High-valence sulfur-containing species in solid electrolyte interphase stabilizes lithium metal anodes in lithium–sulfur batteries

Abstract

The interfacial stability of lithium metal anodes dictated by solid electrolyte interphase (SEI) is essential for long-cycling high-energy-density lithium–sulfur batteries. Nevertheless, critical components of SEI for interfacial stabilization are particularly indistinct. Herein, the effect of various sulfur-containing components in SEI for stabilizing lithium metal anodes is disclosed in lithium–sulfur batteries. High-valence sulfur-containing species (Li2SO3 and Li2SO4) in SEI are conducive to uniform lithium deposition and stabilizing lithium metal anodes. In contrast, low-valence sulfur-containing species (Li2S and Li2S2) in SEI result in aggressive lithium dendrites and dead lithium. This work identifies the role of sulfur-containing components in SEI for stabilizing lithium metal anodes and provides rational design principles of SEI for protecting lithium metal anodes in practical lithium–sulfur batteries.