Ordered Mesoporous Carbons Synthesis Using Different Mesoporous Molecular Sieve And Their Supercapacitance Performance

As a new and environmentally friendly energy storage device,supercapacitor has been widely concerned because of its higher specific energy,specific power and cycle stability than ordinary capacitors.The internal structure and properties of electrode materials are the main factors affecting their performance.Carbon materials have important research and application significance in electric double layer supercapacitors due to their high specific surface area,excellent conductivity and satisfied pore structure.In this thesis,hydrothermal synthesis method was used to synthesize mesoporous silica molecular sieves（SBA-15）with different pore size distributions by regulating hydrothermal temperature,reaction method and time.Ordered mesoporous carbon（OMC）materials with different pore size distributions were synthesized by chemical vapor deposition（CVD）.It was found that the pore size increased with the increasing of hydrothermal synthesis temperature（OMC-n,n is refered to hydrothermal temperature）.The overall pore size distribution was widely arranged,mainly concentrated between 6 nm-13 nm.The experimental reaction mode and time were regulated.The aging method was divided into standing and stirring,and the pore size distribution was between 7 nm and 13 nm.The reaction method changed the sample morphology,and the reaction time changed the pore size distribution.OMC was synthesized by using SBA-15 with different pore sizes as the original template.Reverse replication of ordered mesoporous carbon with different pore size ranges.The material was activated by enhancing the active sites of carbon deposition,and used as the original template,acetylene as the carbon source,CVD carbon deposition,and OMC was obtained after removing the template.The pore size of the samples with hydrothermal temperature of 80,120 and 160°C remained dispersed,and the pore size distribution was between 2.5 nm and 7 nm.The pore size distribution of the samples with static aging time of 6 and 24 hours was relatively concentrated,and the distribution range was 3 nm-5.5 nm.Next,OMCs with different pore sizes were used as electrode materials to explore the performance of supercapacitors in aqueous electrolyte（6M KOH）and organic electrolyte（TEATFB）.The results showed that the OMC-120 with a pore size of 3-4 nm exhibits better electric double layer capacitance in water system.When the charge-discharge current density was 0.10 A g^-1and 0.50 A g^-1,the specific capacitance was 44.50 F g^-1and 54.30 F g^-1.The capacitance retention rate was 99%after 1000 cycles,which is attributed to the appropriate pore size distribution in OMC-120,which effectively improves the utilization of pores.The ordered pore structure accelerates the transfer and exchange of electrolyte ions,shortens the transmission path of ions,and improves the charge-discharge performance and stability of supercapacitor electrodes at high current density.In organic electrolyte,OMC as electrode material did not show good electrochemical performance.This may be because the pore structure of ordered mesoporous carbon did not match well with the size of the existed organic electrolyte,so it did not show good capacitance performance.