Ion‐Transport Kinetics and Interface Stability Augmentation of Zinc Anodes Based on Fluorinated Covalent Organic Framework Thin Films

Abstract Zinc (Zn) emerges as an ideal anode for aqueous‐based energy storage devices because of its safety, non‐toxicity, and cost‐effectiveness. However, the reversibility of zinc anodes is constrained by unchecked dendrite proliferation and parasitic side reactions. To minimize these adverse effects, a highly oriented, crystalline 2D porous fluorinated covalent organic framework (denoted as TpBD‐2F) thin film is in situ synthesized on the Zn anode as a protective layer. The zincophilic and hydrophobic TpBD‐2F provides numerous 1D fluorinated nanochannels, which facilitate the hopping/transfer of Zn 2+ and repel H 2 O infiltration, thus regulating Zn 2+ flux and inhibiting interfacial corrosion. The resulting TpBD‐2F protective film enabled stable plating/stripping in symmetric cells for over 1200 h at 2 mA cm −2 . Furthermore, assembled full cells (Zn‐ion capacitors) deliver an ultra‐long cycling life of over 100 000 cycles at a current density of 5 A g −1 , outperforming nearly all reported porous crystalline materials.