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Na， Mg和Al，由于其成本效益和天然丰度，正成为锂离子电池的有前途的替代品。然而，高性能阴极材料的发展具有优越的容量，可逆性和长期循环性仍然是一个重大的挑战。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有所不足。为了解决这些挑战，氧化还原活性共价有机框架（COFs）作为各种电池的潜在有机正极材料引起了人们的关注。COFs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，本项目旨在设计具有稳定连接的新型氧化还原活性COFs和硫化/硒化COFs（如亚胺，乙烯基，硫-烯胺和硒酸），探索其在基于丰富金属（Na, Mg, Al）的电池中的性能。先进的核磁共振（NMR）表征将用于研究离子的储存机制。非原位/operando核磁共振实验将提供在电压应用过程中电极材料-阳离子相互作用以及循环后潜在老化和降解过程的见解。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、化学稳定的连接和明确的多孔结构的良好COFs提供宝贵的知识。本研究通过阐明氧化还原活性COFs的结构-性能关系，有助于电池技术的进步，从而指导未来基于丰富金属的新型高性能电池有机电极的发展。

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.