石墨烯超级电容器宏观体电极的可控组装及性能调控

Macroscopic graphene architectures with different dimension, such as 1D fibers, 2D films and 3D architectures will be fabricated by controlling the interaction between graphene oxide sheets and the assembly of graphene oxidesheets at nano-, micro- and macro-scale in a time-dependent process. In this process, the orientation of graphene is controlled to programme the features of graphene-based architectures at different scale level. Furthermore, the dependence of the physical and electrochemical properties of macroscopic graphene architectures on their microstructure will be investigated to realize the transfer of the excellent physical and electrochemical properties of graphene sheets to the as-prepared macroscopic graphene architectures. As a result, these graphene architectures possess tunable porous structures to meet different requirements as advanced supercapacitor electrodes, such as good mechanical properties, high electrical conductivity and controlled porous structures. In addition, the porous graphene architectures will act as scaffold to support pseudo-capacitive materials, such as conductive polymer and metal oxides, on their inner surface to further enhance the overall capacitance of graphene-based hybrid architectures. Based on these macroscopic graphene-based architectures, we will fabricate advanced supercapacitors that will be flexible, wearable or stretchable. By studying the dependence of supercapacitor performance on the microstructure of macroscopic graphene-based architectures and the configurations of supercapacitor devices, advanced supercapacitors will be developed through optimizing the microstructure of graphene-based architectures and configurations of supercapacitors to meet the requirement of current portable, flexible, wearable or stretchable electronics. During charge/discharge process, the structure, physical and electrochemical properties of graphene-based architectures will be characterized in real time by combining different measurement techniques. According to real time characterization, chemical thermodynamics and kinetics model of graphene-based architectures during charge/discharge process will be built.

通过有效控制单层石墨烯间不同相互作用力，实现其在各个尺度下的可控组装，制备具有多孔空间构型稳定但可调的石墨烯一维纤维、二维薄膜、三维块体材料，实现石墨烯单元自身优异性质从微观到宏观的有效转移，探索赝电容纳米材料可控掺杂石墨烯宏观体提高其性能的新方法，建立石墨烯宏观体组分、微结构与性能之间的关系，实现石墨烯宏观体性能的调节和优化。直接利用不同维数石墨烯宏观体作为电极，组装具有“柔性、可穿戴、可拉伸”等特点的新型超级电容器，深入了解石墨烯宏观体结构和器件构型设计对超级电容器在不同状态下性能的影响，从而优化石墨烯宏观体结构和超级电容器器件构型，推动新型超级电容器的升级和改造。实现不同物理和电化学测试方法实时检测石墨烯宏观体电极在充放电过程的结构与物性变化，建立不同条件下石墨烯宏观体电极在充放电过程中的化学热力学和化学动力学过程。

随着电子技术的发展，便携式电子器件在不断小型化、轻量化，为了匹配这些新型电子器件，获得自供电的柔性电子系统，开发高性能柔性储能器件势在必行。本项目以石墨烯为研究对象，利用不同方法有效控制单层氧化石墨烯间相互作用力，发展了金属还原自组装、水热自组装和冷冻干燥等制备石墨烯及其复合物薄膜的策略，获得了力学、电学和电化学性能兼备的石墨烯泡沫、石墨烯多孔薄膜、石墨烯与电解质和金属氧化物的复合物薄膜、石墨烯及其复合物的微结构薄膜等柔性石墨烯电极，并研究了其自组装机理，实现了石墨烯与赝电容材料的协同效应的调控和优化，揭示了柔性石墨烯电极的构效关系，基于制备的不同石墨烯宏观体柔性电极，设计组装了薄膜和微结构柔性超级电容器，实现了器件的全固态一体化设计，器件独特结构使其在弯曲180度时仍能保持电化学性能稳定。基于复合物薄膜的柔性超级电容器在未来可穿戴电子设备中会有较大的应用前景。