LAUSR

Zn interfacial issues involved dendrite evolution and undesired parasitic reactions are tough challenges to impede the progress of Zn ion battery. Herein, dendrite‐free Zn anode with boosted stability is achieved by four‐in‐one functional additive triethyl phosphate (TEP). Experiments and theoretical calculation reveal that TEP additive participates in the generation of compact inorganic interface to prevent Zn from corrosion. Meanwhile, the interfacial electrical double layer (EDL) is reconstructed with adsorbed TEP molecules in inner layer and weakened Zn2+ solvation structure in diffusion layer, which efficiently shields Zn from active H2O and moderate electrochemical kinetics, thereby preventing water‐related secondary reaction and Zn electroplating on tip region. Additionally, TEP additive manipulates zinc growth direction by adsorbing on the (002) facet, thus enabling long‐lasting dendrite‐free deposition. Accordingly, Zn||Zn symmetric cell demonstrates an ultralong lifespan over 5000 h (almost 7 months) at 1 mA cm−2, 1 mAh cm−2 and remarkable coulombic efficiency (CE) of ≈97.6% for 1500 cycles. For practical demonstration, Zn||LiFePO4 full cell demonstrates an improved rate capability and an elevated capacity of 116.0 mAh g−1. These findings highlight interface chemistry manipulated by multifunctional additives as an efficient approach to stabilize Zn anode, holding promise for top‐notch Zn‐based batteries with improved longevity.