Communication—First-Principles Simulations of LiPF6 Decomposition in Ethylene Carbonate-Based Electrolytes

Abstract

We revisit a theoretical result by Okamoto (2013 Journal of The Electrochemical Society, 160, A404) who calculated the energy barrier for the decomposition of lithium hexafluorophosphate (LiPF6) into LiF + PF5 when solvated in Ethylene carbonate (EC)-based electrolyte. Using different numerical techniques to discretize the Density Functional Theory (DFT) equations, and different continuum solvation models with the same dielectric constant, our results largely confirm the original calculation. However, simulations with a higher dielectric permittivity value, closer to that of EC, show a lower energy barrier. More importantly, First-Principles simulations with an explicit solvent show a substantially lower energy barrier.