Modulating Diffusion Kinetics and Interfacial Stability via In‐Situ Constructed Self‐Healing Interfaces for Highly Reversible Zinc Metal Anodes

Commercial Zn anodes contain inherent manufacturing defects, such as scratches, rough surfaces, fold lines, and microcracks. These surface defects damage the uniformity of the interfacial electric field, exacerbate hydrogen evolution problem and dendrite growth. Herein, a self-healing polymer interface is constructed by unsaturated N-(hydroxymethyl)acrylamide molecules (NHMA) self-polymerization. The layer effectively suppresses the detrimental tip effect and enhances the interface stability. Meanwhile, it synergistically facilitates the diffusion kinetics of Zn ions and regulates orientated deposition, thereby enabling an efficient repair of scratches on the Zn surface. Furthermore, the NHMA with acylamino and hydroxyl groups is capable of modulating the hydrogen bond network and solvation structure of the electrolyte, further improving the stability of the electrode-electrolyte interface. Benefiting from the enhanced diffusion kinetics and stable NHMA-derived interfaces, the fabricated symmetrical battery demonstrates a 50-fold improvement in cycle life under various testing conditions. Moreover, the full battery can maintain a capacity of 101.8 mAh g^-1 after 3000 cycles at 5 A g^-1 (1.5 times higher than bare Zn//NH₄V₄O₁₀). This work establishes a novel framework for rational electrolyte engineering and interfacial modulation in aqueous Zn metal batteries, offering fresh perspectives for future research toward practical energy storage applications.