Preparation And Capacitance Performance Of Carbon Materials With Controllable Pore Structure By Carbonizing Interpenetrating Polymer Networks

In this paper,the newest development progress in research of supercapacitors and electrode materials of supercapacitors was reviewed,especially focused on the supercapacitor carbon materials controllable preparation and surface modification of structural control technology development status.For electric double layer capacitor,the effect of porosity,pore size distribution of the carbon materials on super capacitor performance is a very important fundamental scientific question.Unfortunately,this problem is basically limited to the qualitative description,no experimental verification,which is attributed to the complexity of the system and the structure of the carbon material.Accordingly,the new idea of preparing structure-controllable carbon material is put forward,which is the high temperature carbonization of the interpenetrating polymer networks.At the same time,the electrochemical performance of electrode material is studied.Moreover,the relationship between the pore structure of interpenetrating polymer networks and electrochemical performance of the carbon material is explored.The work has been carried out following generally the mainline as controlled syntheses of polymer-structure controllable carbon materials-high performance carbon electrode material of supercapacitor.The pore structure of the carbon material is regulated by controlling the relative content of the different networks to adjust the interpenetrating polymer networks morphology.The main contents are presented as follows:(1)A simple carbonization procedure is proposed for the synthesis of hierarchical nanoporous carbons with controllable pore size and effective surface area as electrode materials for high-performance electrochemical double-layer capacitors.The procedure is based on the carbonization of interpenetrating polymer networks(IPNs)composed of cross-linked ploystyrene(PS)and poly(methyl methacrylate)(PMMA).The as-obtained hierarchical nanoporous carbons(HNC-IPNs)have controllable pore size,interconnected pore structure,high specific surface area,excellent electrical conductivity and electrochemical stability with the different mass ratio of PS/PMMA.In addition,there is authentically an excellent linear relationship between effective specific surface area(E-SSA)and specific capacitance.Especially,the HNC-IPN-4 exhibits the highest specific surface area(SSA)of 1346 m2 g-1,relative high E-SSA of 603 m2 g-1,and excellent specific capacitance of 260 F g-1under the current density of 0.5 A g-1 in 6 M KOH.Meanwhile,the HNC-IPN-4exhibits a superior cycling performance without any degradation after 10 000 cycleswith the current density of 2 A g-1 as well as exhibits high capacitance retention,i.e.,96.0% of the initial specific capacitance after 20 000 cycles.(2)A chemical process was developed to prepare the N-doped micro-nano carbon spheres with multi-scale pore structure via carbonization of N-PF/PMMA interpenetrating polymer networks containing the nitrogen source,i.e.,melamine resin,carbon source,i.e.,PF,and a pore-former,i.e.,polymethylmethacrylate(PMMA).The N-contenting of N-doped micro-nano carbon spheres are controlled by adjusting the mass ratio of melamine and phenolic before polymerization.The N-doped micro-nano carbon spheres as electrode materials possess appropriate pore size distribution,higher specific surface area(559 m2 g-1)and consistently dispersed Nitrogen atoms with adjustable doping content.These distinct characters endow the hopeful electrode materials with excellent properties for electrochemical capacitor.Especially,the N-CS-IPN-4 exhibits the highest specific capacitance of 364 F g-1 at0.5 A g-1 in 6 M KOH aqueous electrolyte for the three-electrode system.It also possesses superior rates capability(57.7% retention under the current density from0.5 to 50 A g-1)and excellent cycle performance at 2 A g-1(100% retention after 10000 cycles).All above results confirm that the N-doped micro-nano carbon spheres is a promising electrochemical capacitor material,which possesses preponderance of simple preparation procedure,multi-scale pore structure,higher specific surface area,easier adjustment of N-contenting and excellent electrochemical properties.