Merck, 940496, LiTDI

General description
Lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI) is an innovative electrolytic salt and additive for lithium-ion battery technologies. With a purity level of 99.9%, our battery grade LiTDI is suitable for use in liquid electrolyte formulations and polymer electrolytes.
Application
LiTDI electrolyte powder is a high-purity lithium salt tailored for use in lithium-ion batteries, where it functions as both a salt and an additive. LiTDI stands out for its high thermal stability, capable of withstanding temperatures up to 250 °C, and exhibits high oxidation stability up to 4.6 V versus Li+/Li. These properties make it a suitable alternative to LiPF6, especially in applications with elevated operating temperatures. Additionally, LiTDI-based electrolytes tend to outperform LiPF6-based electrolytes in batteries with nanosilicon anodes, as the former has no side reactions with the active Si materials. However, the solubility profile of LiTDI requires attention in electrolyte formulations; while soluble in carbonate blends like EC/DMC at 1M concentrations, LiTDI shows reduced solubility in EMC, which can influence ionic conductivity. Additionally, electrolyte formulations with LiTDI perform best when SEI forming additives like FEC are included in the formulation.

In practice, LiTDI is often employed in conjunction with LiPF6, serving as an additive or a co-salt in concentrations that range from 2 wt% to 0.5M, to enhance the electrolyte′s thermal stability and to mitigate corrosion issues. The use of LiTDI also extends to polymer electrolytes, such as PEO-LiTDI systems, and offer a niche advantage to operate at very high temperatures (250 °C).