煤沥青基三维多孔类石墨烯纳米片的创制及超电容性能研究

Coal tar pitch, as a by-product from coal processing, is a mixture of many polycyclic aromatic hydrocarbon molecules. It is a challengeable and important issue to realize the green and high added-value utilization of coal tar pitch. This project aims to develop a new procedure to make high-performance three-dimensional porous graphene-like nanosheets with tuned hierarchical pore structure from abundant cheap coal tar pitch by making use of metal hydroxides as a directing and space-confinement template coupled with in-situ chemical activation technique to reveal its potential applications in supercapacitors. This novel synthesis process is simple, and will lead to porous graphene-like nanosheets with tuned hierarchical pore structure and surface properties. The effects of the physical and chemical properties of raw materials, the mass ratio of raw materials, and the template types on the pore structure and the surface properties of the as-made porous graphene-like nanosheets will be addressed in detail. The formation mechanism of the porous graphene-like nanosheets from coal tar pitch involved in the process will be studied in terms of the synergistic effect of metal hydroxide template and the in-situ chemical activation, which will be helpful for establishing a new process for the controllable preparation of porous graphene-like nanosheets with developed hierarchical pore structure and tuned surface properties. The potential of three-dimensional porous graphene-like nanosheets in supercapacitors will be explored in ionic liquid electrolytes with higher decomposition voltage, and the energy storage mechanism involved will be studied. The storage and transport scheme of the charged ions in the hierarchical pores of three-dimensional porous graphene-like nanosheets, and the effects of the pore structure parameters and the surface properties of three-dimensional porous graphene-like nanosheets on the specific capacitance, rate performance and energy density of superapacitor will be investigated in much detail in order to figure out the relationship between the structure-composition-performance parameters of porous graphene-like nanosheets. This work will shed a new light on the energy storage mechanism of three-dimensional porous graphene-like nanosheets for supercapacitors. This project will give a new impetus on the development of coal chemical industry and new energy storage materials, and will lay a solid foundation for the high added-value and green utilization of coal tar pitch and the preparation of high-performance supercapacitor electrode materials.

煤沥青是煤炭加工过程的副产品之一，是多环芳香性分子的混合物，如何实现其绿色化高附加值利用是一个需要关注的富有挑战性的重要课题。本项目提出以煤沥青为碳源，以金属氢氧化物为导向和限域模板，辅以原位化学活化，研究具有分级孔的三维类石墨烯纳米片的合成新方法，揭示所得功能材料作为超级电容器电极材料的潜力和特点。研究原料组成/配比、模板种类等对产物的孔结构和表面性质的影响规律，阐明金属氢氧化物模板协同原位化学活化煤沥青制备多孔类石墨烯纳米片的机制。在分解电压较高的离子液体电解液中，揭示荷电离子在电极材料的层次孔中储存和输运规律及其结构和性质对超级电容器的容量、倍率性能和能量密度的影响规律。诠释所得新型功能材料的结构-组成-性能之间的规律性关系，并建立相应的调控策略。项目的实施将有助于丰富煤化工和储能材料学科的内涵，为煤沥青的高附加值绿色化利用和高性能超级电容器用电极材料的创制奠定坚实的科学基础。

基于“煤化工精细化”的理念，围绕以煤沥青等为原料制备新结构高性能的功能碳材料这一目标开展了系统的研究。开发了以煤沥青或煤焦油为原料选控制备功能性微纳米多孔碳材料的新技术方法，研究了调控微纳米碳材料的结构和形貌、化学组成及物化性质的新方法，揭示了原料分子结构及制备工艺参数对目标功能碳材料的组成、结构及储电性能的影响规律。.（1）针对纳米金属氧化物模板价格高，不易制备这一问题，以廉价易得的氢氧化镁、氢氧化钙等为模板，以煤沥青为碳源，基于模板导向、限域碳化和氢氧化钾原位活化策略，构筑了一系列新结构三维多孔类石墨烯、多孔碳纳米片和碳/碳复合材料；多孔碳上三维相互连接的结构为电子传输提供了通路，薄的碳片上短的孔道为离子快速传输提供了通道，因此，所得材料作为超级电容器电极材料展现出优异的载流子传输性能。.（2）研究了碳源组成、碳化条件、模板种类、碱碳比等制备工艺参数对所得碳材料介/微观结构和储电性能的影响，阐明了煤基多孔碳材料的制备工艺-微观结构-储电性能三者间的内在关系；结合计算模拟，阐述了多孔碳纳米片的形成机理和储电机制。.（3）针对金属氢氧化物硬模板需要酸洗去除，对环境有污染这一工艺弊端，创新性地以离子液体或三聚氰胺等为软模板，以煤焦油为碳源，制备了孔结构参数可控、相互连接的多孔碳纳米片材料，所得材料作为超电电极材料，展现出优异的倍率性能和循环稳定性。.（4）为化工副产物，如煤沥青、煤焦油、洗油、蒽油、芴等煤基衍生物的高附加值利用提供了一种可行的方法。.项目执行期间，作为主要完成人获辽宁省自然科学一等奖1项；以通讯作者发表SCI收录论文12篇，EI论文1篇，其中国产论文5篇，ESI 1% 高被引论文2篇。申请专利3件，获授权专利4件；主办国际学术研讨会2次，参加国内学术会议7次。培养博士生1名并获国家博士研究生奖学金，培养硕士研究生6人，其中3人读博，1人学位论文获中国冶金教育学会2020年优秀硕士学位论文奖。