含Fe金属有机骨架材料(FeMOF)-石墨烯柔性电极的制备,储能机制及组装高性能超级电容器件

Iron-based metal-organic framework (FeMOF) is taken as a promising supercapacitor electrode material due to its structural diversity and high pseudocapacitance. However, the key challenge of FeMOF materials for supercapacitors is their unsatisfied electrochemical and cycling performances as a result of their poor electrical conductivity and structural stability during the charge/discharge process. Furthermore, the energy-storage mechanism and structural effect on energy-storage capacity are still not clear for FeMOF. In this project, a variety of FeMOF materials is synthesized and the structural manipulation is studied. Flexible FeMOF-graphene composite films are subsequently fabricated with the goals of increasing electrical conductivity and enhancing supercapacitive performance. The electrochemical properties of FeMOF and FeMOF-graphene films are studied to clarify the relationship between structure and supercapacitive performance; the reversible Fe3+/Fe2+ redox reaction and the charge transfer process are investigated so as to reveal the energy-storage mechanism, and the effect of electrolytes on the energy-storage mechanism is also included; by the use of FeMOF-graphene films as electrodes, flexible and all-solid-state supercapacitors are assembled and its working mechanism is going to be interpreted. This research has great academic significance and practical vales on enriching the theory and technique of supercapacitor.

具有结构多样性和优异赝电容的含铁金属有机骨架配位聚合物（FeMOF）作为电极材料在超级电容领域显示了良好的应用前景， 然而FeMOF材料亟待解决的关键问题有：①导电性差导致充放电过程中电化学性能降低，②FeMOF材料的储能机理尚存在争议、结构与其储能性能之间的关系尚不明确。本课题研究FeMOF的合成方法并调控结构与形貌，通过制备FeMOF-石墨烯柔性薄膜改善导电性及提高超电容性能，评价电化学性能并阐明构效关系；探讨可逆Fe3+/Fe2+氧化还原反应历程和电荷转移过程，揭示FeMOF的储能机制和电解液性质对储能机制的影响；实现组装以FeMOF-石墨烯柔性薄膜作为电极的全固态柔性超级电容器件并说明其工作原理。课题研究对于丰富超级电容器理论和技术具有重要的学术意义和应用价值。

具有结构多样性和优异赝电容的含铁金属有机骨架配位聚合物（FeMOF）作为电极材料在储能领域显示了良好的应用前景，普鲁士蓝及类普鲁士蓝化合物作为典型的含铁MOF亟待解决的关键问题有：①导电性差导致充放电过程中电化学性能降低，②FeMOF材料的储能机理尚存在争议、结构与其储能性能之间的关系尚不明确。本课题的主要研究内容归纳为三个方面：(1) FeMOF储能机理的新发现，(2) FeMOF(CuFe及CoFe类普鲁士蓝)的合成方法，纳米结构调控及电化学性能, (3) 组装纽扣式非对称和柔性超级电容器件。.在中性水系电解液中，类普鲁士蓝化合物被认为是通过Fe3+/Fe2+氧化还原电对完成电荷储存，其他过渡金属由于水氧化反应不贡献容量。我们调查了类普鲁士蓝化合物的电化学行为：首次确认CoFe类普鲁士蓝的Co3+/Co2+氧化还原电对参与电荷储存, 提出配位诱导激活Co3+/Co2+可逆反应的反应机制, 并且报道CuFe类普鲁士蓝化合物的Cu2+/Cu+氧化还原电对能够贡献赝电容，这些结果极大地丰富了FeMOF储能机理。同时研究了纳米结构的调控, 包括类普鲁士蓝纳米立方，类普鲁士蓝-聚苯胺, 类普鲁士蓝-纳米碳管复合材料, MnO2纳米片包覆CoFe类普鲁士蓝。针对柔性超级电容器件的固态电解质和电极，研究了高分子薄膜和自支撑石墨烯复合膜的制备和电化学性能。聚苯乙烯-聚乙烯-聚丁烯基固体电解质膜展现出可调整的离子通道和良好的离子导电能力。以类普鲁士蓝化合物为正极材料和活性炭为负极材料，实现组装高性能非对称超级电容器件，功率密度为1 kW kg–1下输出能量密度>40 Wh kg–1，并具有良好的循环稳定性。本项目研究对于指导开发类普鲁士蓝基超级电容具重大的科学意义