FEM Analysis on Thermoelectric Properties of Metal/TiO<sub>2–x</sub> Composites with Random Distribution of Metal Powder

Analysis model of finite element method with a random distribution for thermoelectric composites was built. Thermoelectric properties including electrical resistivity, Seebeck coefficient and thermal conductivity of M/TiO 2–x (M = Cu, Ni, 304 stainless steel (304SS)) thermoelectric composites were investigated by the proposed model. Cu/TiO 2–x composite showed a large decrease in electrical resistivity while 304SS/TiO 2–x composite thermal conductivity was slightly increased. Calculated dimensionless figure-of-merit, ZT of Ni/TiO 2–x composite was higher than those of TiO 2–x and the other composites in a wide range of metal volume fractions because Ni has large absolute values of Seebeck coefficient, power factor and dimensionless figure-of-merit compared to the other two metals. It was found that power factor and dimensionless figure-of-merit of thermoelectric composites depended on the balance among electrical resistivity, thermal conductivity and Seebeck coefficient. The results revealed that it is important for M/TiO 2–x composites to choose suitable addition metal with high power factor and dimensionless figure-of-merit.