Functional Electrolyte Additives for Aqueous Zinc-Ion Batteries: Progress and Perspectives

Aqueous zinc-ion batteries (AZIBs) have emerged as promising candidates for next-generation energy storage systems due to their inherent safety, cost-effectiveness, and environmental compatibility. However, practical applications are hindered by challenges, such as zinc (Zn) dendrite formation, hydrogen evolution reactions (HER), and other side reactions. This review systematically explores the role of electrolyte additives in addressing these limitations by modulating Zn²⁺ deposition behavior, suppressing parasitic reactions, and enhancing interfacial stability. Additives are categorized by function: dendrite-inhibiting (e.g., alcohols, surfactants, inorganic salts), interface-stabilizing (ion/ solid-electrolyte interphase-forming agents, pH buffers), ion-transport-optimizing, bioinspired (e.g., trehalose, erythritol), and multifunctional synergistic types. Their mechanisms involve restructuring the Zn²⁺ solvated sheath (e.g., displacing H₂O), forming protective layers (hydrophobic/zincophilic interfaces), suppressing HER/corrosion, and regulating ion flux/deposition uniformity. Future research directions emphasize the development of cost-effective, stable additives, and interdisciplinary approaches to advance AZIBs toward commercialization. This review provides a comprehensive theoretical foundation and strategic guidance for designing high-performance AZIBs.