The Properties Of Ferrite/graphene Composite For Supercapacitor

Supercapacitor as a new type of energy storage components has been become the new research focus of the energy in recent years due to its higher energy density and power density than the traditional capacitor.Electrode materials directly affect the electrochemical performance of the supercapacitor as a major component of the supercapacitor.Graphene processes excellent electrochemical performance with two-dimensional honeycomb structure,unique physical and chemical properties,huge specific surface area and high charge mobility not only as an electric double layer capacitor electrode material,but also as a carrier with other traditional electrodes material to synthesize composite electrode materials of high performance.In this paper,nano-spinel ferrite/graphene composite electrode materials were synthesized by hydrothermal method.The structure,morphology,magnetic properties and electrochemical properties of the composite electrode were studied by XRD,SEM,FTIR,VSM and electrochemical workstation.XRD results show that the graphite oxide processes a strong diffraction peak at2?=11.13°method,indicating the formation of graphite oxide,while the graphene presents a broad and weak intensity at 2?=25.13°.SEM images show that the graphite oxide and graphene are stacked in lamella,and the energy spectrum analysis shows that the graphite oxide is reduced to graphene.FTIR indicates that carbon oxide functional groups are formed in graphite oxide,without in graphene.The optimum process for nickel-zinc ferrite/graphene composites are 200°C for 4 h.XRD indicates that the composite materials are cubic spinel structure.SEM images show that ferrite particles are distributed on the surface and pores of graphene.The results of magnetic measurements of Ni_0.6Zn_0.4Fe₂O₄/graphene composites with graphite oxide of 50%at 180°C for 6 h shows that the saturation magnetization is the largest?57.72 emu/g?.Ni0.8Zn0.2Fe2O4/graphene composites with graphite oxide of 50%at 200°C for 4 h has a maximum capacitance(156.63 F g^-1),energy density(21.75 Wh kg^-1)and a minimum equivalent series resistance0.67?.The optimum process for nickel-zinc-aluminum ferrite/graphene composites is 180°C for 6 h.The result of XRD shows that the composite materials exhibit cubic spinel structure.SEM images show that ferrite nanoparticles are distributed on the surface and porosity of graphene.The magnetization of Ni_0.8Zn_0.2Al_0.1Fe_1.9O₄/graphene composites with graphite oxide of 25%at 180°C for 6 h shows that the saturation magnetization is the largest?78.5emu/g?,and when the graphite oxide is 75%,the maximum specific capacitance(162.99 F g^-1),the energy density of 22.64 Wh kg^-1,the equivalent series resistance of 0.66?.