Decoupling electrocaloric effect from Joule heating in a solid state cooling device

TL;DR

This study analyzes the electrocaloric effect in BaTiO3-based capacitors, distinguishing it from Joule heating through heat dynamics measurements, to improve solid-state cooling device development.

Contribution

It provides a method to decouple electrocaloric effects from Joule heating in solid-state cooling devices using temperature evolution analysis.

Findings

Joule heating and electrocaloric effect occur at different time scales.

Thermal coupling influences the heat dynamics in the device.

Accurate modeling requires considering Joule heating and environmental coupling.

Abstract

We report a heat dynamics analysis of the electrocaloric effect (ECE) in commercial multilayer capacitors based on BaTiO3 dielectric, a promising candidate for applications as a solid state cooling device. Direct measurements of the time evolution of the sample's temperature changes under different applied voltages allow us to decouple the contributions from Joule heating and from the ECE. Heat balance equations were used to model the thermal coupling between different parts of the system. Fingerprints of Joule heating and the ECE could be resolved at different time scales. We argue that Joule heating and the thermal coupling of the device to the environment must be carefully taken in to account in future developments of refrigeration technologies employing the ECE.