Microscopic theory for electrocaloric effects in planar double layer systems

TL;DR

This paper develops a field theory to analyze electrocaloric effects in electrolyte solutions, highlighting the importance of steric effects and dielectric properties, and discovering potential for negative electrocaloric effects.

Contribution

It introduces a novel theoretical framework incorporating steric and dielectric effects to accurately predict electrocaloric responses in electrolyte solutions.

Findings

Electrolyte solutions can exhibit negative electrocaloric effects.

Steric effects and dielectric function are crucial for accurate predictions.

Using fluids with low heat capacity and high salt concentration enhances electrocaloric effects.

Abstract

We present a field theory approach to study changes in local temperature due to an applied electric field (the electrocaloric effect) in electrolyte solutions. Steric effects and a field-dependent dielectric function are found to be of paramount importance for accurate estimations of the electrocaloric effect. Interestingly, electrolyte solutions are found to exhibit negative electrocaloric effects. Overall, our results point toward using fluids near room temperature with low heat capacity and high salt concentration for enhanced electrocalorics.