Designing Chemically Replaced Interfacial Layer via Unveiling the Influence of Zn Crystal Facets for Practical Zn-Metal Anodes

Zn metal anodes (ZMAs) undergo irregular deposition and unfavorable side reactions, which hinders the practical application of aqueous rechargeable Zn metal batteries (ARZMBs). Chemical replacement reaction (CRR) strategies can achieve stable ZMAs, but the effect of the crystal facets of metallic Zn as reductants remains poorly understood. In this study, based on the observation that preferentially exposed Zn crystal facets affect the surface characteristics of chemically replaced layers in Sn-based CRR, a multifunctional Sn-based interfacial layer (ZnTCF@Sn) is designed on the Zn with textured crystal facets using a novel two-step CRR process. ZnTCF@Sn simultaneously provides abundant zincophilic sites and high surface energy and homogenizes the distribution of current/Zn2+ flux, resulting in fast electrochemical kinetics and dendrite-free deposition. Furthermore, the uniform Sn coverage on the ZnTCF@Sn surface inhibits side reactions and enhances reversibility during Zn deposition/dissolution. Thus, the ZnTCF@Sn achieves exceptional cyclability over 1200 h even under harsh operating conditions with a cumulative capacity of 24 Ah cm-2. This study contributes to the development of practical ARZMBs by providing new insights into the effect of the Zn crystal facets on the surface modification of ZMAs through various CRRs. Unveiling the effect of Zn crystal facets in Sn-based chemical replacement reaction (CRR), a Sn-based interfacial architecture (ZnTCF@Sn) via a novel two-step CRR is developed. Owing to its unique crystallographic (high zincophilicity and surface energy), morphological (abundant active sites and uniform current/Zn2+ flux), and compositional (suppressed side reactions of metallic Sn) merits, ZnTCF@Sn can approach a practical Zn-metal anode.image