Microwave-hydrothermal preparation of a graphene/hierarchy structure MnO_2 composite for a supercapacitor

作     者：Zhong Chen Jianling Li Yu Chen Yakun Zhang Guofeng Xu Jun Yang Ye Feng 

作者机构：State Key Laboratory of Advanced MetallurgyUniversity of Science and Technology Beijing30 College Road State Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of Sciences 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2014年第12卷第4期

页      面：27-33页

核心收录：

学科分类：081702[工学-化学工艺] 080801[工学-电机与电器] 0808[工学-电气工程] 08[工学] 0817[工学-化学工程与技术] 

基　　金：supported by the Program for New Century Excellent Talents in University(NCET-09-0215) by a grant from the National Research and Development Program of China (863 Program,2012AA110302) by the State Key Laboratory of Multiphase Complex Systems(MPCS-2011-D-08) 

主　　题：Graphene MnO2 Hierarchy structure Supercapacitor 

摘      要：Graphene/hierarchy structure manganese dioxide （GN/MnO2） composites were synthesized using a simple microwave-hydrothermal method. The properties of the prepared composites were analyzed using field emission scanning electron microscopy （FE-SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, and X-ray photoelectron spectroscopy （XPS） measurements. The electrochemical performances of the composites were analyzed using cyclic voltammetry, electrochemical impedance spectrometry （EIS）, and chronopotentiometry. The results showed that GN/MnO2 （10 wt% graphene） displayed a specific capacitance of 244 F/g at a current density of 100 mA/g. An excellent cyclic stability was obtained with a capacity retention of approximately 94.3% after 500 cycles in a 1 mol/L Li2SO4 solution. The improved electrochemical performance is attributed to the hierarchy structure of the manganese dioxide, which can enlarge the interface between the active materials and the electrolyte. The prepa- ration route provides a new approach for hierarchy structure graphene composites; this work could be readily extended to the preparation of other graphene-based composites with different structures for use in energy storage devices.