Study On The Preparation Of Porous Carbon Materials And Its Application In Supercapacitors

Supercapacitor is a new type of energy storage device,and the electrode material is the key to its development,which affects its performance and production cost.Therefore,the development of supercapacitors is inseparable from ideal electrode materials.Among many electrode materials,porous carbon materials have received extensive attention due to their large specific surface area and abundant pores.In this paper,porous carbon materials with different morphologies and heteroatom doped were synthesized,and their application in the direction of supercapacitors were explored.The main research contents of the paper are as follows:1)In the process of preparing the tubular carbon material,nitrogen-doped tubular mesoporous carbon（NTC）was prepared by a hard template method,with halloysite as a template,phenolic resin and graphene oxide as carbon precursors,and ethylenediamine as a nitrogen source.In this experiment,the effects of ethyl orthosilicate and graphene oxide on the structure and electrochemical performance of NTC were systematically studied.When the halloysite template was coated with a layer of graphene oxide and then the composite of silica and phenolic resin,the NTC-1 obtained has a hollow tubular structure,a high specific surface area(1,126 m²·g^-1),high nitrogen content（4.03%）and abundant mesopores（2.7 nm）.When used as an electrode material,NTC-1 has a high specific capacitance of 277 F·g^-1at 1 A·g^-1.This method provides a way to use natural halloysite minerals as templates to prepare high-performance porous carbon materials simply and inexpensively.2)In the process of preparing the spherical carbon material,nitrogen-doped hollow mesoporous carbon sphere（NHMCS）was prepared with polystyrene spheres as templates.A uniform mesoporous silica layer was coated on the surface of the polystyrene spheres with the cetyltrimethylammonium bromide（CTAB）as the surfactant and pore-forming agent.Then,it was pre-carbonized with sulfuric acid,and melamine was added as a nitrogen dopant.After high temperature pyrolysis and removal of silica,NHMCS with high specific surface(1,716 m²·g^-1)and uniform mesoporous（2.7 nm）distribution was obtained.When used as an electrode material,it has a high specific capacitance of 276F·g^-1and high cycle stability.After 10,000 cycles,the specific capacitance retention rate reaches 97.6%,showing excellent electrochemical performance in all aspects.3)In the process of preparing sheet-shaped carbon material,wrinkled carbon sheet（WCS）was prepared at a relatively low temperature through the hydrothermal reaction of graphene oxide and glucose in an acidic environment.Graphene oxide was used as a morphology directing agent and sulfuric acid was used as a catalyst.The hydrothermal method provides a simple strategy for the synthesis of mesoporous carbon materials,and obtains a carbon material with good morphology,large specific surface area,and abundant mesopores.As an electrode material,WCS exhibits excellent specific capacitance(252F·g^-1at 1 A·g^-1),high cycle stability（94.7%）and high energy density(16.1 Wh·kg^-1).This shows its great potential in the application of electrode materials for supercapacitors.