Roll-To-Roll Coating to Processing Large-Area Zinc Anodes toward Fast and Dendrite-Free Deposition

Surface modification has emerged as a promising approach for manipulating uniform Zn deposition and long-life aqueous Zn batteries. However, challenges related to the complicated fabrication processes and high cost hinder the scale-up deployment of zinc anodes. Herein, a versatile low-cost roll-to-roll coating methodology is demonstrated for expeditiously processing large-area Zn anode. Through a simple liquid-air interfacial deposition and Lewis acid-base coordination, a functional nanofilm can be in situ anchored to the Zn anode to enable planar Zn deposition by providing rich ion migration pathways, homogeneous electric field distribution, and enhanced ion diffusion kinetics. In addition, the water-related side reactions are simultaneously inhibited due to the desolvation effect of the nanofilm. The as-modified Zn anode manifests high Coulombic efficiency up to 99.9% for 1500 cycles, a long lifetime over 2700 h, and a high cumulative capacity of 6.25 Ah cm⁻². Furthermore, the practical feasibility is verified by the remarkable cycling capability in Zn||MnO₂ pouch cells. This study presents a cost-effective and scalable roll-to-roll strategy to fabricating large-area Zn anodes for boosting the practical application of aqueous Zn batteries.