Power Generation Performance of Thermoelectric Module Consisting of Sb-Doped Heusler Fe₂VAl Sintered Alloy

Abstract

Power generation performance of the thermoelectric module consisting of the Sb-doped Heusler Fe₂VAl alloy was evaluated. For the construction of the module, conduction type controlled Fe₂VAl alloys were prepared by adjusting the valence electron density. For the enhancement of thermoelectric properties of the n-type Sb-substituted Fe₂VAl alloy, Al site was additionally substituted by Si. In order to change the conduction type from n-type to p-type, additional Ti substitution for the V site was examined and large positive Seebeck coefficient was obtained. Power generation test of the module consisting of these alloys was conducted on a hot plate of 573 K in air. The maximum output power of the thermoelectric module consisting of 18 pairs of p-n junction was estimated to be 2.5 W. The reduction of thermal conductivity by the Sb-doping increased temperature difference at thermoelectric elements, resulting in the enhancement of output power.