Construction of Organic-Rich Solid Electrolyte Interphase for Long-Cycling Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries promise great potential as high-energy-density energy storage devices. However, the parasitic reactions between lithium polysulfides (LiPSs) and Li metal anodes render limited cycling lifespan of Li-S batteries. Herein, an organic-rich solid electrolyte interphase (SEI) is constructed to inhibit the LiPS parasitic reactions and achieve long-cycling Li-S batteries. Concretely, 1,3,5-trioxane is introduced as a reactive co-solvent that decomposes on Li anode surfaces and contributes organic components to the SEI. The as-constructed organic-rich SEI effectively inhibits the LiPS parasitic reactions and protects working Li metal anodes. Consequently, the cycling lifespan of Li-S coin cells with 50 & mu;m Li anodes and 4.0 mg cm(-2) sulfur cathodes is prolonged from 130 to 300 cycles by the organic-rich SEI. Furthermore, the organic-rich SEI enables a 3.0 Ah-level Li-S pouch cell to achieve a high energy density of 400 Wh kg(-1) and stable 26 cycles. This study affords an effective organic-rich SEI to inhibit the LiPS parasitic reactions and inspires rational SEI design to achieve long-cycling Li-S batteries.