Strategies for the Stabilization of Zn Metal Anodes for Zn-Ion Batteries

Zinc-ion batteries (ZIBs) are regarded as a promising candidate for next-generation energy storage systems due to their high safety, resource availability, and environmental friendliness. Nevertheless, the instability of the Zn metal anode has impeded ZIBs from being reliably deployed in their proposed applications. Specifically, dendrite formation and the hydrogen evolution reaction (HER) on the Zn surface significantly compromise the Coulombic efficiency and cycling stability of ZIBs. In recent years, increasing efforts have been devoted to overcoming these obstacles by electrode structure design, interface modification, and electrolyte/separator optimization. To achieve an insightful and comprehensive understanding of these strategies, it is worth analyzing and categorizing them according to their intrinsic mechanisms. Considering this, an overview of the anodic stabilization strategies is provided. First, the fundamentals of the Zn metal anode are introduced, and the associated reaction mechanisms are presented. Furthermore, strategies of dendrite and HER suppression are categorized, discussed, and analyzed in detail. Last, suggestions for Zn anode deployment in ZIBs from research, industrialization, and commercialization aspects are proposed. It is expected that this Review and the proposed strategies will shed light on the roadmap for the exploration of novel Zn metal anodes for ZIBs.