Mapping the Free Energy of Lithium Solvation in the Protic Ionic Liquid Ethylammonuim Nitrate: A Metadynamics Study

Abstract

Understanding lithium solvation and transport in ionic liquids is important due to their possible application in electrochemical devices. Using first-principles simulations aided by a metadynamics approach we study the free-energy landscape for lithium ions at infinite dilution in ethylammonium nitrate, a protic ionic liquid. We analyze the local structure of the liquid around the lithium cation and obtain a quantitative picture in agreement with experimental findings. Our simulations show that the lowest two free energy minima correspond to conformations with the lithium ion being solvated either by three or four nitrate ions with a transition barrier between them of 0.2 \eV. Other less probable conformations having different solvation pattern are also investigated.

References in corpus (4)

• Polarization effects in ionic solids and melts
• Simulations of room temperature ionic liquids: From polarizable to coarse-grained force fields
• Li+ solvation in pure, binary and ternary mixtures of organic carbonate electrolytes
• From molten salts to room temperature ionic liquids: Simulation studies on chloroaluminate systems