Preparation Of Carbon Nanocomposite Porous Materials And Its Application In Supercapacitors

In recent years,environmental and energy problems have become increasingly fierce and have been widely concerned by the people.The gradual decay of non-renewable resources and the global environment need to be improved.At the same time,people also have higher requirements for high energy density of the energy storage equipment.Among many energy storage devices,supercapacitors have attracted the attention of researchers for their advantages,such as fast charge and discharge,long cycle life,and high energy density.Among the supercapacitor electrode materials,although carbon materials have good electrical conductivity,high specific surface area and good cycle life.They have low specific capacitance and hydrophobic surface.Therefore,it is necessary to composite carbon materials with other pseudocapacitor materials to prepare composite materials,which can not only obtain higher specific capacitance,improve hydrophilicity,but also maintain good cycle life,and obtain higher energy density.In this paper,carbon materials and metal oxide manganese dioxide were compounded,nitrogen-sulfur doped porous carbon nanomaterials were synthesized,and polycyclodextrin-polyaniline/carbon nanotubes(CDP-Pani/CNT)composite nanomaterials,using a variety of analytical methods to characterize the structure and electrochemical performance of the synthesized composite nanomaterials,it includes the following three parts:(1)Preparation of porous carbon/manganese dioxide composite material and its application in supercapacitors.PC was prepared by directly calcining potassium citrate,MnO2 was grown on the surface of PC to prepare PC/MnO2 nanocomposite.In the three-electrode system,the specific capacitance of PC/MnO2 at 1.0 A·g-1 is 337.0 F·g-1,which is mainly due to the synergy between PC and MnO2.Due to the low production cost and excellent electrochemical performance of the prepared PC/MnO2 composite material,it has great potential for application in supercapacitors.(2)Preparation of an N,S-doped porous carbon nanomaterial and its application in supercapacitors.Using potassium citrate as a carbon source,through one-step carbonization and activation,prepared porous carbon(PC)with high specific surface area and interconnected micro-mesopore-macropore,Subsequent N and S doping with thiourea to prepare of nitrogen and sulfur co-doped porous carbon(N,S-PC).The method is simple and easy to implement,and the cost is low.In the experiment,we explored the mass ratio of thiourea and PC and the optimal calcination temperature.It is found through research that when PC:thiourea=1:12 and the calcination temperature is 800℃,the prepared N,S-PC 1:12 nanomaterials has good electrochemical performance.The capacitance value of the N,S-PC 1:12 nanomaterials at 1.0 A·g-1 can reach 674.0 F·g-1.(3)Preparation of polycyclodextrin-polyaniline/carbon nanotube composite and its application in supercapacitors.We have developed a simple and cost-effective polymerization method that uses polycyclodextrin(CDP)to assist the polymerization reaction.In order to obtain carbon nanotubes(CNTs)decorated with a controlled polyaniline(Pani)layer,is CDP-Pani/CNT.The composite material is a shell-core structure and has good electrical conductivity.In a three-electrode system,a high specific capacitance of 720.0 F·g-1 at 1.0 A·g-1 A new electrode material is provided for supercapacitor electrode material.