Lithium bis(trifluoromethanesulfonyl)imide solution

Lithium bis(trifluoromethanesulfonyl)imide in ethylene carbonate and diethylcarbonate, 1.0 M LiTFSI in EC/DEC=50/50 (w/w) is a solution of battery-grade LiTFSI dissolved in a binary mixture of EC/DEC (50:50) wt%. The product is a clear solution with strictly minimized impurities including low moisture (<100 ppm), low trace metals (≤10 ppm Na and K), low chloride (<10 ppm), and low sulfate (<10 ppm).

The main application of 1.0 M LiTFSI in EC/DEC=50/50 (w/w) is as an electrolyte in Li-ion batteries (LIBs). LiTFSI-based electrolytes have advantages over LiPF₆-based electrolytes because they are less sensitive to hydrolysis, safer to handle, and are more stable thermally and electrochemically. The binary mixture of EC/DEC (50:50) wt% is chosen to marry the benefits of ethylene carbonate (EC) and diethyl carbonate (DEC). EC is known to form a stable, conductive solid electrolyte interphase (SEI) with many cathode anode materials, including graphite. Blending EC with DEC, a linear carbonate, results in a less viscous electrolyte that has higher ionic conductivity at ambient and low temperatures and that can better penetrate the battery separator.