Bimetallic Cladding-Constructed Interfacial Microenvironment Enabled Highly Reversible Powder Anode for Zn Metal...

The unstable interface of metal powder anode remains a challenge to achieve long-life Zn powder-based aqueous zinc metal batteries (AZMBs). However, most reported metal composite strategies still suffer from a mismatch between Zn²⁺ diffusion and electron transfer behaviors. Here, a bimetallic cladding strategy with a specific displacement sequence was proposed. Except for inheriting intrinsic advantages of Sn and Cu, the opposite EDL charge distribution of Cu to Zn compensates for the anion adsorption, inhibiting the ZSH-related side reactions. Moreover, abundant in situ constructed surface SnO₂ voids could accommodate stripped Zn²⁺ to avoid disordered diffusion, providing a shorter diffusion distance for the electron acceptance by Zn²⁺ instead of H⁺. Based on the matched electron and ion transport behaviors, the Zn@SC anode exhibited excellent cycle stability of over 2800 h in Zn||Zn cells at 1 mA cm^-2-5 mAh cm^-2, and achieved an areal capacity of 2 mAh cm^-2 in Zn||NH₄V₄O₁₀ cells at 3 A g^-1 and 70% capacity retention after 1000 cycles. As a practical validation, the pouch cell based on Zn@SC anode and high mass-loaded cathode (10.05 mg cm^-2) also exhibits satisfactory cycle stability. This work emphasized the importance of the interfacial microenvironment on the electrochemical performances and provided valuable direction of multi-metal Zn powder anode.