<p>Aqueous zinc-ion batteries (AZIBs) are considered as promising energy storage technologies due to their exceptional reliability and environmental benignity. However, the commercialization of AZIBs is significantly hindered by their inadequate cycling durability and undesirable Coulombic efficiency (CE), primarily caused by dendrite growth and passivation on the Zn anode surface. Herein, a scalable polyacrylic acid (PAA)-decorated separator is designed by coating PAA onto commercial glass fiber (GF) and subsequently heating to crosslink PAA through an esterification reaction between PAA and GF. The thus-derived PAA-GF separator provides abundant surface zincophilic groups (–COOH), which efficiently guide the fast and uniform transportation of Zn²⁺, homogenizing zinc deposition and stripping, thereby suppressing dendrite growth during the electrochemical process. Additionally, the PAA functional layer contributes to forming a stable and robust in-situ SEI layer, acting as a protective barrier that limits direct contact between free water and the Zn anode, thereby significantly suppressing side reactions. Impressively, Zn||Zn symmetric cell using PAA-GF separator achieves stable cycling for over 4160&#xa0;h at 6&#xa0;mA&#xa0;cm⁻²@1 mAh cm⁻². Furthermore, the assembled full cell with the PAA-GF separator maintains a high specific capacity after long cycling. This scalable and effective strategy provides new insights into achieving high-performance Zn anodes.</p> Graphical Abstract <p></p>