Insights into the solvation and dynamic behaviors of a lithium salt in organic- and ionic liquid-based electrolytes

Abstract

Fundamental molecular insights were provided to understand the advantages of IL solvent electrolytes with high conductivity over organic solvent electrolytes.

The Effect of Concentration of Lithium Salt on the Structural and Transport Properties of Ionic Liquid-Based Electrolytes

“…where B ij = 1 if ions i and j are inside the first coordination shell of each other; otherwise, B ij = 0. As mentioned in our previous studies, there was an anion driving effect in the IL electrolytes, i.e., lithium ions mainly interacted with anions of IL in the electrolyte solution (Tong et al, 2019). Therefore, in this section, as shown in Figure 4, we studied the effect of four lithium salt concentration on the structure and interaction of Li ions with anions in ILs by radial distribution function, coordination number, residence time, ion association trend, and solvation effect.…”

“…In Figure 2, the trends of density with concentration of LiTFSI were linear; meanwhile, viscosity was almost exponential for all IL electrolytes in this work. We previously reported that due to their strong interactions between Li + and TFSI − , adding lithium salt LiTFSI to the electrolyte led to the increase of density (Tong et al, 2019). Meanwhile, for a common cation ([C 2 mim] + or [C 4 mim] + ), [TFSI] − -type IL electrolytes had higher density and viscosity than [FSI] − -type IL electrolytes.…”

“…Recently, we also carried out a study on highly concentrated IL electrolytes. By comparing 2 mol/L lithium salt (LiTFSI) with pure organic solvents (DMC and DEC) and IL solvents ([C n mim][BF 4 ] and [C n mim][TFSI] (n = 2, 4)), we found that IL electrolytes had higher conductivity than organic solvents at high concentration of Li salt; meanwhile, the dissolution of LiTFSI in the IL solvents was an anion-driven process (Tong et al, 2019). To sum up, high concentrated IL electrolytes are promising for the development of high voltage and high energy density batteries.…”

Understanding Structural and Transport Properties of Dissolved Li2S8 in Ionic Liquid Electrolytes through Molecular Dynamics Simulations

“…Room temperature ionic liquids (ILs) exhibit prominent properties such as negligible volatility, incombustibility, and high chemical and thermal stability compared to conventional organic solvents, [13] which make them attractive for technological applications as electrolytes in energy conversion and storage devices [14–16] . Since Yang et al [17] .…”

Theoretical Insights into the Structures and Capacitive Performances of Confined Ionic Liquids

“…Despite the fact that a variety of RTILs are widely used in EDLCs, our understanding of the behavior of RTILs at charged interfaces remains elusive [27]. Most surging focus is on the role of steric and electrostatic forces in the behavior of ionic liquids [28,29], which are much stronger than that in usual electrolytes. However, the effects of the intermolecular dispersion force on the EDL structures and capacitances have been less explored.…”