Preparation And Properties Of Ni?OH?₂/g-C₃N₄/RGO Composites For Supercapacitors

In recent years,due to the environmental pollution of traditional automobiles,all kinds of pure electric vehicles have sprung up,but the rapid development of electric vehicles is hindered by battery capacity and charging and discharging speed.Electrochemical Supercapacitor have attracted much attention due to their high power density,long cycle life and large limit capacity,although their energy density is higher than other batteries,efforts should be made to achieve the expected energy density,at present,the research of electrode materials for SE is still the most cutting-edge research field.In this paper,Ni?OH?₂/g-C₃N₄/RGO ternary composite electrode materials were prepared by different methods?hydrothermal method and microwave method?.The composition,morphology,microstructure and reduction degree were characterized by X-ray diffraction?Raman spectroscopy?Infrared spectroscopy?Scanning electron microscopy?Thermogravimetric analysis?X-ray photoelectron spectroscopy and Specific surface area,The cyclic voltammetry?CV?,Galvanostatic charge-discharge?GCD?and AC impedance?EIS?properties of the composite electrode material were measured:1.Graphite oxide?GO?was synthesized by Hummers method through strong oxidant,and three-dimensional graphene oxide was prepared by different reductants and methods,through characterization and analysis,the three-dimensional materials prepared had higher reduction degree and obvious three-dimensional structure;The g-C₃N₄ in RGO/g-C₃N₄ composite electrode material was calcined with urea as raw material,by comparing the effects of different preparation methods such as hydrothermal,microwave and calcination on the physical and electrochemical properties of the composite electrode material,found that the properties of the composite electrode material prepared by calcination method were better than other methods.2.Ni?OH?₂/g-C₃N₄/RGO composite electrode material was synthesized by hydrothermal method.The electrochemical properties,structure and micro morphology of the composite electrode material were compared by controlling variables such as mass ratio of reactants,reaction temperature and reaction time,the results show that the composite electrode material is flower-shaped three-dimensional structure with 16:1:1 mass ratio and 12 h reaction at 120?.After 2000 discharge cycles,the capacitance decay rate of the composite electrode material 1351.3 F/g is15.5%.The composite electrode material has good cycle and rate performance.3.Ni?OH?₂/g-C₃N₄/RGO composites were synthesized by microwave irradiation,the electrochemical properties,structure and micro-morphology of the composites were compared by controlling variables,mass ratio of reactants,reaction temperature and reaction time.The composites were prepared at 16:1:1 mass ratio and microwave irradiation at 190?for 5 min.The composites were lamellar structure,some of the lamellae were decomposed into nanowires,and the specific surface area was relatively large,after 3000 charge-discharge cycles,the capacitance decay rate o f composite 1881.1 F/g is 28.1%,it has good cycle and rate performance.