Transverse Thermoelectricity in Fibrous Composite Materials

Abstract

Transverse thermoelectric elements have the potential to decouple the electric current and the heat flow, which could lead to new designs of thermoelectric devices. While many theoretical and experimental studies of transverse thermoelectricity have focused on layered structures, this work examines composite materials with aligned fibrous inclusions. A simplified mathematical model was derived based on the Kirchhoff Circuit Laws (KCL), which were used to calculate the equivalent transport properties of the composite structures. These equivalent properties, including Seebeck coefficient, electrical conductivity, and thermal conductivity, compared well with finite element analysis (FEA) results. Peltier cooling performance was also examined using FEA, which exhibited good agreement to KCL model predictions. In addition, a survey was conducted on selected combinations of thermoelectric materials and metals to rank their transverse thermoelectricity with respect to the dimensionless figure of merit.

Quantitative Analysis on Influence of Structural Conditions on Thermoelectric Properties of Tilted Rod-Ni/Mg₂Si Composites Based on Finite Element Simulation

“…For manufacturing a ¬-structural thermoelectric module using n-type Mg 2 Si, a p-type material with a similar level of the thermoelectric performance and the coefficient of thermal expansion with Mg 2 Si is required. Although researches on p-type Mg 2 Si-based materials have been reported, 17) the materials with sufficient thermoelectric performance have not been developed yet. Since the fracture toughness of Mg 2 Si is as low as about 20% of Al 2 O 3 and about 60% of Bi 2 Te 3 , 8) cracking due to thermal stress during the production and use of ¬-structural thermoelectric modules poses a problem of element destruction.…”