| As a new type of energy storage device,supercapacitor has been widely studied due to its high power density,long cycle life and high rate of charge and discharge.Mesoporous carbon has become a research hotspot for electrode materials of supercapacitors due to its advantages of large specific surface area,moderate and continuously adjustable pore size.At present,the method for preparing ordered mesoporous carbons is mainly divided into hard template method and soft template method.Among them,the hard template method requires strong corrosive reagents,while there are some problems such as the cumbersome process steps and the long preparation cycle in the soft template method.These problems have limited their application to some extent.In this dissertation,ordered mesoporous carbon(OMC)was prepared by a simple and fast one-pot aqueous route.This method avoids corrosive reagents and a large amount of organic solvents,so it has the advantages of environmental protection,safety,and non-toxicity.In addition,the one-pot aqueous route does not require the preparation of precursors and thermal curing processes and it takes less than 24 hours for its polymerization reaction.Compared with the traditional solvent evaporation induced self-assembly(EISA)method,the entire experimental period is shortened by about one week.However,mesoporous carbon directly used as electrode material still has problems such as low energy density and large internal resistance,which severely limits its application in the energy storage field.Previous studies have shown that the introduction of heteroatoms(N,S,P?B)and graphene can effectively improve the electrochemical performance of mesoporous carbon materials.Therefore,based on the preparation of OMC,the effect of nitrogen doping and graphene composite on the structure and properties of mesoporous carbon materials was studied by introducing different amounts of nitrogen and graphene.This article is dedicated to improving the electrochemical performance of mesoporous carbon materials.The main research contents and conclusions are as follows:(1)This article adopts a simple one-pot aqueous route with resorcinol as a carbon source,F127 as a structure-directing agent,1,3,5-trimethylbenzene as an additive,hexamethylenetetramine as pH buffer and formaldehyde release agent and ammonia as a catalyst to prepare ordered mesoporous carbon materials(OMC).It has a highly ordered two-dimensional hexagonal structure and a specific surface area of 460.42 m2 g-1.The material has the best electrochermical performance at a carbonization temperature of 800 ?.Specifically,the specific capacitance of OMC is 128.9 F g-1 at a current density of 1 A g-1,which is slightly higher than the EISA method(100.0 F g-1)and hydrothermal method(80-124 F g-1)with the same soft template agent.(2)The nitrogen-containing ordered mesoporous carbon materials(NMC-x)with different nitrogen contents were prepared by partially replacing resorcinol with m-aminophenol.The NMC-100 still has a two-dimensional hexagonal structure,and its specific surface area can reach 790.89 m2 g-1.The results of analysis by various test methods show that nitrogen doping is beneficial to improve the wettability and conductivity of the material(the electrical conductivity of OMC is 1.106±0.054 S m-1,and the electrical conductivity of NMC-100 is 4.33 8 ±0.25 S m-1),thereby improving the electrochemical properties.And with the increase of nitrogen content(?4.59 at%),the specific capacitance of the material shows an increasing trend.The specific capacitance of the NMC-100 is up to 223.2 F g-1 at a current density of 1 A g-1.(3)Sulfonated graphene/nitrogen-containing ordered mesoporous carbon composites with different contents of sulfonated graphene(SG/NMC-y)were prepared by compounding different amounts of sulfonated graphene(SG)and NMC-100.The results show that the addition of SG can increase the specific surface area and electrical conductivity of the material.The specific surface area of SG/NMC-0.12 can reach 1039.65 m2 g-1,and its electrical conductivity can reach 7.9881-0.885 S m-1.These are all higher than graphene-free components.Electrochemical test analysis shows that with the increase of the content of SG,the specific capacitance of the material initially increases gradually,but it begins to decrease after reaching a certain amount.At a current density of 1 A g-1,the specific capacitance of the optimal component SG/NMC-0.12 can reach 304.2 F g-1.These results show that the mesoporous carbon material synthesized by a one-pot aqueous route has good energy storage performance.This method is very suitable for industrial production of supercapacitor electrode materials.In the future work,we can explore more different mesoporous carbon materials by choosing other highly water-soluble carbon or nitrogen sources,combining different soft templating agents,catalysts,and sulfonated graphenes to obtain other superior supercapacitor electrode materials with superior performance. |
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