Electrical Double Layer Properties in Diameter Asymmetric Molten Salt Investigated by Grand Canonical Monte Carlo Method

Abstract

Results of the Monte Carlo simulation of the electrode | molten salt interface are reported. The system investigated is represented by a primitive model of electrolyte in contact with a planar charged hard wall. The density of an electrolyte is comparable with the density of real molten salts. The calculations are performed for T = 1500 K, which is above the phase transition temperature determined from Monte Carlo analysis of the heat capacity C V and the radial distribution function. The density and charge profiles reveal a multilayer structure of the electrolyte in the vicinity of the electrode surface. The differential capacitance has a distorted camel-shape similar to that predicted by theory and observed for some ionic liquids.

Influence of cation chemical composition and structure on the double layer capacitance for Bi(111)|room temperature ionic liquid interface

“…The edl structure consisting of alternatingly charged layers was assumed in numerous simulations [55][56][57][58][59][60][61][62], which indirectly confirm an importance of an interesting feature of EMImBF 4 [25] and BMPyBF 4 ionic-pairs [24]. Namely the BF À 4 anion does not form H-bonds with hydrogen atoms of the pyridinium ring, but it does in EMImBF 4 ionic complex.…”

Electrical double layers and differential capacitance in molten salts from density functional theory

“…In Sec. III A, results from the DFT are compared with the Monte Carlo simulations of Lamperski and Kłos,13,14 and show good agreement with the simulations. Next, in Sec.…”

“…Further MC simulations of an asymmetric model in which the ions have different sizes showed a distorted bell-shape, with the maximum slightly negative of the pzc. 14 Recently, there have been a few atomistic molecular dynamics simulations of molten salts that studied the effects of electrode potential on the double layer. Reed et al 15 16 For atomically flat electrodes, they found a pronounced layering of the ions in the electrolyte near the electrode surface.…”

Structure of an electric double layer containing a 2:2 valency dimer electrolyte

“…measurements have begun to expose the limitations of the PM double layer. For example, ionic liquid double layers manifest a variety of C D versus electrode surface charge density σ behaviour [8][9][10][11], which can only be understood at best in rather broad terms using the RPM or the PM [12][13][14][15][16][17][18][19][20][21][22][23]. The primitive models necessarily introduce a shape symmetry in the constituent species of an electrolyte, which is probably not very realistic in the natural world.…”