量子点-3D石墨烯复合材料结构调控对超级电容器储能效应影响研究

Graphene quantum dots and three-dimensional grapheme composites (GQDs–3DG ) was prepared by solvothermal , chemical deposition and electrochemical deposition methods, based on the previous work about the synthesis of graphene quantum dots(GQDs)and three-dimensional grapheme (3DG) .The morphological, atomic, electronic interfacial ultra microstructures of the samples in different stage were characterized by SEM, HRTEM, Raman and XPS etc. The electrical, optical, electrochemical properties of GQDs and 3DG were explored.The reaction process in nano space is explained by the information of microstructures and properties, and the structural regulation of GQDs–3DG was achieved. The parameters of specific capacitance, charge–discharge rate and cycle stability of supercapacitor fabricated by GQDs–3DG were tested, and the relation of microstructure and the performance of supercapacitor was discussed. The relation of mass, structure and energy storage performance were explored by regulating the structure of GQDs–3DG, in order to prove their application in energy storage..This study explained the fundamental scientific problem of graphene functionalization, Which will provide new idea for exploiting the excellent properties and expanding the application in energy storage .

如何克服石墨烯本身易聚集性，最大程度地发挥其在超级电容器电极材料储能问题是亟需解决问题。基于石墨烯量子点(GQDs)和3D石墨烯结构特性，本研究拟采用溶液法、化学沉积法和电化学沉积法合成石墨烯量子点（GQDs）、3D石墨烯（3DG）及石墨烯量子点-3D石墨烯复合材料（GQDs-3DQ）；通过SEM、HRTEM、RAMAN和XPS等测试技术，表征不同阶段产物的形貌、原子、电子、界面等超微观结构；考察量子点、3D石墨烯和GQDs-3DQ的电学、光学、电化学等性能；结合微观结构与性能信息，阐述纳米空间内的反应过程，实现GQDs-3DQ复合材料结构调控；测试GQDs-3DQ复合材料组装器件比电容、储放速率、循环稳定性等特征参数，探索产物微观结构产生的协同效应与高效超级电容器电容特性变化的内在规律。.通过以上对GQDs-3DQ复合材料结构调控，探索其微观结构与储能性能之间的内在关系，寻求其作为优质储

三维石墨烯通常是指具有三维结构的二维石墨烯组装体，不仅具有石墨烯固有的物理化学性质，同时兼备石墨烯组装体独特的柔韧性、多孔性、高活性比表面积、优异传质性能等等，从而使其具有较高的比表面积以保证电子能够更好地产生双电层。石墨烯量子点由于明显的限制边缘效应，使其具有石墨烯和量子点的独特性质。基于上述背景，本项目提出引入过渡金属硫化物、氮化硼、聚乙烯亚胺、氧化钨等化合物合成复合材料，实现了石墨烯量子点、石墨烯基复合材料的成功制备与电化学性能研究。.本项目主要研究内容包括:石墨烯/碳基复合材料的制备及其在电容器、电池中电化学行为调控；非石墨烯/碳基超级电容器复合材料制备及其电容行为调控研究；量子点的制备及其性能表征研究。通过水热法、溶剂热法、化学气相沉积法、高温烧结等方法合成石墨烯、石墨烯量子点及其复合材料，通过XRD、SEM、TEM、Raman、AFM和XPS 等测试技术，表征不同阶段产物的晶型结构、形貌等微观结构，考察微观形貌与光学、生物相容性及电化学储能构效关系，并将复合材料组装成非对称性电容器，测试其循环性能及其容量保持率等。结果表明石墨烯基复合材料在保持石墨烯优良的电子传输能力的同时，兼具了添加材料的本征特性，二者发挥协同作用，为开发兼具高能能量密度和高功率密度的石墨烯基材料在能源领域的应用提供了广阔的思路。