Modelling of segmented high-performance thermoelectric generators with effects of thermal radiation, electrical and thermal contact resistances

Abstract

In this study, segmented thermoelectric generators (TEGs) have been simulated with various state-of-the-art TE materials spanning a wide temperature range, from 300 K up to 1000 K. The results reveal that by combining the current best p-type TE materials, BiSbTe, MgAgSb, K-doped PbTeS and SnSe with the strongest n-type TE materials, Cu-Doped BiTeSe, AgPbSbTe and SiGe to build segmented legs, TE modules could achieve efficiencies of up to 17.0% and 20.9% at ΔT = 500 K and ΔT = 700 K, respectively, and a high output power densities of over 2.1 Watt cm−2 at the temperature difference of 700 K. Moreover, we demonstrate that successful segmentation requires a smooth change of compatibility factor s from one end of the TEG leg to the other, even if s values of two ends differ by more than a factor of 2. The influence of the thermal radiation, electrical and thermal contact effects have also been studied. Although considered potentially detrimental to the TEG performance, these effects, if well-regulated, do not prevent segmentation of the current best TE materials from being a prospective way to construct high performance TEGs with greatly enhanced efficiency and output power density.

Effect of Sn Substitution on the Thermoelectric Properties of Synthetic Tetrahedrite

“…These values are within a factor of 2 compared to other high-performing p-type materials such as Yb 14 MnSb 12 , TAGS, CeFe 4 Sb 12 , 30 and PbTe 0.7 S 0.3 . 31 In conclusion, the near invariance of compatibility factor with temperature coupled with its similar magnitude compared to other materials makes Sn-substituted samples potential candidates for device applications.…”

A Review on Low-Grade Thermal Energy Harvesting: Materials, Methods and Devices

“…The factor (1/2) for the Joule term is necessary to indicate that the total generated Joule heat is equally consumed between hot and cold sides, since TEG modules have an equal number of p-type and n-type elements [79]. …”

Inorganic thermoelectric materials: A review

“…It is made of p ‐and n ‐type legs (it could be semiconductor legs or metal legs), which are placed in series, electrically, and in parallel, thermally. When a temperature gradient, Δ T , is applied in between the two legs, charge carriers in the thermoelectric (TE) material will diffuse from the hot side, T H , to the cold side, T C , and a potential difference, Δ V = S Δ T , will be formed across the material, where, S is the Seebeck coefficient, which is positive for p‐ type and negative for n ‐type conduction . A schematic of a TEG is depicted in Figure , where both the heat and charge flux (ie, electrons and holes) have the same direction, that is, T H to T C , and an electrical current, I , flows from the n‐ to the p‐ type material due to Δ T .…”