The surface coating is effective in suppressing Zn dendrite and side reactions, while the existing processing methods employ complex procedures and expensive equipment. Here, we develop an I 2 -assisted processing method to in situ fabricate the ZnO interface layer on the Zn anode (denoted as IAZO). This strategy features the sustainability that the raw materials, I 2 , could be reused with a recovery ratio of 67.25% and rapid processing time that only takes 5 min. The IAZO anode achieves an extraordinary cycle life of over 3100 h and a high depth of discharge of 52%, much better than the original Zn anode (less than 220 h and 1.7%). Density functional theory calculations and COMSOL simulation reveal that the IAZO anode has a high binding energy with Zn 2+ , which contributes to the uniform distribution of the electric field and Zn 2+ flux.