Our work group member Dr. Vladislav Ivaništšev went to University of Santiago de Compostela, Spain for a short term scientific mission. Thank you for the brilliant work there.
Abstract
In this STSM visit were performed molecular dynamic simulations of mixtures of ionic liquids (ILs) with water, mono- and divalent salts of electrochemical interest both in the bulk and near neutral and charged graphene walls. The focus was on the general trends that determine ionic solvation and solute–electrode interactions in ILs and we show the main mechanisms of ionic solvation in these dense ionic media related to the layered structure of the IL at the electrolyte–electrode interface that imposes potential energy barriers for the ions moving the direction normal to the electrode surface. Specifically, we studied the solvation of mono- and divalent ions in ILs and we also obtained results for structure and single-particle dynamics of mixtures of divalent salts with a 1-butyl-3-methylimidazolium tetrafluoroborate. The effect of salt concentration and of the size and valence of the salt cations on the ionic solvation and on the barriers’ parameters was analyzed. For example, we found that the stronger solvation of Li+ in the ionic liquid leads to a formation of significantly higher interfacial free energy barriers for Li+ to come to the electrode than for K+. Moreover, some preliminary insights were obtained for the interfacial behavior of mixtures of ILs with water, studying the effect of the latter on the structure of the interface under normal and nano-confined conditions.