In Situ X‐ray Absorption Fine Spectroscopy Reveals the Durability of Bismuth‐Coated Zn Metal Anode

Abstract Aqueous zinc metal batteries (AZMBs) have attracted intensive focus owing to their inherent merits for large‐scale, low‐cost, and safe renewable energy storage. However, the water‐induced reactions on the anode, such as the hydrogen evolution reaction and corrosion, heavily hamper the zinc ion electroreduction. Herein, a heterogeneous interface (bismuth layer) is established on Zn introduced in an alcohol‐water system with specific adsorption to boost the zinc ions plating. Theoretical calculations indicate that specific adsorption on the bismuth layer facilitates nucleation while inhibiting parasitic reactions, particularly enhancing the formation of stable nuclei during the early stages. In situ X‐ray absorption fine structure (XAFS) analysis reveals the replacement of Zn─O by newly formed Zn‐Bi, and the durable anode mechanism is the establishment of a stable Bi─(Zn)─Bi triangular coordination that promotes high‐quality heterogeneous nucleation. This well‐regulated nucleation leads to rapid and homogeneous Zn deposition. Exceptional performance is observed on the modified anode with stability of more than 2,500 cycles under a current density of 100 mA cm −2 . The modified anodes achieve a high coulombic efficiency of 99.72% at 5 mA cm −2 . When used in a full cell, the bismuth‐modified anode realizes stable cycling for 10,000 cycles.