Electrochemical Performance Of Doped Manganites/rGO Composites

Manganese oxide is rich in natural mineral resources, and it is friendly tothe environment. Besides, the manganese oxide also has a relatively wideelectric window as supercapacitors. Because of these superior performances,manganese oxides used as electrode material for supercapacitors have excellentdevelopment potential. But manganese oxide also have some problems such aspoor ionic conductivity and poor conductivity. The incorporation of othermaterials into manganese oxide are effective ways to solve above problems. Inthis paper, manganese oxide were doped by Sn or Y，and then composite withgraphene. Electrochemical characteristics were also discussed.MnO2was prepared by the hydrothermal method. When the reactiontemperature and time were set to140oC and12h, nano-rod-like α-MnO2wasprepared. The analysis results show that MnO2materials have goodelectrochemical performance after Sn-or Y-doped. The specific capacitance ofMnO2can reach283F·g-1after doped Sn, and the specific capacitance of MnO2can reach154F·g-1after doped Y. In terms of improving the specific capacitance,Sn is better than Y element. When these materials were composited withgraphene, the electrochemical performance of the composite material has beenimproved. In these prepared materials, the electrochemical performance of Sn-MnO2/graphene electrodes can reach312F·g-1. The specific capacitance of Sn-MnO2/graphene increased by10%. Mn3O4was also prepared by hydrothermalmethod, the reaction temperature and time were set to180oC and10hrespectively. The morphology of the prepared Mn3O4electrode was rod-likeparticle under the scanning electron microscope. The prepared Mn3O4materialshave good electrochemical performance after Sn-or Y-doped. The specificcapacitance of Mn3O4which is doped by Y element is three times than Snelement. When the doped materials were composited with graphene, the specific capacitance of material increased greatly. In these prepared materials, theelectrochemical performance of Y-MnO2/graphene electrodes can reach134F·g-1.The electrode capacitance of Y-Mn3O4/graphene increased by50%.