Investigation of effective thermoelectric properties of composite with interfacial resistance using micromechanics-based homogenisation

TL;DR

This paper develops an analytical model for the effective thermoelectric properties of composites considering interfacial resistances, validated by finite-element analysis, and discusses extensions to large temperature differences.

Contribution

It introduces a micromechanics-based homogenisation method that accounts for interfacial resistances and derives the Eshelby tensor for spherical inclusions, a novel approach.

Findings

Analytical expressions for effective thermoelectric properties were validated against FEA.

The model accurately predicts properties for inclusions up to 15% volume fraction.

A heuristic method is proposed for large temperature difference scenarios.

Abstract

We obtained the analytical expression for the effective thermoelectric properties and dimensionless figure of merit of a composite with interfacial electrical and thermal resistances using a micromechanics-based homogenisation. For the first time, we derived the Eshelby tensor for a spherical inclusion as a function of the interfacial resistances and obtained the solutions of the effective Seebeck coefficient and the electrical and thermal conductivities of a composite, which were validated against finite-element analysis (FEA). Our analytical predictions well match the effective properties obtained from FEA with an inclusion volume fraction up to 15%. Because the effective properties were derived with the assumption of a small temperature difference, we discuss a heuristic method for obtaining the effective properties in the case where a thermoelectric composite is subjected to a large temperature difference.