Solvent-assisted synthesis of carbon nanotubes-manganese oxide hybrid materials for high voltage aqueous supercapacitor

This work relates to the preparation of CNT-MnO2 hybrid electrode by a simple solvent-assisted synthesis. This one-step method is also cost-effective, scalable, and addition of surfactant or other additives for carrying out the synthesis is not necessary. The effect of selected solvents (DMF vs. ethanol) on the properties and performance of the prepared materials is depicted during this work using XRD, Raman, TEM, SEM and porosity estimation by nitrogen adsorption-desorption isotherm at 77 K. The electrochemical behavior was studied using cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy in a K2SO4 aqueous electrolyte. The superior electrochemical performance of the CNT-MnO2 hybrid obtained by DMF assisted synthesis were explicated by its favorable texture and morphology. Furthermore, an asymmetric 2 V aqueous supercapacitor was assembled and tested using hybrid CNT-MnO2 and reduced graphene oxide (rGO) as positive and negative electrodes respectively. The supercapacitor showed an excellent stability under cycling (6000 cycles) with a specific energy of 14 Wh/kg at a power density of 3000Wkg(-1). (C) 2018 Elsevier B.V. All rights reserved.