Stability of ionic liquid modeled by composite Coulomb-Yukawa potentials

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Stability of ionic liquid modeled by composite Coulomb-Yukawa potentials

Guilherme Volpe Bossa and Sylvio May

Phys. Rev. Research 2, 032040(R) – Published 18 August 2020

Abstract

An ionic liquid modeled as a densely packed lattice with composite ion-specific Coulomb-Yukawa pair interactions tends to be unstable near a planar electrode, given the Yukawa potential mediates an effective short-range attraction of the ions. We present a comprehensive mean-field model, accounting for ion-specific electrode-ion interactions and for the propagation of the Yukawa field into the electrode. The surface instability precedes the spinodal instability of the ionic liquid and may thus lead to hysteresis and to a large differential capacitance in the metastable region of the phase diagram, but not necessarily to oscillations of the net charge density.

Received 20 June 2020
Accepted 2 August 2020

DOI:https://doi.org/10.1103/PhysRevResearch.2.032040

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society

Physics Subject Headings (PhySH)

Electrostatic interactions Phase transitions Surface instabilities

Ionic fluids

Mean field theory

Polymers & Soft Matter

Authors & Affiliations

Guilherme Volpe Bossa¹ and Sylvio May ²

¹Department of Physics, São Paulo State University (UNESP), Institute of Biosciences, Humanities and Exact Sciences, São José do Rio Preto, SP 15054-000, Brazil
²Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050, USA