Study On Preparation And Electrochemical Energy Storage Of Multi-level Porous Carbon Materials

Multi-level porous carbon materials,as the current research hotspots,have a wide range of raw materials and diverse preparation methods.They have excellent optical,thermal,magnetic,and electrical properties,and have potential application value in many fields.In this dissertation,different polymers are selected as carbon sources,and multi-level porous carbon materials with different morphologies are prepared by different methods,and their applications as electrode materials in supercapacitors are explored.1.Using waste plastic polypropylene?PP?as a carbon source,adding a certain proportion of sulfur?S?and ferrocene?Fe?C₅H₅?₂?,flower-shaped carbon nanosheets were prepared under high temperature and sealed conditions,and then carbon and the KOH ratio is used to activate the carbon nanomaterial at high temperature to obtain a porous structure.After testing and characterization,it is determined that 1:6 is the optimal carbon-alkali activation ratio,so that the specific surface area of the material is 1922 m²/g,the pore volume is 2.805 cm³/g,and the gravimetric specific capacitance is 233.7 F/g at a current density of 1 A/g.,showing the best electrochemical performance.2.Using waste plastic bottles?PET?as the carbon source and magnesium oxide/cobalt acetylacetonate?Mg O/Co?C₅H₇O₂?₃?as the combined catalyst,carbonization was carried out under high-temperature sealed conditions to prepare porous pleated carbon nanosheets?PCS?.Then PCS-MnO₂-x?x=1,2,4?was obtained by loading MnO₂ with high capacitance and low cost on PCS at 1:1,1:2,and 1:4 mass ratio,respectively.After various tests and characterization comparisons,PCS-MnO₂-2 has a large specific surface area and suitable porous structure compared to other ratios.The gravimetric specific capacitance of PCSMnO₂-2 up to 210.5 F/g at 0.5 A/g,and the areal specific capacitance up to 0.33 F/m² at 1 m V/s,which showed excellent electrochemical performance.3.Polyimide resin?PI?was mixed with potassium oxalate?K₂C₂O₄·H₂O?and melamine polyphosphate?MPP?in different proportions,and carbonized in a high-temperature nitrogen atmosphere to obtain multi-level porous carbon materials with different morphologies.After a series of characterization and comparison,it was found that the combination of K₂C₂O₄·H₂O and MPP can form a fluffy porous structure with PI,increase the specific surface area of the material,and the number of active sites of electrolyte is also improved.The specific surface of the carbon nanosheet is as high as 2194 cm²/g,suitable pore size distribution,and the doped of N and P heteroatoms to improve the conductivity of the material,so that the gravimetric specific capacitance of the material is as high as 304 F/g at a current density of 1 A/g,and has excellent cycle stability.