Preparation And Electrochemical Study Of N-doped Carbon Materials Based On Biomass

As an energy storage device with great application potential,supercapacitors are widely used in portable electronic equipment,electric vehicles and renewable energy storage grids due to its high power density,fast charge and discharge rate and long cycle life,which are also suitable for high power demand systems such as load balancing and emergency braking.In order to improve its electrochemical performance,the electrode material is optimized from two aspects:specific surface area and hetero atom doping.In this paper,carboxymethyl cellulose-based protic polyanion（ionic liquids）and natural biomass strontium were used as precursors to produce nitrogen-containing porous carbon materials,using KOH activation method,which have high specific surface area and excellent electrochemical properties.（1）A carboxymethyl cellulose-based protic polyanion（ionic liquids）were acted as precursors to prepare nitrogen-doped porous carbon materials.The protic polyanion（ionic liquids）with different structures were synthesized by the direct reaction between a polyacid with different small molecular organic bases（1-Mi,TEA,TMG,DBU）.So nitrogen-doped porous carbon materials with different structures were prepared by KOH activation method at different temperatures.For comparison,the following two carbon materials were prepared:a)preparation of a nitrogen-containing carbon material by direct carbonization of protic polyanion（ionic liquids）;b)a porous carbon material prepared by carboxymethyl cellulose through KOH hydrothermal at 900℃.The structure of the nitrogen-containing porous carbon materials was detected by XRD,XPS,BET,SEM,TEM which were used to analyze the graphitization degree,element morphology,specific surface area,surface morphology,etc.The electrochemical performances of carbon materials were tested by three-electrode electrochemical method and 2032 button cell counter electrode method.The effects of nitrogen doping,KOH activation,carbonization temperature and precursor structure on the structure and electrochemical properties of carbon materials were investigated by physical structure test and electrochemical test.（2）Preparation of nitrogen-containing porous carbon materials by cockroach’s precursor.This subject used fertility and harmful cockroaches as a precursor,which is pyrolyzed by KOH activation at different temperatures to obtain nitrogen-containing porous carbon materials with different structures.The effects of KOH activation,activation temperature and heteroatom morphology on the physical properties and electrochemical properties of the materials were investigated by characterizing the degree of graphitization,element morphology,specific surface area,surface morphology and electrochemical properties of the materials.A supercapacitor model with different electrolytes of 1 M Na₂SO₄ and 6 M KOH was used to detect the different electrochemical behaviors of carbon material electrodes in different electrolytes.In addition,adsorption experiments on methylene blue dyes have shown that this carbon material has great potential in the application of pollutant adsorption.