Stable Flavone‐Linked Covalent Organic Frameworks for High‐Performance Lithium‐ion Battery Anodes

The design and synthesis of stable and efficient anode materials for organic lithium-ion batteries (LIBs) are critical for achieving environmental sustainability. Herein, a flavone-linked covalent organic framework (FV-COF) with high crystallinity is synthesized via a cascade reaction based on the Claisen-Schmidt condensation for anodes of LIBs. The incorporation of an oxygen-rich flavonoid structure and a fully conjugated framework endows FV-COF with exceptional physicochemical stability and reversible redox capacity. Thus, FV-COF demonstrates exceptional performance as an anode material, delivering a high steady-state capacity of 1136.8 mA h g^-1 after ten cycles at 0.1 A g^-1 and excellent rate capability. In particular, the cyclic stability of FV-COF retained a capacity of 546.5 mAh g^-1 at 5.0 A g^-1 after 10 000 cycles, accompanied by a Coulombic efficiency exceeding 98%. This work demonstrates that COFs with rich redox site and stable linkages are promising candidates for developing lightweight batteries.