Preparation And Electrochemical Performance Of Carbon-based Electrode Materials For Supercapacitors

With the pollution of the environment and the consumption of fossil energy,various countries have formulated corresponding energy conservation and emission reduction policies.Now the use of clean energy has become the general trend,including the use of wind energy,solar energy,geothermal energy and tidal energy.However,these energy sources are facing a series of important issues such as regional,seasonality,and discontinuities.Therefore,the development of new energy storage devices and the improvement of their performance are topics that need to be continuously explored.Among them,supercapacitors have the excellent property of traditional capacitors and secondary batteries.Supercapacitors have the advantages of high-power density,long cycle life,and high safety.This article aims to explore the application of carbon-based materials and carbon-based composite materials in supercapacitors and improve their electrochemical performance.The specific research content is as follows:(1)Casein,silica sol,and KOH were used as precursors,templates,and activators,respectively.Nitrogen-doped porous carbon prepared by a combination of template and activation methods.The prepared nitrogen-doped porous carbon has the advantages of large specific surface area,controllable pore size,and high porosity.Nitrogen-doped porous carbon electrode material has also high specific capacitance and electrochemical stability.The specific capacitance is 389.3 F/g in a three-electrode system at a current density of 1 A/g.The nitrogen-doped porous carbon can be maintained 93.4%of capacitance after 10,000 cycles at a current density of 10 A/g.(2)Polyacrylamide gel was prepared using acrylamide and N,N-methylenebisacrylamide as a monomer and crosslinking agent,respectively.Nitrogen-doped porous was prepared by vacuum freeze-drying,high-temperature carbonization,and activation process of a polyacrylamide gel.The electrochemical performance in a three-electrode system measured a specific capacitance of 302.1 F/g at a current density of 1 A/g.More importantly,in a two-electrode system,the power density was 450 W/kg and the energy density reached 23.27 Wh/kg.(3)Nitrogen-doped porous carbon prepared by casein template activation method(NC).NC and aniline,disulfide dichloride,hydrogen peroxide and other in-situ polymerization to prepare nitrogen-doped porous carbon/partially poly(2,2’-dithiodiphenylamine)(NC/PDTDA)composite materials.The specific capacitance of the NC/PDTDA composite is 490.5 F/g at a current density of 1A/g.In addition,in a two-electrode system,the NC/PDTDA-2 composite electrode material showed a high energy density of 13.49 Wh/kg at a power density of 699.8 W/kg.(4)Using aniline,ammonium persulfate,disulfide dichloride,hydrogen peroxide,etc.as raw materials,partially poly(2,2’-dithiodiphenylamine)(PDTDA)was prepared and as a precursor.N,S co-doped porous carbon was successfully prepared through carbonization and activation of partial PDTDA.The three-electrode system was used to test its electrochemical performance.The results show that the suitable carbonization temperature was 600 ~oC(ASNC-600-800),which showed excellent capacitance performance.Its specific capacitance reached 500.1 F/g at 1 A/g in a three-electrode system.In addition,N,S co-doped porous carbon possess an energy density of 21.15 Wh/kg at a power density of 450 W/kg.A new path has been opened for the preparation of low cost and high-performance porous carbon electrode materials.