Sporrer Lukas, Guo Quanquan, Li Xiaodong, Wrzesinska-Lashkova Angelika, Reichmayr Fanny, Fu Shuai, Wang Hai I, Bonn Mischa, Li Xiangyu, Laval-Schmidt Paul-Alexander, Wang Mingchao, Lu Yang, Vaynzof Yana, Yu Minghao, Feng Xinliang, Dong Renhao
Chair of Molecular Functional Materials, Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstraße 4, 01069, Dresden, Germany.
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120, Halle, Germany.
Angew Chem Int Ed Engl. 2025 Feb 3;64(6):e202418390. doi: 10.1002/anie.202418390. Epub 2024 Nov 29.
Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) are emerging as promising electrode materials for electrochemical energy storage devices. However, a viable path to realize superior dual-ion storage in 2D c-MOFs has remained elusive. Here, we report the synthesis of Cu(N-OHPTP) 2D c-MOFs (x=0,1,2; OHPTP=octahydroxyphenanthrotriphenylene) with precise aromatic carbon-nitrogen arrangements, based on the π-conjugated OHPTP ligand incorporated with one or two nitrogen atoms. The skeletal nitrogen modification in Cu(N-OHPTP) allows the synergistic introduction of additional redox sites, and thus substantially favors the unique dual-ion adsorption capacity. Consequently, the Cu(N-OHPTP) cathode exhibits a largely enhanced electrochemical performance for dual-ion storage (i.e., Li and Cl) with a high specific capacity of 53.8 mAh g, which is twice that of Cu(N-OHPTP) and 1.3 times that of Cu(N-OHPTP). Furthermore, the Cu(N-OHPTP) electrode displays a favorable rate performance of 52 % and good cycling stability of 96 % after 1000 cycles. We identify N-centered redox sites as additional Li adsorption sites by combining ex situ and in situ spectroscopy measurements and theoretical calculations. In addition, calculations underline the synergistic enhancement of the Cl adsorption energy by about 1.0 eV at the more electron-poor CuO linkages after N-incorporation. This work paves the way for the precise design of 2D c-MOFs with superior electrochemical properties, advancing their application in dual-ion storage applications.
二维共轭金属有机框架（2D c-MOFs）正成为电化学储能装置中颇具前景的电极材料。然而，在二维c-MOFs中实现卓越的双离子存储的可行途径仍然难以捉摸。在此，我们报道了基于掺入一个或两个氮原子的π共轭八羟基菲并三苯（OHPTP）配体，合成具有精确芳族碳氮排列的Cu(N-OHPTP)二维c-MOFs（x = 0,1,2）。Cu(N-OHPTP)中的骨架氮修饰允许协同引入额外的氧化还原位点，因此极大地有利于独特的双离子吸附容量。因此，Cu(N-OHPTP)阴极在双离子存储（即Li和Cl）方面表现出大幅增强的电化学性能，具有53.8 mAh g的高比容量，是Cu(N-OHPTP)的两倍，是Cu(N-OHPTP)的1.3倍。此外，Cu(N-OHPTP)电极在1000次循环后显示出52%的良好倍率性能和96%的良好循环稳定性。通过结合非原位和原位光谱测量以及理论计算，我们确定以N为中心的氧化还原位点为额外的Li吸附位点。此外，计算结果强调了在掺入N后，在电子更贫乏的CuO键处，Cl吸附能协同增强约1.0 eV。这项工作为精确设计具有卓越电化学性能的二维c-MOFs铺平了道路，推动了它们在双离子存储应用中的应用。
