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

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.