Micromechanical model for effective thermoelectric properties of thermoelectric composite containing ellipsoidal inclusions with interfacial resistances

The effective design of thermoelectric composites is of great significance in improving performance of thermoelectric composites. Herein, we develop a homogenization theory to predict the effective thermoelectric properties of thermoelectric composite containing ellipsoidal inclusions whereby interfacial thermal and electrical resistances are considered. Firstly, the closed-form representations of the effective thermoelectric properties are derived under the assumption of a small temperature difference. Then the effective properties of the thermoelectric composite subjecting to a large temperature difference are obtained by cutting the composite to a serial connection of pieces with a small temperature difference. The relationship between the interfacial resistances and the effective properties of thermoelectric composites is discussed systematically under the different conditions of the aspect ratio, volume fraction, size of inclusion and temperature difference in the composite. Our theoretical predictions well match the effective properties obtained from finite element analysis.