Rational Design of Benzo‐Crown Ether Electrolyte Additives for High‐Performance Li‐O₂ Batteries

Abstract Despite theoretical predictions of exceptional gravimetric energy densities in Li‐O₂ batteries (LOBs), the current research forefront faces challenges, including high charge overpotential, cathode clogging, parasitic reactions, and Li anode corrosion. Herein, benzo‐crown ethers (BCEs) with varying cavity sizes are used as electrolyte additives to exploit their strong binding toward Li⁺ and promote the solution growth of Li₂O₂ with reduced particle size. Notably, the cell with benzo‐18‐crown‐6 ether (B18C6) enables the largest discharge capacity of 14948 mAh g⁻¹. Upon charging, these additives accelerate Li₂O₂ oxidation through the strong binding with Li⁺ and the extended electrolyte/Li₂O₂ interface, resulting in improved reversibility, reduced charge overpotential, and prolonged cycle life. Besides, these additives also stabilize the Li anode by regulating Li⁺ migration and electron exchange, reducing dendritic growth and anode corrosion. This work presents insights into the rational design of BCEs as additives for high‐performance LOBs.