2D Materials/Copper Sulfide Composite Electrodes And Their Application In Capacitor Battery

Super capacitor battery is a type of energy storage device that bridge the gap between lithium-ion battery and electrical double layer capacitor,which combine the advantages of both devices by the synergetic hybridization of the battery and capacitor components.Therefore super capacitor battery has great application potential in energy storage fields.However,electrode material is one of the key factors that limit the performance of Super capacitor battery.Development of new electrochemical energy storage devices with high energy density,high power density and long cycle life has becoming the urgent project to be solved,which also get more and more attention of researchers.AS it has ultrahigh theoretical specific surface area,good electronic conductivity and good mechanical property,graphene is considered to be an ideal electrode material,now it also becomes the hot topic about the energy research.In this dissertation,graphene prepared by the modified Oxidation Reduction was used as the research object.Capacitive characteristic of graphene electrode materials are research in detail.For comparison the effect of different diaphragm on electrode characteristics is studied.CuS/graphene nanocomposite was synthesized by hydrothermal method to be used as an electrode material for Super capacitor battery.The morphology and microstructure of the products have been characterized by Scanning electron microscopy(SEM),Energy disperse spectroscopy(EDS).The electrode chemical performance of composite electrode materials were revealed by Cyclic voltammetry(CV),Galvanostatic charge-discharge(GCD),Electrochemical impedance spectroscopy(EIS).The following conclusions were drawn.(1)Graphene prepared by the modified Oxidation Reduction was used as the research object.Capacitive characteristic of grapheme electrode materials are research in detail.SEM result revealed that the composite material was parsed evenly without agglomeration.Electrochemical impedance spectrometry,Cyclic voltammetry,and Galvanostatic charge-discharge tests indicated that the electrode material performed typical capacitance properties,the specific capacitance value of the sample was about 256 F·g-1 in the scan rate of 10 mV·s-1 in 1 mol·L-1 H2SO4,After 600 charge-discharge cycles,the specific capacitance of grapheme electrode maintained at 87%.(2)For comparison the effect of different diaphragm on Electrode Characteristics is studied.It indicates NKK diaphragm electrode shows high current density and high cycle stability.The experimental result indicates that the specific capacitance of the NKK diaphragm electrode is more than 260F·g-1.With the test of 50 mA/cm2 current density and constant current charge and discharge 600 times,the NKK diaphragm electrode specific capacitance is maintain 78% of the initial specific capacitance and shows good electrochemical performance.(3)Although the theoretical value of the specific capacitance of graphene electrode material is very high.The experimental data is very difficult to get high specific capacitance.How to improve the specific capacitance of graphene is still a hot topic.CuS/graphene nanocomposite was synthesized by hydrothermal method to be used as an electrode material for Super capacitor battery.SEM result revealed that the composite material was parsed evenly without agglomeration while its diameter was about 50 nm.The experimental result indicates that the specific capacitance is more than 368 F·g-1.With the test of 50 mA/cm2 current density and constant current charge and discharge 600 times,the specific capacitance is maintain 90% of the initial specific capacitance and shows good electrochemical performance.