Electrochimica Acta, Vol.174, 1234-1243, 2015
Long Cycling Life Supercapacitors Electrode Materials: Ultrathin Manganese Dioxide Nanoscrolls Adhered to Graphene by Electrostatic Self-Assembly
Positively charged amine-MnO2 nanoscrolls obtained by using 3-Aminopropyltriethoxysilane (APTES) to modify hydrothermal synthesized nano-sized MnO2 scrolls, and then adhered to negatively charged reduced graphene oxides (rGO) and fabricated ultrathin MnO2/graphene hybrids (MAG). The electrochemical behaviers of MnO2 nanoscrolls and MAG are systematically investigated by cyclic voltammetry and galvanostatic charge-discharge. As a result, a maximum specific capacitance of 326 Fg(-1) is achieved for the MAG with 10% of rGO (MAG-10), which is much higher than 201 Fg(-1) of MnO2 nanoscrolls at the current density of 0.2 Ag-1. Furthermore, all of the MAG electrodes exhibit excellent cycling performance at the current density of 2 Ag-1. In addition, contributed by the unzipping of MnO2 NSs and the restriction of curving graphene, the specific capacitance of MAG-10 electrode is slightly increased in the beginning 6000 cycles and with the capacitance retention rate of 96.24% after 10000 cycles. (C) 2015 Elsevier Ltd. All rights reserved.