Thermoelectric properties of efficient thermoelectric materials on the basis of bismuth and antimony chalcogenides for multisection thermoelements
【Abstract】
Compositions of effective thermoelectric materials were developed.
Complex investigation of thermal and electrophysical properties were carried out.
Mechanisms of electrical conductivity and thermal conductivity were determined.
Obtained thermoelectric materials are thermally stable at temperatures up to 600 K.
The following effective thermoelectric (TE) materials have been developed: Bi2Te2.8Se0.2 (0.14 wt%CdCl2), Bi0.5Sb1.5Тe3 (2 wt%Te and 0.14 wt% TeI4) obtained by zone melting; Bi2Te2.4Se0.6 (0.18 wt% CuBr) and Bi0.4Sb1.6Te3 (0.12 wt% PbCl2 and 1.50 wt% Te) obtained by extrusion; Bi2Te2.76Se0.24 (0.075 wt% Te and 0.026 wt% CdCl2) and Bi0.46Sb1.54Te3 (0.14 wt% Pb) obtained by rapid solidification. The elemental composition of TE materials was studied using the energy dispersive X-ray spectrometry. TE materials are designed for the manufacture of multisection thermoelements for thermoelectric generators (TEGs). In addition, TE materials obtained by zone melting can be used in the Peltier thermoelements. The electrical conductivity, Seebeck coefficient, thermal conductivity, thermal diffusivity, specific heat of TE materials in the temperature range of 300–600 K were investigated and an interpretation of their temperature dependences is provided. To obtain reliable data, the thermal conductivity was determined by two methods: (i) using the results of measuring the specific heat and thermal diffusivity; (ii) measuring the thermal conductivity by an absolute stationary method. The comparison of the results obtained by the mentioned methods showed that the discrepancy in the values of thermal conductivity does not exceed 8%, which correlates with the measurement error. The components of thermal conductivity were calculated and the mechanisms of heat transfer in TE materials were determined. The temperature dependences of dimensionless figure of merit ZT were defined. The operating temperatures for each material were found, in which ZT has the maximum values from 0.91 to 1.20. It was determined by the differential scanning calorimetry and thermogravimetric analysis that the materials investigated are thermally stable in the temperature range of 300–600 K.
【Author】
MaximShterna, MaximRogacheva, YuryShterna, AlexeySherchenkova, AlexeyBabicha, EgorKorchagina, DmitryNikulinb
【Keywords】
Thermoelectric materials, Thermoelectric properties, ZT values, Multisection thermoelements 
【Journal】
Journal of Alloys and Compounds(IF：4.2) Time：2021-05-16
