Redox-active covalent organic frameworks for batteries based on abundant metals (Na, Mg, Al) (RACOF-NMA)

基于丰富金属的电池，如钠、镁和铝，由于其成本效益和天然储量，正在成为锂离子电池的有前途的替代品。然而，开发具有优异容量、可逆性和长期循环性能的高性能正极材料仍然是一个巨大的挑战。有机化合物以其丰富的资源、可定制的结构和设计灵活性提供了一种解决方案，通过可逆氧化还原反应实现了高效的能量存储。然而，与无机材料相比，有机化合物的稳定性和能量密度都存在不足。为了应对这些挑战，氧化还原活性共价有机骨架(COF)作为各种电池潜在的有机正极材料引起了人们的关注。COF提供可编程的顺序、稳定性、刚性框架和多孔结构。在第一个资助期取得的进展和知识的基础上，该项目旨在设计新型的氧化还原活性COF和具有稳定连接的硫化/硒COF(如亚胺、乙烯、噻吩胺和硒菲)，探索它们在基于丰富金属(Na、Mg、Al)的电池中的性能。先进的核磁共振(核磁共振)表征将用于研究离子存储机制。非原位/OPANDO核磁共振实验将深入了解电压施加过程中电极材料与阳离子的相互作用，以及循环后的电位老化和降解过程。该项目的成功成果将为设计具有丰富的氧化还原活性中心、化学稳定的键和定义良好的多孔结构的良好的COF提供宝贵的知识。本研究通过阐明氧化还原活性COF的结构-性能关系，有助于电池技术的进步，从而指导基于丰富金属的新型高性能有机电池电极的未来发展。

Batteries based on abundant metals, such as Na, Mg, and Al, are emerging as promising alternatives to Li-ion batteries due to their cost-effectiveness and natural abundance. However, the development of high-performance cathode materials with superior capacity, reversibility, and long-term cyclability remains a significant challenge. Organic compounds offer a solution with their abundant resources, customizable structures, and design flexibility, enabling efficient energy storage through reversible redox reactions. However, the stability and energy density of organic compounds fall short compared to inorganic materials. To address these challenges, redox-active covalent organic frameworks (COFs) have garnered attention as potential organic cathode materials for various batteries. COFs offer programmable order, stability, rigid frameworks, and porous structures. Building upon the progress and knowledge gained in the first funding period, this project aims to design novel redox-active COFs and sulfurized/selenized COFs with stable linkages (such as imide, vinyline, thion-enamine, and selenanthrene), exploring their performance in batteries based on abundant metals (Na, Mg, Al). Advanced nuclear magnetic resonance (NMR) characterization will be employed to investigate ion storage mechanisms. Ex-situ/operando NMR experiments will provide insights into electrode material-cation interactions during voltage application and potential aging and degradation processes after cycling. The successful outcome of this project will yield valuable knowledge on designing favorable COFs with rich redox-active centers, chemically stable linkages, and well-defined porous structures. This research contributes to the advancement of battery technologies by elucidating the structure-performance relationship of redox-active COFs, thus guiding the future development of novel high-performance organic electrodes for batteries based on abundant metals.