Enhanced figure of merit in Mg2Si0.877Ge0.1Bi0.023/multi wall carbon nanotube nanocomposites

RSC Advances ◽  
2015 ◽  
Vol 5 (80) ◽  
pp. 65328-65336 ◽  
Author(s):  
Nader Farahi ◽  
Sagar Prabhudev ◽  
Matthieu Bugnet ◽  
Gianluigi A. Botton ◽  
Jianbao Zhao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Power Factor ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Thermoelectric Performance ◽  
Multi Wall Carbon Nanotubes ◽  
Energy Filtering ◽  
Multi Wall Carbon Nanotube

Adding multi wall carbon nanotubes to Mg2Si0.877Ge0.1Bi0.023 led to an increased power factor via energy filtering as well as a lowered thermal conductivity via increased phonon scattering, and thus an enhanced thermoelectric performance.

scholarly journals Macroscopic weavable fibers of carbon nanotubes with giant thermoelectric power factor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Natsumi Komatsu ◽  
Yota Ichinose ◽  
Oliver S. Dewey ◽  
Lauren W. Taylor ◽  
Mitchell A. Trafford ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Fermi Energy ◽  
Performance Enhancement ◽  
Thermoelectric Performance ◽  
Thermoelectric Power Factor ◽  
Large Power ◽  
Energy Tuning

AbstractLow-dimensional materials have recently attracted much interest as thermoelectric materials because of their charge carrier confinement leading to thermoelectric performance enhancement. Carbon nanotubes are promising candidates because of their one-dimensionality in addition to their unique advantages such as flexibility and light weight. However, preserving the large power factor of individual carbon nanotubes in macroscopic assemblies has been challenging, primarily due to poor sample morphology and a lack of proper Fermi energy tuning. Here, we report an ultrahigh value of power factor (14 ± 5 mW m−1 K−2) for macroscopic weavable fibers of aligned carbon nanotubes with ultrahigh electrical and thermal conductivity. The observed giant power factor originates from the ultrahigh electrical conductivity achieved through excellent sample morphology, combined with an enhanced Seebeck coefficient through Fermi energy tuning. We fabricate a textile thermoelectric generator based on these carbon nanotube fibers, which demonstrates high thermoelectric performance, weavability, and scalability. The giant power factor we observe make these fibers strong candidates for the emerging field of thermoelectric active cooling, which requires a large thermoelectric power factor and a large thermal conductivity at the same time.

scholarly journals Centimeter-Long Weavable Fibers of Carbon Nanotubes with Giant Thermoelectric Power Factor

2021 ◽  
Author(s):  
Natsumi Komatsu ◽  
Yota Ichinose ◽  
Oliver Dewey ◽  
Lauren Taylor ◽  
Mitchell Trafford ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Fermi Energy ◽  
Performance Enhancement ◽  
Thermoelectric Performance ◽  
Thermoelectric Power Factor ◽  
Electronic Density ◽  
Large Power

Abstract Low-dimensional materials have recently attracted much interest as thermoelectric materials because of their charge carrier confinement leading to thermoelectric performance enhancement. Carbon nanotubes are promising candidates because of their one-dimensionality in addition to their unique advantages such as flexibility and light weight. However, preserving the large power factor of individual carbon nanotubes in macroscopic assemblies has been challenging, primarily due to poor sample morphology and a lack of proper Fermi energy tuning. Here, we report an unprecedentedly high value of power factor (14±5 mWm-1K-2) for centimeter-long weavable fibers of aligned carbon nanotubes with ultrahigh electrical and thermal conductivity. Our theoretical simulations show that the observed giant power factor originates from the one-dimensional quantum confinement of charge carriers, appearing when the Fermi energy is near a van Hove singularity in the electronic density of states. We fabricated a textile thermoelectric generator based on these carbon nanotube fibers, which demonstrated high thermoelectric performance, weavablity, and scalability. The giant power factor we observed make these fibers strong candidates for the emerging field of thermoelectric active cooling, which requires a large thermoelectric power factor and a large thermal conductivity at the same time.

Enhanced thermoelectric performance through carrier scattering at heterojunction potentials in BiSbTe based composites with Cu3SbSe4 nanoinclusions

2015 ◽  
Vol 3 (27) ◽  
pp. 7045-7052 ◽  
Author(s):  
Yuanyue Li ◽  
Di Li ◽  
Xiaoying Qin ◽  
Xiuhui Yang ◽  
Yongfei Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Power Factor ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Thermoelectric Performance ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Carrier Scattering ◽  
Interface Scattering

Owing to enhanced power factor and reduced lattice thermal conductivity through interface scattering, a largest thermoelectric figure of merit ZT = 1.61 is achieved at 467 K for BiSbTe based composite with Cu3SbSe4 nanoinclusions.

High thermoelectric performance of superionic argyrodite compound Ag8SnSe6

2016 ◽  
Vol 4 (24) ◽  
pp. 5806-5813 ◽  
Author(s):  
Lin Li ◽  
Yuan Liu ◽  
Jiyan Dai ◽  
Aijun Hong ◽  
Min Zeng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Material ◽  
Power Factor ◽  
High Power ◽  
Figure Of Merit ◽  
Environmentally Friendly ◽  
Thermoelectric Performance ◽  
Low Thermal Conductivity ◽  
High Power Factor ◽  
High Figure

A good thermoelectric material usually has a high power factor and low thermal conductivity for high figure of merit (ZT), and is also environmentally friendly and economical.

Strain Engineering of Polar Optical Phonon Scattering Mechanism – An Effective Way to Optimize the Power-factor and Lattice Thermal Conductivity of ScN

2021 ◽  
Author(s):  
Iyyappa Rajan Panneerselvam ◽  
Man Hea Kim ◽  
Carlos Baldo III ◽  
Yan Wang ◽  
Mahalakshmi Sahasranaman
Keyword(s):  
Thermal Conductivity ◽  
Power Factor ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Material Selection ◽  
Strain Engineering ◽  
Polar Optical Phonon ◽  
Thermoelectric Power Factor ◽  
Optical Phonon Scattering

The tug-of-war between the thermoelectric power factor and the figure-of-merit complicates thermoelectric material selection, particularly for mid-to-high temperature thermoelectric materials. Approaches to reduce lattice thermal conductivity while maintaining a high-power...

Experimental investigation and modelling of drilling on multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposites

2016 ◽  
Vol 232 (11) ◽  
pp. 1943-1959 ◽  
Author(s):  
Kalyan Kumar Singh ◽  
Dhiraj Kumar
Keyword(s):  
Carbon Nanotubes ◽  
Surface Roughness ◽  
Carbon Nanotube ◽  
Feed Rate ◽  
Spindle Speed ◽  
Glass Fabric ◽  
Multi Wall Carbon Nanotubes ◽  
Weight Percentage ◽  
Drill Diameter ◽  
Multi Wall Carbon Nanotube

The primary objective of this research is to investigate the effect of multi-wall carbon nanotubes on drilling of multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposites. The experiments were conducted on composites with varying the weight percentage of multi-wall carbon nanotubes content to analyse drilling-induced delamination and surface roughness, which affect the quality and property of the drilled holes. The drilling parameters considered are spindle speed, feed rate and drill diameter. The microstructure of the holes was characterized using field emission scanning electron microscopy methods. For correlating the effect of the weight percentage of carbon nanotubes with the referred drilling parameters, a mathematical model was used, based on response surface methodology. For development of the mathematical model, four factors, namely, spindle speed, feed rate, diameter of drill and weight percentage of carbon nanotubes, were taken into account. The result established that delamination and surface roughness are reduced as multi-wall carbon nanotubes’ content increases. Maximum improvement in delamination factor was observed in the case of 1.0 wt% multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposite, which is 25% and 31.09% at the entrance and exit sides of the hole, respectively. With an increase in the feed rate and the drill diameter, delamination factor increases; however, with an increase in spindle speed, delamination factor decreases. Lower value of surface roughness (1.113 µm) was observed in 1.5 wt% of multi-wall carbon nanotube–embedded epoxy/glass fabric polymeric nanocomposite. However, surface roughness increases with an increase in feed rate and drill diameter.

scholarly journals Substantial thermoelectric enhancement achieved by manipulating the band structure and dislocations in Ag and La co-doped SnTe

2021 ◽  
Author(s):  
Wenjing Xu ◽  
Zhongwei Zhang ◽  
Chengyan Liu ◽  
Jie Gao ◽  
Zhenyuan Ye ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carrier Concentration ◽  
Power Factor ◽  
Figure Of Merit ◽  
Performance Enhancement ◽  
Thermoelectric Performance ◽  
Electronic Band ◽  
Co Doping ◽  
High Carrier ◽  
Valence Bands

AbstractEco-friendly SnTe based thermoelectric materials are intensively studied recently as candidates to replace PbTe; yet the thermoelectric performance of SnTe is suppressed by its intrinsically high carrier concentration and high thermal conductivity. In this work, we confirm that the Ag and La co-doping can be applied to simultaneously enhance the power factor and reduce the thermal conductivity, contributing to a final promotion of figure of merit. On one hand, the carrier concentration and band offset between valence bands are concurrently reduced, promoting the power factor to a highest value of ∼2436 µW·m−1·K−2 at 873 K. On the other hand, lots of dislocations (∼3.16×107 mm−2) associated with impurity precipitates are generated, resulting in the decline of thermal conductivity to a minimum value of 1.87 W·m−1·K−1 at 873 K. As a result, a substantial thermoelectric performance enhancement up to zT ≈ 1.0 at 873 K is obtained for the sample Sn0.94Ag0.09La0.05Te, which is twice that of the pristine SnTe (zT ≈ 0.49 at 873 K). This strategy of synergistic manipulation of electronic band and microstructures via introducing rare earth elements could be applied to other systems to improve thermoelectric performance.

scholarly journals Effects of the Interface between Inorganic and Organic Components in a Bi2Te3–Polypyrrole Bulk Composite on Its Thermoelectric Performance

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3080
Author(s):  
Cham Kim ◽  
David Humberto Lopez
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Thermal Properties ◽  
Seebeck Coefficient ◽  
Power Factor ◽  
Energy Band ◽  
Phonon Scattering ◽  
Thermoelectric Performance ◽  
High Seebeck Coefficient ◽  
Fabrication Condition

We provided a method to hybridize Bi2Te3 with polypyrrole, thus forming an inorganic/organic bulk composite (Bi2Te3–polypyrrole), in which the effects of energy band junction and phonon scattering were expected to occur at the interface of the two components. Bi2Te3–polypyrrole exhibited a considerably high Seebeck coefficient compared to pristine Bi2Te3, and thus it recorded a somewhat increased power factor despite the loss in electrical conductivity caused by the organic component, polypyrrole. Bi2Te3–polypyrrole also exhibited much lower thermal conductivity than pristine Bi2Te3 because of the phonon scattering effect at the interface. We successfully brought about the decoupling phenomenon of electrical and thermal properties by devising an inorganic/organic composite and adjusting its fabrication condition, thereby optimizing its thermoelectric performance, which is considered the predominant property for n-type binary Bi2Te3 reported so far.

scholarly journals Strategy of extra Zr doping on the enhancement of thermoelectric performance for TiZrxNiSn synthesized by a modified solid-state reaction

2021 ◽  
Author(s):  
Jun-Liang Chen ◽  
Hengquan Yang ◽  
Chengyan Liu ◽  
Jisheng Liang ◽  
Lei Miao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Solid State ◽  
Power Factor ◽  
Solid State Reaction ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Heusler Alloys ◽  
Thermoelectric Performance ◽  
Good Mechanical Property ◽  
Large Power

Abstract Half-Heusler alloys, which possess the advantages of high thermal stability, large power factor and good mechanical property, have been attracted increasing interest in mid-temperature thermoelectric application. In this work, the extra Zr-doped TiZrxNiSn samples were successfully prepared by a modified solid-state reaction followed by spark plasma sintering. It demonstrates that extra Zr doping could not only improve the power factor on account of an increase in Seebeck coefficient but also suppress the lattice thermal conductivity originated from the strengthened phonon scattering by the superlattice nanodomains and the secondary nanoparticles. As a consequence, an increased power factor of 3.29 mW m− 1 K− 2 and a decreased lattice thermal conductivity of 1.74 W m− 1 K− 1 are achieved in TiZr0.015NiSn, leading to a peak ZT as high as 0.88 at 773 K and an average ZT value up to 0.62 in the temperature range of 373 − 773 K. This work gives a guidance for optimizing the thermoelectric performance of TiNiSn-based alloys by modulating the microstructures on the secondary nanophases and superlattice nanodomains.

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