The effect of short-range interaction and correlations on the charge and electric field distribution in a model solid electrolyte

TL;DR

This study models a solid electrolyte with mobile cations, examining how short-range interactions and correlations influence charge and electric field distributions within a confined lattice system.

Contribution

It introduces a mean field approach extended to include short-range correlation effects in a lattice model of solid electrolytes.

Findings

Short-range interactions cause asymmetry in charge distribution.

Correlations significantly affect electric field profiles.

Model predicts distribution changes under different conditions.

Abstract

A simple lattice model of a solid electrolyte presented as a xy-slab geometry system of mobile cations on a background of energetic landscape of the host system and a compensating field of uniformly distributed anions is studied. The system is confined in the z-direction between two oppositely charged walls, which are in parallel to xy-plane. Besides the long-range Coulomb interactions appearing in the system, the short-range attractive potential between cations is considered in our study. We propose the mean field description of this model and extend it by taking into account correlation effects at short distances. Using the free energy minimization at each of z-coordinates, the corresponding set of non-linear equations for the chemical potential is derived. The set of equations was solved numerically with respect to the charge density distribution in order to calculate the cations distribution profile and the electrostatic potential in the system along z-direction under different conditions. An asymmetry of charge distribution profile with respect to the midplane of the system is observed. The effects of the short-range interactions and pair correlations on the charge and electric field distributions are demonstrated.