Interface Engineering by Hydrophilic and Zincophilic Aluminum Hydroxide Fluoride for Anode‐Free Zinc Metal Batteries at Low Temperature

Abstract Anode‐free batteriesgreatly promote overall energy density, but they require an extremely high Coulombic efficiency (CE, >99.7%) to function normally. It becomes very challenging in aqueous batteries, because of water‐related parasitic reactions and dendrite growth on Zn anodes. Herein, aluminum hydroxide fluoride coated on Cu foils (Cu@AOF) is used to realize the anode‐free aqueous batteries. AOF exhibits a high adsorption affinity to H 2 O and a low diffusion energy barrier for Zn adatoms, promoting the desolvation process and surface migration. Meanwhile, the strong interaction between AOF and Zn 2+ enables it to regulate the Zn 2+ flux and benefit lateral growth. Then, the anode‐free full cells of Cu@AOF||Zn 0.5 VO 2 exhibit a record‐high cycle life of 2000 cycles at 1 A g −1 with an ultra‐high average CE of 99.95%. More impressively, the full cell shows a long cycle life of 400 cycles with a high CE of 99.94% at −20 °C. This work provides sheds light on the rational engineering of the electrode interfaces to obtain excellent performance at low temperatures.