Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (RECAST), Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin300071, China.
School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore637459, Singapore.
J Am Chem Soc. 2023 Jan 25;145(3):1564-1571. doi: 10.1021/jacs.2c08273. Epub 2023 Jan 12.
Metal-organic frameworks (MOFs) are emerging as attractive electrode materials for lithium-ion batteries, owing to their fascinating features of sustainable resources, tunable chemical components, flexible molecular skeletons, and renewability. However, they are faced with a limited number of redox-active sites and unstable molecular frameworks during electrochemical processes. Herein, we design a novel two-dimensional (2D) iron(III)-tetraamino-benzoquinone (Fe-TABQ) with dual redox centers of Fe cations and TABQ ligands for high-capacity and stable lithium storage. It is constructed of square-planar Fe-NO linkages and phenylenediamine building blocks, between which the Fe-TABQ chains are connected by multiple hydrogen bonds, and then featured as an extended π-d-conjugated 2D structure. The redox chemistry of both Fe cations and TABQ anions is revealed to render its remarkable specific capacity of 251.1 mAh g. Benefiting from the intrinsic robust Fe-N(O) bonds and reinforced Li-N(O) bonds during cycling, Fe-TABQ delivers high capacity retentions over 95% after 200 cycles at various current densities. This work will enlighten more investigations for the molecular designs of advanced MOF-based electrode materials.
金属-有机骨架（MOFs）作为锂离子电池有吸引力的电极材料而崭露头角，这要归功于它们具有可持续资源、可调化学组分、灵活的分子骨架和可再生性等迷人特点。然而，它们在电化学过程中面临着有限的氧化还原活性位点和不稳定的分子框架。在此，我们设计了一种新型二维（2D）铁（III）-四氨基苯醌（Fe-TABQ），具有 Fe 阳离子和 TABQ 配体的双重氧化还原中心，用于高容量和稳定的锂离子存储。它由正方形平面 Fe-NO 键和苯二胺构建块构成，Fe-TABQ 链通过多个氢键连接，然后呈现出扩展的π-d 共轭 2D 结构。Fe 阳离子和 TABQ 阴离子的氧化还原化学被揭示出来，赋予其 251.1 mAh g 的显著比容量。得益于循环过程中固有的强 Fe-N（O）键和增强的 Li-N（O）键，Fe-TABQ 在各种电流密度下经过 200 次循环后，容量保持率超过 95%。这项工作将为先进 MOF 基电极材料的分子设计提供更多的研究启示。
