Thermoelectric materials enable the direct conversion of thermal to electrical energy. One application of this is ambient heat energy harvesting where relatively stable temperature gradients existing between the inside and outside of a building could be utilized to produce electricity. Buildings can thus change from energy consumers to energy generators. This could ultimately help reduce the surface temperatures and energy consumption of buildings, especially in urban areas. In this paper, research work carried out on developing and characterizing a cement-based thermoelectric material is presented. Cement-based samples are doped with different metal oxides (Bi2O3 and Fe2O3) to enhance their thermoelectric properties, which are defined through their Seebeck coefficient, electrical conductivity and thermal conductivity. The study also discusses the positive impact of moisture content on the electrical conductivity
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Characterization and Performance of Cement-based Thermoelectric Materials
Thermoelectric materials enable the direct conversion of thermal energy to electricity. Ambient heat energy harvesting could be an effective route to convert buildings from being energy consumers to energy harvesters, thus making them more sustainable. There exists a relatively stable temperature gradient (storing energy) between the internal and external walls of buildings which can be utilized to generate meaningful energy (that is, electricity) using the thermoelectric principle. This could ultimately help reduce the surface temperatures and energy consumption of buildings, especially in urban areas. In this paper, ongoing work on developing and characterizing a cement-based thermoelectric material is presented. Samples are fabricated using cement as a base material and different metal oxides (Bi₂O₃ and Fe₂O₃) are added to enhance their thermoelectric properties. A series of characterization tests are undertaken on the prepared samples to determine their Seebeck coefficient, electrical and thermal conductivity. The study shows that cement paste with additives possesses physical properties in the range of semiconductors whereby, initially, the resistivity values are low but with time, they increase gradually, thus resulting in lower electrical conductivity. The thermal conductivity of the cement paste with additives is lower than the control sample. Seebeck coefficient values were found to be relatively unstable during the initial set of measurements because the internal and external environment needed to be kept in a thermally stable condition to achieve steady results. The detailed analysis helped determine and eliminate the source of errors in the characterization process and obtain repeatable results. Parameters such as moisture content, temperature, and age were found to have a significant impact on the properties of cement-based thermoelectric materials.
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- Award ID(s):
- 1805818
- NSF-PAR ID:
- 10252965
- Date Published:
- Journal Name:
- Civil Engineering Research in Ireland (CERI) 2020
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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