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arXiv · 2110.07008

Conductivity of Concentrated Electrolytes

Yael Avni·Ram M. Adar·David Andelman·Henri Orland
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Abstract

The conductivity of ionic solutions is arguably their most important trait, being widely used in electrochemical, biochemical, and environmental applications. The Debye-H\"uckel-Onsager theory successfully predicts the conductivity at very low ionic concentrations of up to a few millimolars, but there is no well-established theory applicable at higher concentrations. We study the conductivity of ionic solutions using a stochastic density functional theory, paired with a modified Coulomb interaction that accounts for the hard-core repulsion between the ions. The modified potential suppresses unphysical, short-range electrostatic interactions, which are present in the Debye-H\"uckel-Onsager theory. Our results for the conductivity show very good agreement with experimental data up to 3 molars, without any fit parameters. We provide a compact expression for the conductivity, accompanied by a simple analytical approximation.

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Yael Avni, Ram M. Adar, David Andelman, Henri Orland. 2021-10-13. Conductivity of Concentrated Electrolytes. https://doi.org/10.1103/physrevlett.128.098002

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