• • Ionic liquid electrolytes enable lithium metal anodes with theoretical specific capacity of 3860 mAh g−1 and low reduction potential of −3.04 V vs. SHE, addressing safety issues of flammable organic solvents that cause thermal runaway and explosion.
• • Locally concentrated ionic liquid electrolytes (LCILEs) with low viscosity and fire-retardant properties achieve safe, stable cycling of lithium metal batteries, as demonstrated by Lee et al. (Adv Funct Mater, 2020, 30: 2003132).
• • Anion-reinforced solvating ionic liquid electrolytes stabilize high-nickel cathodes in lithium-metal batteries, as reported by Zou et al. (Adv Mater, 2024, 36: 2400537), enabling high-voltage operation.
• • Inorganic-rich solid electrolyte interphase (SEI) formation via ionic liquid additives improves cycling stability and rate capability, as evidenced by studies on lithiophilic and electrochemically active ionic additives (ACS Energy Lett, 2022, 7: 67–69).