Lithium-metal batteries (LMBs) promise energy densities exceeding 500 Wh/kg by replacinggraphite anodes with metallic lithium, but face critical challenges including unstable solidelectrolyte interphase (SEI) formation, dendrite growth, and electrolyte decomposition athigh voltages (>4.5 V vs. Li/Li ). Sulfone-based solvents offer excellent ⁺ oxidative stabilityand low flammability, yet often exhibit poor compatibility with Li-metal anodes due toinadequate SEI formation and wettability. This paper proposes methyl vinyl sulfone (MVS; CAS 3680-02-2, SMILES: CS(=O)(=O)C=C, IUPAC: ethenyl(methyl)sulfone) as a sacrificial additive tailored for sulfone-basedelectrolytes. The vinyl group conjugated to the sulfone moiety enables preferential reductionat ~1.1 V vs. Li/Li⁺, promoting polymerization and formation of a flexible, inorganic-rich SEIcontaining Li₂SO₃, Li₂SO₄, and polymeric species. This hybrid SEI is designed to be ionicallyconductive, electronically insulating, and mechanically robust—addressing dendritesuppression while maintaining compatibility with high-voltage cathodes such asLiNi₀.₅Mn₁.₅O₄ (LNMO) or NCM811. Supported by frontier molecular orbital considerations (low LUMO for anode priority, highHOMO for cathode stability) and a practical 5-step synthesis route, the additive builds onprecedents of vinyl sulfones as SEI formers and ongoing sulfone electrolyte development.This framework is explicitly hypothesis-generating: while vinyl sulfones have shown promisein carbonate systems and sulfones excel in high-voltage stability, targeted testing in fullsulfone/Li-metal cells is essential to confirm performance, optimal concentration (typically1–5 wt%), and long-term cycling. If successful, MVS could accelerate commercialization ofsafer, higher-energy-density LMBs for electric vehicles, grid storage, and portableelectronics. ETH/EVM Donation: 0xce1E3BEeA89e25B567De17d62dCDE1e8B0C6f7DA
Brent Allen Jensen (Mon,) studied this question.