具有高效协同储能功能的多孔石墨烯复合材料设计制备

The significant problem for enhancing the energy density of the energy storage system such as supercapacitor without sacrificing the powder density and cycling stability is always longing for solving. In this project, adjusting and controlling the surface areas, pore diameters and pore size distributions of the three-dimensional (3D) porous graphene bases will be carried out, and their surface electron transmission functional modification as well as grafting/compositing guests with large electro-capacitance in theory under multiple dimensions/multi-components will be done too. The reversible high-speed redox chemical reaction systems will be built up to increase the powder density of the energy storage system. Further increasing the active centers on the surfaces or at the interfaces will result in the high performance of high energy density and large powder density synergetic exports. The key scientific problem of this project is focus on constructing the high-effective transport paths of electrons and ions in the composite structures. The bonding forms of the carbons in the structure of 3D porous graphene will be adjusted. The functional groups with excellent electron transmission characters will be chosen to modify the surface of 3D porous graphene. The crystallized guests with large electro-capacitance in theory will be composited under multiple dimensions/multi-components in the nanoscales. With the project putting into effects, several kinds of 3D porous graphene based composites possessing of the characters of high energy density and large powder density synergetic exports will be constructed. Additionally, the rule of the relations between structures and properties will be obtained over the 3D porous graphene based energy storage composite materials.

在不损耗大功率密度和高循环稳定性的条件下，增加超级电容器等储能体系的能量密度是其高效应用一直渴望解决的重大问题。本项目从3D多孔石墨烯基体的比表面积、孔道尺寸及孔径分布调控与裁剪，到多孔石墨烯表面电子导通官能团功能化修饰和纳米尺度下的大容量客体多维度/多组分嫁接/复合，在其表面/界面建立可逆的高速氧化还原反应体系，提高其功率密度，再到增加石墨烯基材料的表面/界面有效活性位点的复合可控制备，实现高能量大功率协同输出。项目的关键科学问题聚焦于高效电子/离子传输通道的建立。围绕这一关键科学问题重点开展调控3D多孔石墨烯碳原子键合形态，选择具有优异电子传递特性的官能团进行基体表面修饰，在纳米尺度下多维度/多组分地复合具有结晶结构的客体，对复合结构纳米孔分布进行合理调控。通过本项目的实施，将构筑若干种具有高能量大功率协同输出特性的3D多孔石墨烯复合储能材料，获得3D多孔石墨烯复合储能材料的构效规律。

通过水热法制备了新型的氮掺杂多孔石墨烯气凝胶，利用微波法制备了具有几微米大小的大尺寸石墨烯片。应用生物质碳源和金属有机框架结构配合物碳源，制备了多种碳基储能材料。这些石墨烯和类石墨烯碳基材料应用于超级电容器中作为电极材料展示出了高的电化学容量等优异的储能性能。采用一锅法对氧化石墨烯进行原位还原同时复合硫，获得了系列还原氧化石墨烯与硫的多孔复合材料。采用生物质香蕉皮为碳源，利用高温碳化和氢氧化钾活化技术，制备了多孔碳材料。通过冷冻干燥技术固定多孔PVA/GO溶液的结构，制备了MP-C/rGO/S复合材料。通过一锅法合成了石墨烯/聚吡咯/硫rGO/PPy/S三元复合材料。应用超声分散和冷冻干燥技术获得了氧化石墨烯和壳聚糖均匀分散的前驱体，进一步通过高温热解法制备了氮和氧双掺杂的多级孔结构碳基复合材料。采用微波辅助加热法制备了结晶性良好、尺寸分布在几十纳米的Fe7S8颗粒，与石墨烯进一步复合获得了石墨烯/Fe7S8复合材料。上述石墨烯复合材料在锂硫电池体系中表现出优异的电化学储能功能。制备了多种具有高效储能和能量转换功能的石墨烯基锂离子电池负极材料和氧还原/氧释放催化材料。对于上述储能和能量转换新材料的组成、结构与性能关系进行了系统深入理论分析，得到的相关机理对未来新的高性能石墨烯和类石墨烯碳基储能和能量转换催化材料的获取与应用具有重要的指导意义。4年参加国际国内学术会议16次，其中邀请报告14次，分组报告2次；发表SCI收录学术论文21篇，其中影响因子在6以上的有11篇；申请中国发明专利3项，其中2项授权；培养硕士6名，其中4名毕业并获得硕士学位；培养博士9名，其中5名毕业并获得博士学位。各项指标均已达到，项目目标圆满完成。