Fabrication of Thermoelectric Module Consisting of Rare-Earth-Filled Skutterudite Compounds and Evaluation of Its Power Generation Performance in Air

Abstract

Thermoelectric generation modules consisting of pairs of p-type CeFe₃CoSb₁₂ and n-type Yb_0.15Co₄Sb₁₂ have been fabricated using Ag sheets as electrodes and metal paste as bonding material. In the module using Ag-23mass%Pd paste as the bonding material, the electric resistance was low and the diffusion of atoms between the electrode and device material was the smallest. A 14-pair thermoelectric module was fabricated using Ag-23mass%Pd as the bonding material, and a power generation experiment of the module was carried out in air. When the temperatures at the cold side and the hot side of the module were kept at 293 K and 573 K, respectively, a maximum power density of 0.70 kW/m² was obtained in air, and, during a long priod of operation of 336 h (2 weeks), little change was seen in the electric resistance, open circuit voltage and maximum electric power of the module. In an experiment where the temperature at the hot side of the module was set to 673 K, an increase of electric resistance and a decrease of maximum power of the module were observed around 50 h or more, which was caused by the oxidation and decomposition of the device material.