Fluorocarbon Surfactant‐Derived Ultrathin Porous Carbon Interface Layer for Stable Zn Anode

ABSTRACT Aqueous zinc‐ion batteries are promising for large‐scale energy storage, yet their practical deployment is severely hindered by parasitic hydrogen evolution, dendritic growth, and low Zn utilization. Here, we report an ultrathin (∼5.5 nm) fluorine/oxygen co‐doped porous carbon interface layer constructed on Cu foil via controlled pyrolysis of a fluorocarbon surfactant precursor. This nanoscale interface confines Zn deposition behavior at the Cu interface region, effectively regulating nucleation and growth. The F/O dopants induce localized electronic modulation and hydrophobicity to suppress water‐induced side reactions, while the porous framework facilitates rapid Zn 2+ migration and accelerates the desolvation kinetics. As a result, Zn preferentially deposits beneath the interface layer, leading to dense and uniform metal growth with minimal dead Zn formation. Benefiting from this interfacial confinement effect, the optimized electrode, with a low Zn loading of 5 mAh cm −2 , delivers exceptional reversibility and cycling stability (>1500 cycles at 5 mA cm −2 with 40% depth of discharge). When paired with a MnO 2 cathode, the full cell achieves 88.2% capacity retention after 800 cycles at 1 A g −1 . This work highlights a scalable strategy to engineer ultrathin functional interfaces on current collectors and provides new insights into regulating metal deposition via interfacial confinement for high‐efficiency metal‐based batteries.