Comprehensive Insights Into Electrolyte and Electrode–Electrolyte Interface for Aqueous Lithium‐Ion Batteries

ABSTRACT Aqueous lithium‐ion batteries (ALIBs) stand out as promising grid‐scale energy storage candidates, leveraging aqueous electrolytes to address the safety hazards and environmental concerns of traditional nonaqueous batteries. Their development, however, has long been constrained by the narrow electrochemical stability window of water, which limits cell voltage and promotes parasitic reactions. This review summarizes recent progress in ALIBs from the synergistic perspectives of electrolyte regulation, interfacial reaction mechanisms, and cell‐level engineering considerations in relation to practical metrics, including energy density and long‐term cycling durability. Particular emphasis is placed on the control of Li + solvation environments and the formation of functional interphases, which collectively suppress water‐induced side reactions and expand the accessible operating window. By integrating these tightly linked aspects, this review delineates the mechanistic foundations and design principles that redefine the effective stability boundary of aqueous batteries and support the continued evolution of ALIBs toward scalable, high‐energy, and durable technologies.