Next-generation polymer interphases for durable zinc anodes: From dendrite suppression to corrosion control

The practical application of zinc-ion batteries (ZIBs) is constrained by persistent anode instabilities arising from nonuniform Zn nucleation, dendritic growth, corrosion, and parasitic hydrogen evolution. To mitigate these issues, polymer coatings have recently emerged as an effective interfacial engineering approach owing to their tuneable chemistry, mechanical adaptability, and ability to regulate ion transport at the metal-electrolyte boundary. This review summarizes recent advances in polymer-based stabilization strategies for Zn metal anodes, with emphasis on polymers containing coordinating functional groups, polymer-carbon hybrid interphases, and hydrophilic or adhesion-enhanced coatings. We discuss how tailored chemical functionalities-such as carbonyl, pyridyl, amine, and sulfonic groups-govern Zn²⁺ adsorption strength, surface charge distribution, desolvation behaviour, and preferred crystallographic growth, enabling controlled Zn deposition. Across these platforms, polymeric interphases demonstrate marked improvements in Coulombic efficiency, overpotential, corrosion resistance, and long-term cycling stability, even at high current densities. The review concludes with key design principles and emerging opportunities for next-generation polymer interfaces aimed at realizing highly reversible, dendrite-free Zn metal anodes for durable aqueous energy storage systems.