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

Although sufficient tolerance against attack by superoxide radicals (O-2(-)) has been mainly recognized as an important property for Li-O-2 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 O-1(2) and forming highly decomposable Li2O2. The O-1(2) 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 O-2(-) tolerance. Thus, the present work provides a novel design guideline for the development of LOB electrolytes.

Automated summary

In addition to sufficient tolerance against superoxide radical attack, other factors also play a crucial role in the cyclability of Li-O2 batteries. The use of N,N-dimethylacetamide-based electrolyte can enhance the cyclability by quenching O-1(2) and forming highly decomposable Li2O2.