharge current density of 0.2 Ag−1. The as-prepared dRGO-MnOx composites will find potential use in electrochemical energy storage applications.Developing a high specific-capacitance, quick charging and long cycle supercapacitor electrodes are essential for the future energy storage devices. In this paper, we report defect induced reduced graphene oxide (dRGO)-MnOx composites, which were prepared through redox reaction of KMnO4 and graphene oxide. The deformation/increasing defects in graphene sheets confirmed through micro-Raman studies. The dRGO-MnOx composite exhibit a high specific-capacitance, 264 Fg−1 at 0.2 Ag−1 in 1 M Na2SO4 neutral electrolyte. Most importantly, the dRGO-MnOx electrode was able to inhibit the outstanding cyclic performance of 153% capacitance retention and 100% Coulombic efficiency after 10,000 cycles at a high current density of 10 Ag−1. It also had 85% capacitance at a very short time (1/10 charging time of 0.2 Ag−1) with a charging current density at 1 Ag−1 and discharge current density of 0.2 Ag−1. The as-prepared dRGO-MnOx composites will find potential use in electrochemical energy storage applications.