Large scale production of high efficient and robust p-type Bi-Sb-Te based thermoelectric materials by powder metallurgy

Madavali, Babu; Kim, Hyo-Seob; Lee, Kap Ho; Isoda, Yukihiro; Gascoin, Franck; Hong, Soon‐Jik

doi:10.1016/j.matdes.2016.09.089

Cited by 44 publications

(30 citation statements)

References 43 publications

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“…As shown in Table , the carrier effective mass ( m ∗ ) was roughly estimated from the measured α and n by Equation . As shown in Table , the effective mass increased generally with decreasing particle size . The fluctuation of the effective mass for sample # 3 may be attributed to the non‐parabolic nature of the valence band and complex scattering process .…”

Section: Resultsmentioning

confidence: 83%

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi₂Te₃ Based Polycrystalline Bulks

Zhang

Fan

et al. 2017

Adv Eng Mater

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In this work, n-type Bi 2 Te 2.7 Se 0.3 bulks are prepared by resistance pressure sintering technique from different particle sized powders, and the microstructure and electrical transport properties are investigated as function of the initial particle size distribution. With the initial particle size decreasing, more antisite defects, grain-boundaries and interface defects are introduced, and lead to a larger carrier concentration due to donor-like effect and a lower mobility due to the increasing grain boundary and carrier scattering, which results in a lower Seebeck coefficient and electrical resistivity. As a result, a maximum power factor of about 2.89 mW mK À2 at room temperature is achieved for the bulk sintered from the mix powders with different particle size distribution due to the optimization of the carrier concentration. The band gaps and the intrinsic excitation temperature are effectively adjusted by controlling the particle size in a narrow distribution. The sample sintered from the powders below 400 mesh has the highest average power factor above 2.44 mW mK À2 in the whole testing temperature range due to the improving band gaps and intrinsic excitation temperature.

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Section: Resultsmentioning

confidence: 83%

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi₂Te₃ Based Polycrystalline Bulks

Zhang

Fan

et al. 2017

Adv Eng Mater

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“…In order to prepare the Bi 0.5 Sb 1.5 Te 3 /ZnO (2 wt%) nanocomposite powders, we first prepared p‐type Bi 0.5 Sb 1.5 Te 3 alloy powders by gas atomization (GA), and then, 2 wt% of ZnO nanorods were dispersed into the GA powder via a high‐energy ball milling process at different milling times (5, 10, and 20 minutes) under an argon atmosphere. The nanocomposite powders were subsequently sintered under a compressive stress of 50 MPa at 673 K. The holding time was maintained at about 10 minutes during the sintering.…”

Section: Methodsmentioning

confidence: 99%

Investigation of microstructure and thermoelectric properties of p‐type BiSbTe/ZnO composites

Madavali

Lee

Kim

et al. 2017

Int J Applied Ceramic Tech

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In this research work, p-type BiSbTe/ZnO (2 wt%) nanocomposite powders were fabricated by high-energy ball milling at different milling times, and subsequently, powders were consolidated by spark plasma sintering at 673 K temperature. The existence of nanoinclusions was confirmed by SEM-EDS mapping. Vickers hardness values greatly improved due to reduction in grain size which prevents the crack propagation and dispersion strengthening mechanism. The decrease in carrier density, which plays a critical role in thermoelectrics, dramatically increases the Seebeck coefficient, and subsequently, decreases the electrical conductivity upon the dispersion of ZnO nanorods into the BiSbTe matrix. The thermal conductivity was noticeably reduced by~13% in BiSbTe/ZnO composites for 5-minute samples due to blocking of carriers/phonons at interfaces, and/or grain boundaries. The peak ZT of 0.92 was obtained for BiSbTe matrix, and 0.91 for BiSbTe/ZnO (5 minutes) composites at room temperatures. K E Y W O R D Sball milling, Bi 2 Te 3 alloys, nanocomposites, spark plasma sintering, thermoelectric materials 1 | INTRODUCTION Thermoelectric (TE) materials have been crucially used in renewable energy conversion technologies to overcome the energy crisis in the present world. The efficiency of TE materials can be defined by the dimensionless figure of merit, ZT = (a 2 r/K) T, where a, r, K, and T are the Seebeck coefficient, electrical conductivity, thermal conductivity, and absolute temperature, respectively. 1 In general, the temperature gradient develops an electrostatic potential, which is defined as the Seebeck coefficient (a = DV/DT for small DT). The Seebeck coefficient gradually decreases with carrier density, while the electrical conductivity increases. The thermal conductivity is proportional to the carrier density, which is contributed by both electrons and phonons. The ZT should be high, and at least unity (ZT ≥ 1) to maintain the device efficiency over 10%. 2,3 For ambient room temperature (RT) applications, bismuth telluride (Bi 2 Te 3 )-based alloys are much attracted due to their high-energy conversion thermoelectric efficient at RT. 3 So far, many researchers have studied TE properties and reported improved ZT values by forming composite structures and dispersion of nanoinclusions in bulk matrix thereby controlling the Seebeck coefficient and/or electrical conductivity via introduction of energy filtering effect that can filter the low energy electrons and allows only high energy (hot) electrons. 4,5 In addition, thermal conductivity is also reduced by phonon scattering at grain boundaries and/or interfaces between nanoinclusion and matrix. Hsu et al 6 reported enhanced TE properties in the AgPb m SbTe m+2 system with nanoscale inhomogeneous of Ag and Sb embedded in PbTe matrix that can dramatically decrease the thermal conductivity by increasing phonon scattering without affecting the electrical properties. Li et al 7 reported BiSbTe-based nanocomposites with high ZT values through dispersion of SiC nanopartic...

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“…A review on the synthesis of Bi 2 Te 3 nanostructures has been recently reported elsewhere [7]. Bi 2 Te 3 is normally synthesized by fusion of bismuth (Bi) and tellurium (Te) metals forming an ingot, or by powder metallurgy [8]. Arc melting, a high energy process, has been shown to be a fast and reproducible synthetic method for high performance Bi 2−x Sb x Te 3 structures [9,10], even combined with solidification under magnetic field, yielding textured materials [11].…”

Section: Introductionmentioning

confidence: 99%

Facile Solution Synthesis, Processing and Characterization of n- and p-Type Binary and Ternary Bi–Sb Tellurides

et al. 2020

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The solution synthesis route as a scalable bottom-up synthetic method possesses significant advantages for synthesizing nanostructured bulk thermoelectric (TE) materials with improved performance. Tuning the composition of the materials directly in the solution, without needing any further processing, is important for adjusting the dominant carrier type. Here, we report a very rapid (2 min) and high yield (>8 g/batch) synthetic method using microwave-assisted heating, for the controlled growth of Bi2–xSbxTe3 (x: 0–2) nanoplatelets. Resultant materials exhibit a high crystallinity and phase purity, as characterized by XRD, and platelet morphology, as revealed by SEM. Surface chemistry of as-made materials showed a mixture of metallic and oxide phases, as evidenced by XPS. Zeta-potential analysis exhibited a systematic change of isoelectric point as a function of the material composition. As-made materials were directly sintered into pellets by using spark plasma sintering process. TE performance of Bi2−xSbxTe3 pellets were studied, where the highest ZT values of 1.04 (at 440 K) for Bi2Te3 and 1.37 (at 523 K) for Sb2Te3 were obtained, as n- and p-type TE materials. The presented microwave-assisted synthesis method is energy effective, a truly scalable and reproducible method, paving the way for large scale production and implementation of towards large-area TE applications.

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Large scale production of high efficient and robust p-type Bi-Sb-Te based thermoelectric materials by powder metallurgy

Cited by 44 publications

References 43 publications

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi₂Te₃ Based Polycrystalline Bulks

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi₂Te₃ Based Polycrystalline Bulks

Investigation of microstructure and thermoelectric properties of p‐type BiSbTe/ZnO composites

Facile Solution Synthesis, Processing and Characterization of n- and p-Type Binary and Ternary Bi–Sb Tellurides

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Large scale production of high efficient and robust p-type Bi-Sb-Te based thermoelectric materials by powder metallurgy

Cited by 44 publications

References 43 publications

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi2Te3 Based Polycrystalline Bulks

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi2Te3 Based Polycrystalline Bulks

Investigation of microstructure and thermoelectric properties of p‐type BiSbTe/ZnO composites

Facile Solution Synthesis, Processing and Characterization of n- and p-Type Binary and Ternary Bi–Sb Tellurides

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Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi₂Te₃ Based Polycrystalline Bulks

Changing the Band Gaps by Controlling the Distribution of Initial Particle Size to Improve the Power Factor of N‐Type Bi₂Te₃ Based Polycrystalline Bulks