Synthesis Of Porous Carbon And Their Application In Supercapacitors

Due to the excellent conductivity,high surface area and low cost,the carbon materials have been applied into many energy storage and conversion devices.Because the electrode materials hold the key to the performance of the energy storage devices,many scientists are searching for the ideal materials.High surface area carbon materials made by one-step carbonization can shorten the process and reduce the cost.Aiming to the problems that exist in producing the porous carbon,the formation mechanism and the regulation of pore structure in the process of heat treatment of biomass and alkali metal molecules were investigated,which provided a basis for the preparation and application of porous carbon.It is important to analyze the relationship between pore structure and electrochemical performance of porous carbon.Differences between porous carbon pyrolyzed by different biomass organs,experiments used three biomass:lotus,celery and asparagus lettuce,separated the stems and leaves to analysis.And the experiments show the surface area of S-carbon is 1610 m²g^-1while the L-carbon is 1039 m²g^-11 in the same condition.The specific capacitance of S-carbon is 174 Fg^-1 while the L-carbon is 152 Fg^-11 in the 6M KOH aqueous electrolyte.Different organs have different functions and have different alkali metal ions,it is normal to have differences between them.The surface area of CS-carbon is 2194 m²g^-11 without any extra activation,is even better than the commercial porous carbon.They all prove that one-step carbonization to produce the high surface area carbon is available.By carbonizing the organic salt with alkali metal,it can be further proved that the porous carbon prepared by one-step carbonization method can be industrialized and commercialized.The surface area of HSACS that pyrolyzed EDTA-2K in 850?with3h is 3411m²g^-1.EDTA-2K is not sensitive to the pyrolyzed conditions,the specific surface area of porous carbon obtained in a very wide range is greater than 3000m²g^-1,it is suitable for industrial production.The specific capacitance of HSACS is 281.5Fg^-1 when the current density is 0.2 Ag^-1,and 216 Fg^-1 when the current density is 20Ag^-1 in 6M KOH aqueous electrolyte.The capacitance retention is 76.7%even the current density increased 100 times.The HSACS also show excellent performance in2M Li₂SO₄ aqueous electrolyte and organic electrolyte.