Journal article

Authors list: Deshpande, Radhika; Camut, Julia; Mueller, Eckhard; de Boor, Johannes

Publication year: 2024

Journal: Materials & Design

Volume number: 239

ISSN: 0264-1275

eISSN: 1873-4197

Open access status: Gold

DOI Link: https://doi.org/10.1016/j.matdes.2024.112757

Publisher: Elsevier

Abstract: 
Owing to efficient thermoelectric conversion, non-toxicity, low density and cost, Mg-2(Si,Sn)-based solid solutions hold potential for mid-to-high temperature waste heat recovery. Yet, challenges arise from n-Mg-2(Si,Sn) degradation at >= 400 degrees C caused by Mg loss and charge carrier reduction, particularly in Sn-rich compositions. To build a thermoelectric generator (TEG) stable up to 400 degrees C, we propose binary Mg2Si as the n-type leg. Using Ni45Cu55 and Ni yields low electrical contact resistance (<5 Omega.cm(2)) without altering the thermoelectric properties of n-Mg2Si. We fabricated two 2x2 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 degrees 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/cm(2) at Delta T similar to 375 K and an efficiency competitive to Mg-2(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.

Harvard Citation style: Deshpande, R., Camut, J., Mueller, E. and de Boor, J. (2024) Device level assessment of Ni and Ni₄₅Cu₅₅ as electrodes in Mg₂(Si,Sn)-based thermoelectric generators, Materials & Design, 239, Article 112757. https://doi.org/10.1016/j.matdes.2024.112757

APA Citation style: Deshpande, R., Camut, J., Mueller, E., & de Boor, J. (2024). Device level assessment of Ni and Ni₄₅Cu₅₅ as electrodes in Mg₂(Si,Sn)-based thermoelectric generators. Materials & Design. 239, Article 112757. https://doi.org/10.1016/j.matdes.2024.112757