TFEMS {1,1,1-Trifluoro-2-(methylsulfonyl)ethane, >99.0%} as Battery Electrolyte Additive, 5 g/bottle, CBEATFEMS

1,1,1-Trifluoro-2-(methylsulfonyl)ethane (commonly designated as TFEMS) is a specialized beta-fluorinated sulfone engineered as an advanced high-voltage co-solvent, structural modifier, and functional interphase-directing additive for next-generation lithium-ion and lithium-metal batteries. By incorporating a strongly electron-withdrawing trifluoroethyl group adjacent to a stable sulfonyl center (-SO2-), TFEMS achieves exceptional oxidative stability without the severe cathodic degradation issues characteristic of overly reactive alpha-fluorinated analogues.

Its functional roles in electrolyte engineering are: (1) High-Voltage Anodic Stability: Because of the strong electron-withdrawing influence of the terminal trifluoroethyl segment, TFEMS exhibits high resistance to oxidative decomposition, protecting the electrolyte against premature breakdown when operating upper-cutoff voltages. (2) Interphase & SEI Support: It assists in regulating reductive decomposition pathways at the anode interface, helping construct stable protective layers when paired with appropriate co-solvents (such as fluoroethylene carbonate, FEC). (3) Safety & Thermal Enhancement: The robust sulfone architecture combined with a high fluorine fraction suppresses flammability and elevates thermal stability compared to conventional linear carbonate or ether master matrices.

The primary electrochemical domains are: (1) High-Voltage Lithium-Ion Full Cells: Integrated into specialized electrolyte formulations to support nickel-rich or high-voltage transition metal oxide cathodes operating well above standard electrochemical limits. (2) Wide-Temperature and Extreme-Condition Cells: Deployed to extend operational safety margins and prevent runaway thermal events in demanding storage and cycling environments.

Part Number	CBEATFEMS (C-BEA-TFEMS)
CAS	222611-23-6
Chemical Formula	C₃H₅F₃O₂S
Appearance	Colorless Liquid
Purity	>99.0%
Molecular Weight	162.13 g/mol
Package Size	5 g/bottle

Notes: Please store the TFEMS liquid in the dry place (glovebox is the best).

References: 

1. R. Li, et al. Unified affinity paradigm for the rational design of high-efficiency lithium metal electrolytes, Nature Energy, 2025, 10, 1155–1165
2. Y. H. T. Tran, et al. High-Voltage Electrolyte and Interface Design for Mid-Nickel High-Energy Li-Ion Batteries, ACS Energy Lett. (2025) 10 (1): 356–370.