Affiliation:
1. State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China.
2. School of Applied Chemistry and Engineering University of Science and Technology of China Hefei 230026 China.
3. Department of Chemistry and Waterloo Institute for Nanotechnology University of Waterloo 200 University Ave. W. Waterloo Ontario N2 L 3G1 Canada.
Abstract
AbstractIn the pursuit of next‐generation ultrahigh‐energy‐density Li−O2 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−O2 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 −CH3 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 O2− and 1O2. Additionally, the strong electron‐withdrawing groups (−F) presented in the M3 diluent could facilitate coordination with the electron‐donating groups (−CH3) 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−O2 batteries with the DMA/M3 electrolyte exhibit superior cycling performance at both 30 °C (359th) and −10 °C (120th).