Parametrization with Explicit Water of Solvents Used in Lithium Ion Batteries: Cyclic Carbonates and Linear Ethers

Molecular dynamics simulations are performed to study carbonates and ethers that are widely used in electrolytes of devices to storage energy. The first type contains in their molecular geometry a hydrocarbon tail of ethylene, propylene and butylene while in the second type they are 1,2-dimethoxyethane and 1,2-diethoxyethane. The evaluation of OPLS, CHARMM and GROMOS force fields for some of the solvents shows poor agreement with experimental thermodynamic and transport properties leading us to parameterize those solvents using the OPLS parameters as starting point. A systematic procedure that uses the solubility of the solvents as target property in simulations with explicit water is applied. The transferability of the parameters of the smallest cyclic or linear molecules was used to simulate systems with longer hydrocarbon chains. The optimized parameter reproduce the experimental solubility of butylene carbonate and 1,2-diethoxyethane in water. The interaction parameters were used to obtain the self-diffusion coefficients of ions of the salt LiPF$_{6}$ at 1 M concentration in mixtures with ethylene carbonate or propylene carbonate. The simulation results for pure components and mixtures with the new parameters are in excellent agreement with experimental data.