Molecular dynamics simulations of Lithium Fluoride aqueous solutions: Effects of ion concentration on the structural and dynamical properties at T=300 K

Abstract

Lithium fluoride aqueous system play an important role in a variety of chemical engineering, energy, biochemistry and environmental processes. Lithium salts are also widely used in conventional electrolytes for making lithium-ion batteries. Computer simulation of lithium in fluoride aqueous solution has an important tool in understanding the structural and dynamical characteristics of ionic complexes. In this investigation, the structural and dynamical properties of supersatured LiF systems have been studied by molecular dynamics simulations at different molalities range from 0.05 up to 2.00 mol.Kg-1 using extended simple point charge (SPC/E) water model and the ions which are modeled as charged Lennard-Jones particles. Molecular dynamics simulations return highly complex data. The cartesian positions of each atom of lithium chloride aqueous solution are recorded at every time step of the trajectory. Therefore, the analysis of data requires to calculate the radial distribution functions (RDFs) describing the structure of the hydration shells around the ions in solutions and the hydration number. The structural properties of the water and Li+ and F- ions, such as the coordination number, interparticle distance, self-diffusion coefficient and dielectric constant are strongly depending on the molality and chemical nature of counterions.