Analysis Of Porous Carbon And Electrochemical Performance Based On Template Method And Pyrolysis Oil

Electric double layer capacitors are characterized by high power density,long cycle life,high stability,and low cost.They are the first class of super capacitors in the market.Their electrode materials are mainly carbon materials,while activated carbon and template carbon are the most used widely.The pore size distribution of activated carbon is relatively dispersed,which results in low specific surface area utilization efficiency.In the conventional template carbonization,organic chemical reagents are mostly used as the carbon source,supplemented by the nitrogen doping process,which increases the pressure on environmental protection.In response to the above-mentioned problems,this subject proposes to use nitrogen-rich primary biomass pyrolysis oil as the carbon source,and use different template agents to prepare porous carbon electrode materials with concentrated pore size distribution,adjustable pore structure,and a certain amount of nitrogen-containing functional groups.The specific research contents are as follows:Several conventional biomasses were selected through industrial analysis and elemental analysis.Finally,bean dregs with a carbon content of 48.54%and a nitrogen content of 9.53%was selected as the raw material for pyrolysis oil;the heating rate at5,10,and 20?/min and The pyrolysis of bean dregs under four conditions of rapid pyrolysis,gas chromatography-mass spectrometry,organic elements and mass yield analysis showed that the nitrogen content of bean dregs pyrolysis oil was 4.55%and the mass yield was 45.5%at a heating rate of 20?/min,is the best heating rate of pyrolysis oil preparation.The mesoporous carbon was prepared with bean dregs pyrolysis oil as the carbon source and magnesium citrate as the template agent at the optimal pyrolysis heating rate.The mesoporous carbon was characterized by BET,XRD,FTIR,XPS and other techniques.The performance of mesoporous carbon electrode materials was investigated in KOH electrolyte.The experimental results show that the pore size distribution of mesoporous carbon is concentrated at 2-8nm,the most probable pore size is 4nm;the mass ratio is 1:4,and the carbonization heating rate is 20?/min The maximum specific surface area is 1637m~2/g;the cyclic voltammetry(CV)curves of the mesoporous carbon electrode materials are all rectangular-like,and the constant current charge-discharge(GCD)curve is an isosceles-like triangle,showing a typical double charge The energy storage characteristics of the layer,when the mass ratio is 1:4 and the carbonization heating rate is 10?/min,the specific capacitance of the mesoporous carbon electrode material is the largest,which is 197.95F/g;the nitrogen element introduced by in-situ doping improves the electrode.The adsorption capacity of mesoporous carbon is relatively weak,and the poor ion transport capacity of microporous carbon leads to low specific surface area utilization rate.The subject used bean dregs pyrolysis oil as a carbon source and potassium acetate as a template agent to further prepare mesoporous carbon suitable for aqueous electrolytes,and Through electrochemical analysis method to study its capacitance performance.The study found that the pore size distribution of ultra-microporous carbon is concentrated at 0.5-1.5nm,and the most probable pore size is 0.91nm;when the mass ratio is 1:4 and the carbonization heating rate is 10?/min,the maximum surface area is 1607m~2/g;The CV curves of ultra-microporous carbon electrode materials all show a rectangular shape,and the GCD curve is an obvious isosceles triangle,showing typical electric double layer energy storage characteristics;because ultra-porous carbon has a strong adsorption capacity,the same specific surface area the lower specific capacitance value is much higher than that of mesoporous carbon.When the mass ratio is 1:4 and the carbonization heating rate is 10?/min,the specific capacitance of the ultra-porous carbon electrode material is as high as 398.85F/g.