Electrical conductivity of solutions of lithium bis(fluorosulfonyl)imide in mixed organic solvents and multi-objective solvent optimization for lithium-ion batteries

Abstract

Lithium bis(fluorosulfonyl)imide (LiFSI) is an interesting novel electrolyte for lithium-ion batteries. In the present work, the electrical conductivity of solutions of LiFSI in binary and ternary mixtures of the solvents dimethyl carbonate (DMC), ethylene carbonate (EC) and propylene carbonate (PC) was studied experimentally for concentrations of LiFSI up to 0.2 mol mol −1 at ambient pressure and temperatures between 293 and 333 K. Information on the electrical conductivity of LiFSI in the pure solvents DMC, EC, and PC is available from previous work. An empirical correlation of the electrical conductivity σ of the studied solutions of LiFSI is presented that describes the dependence of σ on the LiFSI concentration, the solvent composition, and the temperature. Based on this correlation, a multi-objective optimization of the LiFSI concentration and the solvent composition was carried out with two conflicting objectives relevant to the performance and costs of batteries: maximizing electrical conductivity and minimizing the amount of the expensive electrolyte LiFSI. The solubility limits of the ternary solvent system DMC-EC-PC were included in the optimization as

Self‐Diffusion Coefficients in Solutions of Lithium Bis(fluorosulfonyl)imide with Dimethyl Carbonate and Ethylene Carbonate

“…Interesting solvents for LiFSI in LiB electrolytes are dimethyl carbonate (DMC) and ethylene carbonate (EC) [7,8,10]. Solutions of LiFSI in these solvents have a high electrical conductivity [6,[11][12][13][14][15][16][17].…”

“…Information on diffusion coefficients is of great interest for the modeling of transport processes in LiB and the rational design of LiB electrolyte solutions . Despite the high interest in LiFSI‐based electrolyte solutions, little is known to date on diffusion coefficients in LiFSI solutions in solvents such as DMC and EC.…”

Transport properties of lithium-ion in green nonaqueous solutions and polymer ionic exchange membranes: an attempt to elaboration of ecological Li-ion battery

“…As shown previously, a strategy was undertaken to find electrolyte solutions of an optimal composition for the conflicting objectives: maximizing electrical conductivity and minimizing conductive lithium salt content. These objectives are representatives of the aims: maximization of performance and reduction costs of lithium-based salts used in Li-ion batteries [6].…”

“…Moreover, due to its high reactivity with oxygen, the electrolytes commonly used in such devices are mixtures of organic solvents and lithium-based salts. Recent experimental study on the electrical conductivity of solutions of lithium bis(fluorosulfonyl) imide (LiFSI) in organic solvents: dimethyl carbonate (DMC), ethylene carbonate (EC) and propylene carbonate (PC), was carried out for low concentrations at ambient, pressure and temperatures between 293 and 333 K, for solvent optimization in lithium-ion battery [6]. More recently, valeronitrile has been proved to be a good solvent for the salt lithium bis(fluorosulfonyl) imide (LiFSI) in lithium batteries, since it forms complexes with the Li + -ions.…”

A review on conductometric studies of electrolytes in mixed solvent systems to understand ion-ion and ion-solvent interactions

“…Another electrolyte Lithium bis(fluorosulfonyl)imide (LiFSI) has taken over the market because of its higher elctrical conductivity in organic solvents [59]. In order to study its physicochemical properties in different organic solvents Johannes Neuhaus and coworkersmeasured the electrical conductivity of solutions of LiFSI in dimethyl carbonate (DMC), ethylene carbonate (EC) and propylene carbonate (PC) [60] and in their binary and ternary mixtures [61]. Optimization of performance and cost of the battery was proposed based on the correlation of electrical conductivity with Li salt concentration, solvent composition and temperature.…”