Multicomponent Copper‐Zinc Alloy Layer Enabling Ultra‐Stable Zinc Metal Anode of Aqueous Zn‐ion Battery

Abstract Constructing stable surface modification layer is an effective strategy to suppress dendrite growth and side reactions of Zinc (Zn) metal anode in aqueous Zn‐ion battery. Herein, a multicomponent Cu−Zn alloy interlayer with superior Zn affinity, high toughness and effective inhibition effect on lattice distortion is constructed on Zn foil (Cu−Zn@Zn) to fabricate ultra‐stable Zn metal anode. Owning to the advantages of high binding energy of Cu−Zn alloy layer with Zn atoms and less contact area between metallic Zn and electrolyte, the as‐prepared Cu−Zn@Zn electrode not only restricts the aggregation of Zn atoms, but also suppresses the pernicious hydrogen evolution and corrosion, leading to homogeneous Zn deposition and outstanding electrochemical performances. Accordingly, the symmetric battery with Cu−Zn@Zn electrode exhibits an ultra‐long cycle life of 5496 h at 1 mA cm −2 for 1 mAh cm −2 , and the Cu−Zn@Zn//V 2 O 5 pouch cell demonstrates excellent cycling stability with a capacity retention of 88 % after 600 cycles.