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.