1,3-PROPANE SULTONE

1,3-Propane Sultone as a Li-ion Electrolyte Additive: How It Builds the SEI, What Battery Grade Really Means, and the Regulatory Record

1,3-Propane sultone (PS, CAS 1120-71-4) appears in almost every high-voltage or high-temperature Li-ion electrolyte recipe. Grounded in first-principles studies and the current ECHA/CLP record, this article covers how PS builds the SEI before the solvent breaks down, the trace parameters that define battery grade, and the regulatory status of a Category 1B carcinogen on the REACH Candidate List.