多酸基阳离子型金属-有机框架的高效制备及其在锂电负极材料上的应用

Polyoxometalate-based metal-organic frameworks (POMOFs), due to their combination values of both polyoxometalates (POMs) and metal-organic frameworks (MOFs), have drawn significant attention in research areas such as energy storage and conversion. Nevertheless, the preparation of POMOFs using redox-active cationic ligands still remains challenging. There are only a few reports in this regard. We thus propose here a new protocol based on 3D printing to tackle the problems facing the syntheses of POM-based cationic MOFs, and prepare a series of novel POMOFs with intriguing structural properties accordingly. We also plan to adopt in situ technology to unveil the formation mechanism of POM-based cationic MOFs by on-line monitoring the 3D printing mutlistep hydrothermal synthesis. Thereafter, the electrochemical performance of the obtained materials will be investigated in detail. By tuning the compositions of POMOFs with different POMs, cationic ligands, and central metal ions, we intend to explore the effect of each component on electrochemical performance, aiming to establish the structure-property relation and screening out POM-based LIBs anode materials with high specific capacity and cycling stability. The implementation of this project not only puts forward a new method for the preparation of POMOFs, but also provides theoretic and experimental bases for the development of high-performance POM-based electrode materials.

多酸基金属-有机框架兼具多酸和金属-有机框架的优势，近年来在能量存储与转化领域受到广泛关注。然而，目前通过具有氧化还原活性的阳离子配体来制备多酸基金属-有机框架仍面临挑战，国内外鲜有相关研究报道。在本项目中，我们拟借助3D打印技术来解决多酸基阳离子型金属-有机框架难以制备的问题，便捷、高效地开发出一系列结构新颖的多酸基金属-有机框架晶体材料。与此同时，项目拟利用原位技术在线监测3D打印多步水热合成的反应过程，揭示多酸基阳离子型金属-有机框架的形成机理；通过调变多酸、阳离子配体、以及中心金属离子，探讨不同组分对于材料电化学性能的作用规律，建立结构与性能之间的构效关系，进而筛选出比容量高、循环性好的多酸基锂电负极材料。本项目的实施不仅为多酸基金属-有机框架的制备提供了一种新的思路，而且也为高性能多酸基电极材料的研制与开发提供了理论和实验依据。

多酸因其结构的多样性和多电子氧化还原的特性，被广泛用于能量转化与存储领域。但因其导电性差和易于团聚析出的特点，极大程度上限制了在电极材料上的应用。金属有机框架作为一类结构可调、孔隙率高、稳定性好的多孔材料，是多酸的理想载体。基于此，本项目通过三维打印的方式设计制备了一类新型的高通量两腔室水热合成反应器，用于多酸基金属有机框架的高效筛选、优化和制备。课题结合了多酸和阳离子型金属有机框架的氧化还原特性，成功开发了出系列比容量高、循环稳定性良好的锂电负极材料，利用多种表征技术揭示了多酸基金属有机框架的结构与其储锂性能之间的构效关系，为高性能多酸基锂电负极材料的开发提供理论和实验依据。此外，项目还探索了多酸的功能有机修饰和不对称合成，为多酸基功能材料的制备提供了新的方法与思路。