Fluoride engineering in zinc-ion batteries: principles, strategies, and perspectives

Zinc-ion batteries (ZIBs) are considered promising candidates for the next-generation energy storage technology due to their high safety, low cost, and high theoretical capacity. However, its practical application is hampered by irregular dendrite growth, hydrogen evolution reaction (HER), and passivation on the anode, as well as the poor structural stability and sluggish kinetics of the cathode. This review systematically investigates the multifunctional roles of fluoride engineering in ZIBs from a holistic “anode-interface-electrolyte-cathode” perspective, encompassing interface regulation and material design. The fluoride-modification of zinc anode is first discussed, including suppression of dendrite growth, reduction of side reactions, and enhancement of ion transport kinetics. Subsequently, fluoride-based interface engineering and fluoride electrolyte optimization are summarized, covering inorganic fluorine-rich solid-electrolyte interphase (SEI) films, inorganic-organic composite fluorine-rich SEI films, and two design strategies for SEI films. Furthermore, the review summarizes fluoride-related cathode design strategies, including fluorine doping, fluoride-based active materials and binder modification. Finally, a brief summary of the current challenges associated with fluorides in ZIBs research, and theoretical insights and technical prospects for the rational design of high-performance ZIBs are prospected.