LiTFSI

Description

Lithium bis(trifluoromethylsulphonyl)imide (LiTFSI) is normally used as a p-dopant to enhance the conductivity and hole mobility of the Spiro-OMeTAD for perovskite solar cells. It is believed that The function of LiTFSI in PSCs is similar to that in solid-state dye-sensitised solar cells.

Chemical Properties

White hygroscopic powder

Uses

Lithium bis(trifluoromethylsulfonyl)imide is used in the preparation of chiral imidazolium salt through an anion metathesis of the corresponding triflate organic electrolyte-based lithium batteries. It finds application in the preparation of rare-earth Lewis acid catalysts. It is also useful in primary and secondary lithium cells using organic liquid electrolytes and polymer batteries.

General Description

Bis(trifluoromethane)sulfonimide lithium salt is a synthetic reagent.

Flammability and Explosibility

Non flammable

Battery Materials

The non-isothermal kinetics of poly (ε-caprolactone) (PCL):lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) and PEO:LiTFSI systems were explored, leading to the identification of different behaviors of effective crystal growth rate dependencies with temperature for PEO:LiTFSI (linear) and PCL:LiTFSI (exponential). Comparative study of these two SPE systems enabled the advancement of understanding on the role of LiTFSI in the crystallization process for both poly (ether) and poly (ester) based solid polymer electrolytes^[1].

Synthesis

5.91 g of anhydrous lithium fluoride and N-butyl-bistrifluoromethylsulfonimide 51.26 g. Add to 250 g of isopropyl acetate and reflux for 10 hours. It was filtered after being cooled to room temperature, and the filtrate was concentrated to dryness under reduced pressure.200 g of dichloromethane was added dropwise, and the mixture was stirred at 20 ° C for 2 hours and then filtered. Wash with dichloromethane. The filter cake was dried at 80 ° C to obtain 39.57 g of Lithium bis(trifluoromethanesulphonyl)imide. The yield is 90.7%.

Properties and Applications

Lithium bis(trifluoromethanesulphonyl)imide (LiTFSI) is a hydrophilic organic salt with many uses in electric and electronic systems. Its bis(trifluoromethane)sulfonimide anion, often called bistriflimide, is helpful in coordinating weakly with cations. LiTFSI's other important property is its extremely high solubility in water: 21 molal or ≈6 kg/L of solution. LiTFSI is safer than the formerly used salt, lithium hexafluorophosphate (LiPF6). To improve the cells' ability to transport electrical charges, researchers are doped with a combination of LiTFSI and a semiconductor called Spiro-OMeTAD1; however, this process is extremely slow. Taylor and his fellow researchers solved the problem by bubbling carbon dioxide into a solution of spiro-OMeTAD and LiTFSI while irradiating the mixture with ultraviolet light. They then cast a film from the solution onto the perovskite light absorber. The process can be completed in ≈1 minute, compared with the older, hours-long doping procedure.

Toxics Screening Level

There are two Initial Threshold Screening Levels (ITSLs) for lithium bis(trifluoromethane sulfonyl)imide (LiTFMSI) (CAS No. 90076-65-6): Acute ITSL: 40 μg/m3 with a 24-hr. averaging time, and Chronic ITSL: 1 μg/m3 with an annual averaging time

References

[1] Perodeau, T., Vargas, J. A., Dollé, M., & Laventure, A. (2026). Exploring the impact of LiTFSI on solid polymer electrolytes crystallization behavior. Polymer, 352, Article 129839. https://doi.org/10.1016/j.polymer.2026.129839