A zincophilic interface coating for the suppression of dendrite growth in zinc anodes

The practical application of Zn anodes for aqueous rechargeable Zn batteries is impeded by an uncontrollable dendritic Zn deposition and the associated interface mechanisms that still remain ambiguous. Herein, we clarify Zn plating behaviors in multi-scale spanning from sub-nanometer to micrometers and disclose a dislocation-rich feature in Zn deposits near the interface for the first time. The refined crystalline diffraction analysis of original Zn foil and deposited Zn also indicates the existence of lattice distortion at the bulk level. Moreover, we construct a (111) plane-oriented Au coating layer on Zn anodes (Au-Zn) guided by DFT calculations and reveal its zin-cophilicity by in situ optical observations. The zincophilic interlayer integrates the advantages of inducing spacious Zn nucleation and enhancing the wettability of electrodes to aqueous electrolyte, which thus leads to effective control of Zn deposition with suppressed crystalline defects and dendrites. Tested on coin-type cells, Au-Zn electrodes show lower overpotentials and higher stability compared to bare Zn electrodes (490 h vs 68 h). Findings in this work shed light on fundamental understanding of material electrochemistry and are instructive to future interfacial design for aqueous rechargeable Zn batteries.

Automated summary

In this study, the uncontrollable dendritic Zn deposition and associated interface mechanisms in aqueous rechargeable Zn batteries were investigated. Zn plating behaviors in different scales were clarified, and a dislocation-rich feature in Zn deposits near the interface was discovered. By constructing a (111) plane-oriented Au coating layer on Zn anodes (Au-Zn), the zincophilic interlayer was found to effectively control Zn deposition with suppressed crystalline defects and dendrites. Coin-type cells with Au-Zn electrodes exhibited lower overpotentials and higher stability compared to bare Zn electrodes (490 h vs 68 h). These findings provide important insights into material electrochemistry and offer guidance for future interfacial design for aqueous rechargeable Zn batteries.