石墨烯三维多孔杂化结构的原位合成及其储能特性

Carbon nano materials have good application prospect in the field of energy materials due to their excellent physical, chemical and mechanical properties. But the aggregation of single carbon nano materials, which results in low effective specific surface area, poor structural stability and wettability for electrode applications, restricts the display of their excellent performance. In this research, we focus on the synthesis of carbon nano-onions (CNOs) embedded three-dimensional (3-D) graphene porous hybrid structure and its electrochemical properties. Combined chemical method with powder metallurgy cold pressing-sintering, CNOs/Cu block precursor will be obtained. The graphene will be synthesized in-situ on Cu surface by the reaction of graft molecular chain on CNOs as carbon source and the Cu framework as template and catalyst during sintering process. Thus, the CNOs embedded graphene 3-D porous composite will be obtained. The effect factors and mechanism of grafting of CNOs, growing and in-situ doping of graphene, will be studied systematically in order to understanding the formation rule and controllable methods of the graphene. The influence of CNOs content, pore structures, pore sizes and distribution on the strength and the electrochemical properties of 3-D porous composite will also be explored. In addition, combined with theoretical calculation, the critical issues on electrochemical properties will be analyzed, and the electrochemical energy storage mechanism model will be built and discussed. As a result, it is hopeful to acquire a kind of carbon nano composites for supercapacitor electrode with high electrical conductivity, high strength and high efficiency. Moreover, the results will be able to provide theoretical guidance and technological approach for the development and application of high-performance electrochemical energy storage devices.

碳纳米材料具有优异的物理、化学和力学性能，在能源材料领域极具应用前景。但单一结构碳纳米材料易团聚而导致的有效比表面低、作为电极材料的结构稳定性和浸润性差等问题限制了其性能的发挥。本课题以新型石墨烯内嵌碳纳米洋葱（CNOs）三维多孔杂化结构的制备及其电化学特性为研究目标，将化学法和粉末冶金法相结合，在冷压CNOs/铜形成的预制体内，以CNOs表面接枝的分子链段为碳源，以铜粉骨架为模板和催化剂，经烧结实现石墨烯的原位生长，获得CNOs/石墨烯多孔复合结构。研究CNOs接枝、石墨烯生长和原位掺杂的影响因素和机理，探明石墨烯可控生长规律和调控途径；研究CNOs含量、孔结构对复合材料强度和电化学性能的影响；结合理论计算，探讨影响其电化学性能的关键因素，建立储能模型并阐明机理。该研究结果可望获得高导电、高强度、高效能的超电容电极用碳纳米复合材料，为高性能电化学储能器件的开发应用提供理论指导和技术途径。

三维石墨烯具有优良的物理、化学和力学性能，在能源材料领域极具应用前景。如何实现三维石墨烯材料的可控生长，一直是相关领域的关键问题。此外，将三维石墨烯与其它纳米材料相结合，以构筑杂化与复合结构，可克服单一种类材料由本身结构限制而带来性能不足，对促进本领域的发展具有重要意义。本项目将模板法与化学气相沉积、粉末冶金、3D打印等技术相结合，利用金属粉末、纳米多孔金属、可溶盐等作为模板，以葡萄糖、蔗糖、乙炔等作为碳源，实现了三维多孔石墨烯材料可控制备。系统地探究了前驱体种类、模板成分与尺寸、生长温度等因素对三维多孔石墨烯生长形成的影响。在此基础上，通过对模板种类和前驱体的调控，实现了碳纳米杂化结构的可控合成，设计并合成了碳纳米洋葱/三维石墨烯杂化结构、碳纳米管/三维石墨烯杂化结构、氮氧掺杂三维多孔碳网络、三维石墨烯基复合材料等新材料。以所制备三维石墨烯基材料作为电极，研究了其在超级电容器和二次电池等储能器件中的电化学性能，并对其储能机理进行了探讨。该研究实现了三维多孔石墨烯基材料的可控制备，为先进碳纳米材料的发展开辟一条新的有效途径。.项目发表SCI收录标注有项目资助的论文23篇，申请发明专利7项，培养博士研究生5人，硕士研究生5人，达到预期目标，完成项目规定的研究任务。