Fabrication of layered p-type AgSbTe2- (Bi,Sb)2Te3thermoelectric module and its performances


M. Kubo, T. Itoh, K. Tokuda, J. Shan, K.Kitagawa


Research Center for Advanced EnergyConversion, Nagoya UniversityFuro-cho, Chikusa-ku, Nagoya 464-8603, Japan


Functionallygraded thermoelectric modules isare hopefulpromising for thethermoelectric devicesthat generates electric power from waste heat havingat temperatures ofabove 600K. over. A layeredp-type thermoelectric module of AgSbTe2-(Bi,Sb)2Te3 werefabricated by a SparkPlasma Sintering (SPS) process and its performances were evaluated inwith both calculationand measurement. Each powder of AgSbTe2 and (Bi,Sb)2Te3 wasconsolidated by the SPSprocess. Their properties such as thermoelectromotive force, electricalresistivity and thermal conductivity were evaluated. Next, various temperaturedistributions in the two-layered module were simulated by solving thean unsteadyone-dimensional equation of heat conduction according tobased on the obtaineddata of thermoelectric properties. An optimum junction point of two elementswas predicted from numerical changes in the performances such as figure ofmerit, electric power and conversion efficiency with the connecting position oftwo materials. Several materials for the electrodes were used tested to find betterbonding condition between the thermoelectric material and the electrode.Finally, the layered thermoelectric module with the electrodes was fabricated by the SPS process. Theperformances of the resultingmodule were measured. It was found that the performances predicted by the calculation were infairly good agreement with the measured ones.