A High-performance Carbon Prepared By Pyrolysis Of Block Copolymer And Supercapacitance Properties

In this paper, the newest development progress in research of Ultra Capacitors and electrode materials of Electrochemical Capacitors 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 Porous Carbon is put forward, which is the high temperature carbonization of the block copolymer. At the same time, the electrochemical performance of electrode material is studied. Moreover, the relationship between the structure of block copolymer, pore structure 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 flexibility of the block polymers segment, changing the molecular weight of the segment and the relative content of the different segments of the block copolymer morphology. The main contents are presented as follows:(1) In this study, well-ordered mesoporous carbon materials with high surface area were prepared through direct pyrolysis of block copolymer (PMMA-b-PAN-b-PMMA), which was synthesized by reversible addition-fragmentation chain transfer. During carbonization, the block copolymer with a broad multimodal pore size distribution formed during pyrolysis of PMMA segment and PAN segment is reorganized firstly into nonporous semi-carbonized. The as-harvested highly microporous carbon exhibits an high micropore rate of67%, in addition to two pore size distribution (3.8nm and14nm) and a high BET surface area (1246m2g-1). Moreover, as-harvested carbon is found to be a good candidate for supercapacitor electrodes; Meanwhile the as-harvested carbons have a remarkable long cycle life (98%of initial capacitance after10000cycles) in2M KOH aqueous electrolyte. It is remarkable that direct pyrolysis of the block copolymeric precursor produced a high quality mesoporous carbon with high surface area and narrow pore size distribution. The novel structure of mesoporous carbon materials with facile processability has great potential to open a new field for the generation of mesostructured nonoxide materials for a broad class of applications.(2) Novel nanoporous carbon materials was prepared through a simple carbonization procedure of well-defined block-copolymer precursors PAN-b-PS-b-PAN. The key point of this synthesis relies on meticulous design of block-copolymer by reversible addition-fragmentation chain transfer (RAFT) with well-controlled molecular weight and narrow polydispersity. The obtained mesoporous carbon materials showed a high specific surface area (950m2g-1) and well-controlled pore size of2-4nm. Furthermore, it exhibited a high specific capacitance (185F g-1at0.625A g-1) and a remarkable long cycle life (97.5%of initial capacitance after2000cycles) in2M KOH aqueous electrolyte. Our results proved a promising synthetic method for designing new carbon based materials from different polymers for high-performance energy applications.