刻孔三维石墨烯/一维石墨烯纳米卷电极材料设计及在锂离子电容器中的应用

Lithium-ion capacitors (LIC), a new type of electrochemical storage device, have become a research hotspot in recent years. LIC can deliver high energy in much short time than lithium-ion battery (LIB) and store more energy than electric double layer capacitor (EDLC). The most important challenge LIC are facing today is to design electrode materials for the two electrodes. In this project, we will design some novel graphene-based materials for LIC as the supercapacitor electrode materials and the battery electrode materials. For the oxidate/supercapacitor electrode material system of LIC, etching graphene nanoscroll wrapping active material (such as ZnO and Fe2O3) is designed to improve the power density of the LIC, and used as the battery electrode material to improve the conductivity of oxidate and the Li+ transportant in the materials. In addition, because of the large surface area, the etching 3D graphene is chosen as the supercapacitor electrode material. We do in-depth research on the mechanism and influencing factors of materials tuning, obtain the rules of the materials structure with the performance of the LIC. Through completing this project, we will make a breakthrough in the design and assembly of novel ultrahigh-energy LIC and give the scientific basis for their applications in the field of electric vehicles and smart electrical grid, etc.

锂离子电容器可同时克服超级电容器能量密度低和电池功率密度低的缺点，如何合理地设计正、负极材料以分别满足电荷吸脱附和离子扩散的要求是当前混合超级电容器迫切需要解决的问题。本项目针对锂离子电容器中的金属氧化物/电容材料体系中两极材料，重点针对氧化物一极，设计刻孔一维石墨烯纳米卷包裹电池活性物质（如ZnO、Fe2O3等）的结构作为不对称电容器的电池极材料，解决氧化物的导电性、锂离子的扩散动力学以及循环稳定性等问题。电容极设计刻孔的三维石墨烯材料与其匹配。深入研究刻孔一维石墨烯纳米卷包裹结构以及刻孔三维石墨烯的优化设计方法以及刻孔机理，探明刻孔的一维包裹材料结构以及三维结构与电化学性能之间的构效关系，探讨石墨烯基锂离子电容器的优化组装原理。预计完成本项目可为混合超级电容器在电动车和智能电网等应用进一步奠定科学基础。

本项目提出针对锂离子电容器中的两极材料，分别设计一维刻孔石墨烯纳米卷包裹电池活性物质的结构及三维石墨烯作为不对称电容器的电极材料，解决锂离子的扩散动力学以及循环稳定性等问题。本项目主要在刻孔石墨烯材料的控制制备、石墨烯纳米卷及石墨烯纳米卷复合电极材料的控制制备、三维石墨烯复合电极材料的制备及其在超级电容器和锂离子电池性能研究等方面开展了一系列的工作，发现通过结构设计，刻孔石墨烯、石墨烯纳米卷复合结构及三维石墨烯结构都能够在一定程度上提高其锂离子电池或超级电容器的性能。同时，项目中还延伸至其他碳基电极材料并测试其电化学性能。课题成果丰富了石墨烯基衍生材料的制备方法及制备技术，对石墨烯及石墨烯基材料在储能领域的应用具有一定的引领作用。