Synergistic Dual-Fluorinated Hybrid Interphase for Ultra-Stable Zn Anodes under High Current Densities

Unstable interfacial reactions on Zinc (Zn) anodes, including hydrogen evolution, dendrite growth, and surface passivation, significantly hinder the cycling stability and practical applications of aqueous Zn-ion batteries (AZIBs), especially under high current densities. Herein, we propose an in situ constructed, mechanically reinforced dual-fluorinated hybrid interfacial layer (cPVDF-In@Zn–F) for highly durable Zn metal anodes. Modified PVDF (cPVDF) as the upper part of the hybrid interfacial layer is rich in β-phase, which is characterized by high modulus, hydrophobicity, and grafted polar groups, providing a multiple synergistic protection mechanism encompassing stress relaxation, electric field modulation, chemisorption, and hydrophobic barrier. Meanwhile, the underlying ZnF 2 /InF 3 /In conductive network reduces Zn 2+ adsorption energy and facilitates uniform three-dimensional current distribution, effectively mitigating dendrite formation and side reactions. Benefiting from this integrated design, the cPVDF-In@Zn–F anode delivers outstanding cycling stability at high current densities and large areal capacities (over 1450 h at 25 mA cm –2 and 5 mAh cm –2 ), while full batteries paired with V 2 O 5 cathodes exhibit excellent long-term durability, achieving 90% capacity retention and nearly 100% Coulombic efficiency after 4000 cycles at 3.5 A g –1 . This work highlights a promising interfacial engineering strategy for advancing practical and high-rate AZIBs.