Analysis of the Electrochemical Behavior of Ionic Liquids and Their Application to Next-generation Energy Storage Devices

Ionic liquids show outstanding thermal stability, non-flammability, electrochemical stability, and high structural tunability.These characteristics make ionic liquids promising electrolytes for many types of secondary batteries, including alkali-ion batteries, metal-anode batteries, solid-state batteries (as additives), and dual-ion batteries.By selecting appropriate combinations of cations and anions, their properties can be tuned to suit specific electrochemical environments.For this reason, the coordination structures, ion-ion interactions, and the evolving interfacial behaviors of ionic liquids are considered especially important for the development of ionic liquid electrolytes.In this comprehensive paper, several strategies for ionic liquid utilization, developed primarily through the author's research, are introduced.These strategies include cation-and anion-regulated ionic liquid systems, molten-salt-inspired formulations, hybrid electrolytes that combine ionic liquids with organic solvents, and solidliquid composites to enhance interfacial properties.Overall, this comprehensive paper suggests that continued advances in ionic liquid research can contribute not only to the development of next-generation rechargeable batteries but also to a deeper understanding of the fundamental physicochemical properties that govern ionic liquid behavior.