On the theory of electric double layer with explicit account of a polarizable co-solvent

TL;DR

This paper develops a modified Poisson-Boltzmann theory incorporating co-solvent polarizability to better understand the electric double layer's differential capacitance, extending previous models with a density functional approach.

Contribution

It introduces a new theoretical framework that explicitly accounts for co-solvent polarizability within the Poisson-Boltzmann equation using a density functional approach.

Findings

Enhanced understanding of co-solvent effects on electric double layer capacitance

Derivation of a modified Poisson-Boltzmann equation considering polarizability

Application to electric double layer theory with improved accuracy

Abstract

We present a continuation of our theoretical research into the influence of co-solvent polarizability on a differential capacitance of the electric double layer [EPL 111, 28002 (2015)]. We formulate a modified Poisson-Boltzmann theory, using the formalism of density functional approach on the level of local density approximation taking into account the electrostatic interactions of ions and co-solvent molecules as well as their excluded volume. We derive the modified Poisson-Boltzmann equation, considering the three-component symmetric lattice gas model as a reference system and minimizing the grand thermodynamic potential with respect to the electrostatic potential. We apply present modified Poisson-Boltzmann equation to the electric double layer theory.