Progress in anode engineering for rechargeable zinc-ion batteries: strategies for dendrite suppression and host architectures

Abstract

Rechargeable zinc-ion batteries (ZIBs) are promising energy storage systems for large-scale and stationary applications due to their intrinsic safety, low cost, environmental friendliness, and the natural abundance of zinc metal. However, their practical development is severely hindered by the poor electrochemical reversibility and structural instability of zinc metal anodes during repeated plating and stripping. In aqueous electrolytes, zinc anodes suffer from dendritic growth, hydrogen evolution, corrosion, surface passivation, and the formation of electrochemically inactive dead zinc, resulting in rapid capacity decay and low coulombic efficiency. These failure mechanisms originate from nonuniform zinc nucleation, anisotropic crystal growth, heterogeneous electric field and current density distributions, Zn²⁺ solvation–desolvation behavior, and unstable zinc–electrolyte interfacial chemistry. This review critically summarizes recent advances in understanding the fundamental mechanisms governing zinc anode behavior in aqueous ZIBs, with an emphasis on the origin of morphological instability and dendrite formation. Based on these insights, state-of-the-art anode engineering strategies are comprehensively reviewed, including electrolyte and solvation-structure engineering, functional electrolyte additives, artificial solid–electrolyte interphase construction, separator design, surface chemistry modulation, and host-structure engineering using porous carbon frameworks, metallic scaffolds, and zincophilic composite architectures. Finally, key challenges related to long-term cycling stability, high-areal-capacity operation, lean electrolyte conditions, and practical scalability are discussed to provide guidance for the rational design of dendrite-free and highly reversible zinc metal anodes.