The Thermoelectric Process

1997 ◽  
Vol 478 ◽  
Author(s):  
C. B. Vining

AbstractThe efficiency of thermoelectric technology today is limited by the properties of available thermoelectric materials and a wide variety of new approaches to developing better materials have recently been suggested. The key goal is to find a material with a large ZT, the dimensionless thermoelectric figure of merit. However, if an analogy is drawn between thermoelectric technology and gas-cycle engines then selecting different materials for the thermoelements is analogous to selecting a different working gas for the mechanical engine. And an attempt to improve ZT is analogous to an attempt to improve certain thermodynamic properties of the working-gas. An alternative approach is to focus on the thermoelectric process itself (rather than on ZT), which is analogous to considering alternate cycles such as Stirling vs. Brayton vs. Rankine etc., rather than ‘merely’ considering alternative ‘gases’. Focusing on the process is a radically different approach compared to previous studies focusing on ZT. Aspects of the thermoelectric process and alternative approaches to efficient thermoelectric conversion are discussed.

2007 ◽  
Vol 534-536 ◽  
pp. 161-164 ◽  
Author(s):  
Taek Soo Kim ◽  
Byong Sun Chun

N-type Bi2Te3-Sb2Te3 solid solutions doped with CdCl2 was prepared by melt spinning, crushing and vacuum sintering processes. Microstructure, bending strength and thermoelectric property were investigated as a function of the doping quantity from 0.03wt.% to 0.10wt.% and sintering temperature from 400oC to 500oC, and finally compared with those of conventionally fabricated alloys. The alloy showed a good structural homogeneity as well as bending strength of 3.88Kgf/mm2. The highest thermoelectric figure of merit was obtained by doping 0.03wt.% and sintering at 500oC.


1998 ◽  
Vol 545 ◽  
Author(s):  
Ctirad Uher ◽  
Jihui Yang ◽  
Siqing Hu

AbstractA useful approach to identify materials with high thermoelectric figure of merit is to search for solids that offer great flexibility to modify and tailor the structure so as to achieve the optimal transport behavior. Among the most promising novel thermoelectric materials are solids with “open crystal structure”. They may be typified by structures with unfilled cages, crystals with an empty atomic sublattice, and by a network of polyhedral cages enclosing guest species. In this paper we present our latest results concerning transport properties in the above classes of solids. Specifically, we focus on the filled skutterudites, half-Heusler alloys, and clathrates.


2020 ◽  
Vol 8 (17) ◽  
pp. 8455-8461 ◽  
Author(s):  
Yehao Wu ◽  
Feng Liu ◽  
Qi Zhang ◽  
Tiejun Zhu ◽  
Kaiyang Xia ◽  
...  

Suppressed grain boundary scattering contributes to enhanced electrical conductivity and device zT in elemental Te based thermoelectric materials.


2015 ◽  
Vol 3 (20) ◽  
pp. 10777-10786 ◽  
Author(s):  
A. Bhardwaj ◽  
N. S. Chauhan ◽  
D. K. Misra

Several nanostructuring methods have been demonstrated to produce a variety of nanostructured materials, and these methods are well recognized as effective paradigms for improving the performance of thermoelectric materials.


1997 ◽  
Vol 478 ◽  
Author(s):  
Jon L. Schindler ◽  
Tim P. Hogan ◽  
Paul W. Brazis ◽  
Carl R. Kannewurf ◽  
Duck-Young Chung ◽  
...  

AbstractNew Bi-based chalcogenide compounds have been prepared using the polychalcogenide flux technique for crystal growth. These materials exhibit characteristics of good thermoelectric materials. Single crystals of the compound CsBi4Te6 have shown conductivity as high as 2440 S/cm with a p-type thermoelectric power of ≈ +110 μV/K at room temperature. A second compound, β-K2Bi8Se13 shows lower conductivity ≈ 240 S/cm, but a larger n-type thermopower ≈ −200 μV/K. Thermal transport measurements have been performed on hot-pressed pellets of these materials and the results show comparable or lower thermal conductivities than Bi2Te3. This improvement may reflect the reduced lattice symmetry of the new chalcogenide thermoelectrics. The thermoelectric figure of merit for CsBi4Te6 reaches ZT ≈ 0.32 at 260 K and for β-K2Bi8Se13 ZT ≈ 0.32 at room temperature, indicating that these compounds are viable candidates for thermoelectric refrigeration applications.


2018 ◽  
Vol 6 (48) ◽  
pp. 13269-13274 ◽  
Author(s):  
Guangqian Ding ◽  
Junjie He ◽  
Zhenxiang Cheng ◽  
Xiaotian Wang ◽  
Shuo Li

Thallium compounds as promising bulk thermoelectric materials.


2015 ◽  
Vol 3 (40) ◽  
pp. 10494-10499 ◽  
Author(s):  
Min Ho Lee ◽  
Ka-Ryeong Kim ◽  
Jong-Soo Rhyee ◽  
Su-Dong Park ◽  
G. Jeffrey Snyder

Sb2Te3/Ag2Te (ST/AT) composites with ST/AT molar ratios of 1/1, 2/1, 4/1, 8/1, 16/1, and 32/1 were synthesized, and high ZT values were achieved compared with other Pb-free p-type chalcogenide thermoelectric materials.


2016 ◽  
Vol 4 (39) ◽  
pp. 15207-15214 ◽  
Author(s):  
Yuta Kikuchi ◽  
Yohan Bouyrie ◽  
Michihiro Ohta ◽  
Koichiro Suekuni ◽  
Makoto Aihara ◽  
...  

We have successfully developed environmentally-friendly and cost-effective thermoelectric materials based on colusites Cu26A2Sn6S32 (A = Nb, Ta). The vanadium-free colusites show enhanced thermoelectric figure of merit ZT at high temperature.


2013 ◽  
Vol 1490 ◽  
pp. 205-222 ◽  
Author(s):  
M. Winkler ◽  
X. Liu ◽  
U. Schürmann ◽  
J. D. König ◽  
L. Kienle ◽  
...  

ABSTRACTRoughly a decade ago an outstanding thermoelectric figure of merit ZT of 2.4 was reported for nanostructured Bi2Te3/Sb2Te3-based thin film superlattice (SL) structures. The published results strongly fueled and renewed the interest in the development of efficient novel nanostructured thermoelectric materials. This review article shall give an overview over the most recent theoretical and experimental advances on Bi2Te3/Sb2Te3 SLs and related superlattice systems. The presented theoretical models are subdivided into electronic and phononic aspects. The experimental results are summarized with regard to the method used. A more detailed elaboration on structural and transport properties is given in the subsequent sections.


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