聚苯胺基碳源近表面化学成分对超容碳大微孔孔道结构的优化机理及其离子液体电吸附动力学和循环改善机制的研究

This application proposes that the controllable preparation of large micropores-rich carbon electrode material can be achieved by adjusting the subsurface chemical composition of the polyaniline (PANI)-based carbon source. Meanwhile, a new thought of revealing the high IL (ionic liquid) SC (supercapacitor) rate capability mechanism through the electro-adsorption dynamic approach and a new method of exploring the mechanism of the improved cycling performance through ex-situ/in-situ spectroscopy techniques are also put forward. In this project, a particular ammonia-activation process will be used. The chemical reaction thermodynamics during the ammonia -activation process are also studied. The mechanism of the subsurface composition of PANI-based carbon source influencing on the pores structure of the carbon electrode material is investigated. Hence, the ablation of the pores can be deeply understood. The electrochemical properties of the big microporous carbon electrode materials are characterized. The mechanism of pores structure on the high rate capability of this material is investigated by an in-situ electro-adsorption dynamic experiment. The ex-situ/in-situ electrochemical spectroscopy and X-ray computed tomography were used to characterize the evolution of pore structure and electrode strain of the carbon electrode during the charge and discharge of SC. The mechanism of improved SC cycling performance by using the large micropores-rich carbon electrode is also investigated. The results of the research can help to understand not only the formation and charge/discharge mechanisms for the particular pores structure of the carbon electrode material, but also the mechanism of improved cycling performance for this kind of IL SC.

本申请提出从调整聚苯胺基碳源近表面化学成分的角度来实现大微孔碳电极材料的可控制备，从电吸附动力学的角度揭示该材料在离子液体中高电容倍率性能机理的新思路，以及从异位/原位光谱学角度探究该材料充放电循环改善机制的新方法。计划采用氨气活化工艺，研究氨气活化化学反应热力学过程。考察聚苯胺基碳源的近表面化学成分对氨气活化后的碳材料的孔道结构的影响机理，深刻理解孔道烧蚀过程。表征聚苯胺基大微孔碳电极材料的电化学性能，通过原位电吸附动力学实验，揭示孔道结构对材料高倍率性能的影响机理。采用原位/异位电化学光谱技术和X射线体层成像技术，表征碳电极在充放电循环过程中孔道结构、极片应变等演变规律，揭示大微孔孔道结构对循环改善的机理。本项目的研究结果不仅有助于深入理解氨气活化下的大微孔碳材料的多级孔道结构的形成机制和该材料的充放电机制，还有助于从微观孔道到宏观极片的多角度理解离子液体电容器循环性能改善的机理。

在本工作中，采用聚苯胺为原料，探究了H2O(gas)的量和CO2分压对活化产物的影响。所制备的活性碳比表面积和孔体积分别达到2357 m2·g-1和1.45 cm3·g-1。在采用离子电解液(EMIMBF4)的条件下，其容量达到203 F·g-1，在10000次充放电循环(5 A·g-1) 后具有91％的容量保持率。.在本工作中，研究发现聚苯胺碳中大量亚微孔(0.7-2 nm)的存在会极大地改善超级电容器在-40 °C下的低温性能，我们提出了“逐步去溶剂化机理”。同时，亚微孔和中孔结构相结合的官能团化碳纳米海绵活性碳(FCNSs)比容量高达131 F·g-1，在-40 °C的低温条件下，容量保持率可达100%。.在此，我们通过使用功能化纳米海绵聚苯胺碳作为正极，金属锌作为负极揭示了质子转移效应在离子电解液和有机电解液中的微观机理。采用离子电解液制所制作成的软包器件的体积能量密度(2.4V)高达54.3 Wh·L-1。同时，采用有机电解液时器件的体积能量密度达18.8 Wh·L-1，且具有超高的功率密度，器件的功率密度高达17.7 kW·L-1。.研究发现，通过控制微孔结构可以提高含氢官能团(-OH和-NH官能团)聚苯胺碳材料的综合电化学性能。FACs样品的容量高达435 F·g-1且循环稳定性十分优异，在2 A·g -1的电流密度下充放电循环10000后，容量保持率高达89%。.用一种简便的中试级无溶剂方法，结合高速气流研磨、热辊压以及与铝箔热压复合工艺制备了干法电极。LFP-AC//LTO-AC SF全电池结合了电池和电容器的特性，更像是一个混合电容器。因为SF电极的厚电极、高压实密度设计，SF全电池呈现出单电极上的高面积比容量1.4 mAh cm-2（97.3 mAh g-1）以及95 Wh L-1的高体积能量密度。全电池在持续5000多个循环后呈现出92%的良好容量保持率。