MnO_2/石墨烯复合电极材料的制备与储能性能

以葡萄糖为还原剂,天然石墨片为原料,采用Hummer法制备了石墨烯粉末(Graphene);并以该产物、KMnO4和HCl为原料,采用水热法制备了MnO2/Graphene复合材料。用扫描电子显微镜和X射线衍射对所制备的复合材料进行了表征,结果表明,水热法制备的MnO2材料为纯的α-MnO2相,且石墨烯粉末的加入并没有影响MnO2的晶体结构。在1mol/L Na2SO4电解液中进行了循环伏安和计时电位扫描测试,电极材料电化学性能稳定,具有较好的可逆性,在1.27mA/cm2电流密度下进行充放电测试时,电极比电容为147.9F/g;再循环1000次后,电极仍能保持稳定的电容,是一种理想的电化学电极材料。

Preparation and performance of MnO2/graphene composite electrode materials

In this paper, graphene is synthesized from natural graphite by a modified Hummers method and glucose is added as reducing agent. Hydrothermal method is used to prepare MnO2/graphene composite using KMnO4 and HCl as raw materials. The structure is characterized by SEM and XRD. The result shows that MnO2 prepared by hydrothermal method is pure -MnO2, and the addition of graphene powder doesnt influence its crystal structure. Electrochemical characterization is performed using cyclic voltammetry and chronopotentiometry in 1 mol/L Na2SO4 aqueous solution electrolyte. The electrode has a stable electrochemistry performance, and preferable reversibility, the specific capacitance of MnO2/graphene electrode is 147.9 F/g under 1.27 mA/cm2 current densities. The electrode presents a stable capacitiance after 1000 cycles and it is an ideal electrochemical material.