Second‐Scale Surface Reconstruction of Zn Anodes via Rapid Microwave Etching Coupled With Polydopamine Protection for Practical Long‐Life Aqueous Zinc‐Ion Batteries

ABSTRACT Aqueous zinc‐ion batteries (ZIBs) offer intrinsic safety, low cost, and high theoretical capacity (820 mAh g −1 , and 5855 mAh cm −3 ), yet dendrite formation and parasitic side reactions on Zn anodes hinder practical application. Here, a synergistic surface engineering strategy combining rapid microwave‐assisted etching with a conformal polydopamine (PDA) coating is presented. Microwave irradiation creates hierarchical stepwise pores that expose (101) facets, providing abundant nucleation sites for Zn 2+ and guiding the directional growth of Zn, as supported by molecular dynamics simulations. The PDA layer captures H 2 O molecules near hydrated Zn 2+ , suppressing hydrogen evolution, corrosion, and byproduct formation. Consequently, PDA‐coated eZn (PDA‐eZn) symmetric cells exhibit stable cycling over 526 h at 10 mA cm −2 and 5 mAh cm −2 , while PDA‐eZn//V 2 O 5 full cells retain 73.6% capacity after 1500 cycles at 3 A g −1 , with robust rate performance across a wide current density range. This scalable and generalizable approach establishes a clear design principle for dendrite‐free, high‐performance Zn anodes and can be extended to other metal anodes, advancing safe, durable, and high‐power aqueous energy storage systems.