Development of coarse-grained force field to investigate sodium-ion transport mechanisms in cyanoborate-based ionic liquid

Autor: Rafael Maglia de Souza, Tuanan C. Lourenço, Luís G. Dias, Juarez L. F. Da Silva, Mikko Karttunen, Leonardo J. A. Siqueira
Rok vydání: 2021
Předmět:
Zdroj: Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP
Popis: Sodium-ion batteries have a great potential for energy storage applications, however, its realization depends strongly on a deep atomistic understanding of the sodium-ion transport mechanisms, which is a key step to optimize its performance. A complete characterization of sodium-ion transport mechanism requires large time-scale calculations, which is a challenge even for classical atomistic force-field molecular dynamics simulations. Thus, in this work, we performed a calibration of a coarse-grained force-field to describe the thermodynamic and transport properties of sodium-ion for the particular case of cyanoborate-based ionic liquid using different molar fractions of sodium tetracyanoborate salt dissolved in 1-ethyl-3-methyl-imidazolium tetracyanoborate. The results from coarse-grained modeling were found to be in fair agreement with atomistic simulations and experimental data, and they captured concentration dependence of [Nax[Anion]y]x−y aggregate sizes. In particular, two distinct populations of sodium-ions were identified inside the [Nax[Anion]y]x−y aggregates: 1) a slow one in vehicular diffusion and 2) a fast one in hoping diffusion. Both of them contribute to sodium ion transport and occur preferentially at different sodium-ion concentrations. The present findings were obtained for a cyanoborate-based ionic liquid, however, we expect that our insights can be used to understand similar ionic liquids.
Databáze: OpenAIRE