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Covalent organic frameworks (COFs) have attracted considerable attention as a facile and versatile design platform for advanced energy storage materials owing to their structural diversity, ordered porous structures, and chemical stability. In this study, a redox‐active COF (TP–OH–COF) that can accommodate 30 Li+ ions is synthesized for potential use as an ultralong cyclable high‐capacity lithium‐ion battery electrode material. The TP–OH–COF is synthesized using triformylpholoroglucinol and 2,5‐diaminohydroquinone dihydrochloride under solvothermal conditions. The accommodation of such exceptional Li+ ion content in the TP–OH–COF is achieved by alternately tethering redox‐active hydroxyl and carbonyl sites on the pore walls. Owing to this unique chemical/structural feature, the TP–OH–COF delivers a high specific capacity of 764.1 mAh g–1, and capacity retention of 63% after 8000 cycles at a fast current density of 5.0 A g–1. [ABSTRACT FROM AUTHOR]

Despite the enormous interest in Li metal as an ideal anode material, the uncontrollable Li dendrite growth and unstable solid electrolyte interphase have plagued its practical application. These limitations can be attributed to the sluggish and uneven Li + migration towards Li metal surface. Here, we report olefin-linked covalent organic frameworks (COFs) with electronegative channels for facilitating selective Li + transport. The triazine rings and fluorinated groups of the COFs are introduced as electron-rich sites capable of enhancing salt dissociation and guiding uniform Li + flux within the channels, resulting in a high Li + transference number (0.85) and high ionic conductivity (1.78 mS cm -1 ). The COFs are mixed with a polymeric binder to form mixed matrix membranes. These membranes enable reliable Li plating/stripping cyclability over 700 h in Li/Li symmetric cells and stable capacity retention in Li/LiFePO 4 cells, demonstrating its potential as a viable cationic highway for accelerating Li + conduction., (© 2023 Wiley-VCH GmbH.)