A renaissance of N,N-dimethylacetamide-based electrolytes to promote the cycling stability of Li–O2 batteries

Abstract

Li–O₂ batteries with ultrahigh theoretical energy density have been regarded as a promising successor to Li-ion batteries for next-generation energy storage. However, their practical application is still facing many critical issues, especially the lack of suitable electrolytes that can tolerate a strong oxidizing environment as well as being compatible with a Li metal anode. Here, we design a new N,N-dimethylacetamide (DMA)-based electrolyte by regulating the Li⁺ solvation structure under medium concentration to promote the cycling stability of Li–O₂ batteries. And it is also a better lithium metal anode stabilization strategy than using high concentration electrolytes. In contrast to high concentration electrolytes with expensive cost, limited protection ability toward the Li anode, sluggish kinetics and slow mass transfer, this new electrolyte with intrinsic better endurance towards the rigorous oxidative species can simultaneously stabilize the Li anode by facilitating the formation of a LiF and LiN_xO_y coexisting solid electrolyte interphase (SEI) film and enable faster kinetics/mass transfer. As a result, both the symmetrical batteries (1800 hours) and the Li–O₂ batteries (180 cycles) achieve the best cycling performances in DMA-based electrolytes to our knowledge. This study breathes new life into the electrolyte regulation strategy and paves the way for the development of alkali–O₂ batteries.