Nitrogen-rich redox-active monomers for COF battery materials (NITROCOF)

共价有机骨架(COF)是获得高性能有机电极材料的通用平台。氧化还原活性亚基易于安装，其多孔性允许有效的离子扩散。然而，大多数报道的COF作为电极材料使用n型氧化还原活性，这意味着电子在插入电解液中的金属阳离子的同时可逆存储，以实现电荷平衡。在这项联合提案中，我们将系统地研究2D-COFS中包含的氧化还原活性单元中氮的浓缩效应。提出了提高氮杂原子含量的两个主要优点：1)可以解决p型材料中具有多个电子转移的可逆氧化还原过程；2)N-杂原子与反离子的配位作用更好，从而更好地存储离子。因此，我们将研究COF芳香族亚基中N-杂原子的富集度与其在锂或镁电池中的电极性能的关系。在该SPP项目中，将合成新型2D-COF(Dumele基团)和具有直接可比氧化还原活性单元的选定线性非晶态聚合物(Esser基团)。我们设想使用各种富氮模式和结构基序来揭示基本的电荷和自由基稳定机制。这种基于COF的电极材料的联合方法将有助于从根本上设计用于储能装置的聚合物支架。

Covalent organic frameworks (COFs) are a versatile platform for achieving high-performance organic electrode materials. Redox-active subunits are readily installed and their porosity allows for efficient ion diffusion. However, most reported COFs as electrode materials use an n-type redox activity, meaning that electrons are reversibly stored concurrently with the insertion of metal cations from the electrolyte for charge balancing. In this joint proposal, we will systematically study the effect of nitrogen enrichment in the redox-active units incorporated in 2D-COFs. Two main advantages are proposed when enhancing the nitrogen heteroatom content: 1) reversible redox processes with multiple electron transfers as p-type materials can be addressed, and 2) improved coordination by N-heteroatoms to counterions for better ion storage. Hence, the enrichment of N-heteroatoms in aromatic subunits of COFs will be studied in relation to their electrode performance in lithium- or magnesium-based batteries. The synthesis of novel 2D-COFs (Dumele group) and selected linear amorphous polymers (Esser group) bearing directly comparable redox-active units will be achieved within this SPP project. We envision revealing fundamental charge and radical stabilization mechanisms using various nitrogen-enriched patterns and structure motifs. This joint approach to COF-based electrode materials will help to design polymeric scaffolds for energy storage devices fundamentally.