Designing metal oxide-vertical graphene nanosheets structures for 2.6 V aqueous asymmetric electrochemical capacitor

摘要

The asymmetric electrochemical capacitor was realized by MnO2/Vertical graphene nanosheets (VGN) and Fe2O3/VGN as positive and negative electrodes, respectively. The surface of VGN skeleton is independently decorated with MnO2 having sponge gourd-like morphology and Fe2O3 having nanorice like morphology. Both the electrodes have shown around 250 times higher charge-storage capacity than the bare VGN (0.47 mF/cm(2)) with the specific capacitance of 118 (MnO2/VGN) and 151 mF/cm(2) (Fe2O3/VGN). The fabricated asymmetric device exhibited a specific capacitance of 76 mF/cm(2) and energy density of 71 mu Wh/cm(2) with an excellent electrochemical stability up to 12,000 cycles, over a potential window of 2.6 V. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.