Modelling a Segmented Skutterudite-Based Thermoelectric Generator to Achieve Maximum Conversion Efficiency

Aminu Yusuf,Sedat Ballikaya

doi:10.3390/app10010408

Aminu Yusuf, Sedat Ballikaya

Open Access

https://doi.org/10.3390/app10010408

Copy DOI

Abstract

Thermoelectric generator (TEG) modules generally have a low conversion efficiency. Among the reasons for the lower conversion efficiency is thermoelectric (TE) material mismatch. Hence, it is imperative to carefully select the TE material and optimize the design before any mass-scale production of the modules. Here, with the help of Comsol-Multiphysics (5.3) software, TE materials were carefully selected and the design was optimized to achieve a higher conversion efficiency. An initial module simulation (32 couples) of unsegmented skutterudite Ba0.1Yb0.2Fe0.1Co3.9Sb12 (n-type) and Ce0.5Yb0.5Fe3.25Co0.75Sb12 (p-type) TE materials was carried out. At the temperature gradient T∆ = 500 K, a maximum simulated conversion efficiency of 9.2% and a calculated efficiency of 10% were obtained. In optimization via segmentation, the selection of TE materials, considering compatibility factor (s) and ZT, was carefully done. On the cold side, Bi2Te3 (n-type) and Sb2Te3 (p-type) TE materials were added as part of the segmentation, and at the same temperature gradient, an open circuit voltage of 6.2 V matched a load output power of 45 W, and a maximum simulated conversion efficiency of 15.7% and a calculated efficiency of 17.2% were achieved. A significant increase in the output characteristics of the module shows that the segmentation is effective. The TEG shows promising output characteristics.

Highlights

Carbon emission is among the factors that cause global warming; a major source of carbon emission is the burning of fossil fuels
Thermoelectric generator (TEG) devices could be widely used if the conversion efficiency was increased
The skutterudite materials were prepared via melting and annealing, bismuth telluride was prepared via a chemical synthesis route, and antimony telluride was prepared via physical vapor deposition followed by spark plasma and/or hot press methods [3,32,33,34]

Summary

Introduction

Carbon emission is among the factors that cause global warming; a major source of carbon emission is the burning of fossil fuels. Thermoelectric generators (TEGs) are among the promising alternatives for sustainable energy sources that can convert heat directly into electricity. This technology, if successful, will serve as a major source of energy on both the moon (space missions) and the earth (terrestrial applications). Thermoelectric generators generally have a low conversion efficiency This conversion efficiency depends on the transport properties of the thermoelectric (TE) material and is limited by electrical resistance and thermal contact resistance. Another factor that limits the conversion efficiency of TEG devices is Carnot efficiency [2].

Methods

Results

Conclusion