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

Abstract 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.