Additive-Induced Interfacial Chemistry: The Key to Next-Generation Lithium Metal Batteries

The practical deployment of high-energy-density lithium metal batteries is critically hindered by their poor cycling stability, stemming from inherent electrode/electrolyte interfacial instability. Addressing this challenge requires strategic electrolyte design to stabilize electrode interfaces (that is, solid-electrolyte interphase) and suppress parasitic side reactions. Among the most promising approaches, electrolyte additives stand out by selectively modifying interfacial chemistry through in-situ chemical or electrochemical reactions, effectively prolonging battery lifespan without compromising energy density. This review transcends conventional classification by chemical composition or phase, proposing a mechanism-based framework that categorizes additives as decomposable, suspension, sustained-release, and electrode-adsorbing functional chemical regulators. By addressing practical challenges, it systematically elucidates how molecular structures and physicochemical properties govern interfacial reactions and electrochemical performance, particularly their interactions with bulk/interface chemistries. Furthermore, it offers forward-looking strategies emphasizing synergistic integration of interfacial engineering and data-driven approaches like artificial intelligence to predict molecular reactivity and interfacial efficiency. These insights deepen fundamental understanding of additive mechanisms, accelerating the design of next-generation additives through tailored liquid/interface chemistry for stable high-performance lithium metal batteries.