Fluorine-Functionalized Chemistry Toward Stable Zn Anode in Aqueous Zn-Ion Batteries

Fluorine-functionalized materials, characterized by their strong electronegativity, hydrophobic properties, and capacity to form stable interfacial layers, effectively mitigate critical challenges, including dendrite formation, hydrogen evolution, and corrosion, thereby cementing fluorine chemistry as a vital enabler of practical Zn-ion batteries (ZIBs). Despite these advantages, a systematic review of fluorine's multifaceted roles in anode stabilization remains scarce. This review underscores the essential contributions of fluorine chemistry in crafting sophisticated protective layers, fine-tuning electrolytes, and developing functional separators. Fluorinated protective layers are instrumental in manipulating zincophilic sites, augmenting corrosion resistance, regulating Zn2+ ion transport, strengthening confinement effects, and directing Zn (002) plane deposition. Within electrolytes, fluorinated Zn salts, additives, and co-solvents enhance ionic conductivity, broaden the electrochemical stability potential window, and facilitate forming durable solid-electrolyte interphase (SEI) layers to inhibit side reactions. Moreover, fluorine-modified separators balance hydrophilic and hydrophobic characteristics and improve mechanical robustness, effectively deterring dendrite formation. This review explores fluorinated interphase structure-property correlations and modern analytical approaches to understand fluorine's role in ZIBs. Finally, the current obstacles and prospective strategies for harnessing fluorine chemistry are further delineated to advance the development of safe, long-lasting, and sustainable ZIBs.