Thermal conductivity and thermoelectric properties in 3D macroscopic pure carbon nanotube materials

Abstract Sintered carbon nanotube (CNT) blocks and porous CNT sponges were prepared, and their thermoelectric properties were measured. The maximum dimensionless thermoelectric figure-of-merit, ZT, at room temperature of the sintered single-walled carbon nanotube (SWCNT) block is 9.34 × 10−5, which is twice higher than that of the sintered multi-walled carbon nanotube (MWCNT) block in this work and also higher than that of other sintered MWCNT blocks reported previously. In addition, the porous MWCNT sponge showed an ultra-low thermal conductivity of 0.021 W/(m K) and significantly enhanced ZT value of 5.72 × 10−4 at room temperature and 1 atm. This ZT value is higher than that of other 3D macroscopic pure CNT materials reported. The pronounced enhancement of the ZT in the porous MWCNT sponge is attributed to the ultra-low density, ultra-high porosity, and interconnected structure of the material, which lead to a fairly low thermal conductivity and better Seebeck coefficient. The finding of this work provides an understanding for exploring potential enhancement mechanisms and improving the thermoelectric properties of CNT-based thermoelectric composites.

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Thermal Transport Properties of Multi-Walled Carbon Nanotube Arrays

First International Conference on Integration and Commercialization of Micro and Nanosystems, Parts A and B ◽

10.1115/mnc2007-21033 ◽

2007 ◽

Author(s):

Huaqing Xie ◽

An Cai ◽

Xinwei Wang

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotube ◽

Thermal Diffusivity ◽

Room Temperature ◽

Infrared Detector ◽

Laser Flash ◽

Temperature Range ◽

Nanosecond Pulsed Laser ◽

Multi Walled Carbon Nanotube ◽

Individual Cnts

A laser flash technique was applied to measure the thermal diffusivity along a multi-walled carbon nanotube (CNT) array in temperature range of −55∼200 °C. In the measurements, a nanosecond pulsed laser was used to realize noncontact heating and the temperature variations were recorded by an infrared detector. The experimental results show that the thermal diffusivity of the CNT array increases slightly with temperature in the −55∼70 °C temperature range and exhibits no obvious change in the −75∼200 °C temperature range. The CNT array has much larger thermal diffusivity than several known excellent thermal conductors, reaching about 4.6 cm2s−1 at room temperature. The mean thermal conductivity (λ) of individual CNTs was further estimated from the thermal diffusivity, specific heat (Cp), and density (ρ) by using the correlation of λ = αρCp. The thermal conductivity of individual CNTs increases smoothly with the temperature increase, reaching about 750 Wm−1K−1 at room temperature.

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Thermoelectric properties of the Al-TM-Si (TM = Mn, Re) 1/1-cubic approximant

MRS Proceedings ◽

10.1557/proc-805-ll3.3 ◽

2003 ◽

Vol 805 ◽

Cited By ~ 1

Author(s):

Tsunehiro Takeuchi ◽

Toshio Otagiri ◽

Hiroki Sakagami ◽

Uichiro Mizutani

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Thermoelectric Power ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Room Temperature ◽

Low Thermal Conductivity ◽

Dimensionless Figure Of Merit

ABSTRACTThe electrical resistivity, thermoelectric power, and thermal conductivity were investigated for the Al71.6-xMn 17.4Six and Al71.6-xRe 17.4Six (7 ≤ x ≤ 12) 1/1-cubic approximants. A large thermoelectric power ranging from -40 to 90 μV/K and a low thermal conductivity less than 3 W/K·cm were observed at room temperatures. The electrical resistivity at room temperature for these approximants was kept below 4,000 μΩcm, that is much smaller than that in the corresponding quasicrystals. As a result of the large thermoelectric power, the low thermal conductivity, and the low electrical resistivity, large dimensionless figure of merit ZT = 0.10 (n-type) and 0.07 (p-type) were achieved for the Al71.6Re17.4Si11 and Al71.6Mn17.4Si11 at room temperature, respectively.

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Extremely Low Thermal Conductivity Substances as Novel Thermoelectric Materials

MRS Proceedings ◽

10.1557/proc-0886-f09-05 ◽

2005 ◽

Vol 886 ◽

Cited By ~ 3

Author(s):

Shinsuke Yamanaka ◽

Ken Kurosaki ◽

Atsuko Kosuga ◽

Keita Goto ◽

Hiroaki Muta

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Room Temperature ◽

State Of The Art ◽

Thermoelectric Figure ◽

Low Thermal Conductivity ◽

Thallium Compounds ◽

Thallium Tellurides

ABSTRACTWe have prepared polycrystalline bulk samples of various thallium compounds and measured their thermoelectric properties. The most remarkable point of the thermoelectric properties of the thallium compounds is the extremely low thermal conductivity. The state-of-the-art thermoelectric materials such as Bi2Te3 and TAGS materials indicate relatively low the thermal conductivity, around 1.5 W/m/K. However, the thermal conductivity of the thallium compounds is below 0.5 W/m/K; especially that of silver thallium tellurides is around 0.25 W/m/K at room temperature. This extremely low thermal conductivity leads a great advantage for an enhancement of the thermoelectric performance. In this paper, we report on the properties of some thallium compounds selected for study as novel thermoelectric materials. One of these compounds seems to have a thermoelectric figure of merit comparable to those of state-of-the-art materials.

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Thermoelectric Properties of Tl2Te-Sb2Te3 Pseudo-Binary System

MRS Proceedings ◽

10.1557/proc-0886-f08-03 ◽

2005 ◽

Vol 886 ◽

Author(s):

Ken Kurisaki ◽

Keita Goto ◽

Atsuko Kosuga ◽

Hiroaki Muta ◽

Shinsuke Yamanaka

Keyword(s):

Thermal Conductivity ◽

Binary System ◽

Thermoelectric Properties ◽

Room Temperature ◽

State Of The Art ◽

Electrical Performance ◽

Low Thermal Conductivity ◽

Maximum Value ◽

P Type ◽

Type Conduction

ABSTRACTPolycrystalline-sintered samples of thallium based substances, (Tl2Te)100−x(Sb2Te3)x (x= 0, 1, 5, 10), were prepared by melting Tl2Te and Sb2Te3 ingots followed by annealing in sealed quartz ampoules. The thermoelectric properties were measured from room temperature to around 600 K. The values of the Seebeck coefficient of all samples are positive, indicating a p-type conduction characteristic. The maximum value of the power factor is 6.53×10−4 Wm−1K−2 at 591 K obtained for x= 10 (Tl9SbTe6), which is about one order lower than those of state-of-the-art thermoelectric materials. All samples indicate an extremely low thermal conductivity, for example that of Tl2Te is approximately 0.35 Wm−1K−1 from room temperature to around 600 K. Although the electrical performance of the samples is not so good, the ZT value is relatively high due to the extremely low thermal conductivity. The maximum ZT value is 0.42 at 591 K obtained for Tl9SbTe6.

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Effects of the Addition of Rhenium on the Thermoelectric Properties of the AlPdMn Quasicrystalline System

MRS Proceedings ◽

10.1557/proc-626-z5.1 ◽

2000 ◽

Vol 626 ◽

Author(s):

A. L. Pope ◽

R. Gagnon ◽

R. Schneidmiller ◽

P. N. Alboni ◽

R. T. Littleton ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Transport Property ◽

Periodic Structure ◽

Thermoelectric Properties ◽

Electrical Transport ◽

Room Temperature ◽

Phonon Scattering ◽

X Ray ◽

Low Thermal Conductivity

ABSTRACTPartially due to their lack of periodic structure, quasicrystals have inherently low thermal conductivity on the order of 1 - 3 W/m-K. AlPdMn quasicrystals exhibit favorable room temperature values of electrical conductivity, 500–800 (Ω-cm)-1, and thermopower, 80 μV/K, with respect to thermoelectric applications. In an effort to further increase the thermopower and hopefully minimize the thermal conductivity via phonon scattering, quartenary Al71Pd21Mn8-XReX quasicrystals were grown. X-ray data confirms that the addition of a fourth element does not alter the quasiperiodicity of the sample. Al71Pd21Mn8-XReX quasicrystals of varying Re concentration were synthesized where x had values of 0, 0.08, 0.25, 0.4, 0.8, 2, 5, 6, and 8. Both thermal and electrical transport property measurements have been performed and are reported.

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Fabrication of Porous Polyvinylidene Fluoride/Multi-Walled Carbon Nanotube Nanocomposites and Their Enhanced Thermoelectric Performance

Polymers ◽

10.3390/polym10070797 ◽

2018 ◽

Vol 10 (7) ◽

pp. 797 ◽

Cited By ~ 12

Author(s):

Fei-Peng Du ◽

Xuan Qiao ◽

Yan-Guang Wu ◽

Ping Fu ◽

Sheng-Peng Liu ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Carbon Nanotube ◽

Seebeck Coefficient ◽

Porous Structure ◽

Thermoelectric Properties ◽

Polyvinylidene Fluoride ◽

Pvdf Film ◽

Solvent Vapor ◽

Multi Walled Carbon Nanotube

In this paper, a solvent vapor-induced phase separation (SVIPS) technique was used to create a porous structure in polyvinylidene fluoride/Multi-walled carbon nanotube (PVDF/MWNTs) composites with the aim of increasing the electrical conductivity through the incorporation of MWNTs while retaining a low thermal conductivity. By using the dimethylformamide/acetone mixture, porous networks could be generated in the PVDF/MWNTs composites upon the rapid volatilization of acetone. The electrical conductivity was gradually enhanced by the addition of MWNTs. At the same time, the thermal conductivity of the PVDF film could be retained at 0.1546 W·m−1·K−1 due to the porous structure being even by loaded with a high content of MWNTs (i.e., 15 wt.%). Thus, the Seebeck coefficient, power factor and figure of merit (ZT) were subsequently improved with maximum values of 324.45 μV/K, 1.679 μW·m−1·K−2, and 3.3 × 10−3, respectively. The microstructures, thermal properties, and thermoelectric properties of the porous PVDF/MWNTs composites were studied. It was found that the enhancement of thermoelectric properties would be attributed to the oxidation of MWNTs and the porous structure of the composites. The decrease of thermal conductivity and the increase of Seebeck coefficient were induced by the phonon scattering and energy-filtering effect. The proposed method was found to be facile and effective in creating a positive effect on the thermoelectric properties of composites.

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Structure and Thermoelectric Properties of New Quaternary Tin and Lead Bismuth Selenides, K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1+xSn5-xBi11+xSe22

MRS Proceedings ◽

10.1557/proc-626-z8.4 ◽

2000 ◽

Vol 626 ◽

Author(s):

Antje Mrotzek ◽

Kyoung-Shin Choi ◽

Duck-Young Chung ◽

Melissa A. Lane ◽

John R. Ireland ◽

...

Keyword(s):

Thermal Conductivity ◽

Single Crystal ◽

Thermoelectric Properties ◽

Three Dimensional ◽

Structure Type ◽

Narrow Gap ◽

Low Thermal Conductivity ◽

Seebeck Coefficients ◽

Metal Atoms ◽

Anionic Framework

ABSTRACTWe present the structure and thermoelectric properties of the new quaternary selenides K1+xM4–2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22. The compounds K1+xM4-2xBi7+xSe15 (M= Sn, Pb) crystallize isostructural to A1+xPb4-2xSb7+xSe15 with A = K, Rb, while K1-xSn5-xBi11+xSe22 reveals a new structure type. In both structure types fragments of the Bi2Te3-type and the NaCl-type are connected to a three-dimensional anionic framework with K+ ions filled tunnels. The two structures vary by the size of the NaCl-type rods and are closely related to β-K2Bi8Se13 and K2.5Bi8.5Se14. The thermoelectric properties of K1+xM4-2xBi7+xSe15 (M = Sn, Pb) and K1-xSn5-xBi11+xSe22 were explored on single crystal and ingot samples. These compounds are narrow gap semiconductors and show n-type behavior with moderate Seebeck coefficients. They have very low thermal conductivity due to an extensive disorder of the metal atoms and possible “rattling” K+ ions.

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Thermoelectric properties of PEDOT:PSS aerogel secondary-doped in supercritical CO2 atmosphere with low thermal conductivity

Polymer ◽

10.1016/j.polymer.2020.122912 ◽

2020 ◽

Vol 206 ◽

pp. 122912

Author(s):

Naoya Yanagishima ◽

Shinji Kanehashi ◽

Hiromu Saito ◽

Kenji Ogino ◽

Takeshi Shimomura

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Supercritical Co2 ◽

Low Thermal Conductivity ◽

Co2 Atmosphere

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Synthesis and Characterization of Poly(2,5-benzimidazole) (ABPBI) Grafted Carbon Nanotubes

MRS Proceedings ◽

10.1557/proc-1240-ww09-02 ◽

2009 ◽

Vol 1240 ◽

Cited By ~ 1

Author(s):

Ji-Ye Kang ◽

Su-Mi Eo ◽

Loon-Seng Tan ◽

Jong-Beom Baek

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Interfacial Adhesion ◽

Synthesis And Characterization ◽

Acylation Reaction ◽

Single Walled Carbon Nanotube ◽

Mechanical And Electrical Properties ◽

Multi Walled Carbon Nanotube

AbstractSingle-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube (MWCNT) were functionalized with 3,4-diaminobenzoic acid via “direct” Friedel-Crafts acylation reaction in PPA/P2O5 to afford ortho-diamino-functionalized SWCNT (DIF-SWCNT) and MWCNT (DIF-MWCNT). The resultant DIF-SWCNT and DIF-MWCNT showed improved solubility and dispersibility. To improve interfacial adhesion between CNT and polymer matrix, the grafting of ABPBI onto the surface of DIF-SWCNT (10 wt%) or DIF-MWCNT (10 wt%) was conducted by simple in-situ polymerization of AB monomer, 3,4-diaminobenzoic acid dihydrochloride, in PPA. The resultant ABPBI-g-MWCNT and ABPBI-g-SWCNT showed improved the mechanical and electrical properties.

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