Details
| Original language | English |
|---|---|
| Article number | 803 |
| Journal | Entropy |
| Volume | 22 |
| Issue number | 8 |
| Publication status | Published - 22 Jul 2020 |
Abstract
The basic principles of thermoelectrics rely on the coupling of entropy and electric charge. However, the long-standing dispute of energetics versus entropy has long paralysed the field. Herein, it is shown that treating entropy and electric charge in a symmetric manner enables a simple transport equation to be obtained and the power conversion and its efficiency to be deduced for a single thermoelectric material apart from a device. The material's performance in both generator mode (thermo-electric) and entropy pump mode (electro-thermal) are discussed on a single voltage-electrical current curve, which is presented in a generalized manner by relating it to the electrically open-circuit voltage and the electrically closed-circuited electrical current. The electrical and thermal power in entropy pump mode are related to the maximum electrical power in generator mode, which depends on the material's power factor. Particular working points on the material's voltage-electrical current curve are deduced, namely, the electrical open circuit, electrical short circuit, maximum electrical power, maximum power conversion efficiency, and entropy conductivity inversion. Optimizing a thermoelectric material for different working points is discussed with respect to its figure-of-merit zT and power factor. The importance of the results to state-of-the-art and emerging materials is emphasized.
Keywords
- Altenkirch-Ioffe model, Efficiency, Entropy pump mode, Figure of merit, Generator mode, Power conversion, Power factor, Thermoelectrics, Voltage-electrical current curve, Working point
ASJC Scopus subject areas
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In: Entropy, Vol. 22, No. 8, 803, 22.07.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Power conversion and its efficiency in thermoelectric materials
AU - Feldhoff, Armin
N1 - Funding Information: Funding: This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – project number 325156807. The publication of this article was funded by the Open Access Fund of the Leibniz Universität Hannover.
PY - 2020/7/22
Y1 - 2020/7/22
N2 - The basic principles of thermoelectrics rely on the coupling of entropy and electric charge. However, the long-standing dispute of energetics versus entropy has long paralysed the field. Herein, it is shown that treating entropy and electric charge in a symmetric manner enables a simple transport equation to be obtained and the power conversion and its efficiency to be deduced for a single thermoelectric material apart from a device. The material's performance in both generator mode (thermo-electric) and entropy pump mode (electro-thermal) are discussed on a single voltage-electrical current curve, which is presented in a generalized manner by relating it to the electrically open-circuit voltage and the electrically closed-circuited electrical current. The electrical and thermal power in entropy pump mode are related to the maximum electrical power in generator mode, which depends on the material's power factor. Particular working points on the material's voltage-electrical current curve are deduced, namely, the electrical open circuit, electrical short circuit, maximum electrical power, maximum power conversion efficiency, and entropy conductivity inversion. Optimizing a thermoelectric material for different working points is discussed with respect to its figure-of-merit zT and power factor. The importance of the results to state-of-the-art and emerging materials is emphasized.
AB - The basic principles of thermoelectrics rely on the coupling of entropy and electric charge. However, the long-standing dispute of energetics versus entropy has long paralysed the field. Herein, it is shown that treating entropy and electric charge in a symmetric manner enables a simple transport equation to be obtained and the power conversion and its efficiency to be deduced for a single thermoelectric material apart from a device. The material's performance in both generator mode (thermo-electric) and entropy pump mode (electro-thermal) are discussed on a single voltage-electrical current curve, which is presented in a generalized manner by relating it to the electrically open-circuit voltage and the electrically closed-circuited electrical current. The electrical and thermal power in entropy pump mode are related to the maximum electrical power in generator mode, which depends on the material's power factor. Particular working points on the material's voltage-electrical current curve are deduced, namely, the electrical open circuit, electrical short circuit, maximum electrical power, maximum power conversion efficiency, and entropy conductivity inversion. Optimizing a thermoelectric material for different working points is discussed with respect to its figure-of-merit zT and power factor. The importance of the results to state-of-the-art and emerging materials is emphasized.
KW - Altenkirch-Ioffe model
KW - Efficiency
KW - Entropy pump mode
KW - Figure of merit
KW - Generator mode
KW - Power conversion
KW - Power factor
KW - Thermoelectrics
KW - Voltage-electrical current curve
KW - Working point
UR - http://www.scopus.com/inward/record.url?scp=85089552357&partnerID=8YFLogxK
U2 - 10.3390/E22080803
DO - 10.3390/E22080803
M3 - Article
AN - SCOPUS:85089552357
VL - 22
JO - Entropy
JF - Entropy
SN - 1099-4300
IS - 8
M1 - 803
ER -