Manufacturing and performances of silicide-based thermoelectric modules. (15th August 2021)

• Record Type: Journal Article
• Authors: Ihou Mouko, H.; Romanjek, K.; Mejri, M.; Oulfarsi, M.; El Oualid, S.; Malinconi, P.; Thimont, Y.; Malard, B.; Estournès, C.; David, N.; Dauscher, A.
• Is Part Of: Energy conversion and management. Volume 242(2021)
• Publication Date: 2021-08-15
• Subjects: Silicide-based thermoelectric materials -- Spark plasma sintering -- Thermoelectric modules processing -- Modules performance and reproducibility -- Waste heat recovery -- Finite element modelling; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2021.114304
• Languages: English
• ISSNs: 0196-8904

Abstract

Graphical abstract: Highlights: Development of half skeleton structures for silicide-based thermoelectric modules. Fabrication of twenty-two (four legs) silicide-based thermoelectric modules. Excellent repeatability of the achieved output power. State of the art power density performance. Use of mass-produced materials and simple fabrication tools. Abstract: Silicide-based materials are among the most promising candidates for a mass manufacturing of thermoelectric devices allowing converting waste heat into electricity in the medium temperature range (250–500 °C), as they are formed from abundant, low cost and non-toxic elements while exhibiting good thermoelectric properties. In order to manage the detrimental mismatch of thermal expansion coefficients between the n and p -type materials constituting the thermoelectric legs, inducing thus thermomechanical stresses, we propose in this paper a new design of modules having a 'half-skeleton' structure. Twenty-two modules consisting of two couples of thermoelectric legs combining n -type magnesium silicide Mg2 (Si, Sn) and p -type higher manganese silicide have been fabricated according to this design, the thermoelectric materials being manufactured by kilograms. It is clearly shown that all the interfaces present in the modules are free from cracks, oxygen, and diffusion. The remarkable repeatability of the measured thermoelectric performance attests the robustness of our manufacturing process. An average power output of 0.37 W has been achieved, i.e. a power density of 0.95 W/cm 2, for a temperature difference of 400 °C (hot side temperature of 450 °C), placing our modules at the state of the art level while using simple production tools and materials mass production. Comparing this performance to finite elements modelling, the performance could be even enhanced. Long term stability tests at a given temperature and under cycling conditions in different working atmospheres are underway.