Work

Performance evaluation and stability of silicide-based thermoelectric modules

Year: 2020

Type: article

Abstract: Long-term studies on thermoelectric generators based on N-type magnesium silicide (Mg 2.01 Si 0.49 Sn 0.5 Sb 0.01 ) and P-type higher manganese silicide (Mn 0.98 Mo 0.02 Si 1.73 Ge 0.02 ) materials are presented, in the operating temperature range of 200 °C–400 °C. Emphasis is put on the performance and reliability of the current collector configuration, especially on the hot side of the module, and on the thermomechanical stresses that are created during operation and lifetime testing as a result of large temperature gradients experienced across the thermoelectric legs. With silver (Ag) paste as contact material, the long term-stability of the uni-couples was carried out on non-metalized legs and gold metalized legs under ambient conditions. Under isothermal and thermocycling tests, the non-metalized legs showed a gradual decrease in open circuit voltage (after a period of 200 h) and increase in internal resistance. Conversely, the module made of metalized legs was robust and stable for the same isothermal period. However, after 300cycles the n-type material showed mechanical failure (cracks) but the p-type resisted. Post-operation analysis by SEM/EDS and mechanical testing revealed that oxidation , adherence of the contact material and diffusion of the bonding material were the cause of performance degradation of the unicouples.

Source: Materials Today Proceedings

DOI: 10.1016/j.matpr.2020.05.193

Authors: Antoine de Padoue Shyikira, Gustein Skomedal, Peter Hugh Middleton

Institutions: University of Agder, Elkem (Norway)

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $150