Artificial Interfacial Protective Layers for Zinc Anodes in Aqueous Zinc-Ion Batteries: Design Principles and Stabilization Mechanisms.

Abstract

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage owing to their high safety, low cost, abundant Zn resources, and environmental compatibility. However, Zn metal anodes suffer from interfacial instability in aqueous electrolytes, including dendrite growth, hydrogen evolution, corrosion/passivation, and insulating by-products, which impair reversible Zn2+ plating/stripping and cycling durability. Artificial interfacial protective layers offer an effective route to stabilize Zn anodes by integrating protective and regulatory functions at the Zn/electrolyte interface. This review summarizes the failure mechanisms of Zn anodes and the design principles of artificial interphases, emphasizing homogenized Zn2+ flux and electric-field distribution, suppression of active water and side reactions, and improved ionic conductivity and interfacial stability. The compositions, fabrication methods, mechanisms, advantages, and limitations of inorganic, organic/polymeric, and organic-inorganic hybrid interphases are discussed. Finally, current challenges, including molecular-level mechanism identification, long-term structural stability, practical-condition evaluation, and scalable fabrication, are highlighted. A mechanism-oriented framework linking interfacial composition, Zn2+ transport, desolvation, water activity regulation, electric-field homogenization, and structural adaptability is proposed to guide advanced Zn-anode protection.