Preparation And Electrochemical Performance Of Sulfonated Graphene Composites

Among various energy storage devices,supercapacitors have attracted great interest as new types of electrochemical capacitors.Compared to traditional batteries,supercapacitors have a series of advantages,high power density,long cycle life,and fast charge and discharge rates in seconds.In this paper,the transition metal?hydrogen?oxide?Ni?OH?₂,NiO?and conductive polymer?PPy,PANI?composite electrode materials were prepared by a simple and highly efficient method using a modified sulfonated graphene?SGO?substrate.And explore its electrochemical properties.The main tasks of this project are as follows:1.The graphene oxide prepared by the Hummers'method is modified with diazonium salt of sulfanilic acid to obtain SGO,and hydrothermal method is used to anchor Ni?OH?₂ on the SGO.The morphology and structure of the SGO/Ni?OH?₂composite is obtained by various characterization methods.The composite is tested capacitance,cycle stability and electrochemical properties such as energy density and power density by cyclic voltammetry?CV?,constant charge-discharge?GCD?,electrochemical impedance spectroscopy?EIS?.The result shows that SGO/Ni?OH?₂composites can provide excellent electrochemical performance.The material has a specific capacity of 1817.5 F g^-11 at a current density of 1 A g^-1,and its capacity retention rate is as high as 89.5%after 1000 cycles,indicating that the electrode material has great potential in the supercapacitors.At the same time,the prepared all-solidstatedasymmetricsupercapacitorSGO/Ni?OH?₂//AChasspecific capacitance of 80.44 F g^-1,high energy density(7.15 Wh kg^-1)and high power density at 50 mA g^-1(20 W kg^-1),stable cycle life?capacitance retention after 75%cycling1000 times?and lights a green LED.2.PPy/Ni?OH?₂/SGO ternary composites with cauliflower-like surface is prepared by in situ chemical oxidation and hydrothermal method.The structure and morphology of the material is measured by FR-IT,XPS,SEM and TEM.The material is prepared into electrodes and the electrochemical performances of the electrode are calculated by CV,GCD,EIS and other test methods.The PPy/Ni?OH?₂/SGO ternary composite material exhibits a high specific capacitance of 1632.5 F g^-11 at a current density of 1 A g^-11 and a capacity retention rate of 86%after 1000 cycles.The prepared all-solid stated asymmetric supercapacitor PPy/Ni?OH?₂/SGO//AC has a high specific capacity of 224 F g^-1,a high energy density(79.6 Wh kg^-1)and a power density(0.8kW kg^-1),a stable cycle life?capacitance retention after 62 cycles of 62.5%?,while the green LED indicator lights up.3.The SGO/NiO/PANI ternary composite with core-shell structure is prepared by hydrothermal,calcination and in-situ chemical oxidation method.The structure and morphology of the material is measured by FR-IT,XRD,Raman,BET,SEM,and TEM.The material is prepared into an electrode and employed to CV,GCD,EIS.The SGO/NiO/PANI ternary composite material has a high specific capacitance of 2482 F g^-11 at a current density of 1 A g^-11 and a capacity retention rate of 84%after 1000 cycles,which shows that it has good cycle stability.The prepared all-solid stated asymmetric supercapacitor SGO/NiO/PANI/AC has high specific capacity of 308.8 F g^-1,high energy density(109.8 Wh kg^-1),power density(0.8 kW kg^-1)and stable cycle life?capacitor retention rate after 66 cycles is 66.7%?,while a green LED indicator is illuminated.