On the key role of electrolyte–electrode van der Waals interactions in the simulation of ionic liquids-based supercapacitors - Archive ouverte HAL Access content directly
Journal Articles Electrochimica Acta Year : 2023

On the key role of electrolyte–electrode van der Waals interactions in the simulation of ionic liquids-based supercapacitors

Abstract

The performance of supercapacitors is governed by the structure and dynamics of ions at the solid/liquid interface. At the molecular scale, these properties result from a subtle combination of electrolyte-electrolyte and electrolyte-electrode interactions. Although the former are well captured by conventional force fields, validated against experiments, the latter are much more difficult to parameterize accurately. In this work, by using constant potential classical molecular dynamics, we investigate the effect of the strength of the electrode-electrolyte van der Waals interactions on the interfacial properties for a system composed of the 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid and a graphite electrode. We show that stronger van der Waals interactions lead to a decrease in the exchange of co-ions by counter-ions with the increase of potential difference and, thus, to a lower capacitance of the devices. The ion exchange dynamics is strongly affected, but the charging rate remains constant over the whole range of studied parameters. This study emphasizes the need for a careful parameterization of force fields for electrode materials in future classical molecular dynamics studies.
Fichier principal
Vignette du fichier
Bacon23_accepted.pdf (1.77 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Licence : CC BY - Attribution

Dates and versions

hal-04131515 , version 1 (16-06-2023)

Identifiers

Cite

Camille Bacon, Alessandra Serva, Céline Merlet, Patrice Simon, Mathieu Salanne. On the key role of electrolyte–electrode van der Waals interactions in the simulation of ionic liquids-based supercapacitors. Electrochimica Acta, 2023, 455, pp.142380. ⟨10.1016/j.electacta.2023.142380⟩. ⟨hal-04131515⟩
41 View
14 Download

Altmetric

Share

Gmail Facebook X LinkedIn More