Diffusion in ternary electrolyte mixtures by dynamic light scattering and molecular dynamics simulations

Kankanamge CJ, Senadeera KR, Klein T, Fröba AP (2026)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2026

Journal

Electrochimica Acta Elsevier

Book Volume: 574

Article Number: 149452

DOI: 10.1016/j.electacta.2026.149452

Abstract

This work contributes to the development of an understanding of diffusive mass transport in ternary electrolyte mixtures of technical relevance. For this, ternary electrolyte mixtures containing lithium bis(trifluoromethylsulfonyl)imide ([Li][NTf2]) dissolved in binary mixtures of acetonitrile (ACN) with either dimethyl carbonate (DMC) or dimethyl sulfoxide (DMSO) are characterized by determining mass diffusivities using dynamic light scattering (DLS) and equilibrium molecular dynamics (MD) simulations over a broad range of temperatures, as well as solute and solvent compositions. By DLS, the eigenvalues of the second-order Fick diffusion coefficient matrix D could be accessed with an average expanded experimental uncertainty (coverage factor k = 2) of 11%. For the first time, the methodology for accessing Fick diffusion coefficients Dij of ternary electrolyte mixtures in the amount-averaged reference frame by MD simulations is presented. For this, Maxwell–Stefan (MS) diffusion coefficients Đij and thermodynamic factors Γij are obtained separately and combined to obtain Dij . With the help of the eigenvalues of D from DLS, the MD simulations and the employed force fields could be validated. By combining the results from DLS and MD simulations, the influence of the intermolecular interactions on the diffusive mass transport could be studied. For mixtures based on ACN and DMC, for example, negative off-diagonal elements of D could be linked to a diffusion of ACN molecules towards lithium cations due to the involvement in the dissociation of the ions. These observations were further corroborated by MD simulations by studying the composition of the solvation shell surrounding the cations.

Authors with CRIS profile

Kisal Randula Senadeera Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Tobias Klein Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Andreas Paul Fröba Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP)

Additional Organisation(s)

Erlangen Graduate School in Advanced Optical Technologies (SAOT)

Related research project(s)

Characterization of molecular diffusion in electrolyte systems July 1, 2021 - June 30, 2024

How to cite

APA:

Kankanamge, C.J., Senadeera, K.R., Klein, T., & Fröba, A.P. (2026). Diffusion in ternary electrolyte mixtures by dynamic light scattering and molecular dynamics simulations. Electrochimica Acta, 574. https://doi.org/10.1016/j.electacta.2026.149452

MLA:

Kankanamge, Chathura J., et al. "Diffusion in ternary electrolyte mixtures by dynamic light scattering and molecular dynamics simulations." Electrochimica Acta 574 (2026).

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