First-principles molecular dynamics study for S − O bond dissociation of sulfolane on Li-metal negative electrode

Highlights: • Two S$-$O bonds of sulfolane preferentially dissociate on the Li surface. • The second S$-$O dissociation reaction is much faster than the first one. • Li₂O might have been formed on the surface of Li-metal. Sulfolane (SL) has attracted a great deal of interest as an electrolyte solvent in Li-metal batteries owing to its suitable properties. In this study, we performed a first-principles molecular dynamics simulation involving an Li metal $|$ LiB$F_4$-SL liquid interface. It was found that two S$-$O bonds of SL preferentially dissociate on the Li surface, while decomposition of B$F_4$ was not observed. Since the dissociated O atoms dissolved into the Li surface, our results indicate that an Li-oxide layer formed on the Li surface, which suggests that a preferable performance of the Li-metal negative electrode can be expected for this system.