1,1‐Diethoxyethane as an interfacial‐stabilizing solvent for lithium–sulfur batteries

Abstract Lithium–sulfur batteries (LSBs) have gained remarkable attention over the past several years, however, their inherent limitations, such as the poor interfacial stability of their Li anodes and the severe dissolution of polysulfide, are regarded as bottlenecks that prevent these batteries from entering commercial markets. In this study, a 1,1‐diethoxyethane (DEE), which has been functionalized with acetal groups, is proposed as an electrolyte cosolvent to complement the limitations of the electrode materials of LSBs. In Li/Li symmetric cells, the DEE cosolvent exhibited stable cycling behavior, whereas the cell with the baseline electrolyte exhibited rapidly increasing polarization, even after 650 h. In LSB cells, the electrolyte that contains 50% DEE exhibits the highest cycling retention (65.0%) compared to the baseline electrolyte (49.8%) because it effectively protects the interface of the Li anode, but also suppresses the dissolution of polysulfide species.