Stable Lithium Oxygen Batteries Enabled by Solvent‐diluent Interaction in N,N‐dimethylacetamide‐based Electrolytes

Abstract In the pursuit of next‐generation ultrahigh‐energy‐density Li−O 2 batteries, it is imperative to develop an electrolyte with stability against the strong oxidation environments. N,N‐dimethylacetamide (DMA) is a recognized solvent known for its robust resistance to the highly reactive reduced oxygen species, yet its application in Li−O 2 batteries has been constrained due to its poor compatibility with the Li metal anode. In this study, a rationally selected hydrofluoroether diluent, methyl nonafluorobutyl ether (M3), has been introduced into the DMA‐based electrolyte to construct a localized high concentration electrolyte. The stable −CH 3 and C−F bonds within the M3 structure could not only augment the fundamental properties of the electrolyte but also fortify its resilience against attacks from O 2 − and 1 O 2 . Additionally, the strong electron‐withdrawing groups (−F) presented in the M3 diluent could facilitate coordination with the electron‐donating groups (−CH 3 ) in the DMA solvent. This intermolecular interaction promotes more alignments of Li + ‐anions with a small amount of M3 addition, leading to the construction of an anion‐derived inorganic‐rich SEI that enhances the stability of the Li anode. As a result, the Li−O 2 batteries with the DMA/M3 electrolyte exhibit superior cycling performance at both 30 °C (359 th ) and −10 °C (120 th ).