Synthesis,modification And Electrochemical Energy Storage Properties Of Distilled Grains Biomass Carbon Materials

Biomass has the characteristics of abundant resources,wide distribution,reproducibility and low pollution.Therefore,the resource utilization of biomass has always been one of the most concerned issues.At present,the resource utilization of biomass mainly includes:soil fertilizer improvement,animal feed processing and biomass gas and fuel oil production.However,the existing resource utilization methods are faced with the problems of secondary pollution,low energy utilization rate and low added value of products.In order to further explore the efficient and comprehensive utilization of biomass,this dissertation uses distilled grains biomass as raw material,and aims to prepare active electrode energy storage carbon materials with excellent electrochemical performance through simple physical and chemical treatment processes.The main research contents are as follows:（1）Preparation of distilled grain biomass carbon and its application as potassium ion anode material.The distilled grains biomass charcoal is used as raw material,porous carbon nano-functional materials with Fe₃C embedded nitrogen-doped carbon nanotubes were prepared by hydrothermal nitrogen doping,pre-carbonization,Fe Cl₃/Zn Cl₂chemical activation and high temperature carbonization.The effects of nitrogen dopant type,chemical activator type and carbonization temperature on the carbon morphology and composition of distilled grains biomass were investigated.The results show that:after melamine hydrothermal nitrogen doping and Fe Cl₃/Zn Cl₂activation treatment,Under the condition of carbonization at 900℃,Fe₃C embed in nitrogen-doped carbon nanotubes to coat the carbon nanotubes on the surface of porous carbon nanomaterials,which effectively increases the pore structure and specific surface area.Nitrogen doping with melamine enriches the nitrogen and oxygen functional groups on the surface of the material.It exhibits excellent potassium storage capacity(294.8 m Ah g^-1at a current density of 50 m A g^-1),cycling stability（0.016%capacity loss per cycle）and rate capability as an anode material for potassium-ion batteries.The transformation of distilled grains biomass waste into high-performance potassium ion anode material by modifying the structure and composition of distilled grains biomass carbon.（2）Preparation of distilled grains cellulose carbon aerogel and its application in supercapacitors.The distilled grains are used as raw materials to extract plant cellulose through a nitric acid/ethanol mixture,and distilled grains cellulose carbon aerogel with ultra-high specific surface area and pore structure was prepared by Na OH low-temperature sol-gel process,freeze-drying and high-temperature carbonization.The effects of carbonization temperature and cellulose concentration during regeneration on the morphology and pore structure of distiller’s grains cellulose carbon aerogels were investigated.The electrochemical performance of the corresponding supercapacitor electrodes is discussed in conjunction with the difference analysis of morphology and composition.The results show that the material at the carbonization temperature of 700℃has a certain pseudo-graphite domain structure while retaining a certain fiber structure.The specific capacitances are 184,160,133,112 and 90 F g^-1at current densities of 1,2,5,10,20 A g^-1,respectively.In the sol-gel process,the cellulose mixture with a mass fraction of 6%has an ultra-high specific surface area(999.8 m²g^-1)and a porous structure after aging,freeze-drying and high-temperature carbonization.The cellulosic carbon aerogel electrode after sol-gel regeneration treatment exhibits the characteristics of electric double layer energy storage.The specific capacitances are 277.2,217.5,190.5,177.0and 165.4 F g^-1at current densities of 1,2,5,10,20 A g^-1,respectively.