Determination of figure of merit (zT) of thermoelectric devices in a single experiment

Determination of figure of merit (zT) of thermoelectric devices in a single experiment

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The article describes the method for the determination of thermoelectric parameters of geopolymer samples (alkali-activated slag – AAS) with different concentrations of conductive admixtures (graphite powder – GP, carbon black – CB, alkali-activated metashale composite with graphite powder – MGP) in only one optimally designed experiment. The zT value (the figure of merit – FoM) was determined from the thermal conductivity the electrical conductivity and the thermoelectric voltage VTE (i.e. from the Peltier coefficient and the Seebeck coefficient. The thermal conductivity was calculated from the temperature differences between the hot and cold sides of the sample at steady state during gradual thermal heating/cooling. The process of heating and cooling for four different heating pulses was also monitored by thermocamera Fluke TI55. The electrical conductivity and the thermoelectric voltage were determined from the current-voltage (I-V) characteristics, which were measured simultaneously. The open-circuit voltage in this I-V characteristic represents the Peltier coefficient, the slope of this curve in the short-circuit current represents the electrical conductivity. These experiments show that the addition of a small concentration of conductive dopant (GP, CB) increases the zT value by one order of magnitude compared to the reference sample. On the other hand, a high concentration of conductive additives (GP, MGP) reduces the FoM by three orders of magnitude.

The article describes the method for the determination of thermoelectric parameters of geopolymer samples (alkali-activated slag – AAS) with different concentrations of conductive admixtures (graphite powder – GP, carbon black – CB, alkali-activated metashale composite with graphite powder – MGP) in only one optimally designed experiment. The zT value (the figure of merit – FoM) was determined from the thermal conductivity the electrical conductivity and the thermoelectric voltage VTE (i.e. from the Peltier coefficient and the Seebeck coefficient. The thermal conductivity was calculated from the temperature differences between the hot and cold sides of the sample at steady state during gradual thermal heating/cooling. The process of heating and cooling for four different heating pulses was also monitored by thermocamera Fluke TI55. The electrical conductivity and the thermoelectric voltage were determined from the current-voltage (I-V) characteristics, which were measured simultaneously. The open-circuit voltage in this I-V characteristic represents the Peltier coefficient, the slope of this curve in the short-circuit current represents the electrical conductivity. These experiments show that the addition of a small concentration of conductive dopant (GP, CB) increases the zT value by one order of magnitude compared to the reference sample. On the other hand, a high concentration of conductive additives (GP, MGP) reduces the FoM by three orders of magnitude.

Alkali-activated slag; graphite powder; thermal conductivity; electrical conductivity; Peltier and Seebeck coefficient

Alkali-activated slag; graphite powder; thermal conductivity; electrical conductivity; Peltier and Seebeck coefficient

ZMEŠKAL, O.; FILIPSKÁ, K.; POSPÍŠIL, J.; FIALA, L.; PAVLÍK, Z.

07.05.2026

AIP Publishing

AIP Conference Proceedings, INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS: ICNAAM2024

AIP conference proceedings

3489

070007 (2026)

Spojené státy americké

070007-1

070007-6

6

https://doi.org/10.1063/5.0328759