Zn/Cu Co‐Deposition Enables Dynamic Interfacial Reconstruction for Stable Zinc‐Metal Batteries

The instability of Zn anodes arising from uncontrolled deposition remains a critical bottleneck for zinc‐metal batteries. Here, a sustainable Zn/Cu co‐deposition strategy is reported via a cost‐effective ethanol‐based hybrid electrolyte (EtZCL‐Cu) containing ZnCl 2 and insoluble Cu(OH) 2 additives. The high Cl − concentration enables continuous Cu 2+ release via complexation‐driven Cu(OH) 2 dissolution, facilitating spontaneous Zn/Cu displacement‐alloying reactions during cycling. This dynamic reconstruction mechanism ensures long‐term exposure of zincophilic Cu sites on the electrodeposited Zn surface, thereby effectively preventing the defunctionalization of zincophilic alloy interfaces. The reconfigurable alloy interface maintains zero nucleation overpotential and enables dendrite‐inhibited Zn electrodeposition, achieving exceptional cycling stability (>6000 h) in Zn symmetric cells. The ethanol solvent and Cl − complexed Cu + /Cu 2+ redox couple cooperatively increase the capacity of the activated carbon cathode full cells, delivering >90 mAh g −1 over 10,000 cycles at 0.5 A g −1 , with 95.9% capacity retention. This work establishes a sustainable interfacial engineering paradigm through electrolyte‐mediated in situ alloying, effectively addressing the critical challenge of zincophilic interface defunctionalization in Zn‐metal battery systems.