Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generators
Owing to efficient thermoelectric conversion, non-toxicity, low density and cost, Mg2(Si,Sn)-based solid solutions hold potential for mid-to-high temperature waste heat recovery. Yet, challenges arise from n-Mg2(Si,Sn) degradation at ≥400 °C caused by Mg loss and charge carrier reduction, particular...
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| Format: | Article |
| Language: | English |
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Elsevier
2024-03-01
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| Series: | Materials & Design |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127524001291 |
| _version_ | 1797256452768792576 |
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| author | Radhika Deshpande Julia Camut Eckhard Müller Johannes de Boor |
| author_facet | Radhika Deshpande Julia Camut Eckhard Müller Johannes de Boor |
| author_sort | Radhika Deshpande |
| collection | DOAJ |
| description | Owing to efficient thermoelectric conversion, non-toxicity, low density and cost, Mg2(Si,Sn)-based solid solutions hold potential for mid-to-high temperature waste heat recovery. Yet, challenges arise from n-Mg2(Si,Sn) degradation at ≥400 °C caused by Mg loss and charge carrier reduction, particularly in Sn-rich compositions. To build a thermoelectric generator (TEG) stable up to 400 °C, we propose binary Mg2Si as the n-type leg. Using Ni45Cu55 and Ni yields low electrical contact resistance (<5 µΩ.cm2) without altering the thermoelectric properties of n-Mg2Si. We fabricated two 2×2 leg TE modules with the same electrode/TE combination for the p-type legs and with Ni or Ni45Cu55 for their n-type legs and tested up to 400 °C, allowing for a direct comparison between these two electrodes for n-Mg2Si at the device level. Ni45Cu55 outperformed Ni, resulting in a peak power density of 0.79 W/cm2 at ΔT ∼375 K and an efficiency competitive to Mg2(Si,Sn)-only TEG. Comparative simulations using a constant property model revealed a strong reduction of internal losses when using Ni45Cu55 as the electrode for n-Mg2Si as the main reason for the high performance. The presented design overcame challenges such as Mg sublimation at targeted application temperature or electrode induced defect formation, resulting in a stable TEG. |
| first_indexed | 2024-03-07T20:06:33Z |
| format | Article |
| id | doaj.art-f1478cb5ae4d49daad35df1e2c6f1fe2 |
| institution | Directory Open Access Journal |
| issn | 0264-1275 |
| language | English |
| last_indexed | 2024-04-24T22:21:58Z |
| publishDate | 2024-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj.art-f1478cb5ae4d49daad35df1e2c6f1fe22024-03-20T06:08:14ZengElsevierMaterials & Design0264-12752024-03-01239112757Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generatorsRadhika Deshpande0Julia Camut1Eckhard Müller2Johannes de Boor3Institute of Materials Research, German Aerospace Centre (DLR), Cologne, Germany; Corresponding authors.Institute of Materials Research, German Aerospace Centre (DLR), Cologne, GermanyInstitute of Materials Research, German Aerospace Centre (DLR), Cologne, Germany; Institute of Inorganic and Analytical Chemistry, Justus Liebig University of Giessen, Giessen, GermanyInstitute of Materials Research, German Aerospace Centre (DLR), Cologne, Germany; Institute of Technology for Nanostructures (NST) and CENIDE, Faculty of Engineering, University of Duisburg, Essen, Germany; Corresponding authors.Owing to efficient thermoelectric conversion, non-toxicity, low density and cost, Mg2(Si,Sn)-based solid solutions hold potential for mid-to-high temperature waste heat recovery. Yet, challenges arise from n-Mg2(Si,Sn) degradation at ≥400 °C caused by Mg loss and charge carrier reduction, particularly in Sn-rich compositions. To build a thermoelectric generator (TEG) stable up to 400 °C, we propose binary Mg2Si as the n-type leg. Using Ni45Cu55 and Ni yields low electrical contact resistance (<5 µΩ.cm2) without altering the thermoelectric properties of n-Mg2Si. We fabricated two 2×2 leg TE modules with the same electrode/TE combination for the p-type legs and with Ni or Ni45Cu55 for their n-type legs and tested up to 400 °C, allowing for a direct comparison between these two electrodes for n-Mg2Si at the device level. Ni45Cu55 outperformed Ni, resulting in a peak power density of 0.79 W/cm2 at ΔT ∼375 K and an efficiency competitive to Mg2(Si,Sn)-only TEG. Comparative simulations using a constant property model revealed a strong reduction of internal losses when using Ni45Cu55 as the electrode for n-Mg2Si as the main reason for the high performance. The presented design overcame challenges such as Mg sublimation at targeted application temperature or electrode induced defect formation, resulting in a stable TEG.http://www.sciencedirect.com/science/article/pii/S0264127524001291Mg2SiThermoelectricElectrodesDevice Modelling |
| spellingShingle | Radhika Deshpande Julia Camut Eckhard Müller Johannes de Boor Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generators Materials & Design Mg2Si Thermoelectric Electrodes Device Modelling |
| title | Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generators |
| title_full | Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generators |
| title_fullStr | Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generators |
| title_full_unstemmed | Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generators |
| title_short | Device level assessment of Ni and Ni45Cu55 as electrodes in Mg2(Si,Sn)-based thermoelectric generators |
| title_sort | device level assessment of ni and ni45cu55 as electrodes in mg2 si sn based thermoelectric generators |
| topic | Mg2Si Thermoelectric Electrodes Device Modelling |
| url | http://www.sciencedirect.com/science/article/pii/S0264127524001291 |
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