An Effective Approach To Protect Lithium Anode and Improve Cycle Performance for Li–S Batteries

Lithium oxalyldifluoroborate (LiODFB) has been investigated as an organic electrolyte additive to improve the cycling performance of Li-S batteries. Cell test results demonstrate that an appropriate amount of LiODFB added into the electrolyte leads to a high Coulombic efficiency. Analyses by energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and the density functional theory showed that LiODFB promotes the formation of a LiF-rich passivation layer on the lithium metal surface, which not only blocks the polysulfide shuttle, but also stabilizes the lithium surface.