Lotus Effect Inspired Hydrophobic Strategy for Stable Zn Metal Anodes

Abstract Zn‐ion batteries (ZIBs) have long suffered from the unstable Zn metal anode, which faces numerous challenges concerning dendrite growth, corrosion, and hydrogen evolution reaction. The absence of H 2 O adsorption control techniques has become a bottleneck for the further development of ZIBs. Using the stearic acid (SA)‐modified Cu@Zn (SA‐Cu@Zn) anode as an example, this work illustrates how the lotus effect controls the H 2 O adsorption energy on the Zn metal anode. In situ integrated Cu nanorods arrays and hydrophobic long‐chain alkyl groups are constructed, which provide zincophilic ordered channels and hydrophobic property. Consequently, the SA‐Cu@Zn anode exhibits long‐term cycling stability over 2000 h and high average Coulombic efficiency (CE) of 99.83% at 1 mA cm −2 for 1 mAh cm −2 , which improves the electrochemical performance of the Zn||V 2 O 5 full cell. Density functional theory (DFT) calculations combined with water contact angle (CA) measurements demonstrate that the SA‐Cu@Zn exhibits larger water CA and weaker H 2 O adsorption than Zn. Moreover, the presence of Cu ensures the selective adsorption of Zn on the SA‐Cu@Zn anode, well explaining how the excellent reversibility is achieved. This work demonstrates the effectiveness of the lotus effect on controllable H 2 O adsorption and Zn deposition mechanism, offering a universal strategy for achieving stable ZIB anodes.