Monte Carlo simulations of ion correlations and transport in highly concentrated liquid electrolytes

Abstract

Highly concentrated electrolytes (HCEs) exhibit promising properties for battery applications, such as low vapor pressure, high thermal stability and good compatibility with electrode materials. However, the charge and mass properties of HCEs in batteries are strongly influenced by volume conservation constraints as well as by interionic Coulomb interactions and cation–solvent interactions. In order to obtain a better understanding of the influence of volume conservation and different types of interactions on correlated movements of ions and solvent molecules as well as on the resulting transport properties, dynamic Monte Carlo simulations of highly concentrated electrolytes were carried out. Diffusion coefficients and Onsager transport coefficients were calculated for variable molar ratios of salt to solvent, variable partial volume ratios of solvent molecules to anions and for variable interaction strengths. The simulation results were compared to recent experimental results.