Study On Structure Construction And Properties Of Graphitized Porous Carbon Materials Based On Biomass Primary Structure Design

Due to the rapid consumption of oil and other traditional fossil resources and increasingly serious environmental problems,it is increasingly important for researchers to develop efficient and clean new energy sources.In recent years,we have been seeking a storage facility that can further enhance energy storage capacity and at low cost to meet the rapidly growing energy demand.Supercapacitors,as a new type of energy storage system,have attracted the attention of researchers because of their advantages such as fast charging and discharging speed,high power density and long cycle life.However,due to the rapid development of energy storage,the development of supercapacitors is faced with many problems,such as smaller than capacitors,fast discharge speed and low energy density.The key to solve the problem is the choice of electrode materials.Common electrode materials currently used include carbon nanofibers,activated carbon,carbon nanotubes,graphene,conductive polymers,metal oxides and their complexes.Because of the advantages of low price,good electrical conductivity,larger surface area and better chemical stability,porous biomass carbon materials have become the focus of scientific research.Starch is a natural,renewable and biodegradable polymer that is widely available from a variety of crops and contains more than 49%oxygen.Due to the high content of oxygen in starch,the surface of starch derived porous structure will produce a large number of hydrophilic groups.Moreover,the porous carbon is cheap and environmentally friendly,and has a high application prospect in the development of environmentally friendly starch carbon electrode materials.This topic,starting from the microscopic structure of starch,according to three different content of amylopectin of biomass as raw material,USES the different starch granule size of biomass to design the preparation has the suitable graphitization degree of porous carbon materials,and as a super capacitor electrode materials were a series of experiments and electrochemical performance test,showed excellent electrochemical performance,living material on the super capacitor application provide the scientific basis.The specific work of this paper is summarized as follows:（1）Porous carbon materials with appropriate degree of graphitization were prepared from taro,sweet potato and potato by low temperature carbonization and mature KOH activation technology.Through characterization test and electrochemical performance test of the material,the electrochemical performance is extremely excellent.In the three-electrode system,the ultrahigh specific capacitance of 397 F g^-1 was obtained at the current density of 0.5 A g^-1 and the electrolyte of 6 mol/L KOH.In the two-electrode system,the energy density reached 22.59 wh kg^-1,and the power density reached 148 w kg^-1.Moreover,under the current density of 5 A g^-1,the circulating 20,000 cycles of the capacitor could still maintain the original 97%,showing an extremely long cycle life.（2）In this section,porous carbon materials with appropriate degree of graphitization were prepared with degelatinized silkworm cocoons as raw materials and with different activators of Fe Cl₃,K₂CO₃,Fe Cl₃ and K₂CO₃.The characterization and electrochemical properties of the material showed that the capacitance of the cocoon-based material was160 F g^-1 at 0.5 A g^-1.The cocoon-based carbon materials obtained by double activation showed excellent electrochemical properties.