三维rGO/MnO_2复合材料的合成及其电化学性能

Synthesis and electrochemical properties of 3D-reduced graphene oxide supported MnO_2 composite electrode materials

本文以VC为还原剂,从氧化石墨烯(GO)获得了三维结构的还原氧化石墨烯(3D-rGO),之后与KMnO_4反应制备了3D-rGO/MnO_2复合材料,直接作为超级电容器用无添加剂的电极.采用XRD,FTIR,XPS,SEM和TEM等手段对材料进行了表征,通过循环伏安、交流阻抗和恒流充放电等曲线,测试了复合电极在1mol/LH_2SO_4中的电化学性能.结果显示:在1A/g电流密度的下,3D-rGO/MnO_2的比电容可达308F/g,远高于3D-rGO,经过500次循环后,电容保持率达到96%.

3D-rGO was prepared by VC reduction of graphene oxide,and then the 3D-rGO supported MnO2 composite was prepared by reaction with KMnO4 at room temperature. By controlling the reaction time,the amount of MnO2 in the composite materials and its electrochemical properties were controlled. The morphology and microstructure of the nanocomposites were characterized by X-ray diffraction（ XRD） analysis,X-ray Photoelectron Spectroscopy（ XPS）,Fourier transform infrared（ FTIR） spectroscopy,transmission electron microscope（ TEM）,scanning electron microscope（ SEM） and field emission scanning electron microscope（ FESEM）. In addition,the electrochemical properties of free binder and free standing of the composite were investigated by cyclic voltammetry（ CV）,galvanostatic charge / discharge and electrochemical impedance spectroscopy techniques. The results indicate that in the optimal case,a specific capacitance of 308 F / g can be obtained in 1 mol / L H2SO4 at a scan current density of 1 A / g,with a capacitance retention of 96 % after500 cycles.