Enhancing the Figure of Merit of Heavy‐Band Thermoelectric Materials Through Hierarchical Phonon Scattering

AbstractNanostructured materials have been shown to enhance phonon scattering and improve the figure of merit of thermoelectric materials. Solvothermal syntheses of nano-engineered CoSb3 skutterudite have been studied in the present work in which CoCl2 and SbCl3 were used as precursors and NaBH4 as a reductant. Elemental, structural and morphology characterization techniques including: XRD, SEM, TEM and EDAX were used to identify and characterize the products. NaBH4 was found to be a necessary factor in forming cobalt antimonide. It was detected the products' phase transited from Sb2Co to CoSb3 in conjunction with the amount increase of NaBH4. The change of synthesis time and temperature contributed little on the products' phases under the present experimental routes. Single-phased CoSb3 skutterudites was obtained from the solvothermal syntheses combined with an acid wash. The as-prepared CoSb3 powders consist of irregular nanoparticles with 15∼20 nm in size. A possible chemical mechanism was also discussed.

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High-entropy-stabilized chalcogenides with high thermoelectric performance

Science ◽

10.1126/science.abe1292 ◽

2021 ◽

Vol 371 (6531) ◽

pp. 830-834 ◽

Cited By ~ 6

Author(s):

Binbin Jiang ◽

Yong Yu ◽

Juan Cui ◽

Xixi Liu ◽

Lin Xie ◽

...

Keyword(s):

Thermoelectric Materials ◽

Performance Optimization ◽

Figure Of Merit ◽

Phonon Scattering ◽

Waste Heat ◽

Configurational Entropy ◽

Thermoelectric Performance ◽

Structural Stabilization ◽

High Entropy ◽

Thermoelectric Conversion

Thermoelectric technology generates electricity from waste heat, but one bottleneck for wider use is the performance of thermoelectric materials. Manipulating the configurational entropy of a material by introducing different atomic species can tune phase composition and extend the performance optimization space. We enhanced the figure of merit (zT) value to 1.8 at 900 kelvin in an n-type PbSe-based high-entropy material formed by entropy-driven structural stabilization. The largely distorted lattices in this high-entropy system caused unusual shear strains, which provided strong phonon scattering to largely lower lattice thermal conductivity. The thermoelectric conversion efficiency was 12.3% at temperature difference ΔT = 507 kelvin, for the fabricated segmented module based on this n-type high-entropy material. Our demonstration provides a paradigm to improve thermoelectric performance for high-entropy thermoelectric materials through entropy engineering.

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Crystal Lattice Controlled SiGe Thermoelectric Materials with High Figure of Merit

MRS Proceedings ◽

10.1557/opl.2011.512 ◽

2011 ◽

Vol 1314 ◽

Cited By ~ 1

Author(s):

Hyun Jung Kim ◽

Yeonjoon Park ◽

Glen C. King ◽

Kunik Lee ◽

Sang H. Choi

Keyword(s):

Thermal Conductivity ◽

Energy Conversion ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Phonon Scattering ◽

Waste Heat ◽

Lattice Structure ◽

Measurement Techniques ◽

Process Conditions ◽

Working Pressure

ABSTRACTDirect energy conversion between thermal and electrical energy, based on thermoelectric (TE) effect, has the potential to recover waste heat and convert it to provide clean electric power. The energy conversion efficiency is related to the thermoelectric figure of merit ZT expressed as ZT=S2σT/κ, T is temperature, S is the Seebeck coefficient, σ is conductance and κ is thermal conductivity. For a lower thermal conductivity κ and high power factor (S2σ), our current strategy is the development of rhombohedrally strained single crystalline SiGe materials that are highly [111]-oriented twinned. The development of a SiGe “twin lattice structure (TLS)” plays a key role in phonon scattering. The TLS increases the electrical conductivity and decreases thermal conductivity due to phonon scattering at stacking faults generated from the 60° rotated primary twin structure. To develop high performance materials, the substrate temperature, chamber working pressure, and DC sputtering power are controlled for the aligned growth production of SiGe layer and TLS on a c-plane sapphire. Additionally, a new elevated temperature thermoelectric characterization system, that measures the thermal diffusivity and Seebeck effect nondestructively, was developed. The material properties were characterized at various temperatures and optimized process conditions were experimentally determined. The present paper encompasses the technical discussions toward the development of thermoelectric materials and the measurement techniques.

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Effects of Co Doping on the Thermoelectric Properties of Cu3SbSe4 at Moderate Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.993.899 ◽

2020 ◽

Vol 993 ◽

pp. 899-905

Author(s):

Lin Bo ◽

Wen Ying Wang ◽

Yong Peng Wang ◽

Lin Wang ◽

Min Zuo ◽

...

Keyword(s):

Thermoelectric Properties ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Phonon Scattering ◽

Energy Gap ◽

Average Power ◽

Moderate Temperature ◽

Thermoelectric Figure ◽

Co Doping ◽

Type Semiconductor

Cu3SbSe4-based thermoelectric materials are a class of thermoelectric materials with diamond-like structure which exhibit high thermoelectric properties at moderate temperature region and have broad research prospects. In this study, the p-type Co-doped Cu3-xCoxSbSe4 (x=0-0.015) thermoelectric materials were fabricated by melting-annealing-ball milling-hot pressing process to investigate the effects of Co doping on the thermoelectric properties of Cu3SbSe4. It is found that the average power factor of Cu2.995Co0.005SbSe4 was increased by 30% compared with the pure sample, indicating that Co doping had a great effect on the electrical properties of Cu3SbSe4. The energy gap of ternary p-type semiconductor Cu3SbSe4 was around 0.27eV. As the Co content increasing, the lattice distortion enhanced the phonon scattering, which led to the decrease in lattice thermal conductivity. The maximum thermoelectric figure of merit, ZTmax, reached 0.46 at 600K for the Cu2.995Co0.005SbSe4.

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Energy Challenges and Optimization of Figure of Merit for Thermoelectric Materials

International Journal of Innovative Research in Science Engineering and Technology ◽

10.15680/ijirset.2014.0310010 ◽

2014 ◽

Vol 03 (10) ◽

pp. 16475-16479

Author(s):

ASHAQ HUSSAIN SOFI ◽

BAASIT ABUBAKR ◽

ANIL MAINI ◽

MOHAMMAD ASHRAF SHAH

Keyword(s):

Thermoelectric Materials ◽

Figure Of Merit

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Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

MRS Proceedings ◽

10.1557/proc-1044-u03-14 ◽

2007 ◽

Vol 1044 ◽

Author(s):

Mi-kyung Han ◽

Huijun Kong ◽

Ctirad Uher ◽

Mercouri G Kanatzidis

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Lattice Thermal Conductivity ◽

Substitution Effect ◽

Dimensionless Figure Of Merit ◽

The Matrix ◽

Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

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Thermoelectric Materials for Textile Applications

Molecules ◽

10.3390/molecules26113154 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3154

Author(s):

Kony Chatterjee ◽

Tushar K. Ghosh

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Inorganic Materials ◽

Peltier Effect ◽

Electronic Textiles ◽

Heating And Cooling ◽

Recent Attention

Since prehistoric times, textiles have served an important role–providing necessary protection and comfort. Recently, the rise of electronic textiles (e-textiles) as part of the larger efforts to develop smart textiles, has paved the way for enhancing textile functionalities including sensing, energy harvesting, and active heating and cooling. Recent attention has focused on the integration of thermoelectric (TE) functionalities into textiles—making fabrics capable of either converting body heating into electricity (Seebeck effect) or conversely using electricity to provide next-to-skin heating/cooling (Peltier effect). Various TE materials have been explored, classified broadly into (i) inorganic, (ii) organic, and (iii) hybrid organic-inorganic. TE figure-of-merit (ZT) is commonly used to correlate Seebeck coefficient, electrical and thermal conductivity. For textiles, it is important to think of appropriate materials not just in terms of ZT, but also whether they are flexible, conformable, and easily processable. Commercial TEs usually compromise rigid, sometimes toxic, inorganic materials such as bismuth and lead. For textiles, organic and hybrid TE materials are more appropriate. Carbon-based TE materials have been especially attractive since graphene and carbon nanotubes have excellent transport properties with easy modifications to create TE materials with high ZT and textile compatibility. This review focuses on flexible TE materials and their integration into textiles.

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Influence of multi-sintering on the thermoelectric properties of Bi2Sr2Co2Oy ceramics

Modern Physics Letters B ◽

10.1142/s0217984920500190 ◽

2019 ◽

Vol 34 (02) ◽

pp. 2050019 ◽

Cited By ~ 2

Author(s):

Y. Zhang ◽

M. M. Fan ◽

C. C. Ruan ◽

Y. W. Zhang ◽

X.-J. Li ◽

...

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Phonon Scattering ◽

Sintered Sample ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

The Third ◽

Ceramic Samples ◽

Optimum Formula

[Formula: see text] ceramic samples have a structure similar to phonon glass electronic crystals, and their thermoelectric properties can be effectively adjusted through repeated grinding and sintering. The results show that multi-sintering can make their grain refined and increase their grain boundary, which will effectively increase density and phonon scattering. Finally, multi-sintering can reduce the resistivity and thermal conductivity, thus obviously improve thermoelectric figure of merit [Formula: see text] of [Formula: see text]. The optimum [Formula: see text] value of 0.26 is achieved at 923 K by the third sintered sample.

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Thermoelectric Properties of n-Type 90% Bi2Te3+10%Bi2Se3 Thermoelectric Materials Produced by Melt Spinning Method and Sintering

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.161 ◽

2007 ◽

Vol 534-536 ◽

pp. 161-164 ◽

Cited By ~ 3

Author(s):

Taek Soo Kim ◽

Byong Sun Chun

Keyword(s):

Solid Solutions ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Melt Spinning ◽

Bending Strength ◽

Sintering Temperature ◽

Thermoelectric Figure Of Merit ◽

Vacuum Sintering ◽

Thermoelectric Figure ◽

Sintering Processes

N-type Bi2Te3-Sb2Te3 solid solutions doped with CdCl2 was prepared by melt spinning, crushing and vacuum sintering processes. Microstructure, bending strength and thermoelectric property were investigated as a function of the doping quantity from 0.03wt.% to 0.10wt.% and sintering temperature from 400oC to 500oC, and finally compared with those of conventionally fabricated alloys. The alloy showed a good structural homogeneity as well as bending strength of 3.88Kgf/mm2. The highest thermoelectric figure of merit was obtained by doping 0.03wt.% and sintering at 500oC.

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Fabrication of Bi-Te Based Thermoelectric Semiconductors by Using Hybrid Powders

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.297-300.875 ◽

2005 ◽

Vol 297-300 ◽

pp. 875-880

Author(s):

Cheol Ho Lim ◽

Ki Tae Kim ◽

Yong Hwan Kim ◽

Dong Choul Cho ◽

Young Sup Lee ◽

...

Keyword(s):

Mechanical Properties ◽

Single Crystals ◽

Thermoelectric Properties ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Bending Strength ◽

Mixing Ratio ◽

Plasma Sintering ◽

Spark Plasma ◽

P Type

P-type Bi0.5Sb1.5Te3 compounds doped with 3wt% Te were fabricated by spark plasma sintering and their mechanical and thermoelectric properties were investigated. The sintered compounds with the bending strength of more than 50MPa and the figure-of-merit 2.9×10-3/K were obtained by controlling the mixing ratio of large powders (PL) and small powders (PS). Compared with the conventionally prepared single crystal thermoelectric materials, the bending strength was increased up to more than three times and the figure-of-merit Z was similar those of single crystals. It is expected that the mechanical properties could be improved by using hybrid powders without degradation of thermoelectric properties.

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