Overlooked Factors Required for Electrolyte Solvents in Li–O2 Batteries: Capabilities of Quenching 1O2 and Forming Highly‐Decomposable Li2O2

Abstract

AbstractAlthough sufficient tolerance against attack by superoxide radicals (O2−) has been mainly recognized as an important property for Li–O2 battery (LOB) electrolytes, recent evidence has revealed that other critical factors also govern the cyclability, prompting a reconsideration of the basic design guidelines of LOB electrolytes. Here, we found that LOBs equipped with a N,N‐dimethylacetamide (DMA)‐based electrolyte exhibited better cyclability compared with other standard LOB electrolytes. This superior cyclability is attributable to the capabilities of quenching 1O2 and forming highly decomposable Li2O2. The 1O2 quenching capability is equivalent to that of a tetraglyme‐based electrolyte containing a several millimolar concentration of a typical chemical quencher. Based on these overlooked factors, the DMA‐based electrolyte led to superior cyclability despite its lower O2− tolerance. Thus, the present work provides a novel design guideline for the development of LOB electrolytes.