Molecular dynamics simulations of the structure of mixtures of protic ionic liquids and monovalent and divalent salts at the electrochemical interface

Abstract

We perform molecular dynamics simulations of mixtures of a prototypical protic ionic liquid, ethylammonium nitrate, with lithium or magnesium nitrate (LiNO3/Mg(NO3)2) confined between two graphene walls. The structure of the system is analyzed by means of ionic density profiles, angular orientations of ethylammonium cations close to the wall and the lateral structure of the first layer close to the graphene wall. All these results are compared to those of the corresponding aprotic ionic liquid systems, analyzing the influence of the graphene wall charge in the structure of the protic and aprotic mixtures. Moreover, vibrational densities of states are calculated for the salt cations close to the walls. Finally, we investigate the structure of the mixture with Li salt near the interface using ab initio density functional theory, and the results are compared with those obtained by classical molecular dynamics simulations.

Borophene vs. graphene interfaces: Tuning the electric double layer in ionic liquids

“…2 bottom). This phenomenon matches the already well-known resiliency of IL structure upon salt doping, which has been reported in previous works [41][42][43]71]. There are, however, some small differences in the structure of the electric double layer when lithium cations are added, especially in the neutral interface, where the presence of Li + ions at 0.65 nm ( Fig.…”

“…A great number of publications centered around this particular topic have been reported, dealing with alkali metals combined with various ILs (mainly bis(trifluoromethylsulfonyl)imide, TFSI, as the anion, and cations belonging to the pyrrolidinium, piperidinium, alkylammonium or imidazolium families) , but also with some higher-valence salts [35][36][37][38][39][40][41][42][43]. Some of these studies have been done using computer simulation, including classical molecular dynamics (MD) and density functional theory (DFT), to analyze the microscopic mechanisms behind solvation, structure, and transport in these media, both in the bulk or at the electrochemical interface, usually represented by a graphene virtual electrode (see, e. g., Refs.…”

“…44 and 45). The ordering of IL-based electrolytes at this electrochemical interface has been studied with great detail for mixtures of ILs with Li [41,42,46,47], Mg [41,42], and Al [43].…”

Capacitive Performance of Water-in-Salt Electrolytes in Supercapacitors: A Simulation Study

“…7,8 In general, the main changes are attributed to the interfacial layer structure (or local structure) of the liquid electrolyte. [9][10][11][12][13] Different pore sizes in nanoporous electrodes accompanying complex local structures have a large impact on the capacitance compared with non-porous electrodes. [14][15][16][17] However, the capacitance can also take a wide range of values both in experiment and simulation even if the electrodes are planar.…”

Interparticle interactions and dynamics in BmimBF4 and LiBF4 solutions in propylene carbonate: MD simulation

“…https://doi.org/10.26565/2220-637X-2019- Как известно, методы молекулярного моделирования, в частности -молекулярнодинамического моделирования (МДМ), являются одними из самых мощных методов анализа таких систем [10][11][12][13][14][15][16]. В числе прочего, они позволяют исследовать микроскопические характеристики ионной сольватации в них, которые являются труднодоступными для получения в «классических» экспериментах [17][18][19].…”