Preparation Of Ultramicroporous Carbon By Carbonizating Interpenetrating Polymer Networks And Its Electrochemical Performanc

Carbon-based supercapacitors are electrochemical devices that store electrical energy by adsorbing ions from the electrolyte on the surface of a porous electrode.For a long time,the specific surface area and pore size distribution of carbon materials have been considered as the main factors affecting the performance of carbon-based supercapacitors.The existence of micropores and even ultramicropores can greatly optimize the pore structure characteristics of the material and increase the capacitance per unit specific surface area.Therefore,it is necessary to conduct systematic research on microporous and even ultramicroporous carbon to enrich the existing research results.However,to date,the preparation strategies of ultra-microporous nano-carbon materials are still extremely finite,and research on the electrochemical behavior of ultra-micro-porous carbon and its relationship with the pore structure has therefore been limited.Based on this,we propose the use of interpenetrating polymer network carbonization to prepare ultra-microporous carbon with controlled pore size.This article focuses on the synthesis of ultra-microporous carbon materials,and proposes the use of interpenetrating polymer network carbonization to prepare ultra-microporous carbon materials with controlled pore size.The specific surface area,pore size distribution,and element distribution are measured.The relationship between the pore structure characteristics and electrochemical performance?specific capacity,rate performance,cyclic stability,electrochemical resistance,etc.?ultra-microporous carbon was studied,and further proved the advantages of interpenetrating polymer carbonization method in the preparation of ultra-microporous carbon and pore size control.In addition,by adjusting the relative content of the polymer networks,the porosity of the ultra-microporous carbon was adjusted,and the effects of changes in porosity on other parameters of the pore structure and the changes in the electrochemical properties were analyzed.The experimental results are systematically analyzed from the aspects of polymer structure design,process parameters,pore structure characteristics,and electrochemical performance,clarify their correlation,and give a scientific and reasonable explanation.The main research contents and research results are as follows:1.using melamine,aqueous formaldehyde,sodium polyacrylate and sodium hydroxide as raw materials,the melamine formaldehyde resin/sodium polyacrylate interpenetrating polymer networks?MF/PAAS IPNs?was synthesized by two-step water bath heating,using this as a precursor,prepared a porous carbon material with a pore size of about 0.6 nm.By comparing its differences in pore structure parameters and electrochemical performance with MF/PAAS blends and MF derived porous carbon,the advantages of ultra-microporous carbons'structure and performance are highlighted.The obtained ultra-microporous carbon channels are interconnected with each other.Such a nanostructure is beneficial to provide more electroactive sites for electrolyte ions,and can effectively shorten the transmission distance of the electrolyte ions,effectively improving the overall electrochemical reaction kinetics of the material.It exhibits excellent electrochemical performance:the specific capacity is 268 F g^-1 at a current density of 0.5 A g^-1,and when the current density is increased from 0.5 A g^-1 to 10 A g^-1,the rate was 79.5%,and after 10,000 cycles at a current density of 6 A g^-1,the capacity was 96%of the original specific capacity.In addition,from the perspective of kinetic analysis,the surface capacitance effect is dominant,reaching 85.4%.As a symmetrical device,its maximum power density and energy density in 1 mol L^-1 Na₂SO₄ are 18 kW kg^-1 and 17.13 Wh kg^-1,respectively,showing excellent electrochemical performance.2.In order to verify the conclusions obtained and adjust the porosity of the ultra-microporous carbon materials,try to use purified aniline,formaldehyde solution,sodium polyacrylate and sodium hydroxide as raw materials,through two steps of dehydration condensation reaction,the aniline prepolymers were introduced into the sodium polyacrylate network,and further reacted to synthesize aniline formaldehyde resin/sodium polyacrylate interpenetrating polymer networks?AF/PAAS IPNs?.After high temperature carbonization,ultra-microporous carbon with controlled pore size was obtained.First,the differences between the pore structure and electrochemical behavior of AF/PAAS IPNs,AF/PAAS blends,and AF resin derived porous carbon were explored through a comparison method,revealing the intrinsic relationship between its excellent properties and pore structure.Second,by adjusting the relative content of AF,the porosity of ultra-microporous carbon was adjusted in a series.Based on the control results,the effects of specific surface area and porosity on its electrochemical performance were explored.It was found through experiments that as the content of AF gradually increased,the porosity increased first and then decreased,and the corresponding electrochemical performance also showed the same change.More importantly,when the current density is 0.5 A g^-1,the specific capacitance of the optimal sample MC-IPN3 is the highest,which is 240.5 F g^-1.Under a current load of 6 A g^-1,a 100%capacity retention rate after 10,000 cycles indicates long-term chemical stability.At the same time,the assembled symmetrical capacitor has a high energy density of 11.95 Wh kg^-1 at 900 W kg^-1 in a neutral electrolyte.Therefore,this work enriches the strategy of synthesizing microporous carbon with controlled pore size,and has played a huge application potential as an electrode material in supercapacitors.