Fluorine-Rich Double-Network Interfacial Layer Enabling Dynamic Interphase Reconstruction for High-Capacity Zinc Metal Batteries.

Abstract

Developing large-scale, dendrite-free zinc (Zn) anodes is pivotal for the practical deployment of aqueous Zn-metal batteries (AZMBs), yet maintaining interfacial stability under high-areal-capacity conditions remains challenging. Here, we report an adaptive artificial solid-electrolyte interphase (ASEI) based on a single-ion-conducting fluorine-rich double network (SFDN) that enables in situ dynamic reconstruction of the Zn/electrolyte interphase. The SFDN, comprising an Al(OR)₄ ^--based (R = -CH₂-(CF₂)₇-CH₂-) dynamic crosslinked network integrated within PVDF-HFP matrix, delivers a high Zn²⁺ transference number (0.78) and hydrophobic/zincophilic properties. During cycling, residual monomers within the SFDN fulfill a dual-functional role: coordinating with Zn²⁺ to establish a dynamic Zn(OR)₂ ^--based network while undergoing sacrificial decomposition to form a robust ZnF₂-rich inner SEI. This evolution yields a multilayered architecture that effectively suppresses water-induced side reactions, homogenizes Zn²⁺ flux, and provides self-healing. Consequently, the SFDN@Zn anode achieves an extraordinary lifespan of over 4,000 h at 10 mA cm^- ²/10 mAh cm^- ², and a high average Coulombic Efficiency of 99.9% at 5 mA cm^- ². Furthermore, a ∼900 mAh Zn||I₂ pouch cell achieves a high energy density of 196 Wh kg^- ¹ with 97.8% capacity retention over 300 cycles. This work presents a dynamic self-adaptive interphase engineering, offering fundamental insights into Zn-anode stabilization, and extending to other metal-based battery systems.