Yingjun Cai - Photo: Christian Ove Carlsson

CERE Seminar by Yingjun Cai

"Performance of VAIMTFSI((1-vinyl-3-acetamido imidazole bis(trifluoromethylsulfonyl) imide) ionic liquid in Binary and Ternary Mixtures"

Ionic liquids were intensively studied as one component of the electrolyte in lithium batteries, owing to their perfect characteristics of having low melting-temperature, being non-volatile, having high specific conductivity and having a wide ranging electrochemical window.

Acetonitrile has a convenient liquid range and a high dielectric constant of 38.8, which is often used as solvent in electric devices such as lithium batteries and supercapacitors. Acetonitrile can easily dissolve solutes exhibiting excellent ionic conductivity that may contribute to fast-charging lithium batteries.

In this research, a new type of multifunctional ionic liquid, 1-vinyl-3-imidazole bis(trifluoromethylsulfonyl) imide ([VAIM][TFSI]) was synthesized. The physicochemical and electrochemical properties of pure ionic liquid and binary and ternary mixtures were measured at temperatures from 298.15 to 333.15 K and at pressure of 0.1 MPa.  Excellent properties of pure ionic liquid were found, including high thermal stability, wide temperature adaptability and definite conductivity. The highest conductivity was obtained for the binary mixture with 0.07 mole fraction ionic liquid. The ternary mixture of ionic liquid, acetonitrile and lithium salt has  better properties as battery electrolyte. The ionic liquid is used as an additive to enhance the conductivity of the electrolyte and can form a film, which can improve the cyclic life of lithium batteries.


Thu 03 May 18
9:00 - 10:00