Dynamic Dipole-Flipping Interlayer: Switchable Molecular-Level Electric Field Enables Full-Cycle Stable Zinc Anodes.

Abstract

Nonuniform Zn²⁺ flux, which triggers dendritic growth and accompanying side reactions, severely bottlenecks the practical implementation of aqueous zinc-ion batteries. While the interfacial electric field governs Zn²⁺ flux uniformity, existing modulation strategies rely on static unidirectional fields remains intrinsically decoupled from the bidirectional, field-reversing dynamics of cyclic Zn deposition/stripping. Herein, we engineer a dynamic dipole-flipping interlayer (DDL) on Zn anode that generates a switchable molecular-level electric field to enable uniform Zn²⁺ flux regulation during cycling. Specifically, the DDL is constructed from a rationally designed polyamide derivative featuring inherently large amide dipole moments; increased free volume and chain flexibility disrupt dense chain packing and enable rapid, reversible dipole reorientation. During Zn deposition/stripping, the amide dipoles reorient dynamically to generate polarity-switchable interfacial molecular‑level electric fields, which direct homogeneous Zn²⁺ redistribution and suppress preferential nucleation. Beyond electric‑field regulation, fluorinated segments within the DDL impart interfacial hydrophobicity and further suppress side reactions. Consequently, the DDL-modified Zn anode cycles stably for over 3200 h at 0.5 mA cm^-2, while the Zn||MnO₂ full cell delivers 97.3% capacity retention after 1600 cycles at 1 A g^-1. This work pioneers a versatile paradigm for interfacial electric field regulation by dipole dynamics toward high-performance aqueous metal-based batteries.