| 1. |
- Du, Yong, et al.
(författare)
-
Flexible n-Type Tungsten Carbide/Polylactic Acid Thermoelectric Composites Fabricated by Additive Manufacturing
- 2018
-
Ingår i: Coatings. - : MDPI AG. - 2079-6412. ; 8:1
-
Tidskriftsartikel (refereegranskat)abstract
- Flexible n-type tungsten carbide/polylactic acid (WC/PLA) composites were fabricated by additive manufacturing and their thermoelectric properties were investigated. The preparation of an n-type polymer-based thermoelectric composite with good stability in air atmosphere via additive manufacturing holds promise for application in flexible thermoelectric devices. For WC/PLA volume ratios varying from similar to 33% to 60%, the electrical conductivity of the composites increased from 10.6 to 42.2 S/cm, while the Seebeck coefficients were in the range -11 to -12.3 V/K. The thermal conductivities of the composites varied from similar to 0.2 to similar to 0.28 Wamp;lt;boldamp;gt;mamp;lt;/boldamp;gt;-1amp;lt;boldamp;gt;Kamp;lt;/boldamp;gt;-1 at similar to 300 K.
|
|
| 2. |
- Du, Yong, et al.
(författare)
-
Flexible ternary carbon black/Bi2Te3 based alloy/polylactic acid thermoelectric composites fabricated by additive manufacturing
- 2020
-
Ingår i: Journal of Materiomics. - : ELSEVIER. - 2352-8478 .- 2352-8486. ; 6:2, s. 293-299
-
Tidskriftsartikel (refereegranskat)abstract
- Flexible ternary carbon black/Bi2Te3 based alloy/polylactic acid (CB/BTBA/PLA) composites were fabricated by additive manufacturing and their thermoelectric properties were investigated from 300 K to 360 K. At 300 K, as the mass ratios of BTBAs in the composites increased from 38.5% to 71.4%, both the electrical conductivity and Seebeck coefficient of the composites increased from 5.8 S/cm to 13.3 S/cm, and from 60.2 mV/K to 119.9 mV/K, respectively, and the thermal conductivity slightly increased from 0.15 W m(-1)K(-1) to 0.25 W m(-1)K(-1), as a result, the ZT value of the composites increased from 0.004 to 0.023. As the temperature increased from 300 K to 360 K, the electrical conductivity of all the composites slightly decreased, while the thermal conductivity slowly increased, and a highest ZT value of 0.024 was achieved for the composites with 71.4% BTBAs at 320 K. Unlike traditional sterolithography, fused deposition modeling, selective laser melting, etc., this additive manufacturing process can directly print the solutions which contain inorganic fillers and polymer matrixes into almost any designed intricate geometries of thermoelectric composites, therefore this process has great potential to be used for fabrication of flexible polymer based thermoelectric composites and devices. (C) 2020 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.
|
|
| 3. |
- Du, Yong, et al.
(författare)
-
Flexible Thermoelectric Double-Layer Inorganic/Organic Composites Synthesized by Additive Manufacturing
- 2020
-
Ingår i: Advanced Electronic Materials. - : WILEY. - 2199-160X. ; 6:8
-
Tidskriftsartikel (refereegranskat)abstract
- This study shows an approach to combine a high electrical conductivity of one composite layer with a high Seebeck coefficient of another composite layer in a double-layer composite, resulting in high thermoelectric power factor. Flexible double-layer-composites, made from Bi2Te3-based-alloy/polylactic acid (BTBA/PLA) composites and Ag/PLA composites, are synthesized by solution additive manufacturing. With the increase in Ag volume-ratio from 26.3% to 41.7% in Ag/PLA layers, the conductivity of the double-layer composites increases from 12 S cm(-1)to 1170 S cm(-1), while the Seebeck coefficient remains approximate to 80 mu V K(-1)at 300 K. With further increase in volume ratio of Ag until 45.6% in Ag/PLA composite layer, the electrical conductivity of the double-layer composites increases to 1710 S cm(-1), however, with a slight decrease of the Seebeck coefficient to 64 mu V K-1. The electrical conductivity and Seebeck coefficient vary only to a limited extent with the temperature. The high Seebeck coefficient is due to scattering of low energy charge carriers across compositionally graded interfaces. A power factor of 875 mu W m(-1) K(-2)is achieved at 360 K for 41.7 vol.% Ag in the Ag/PLA layers. Solution additive manufacturing can directly print this double-layer composite into intricate geometries, making this process is promising for large-scale fabrication of thermoelectric composites.
|
|
| 4. |
- Du, Yong, et al.
(författare)
-
Flexible thermoelectric materials and devices
- 2018
-
Ingår i: APPLIED MATERIALS TODAY. - : ELSEVIER SCIENCE BV. - 2352-9407. ; 12, s. 366-388
-
Forskningsöversikt (refereegranskat)abstract
- Thermoelectric generators (TEGs) can directly convert waste heat into electrical power. In the last few decades, most research on thermoelectrics has focused on inorganic bulk thermoelectric materials and corresponding devices, and their thermoelectric properties have been significantly improved. An emerging topic is flexible devices, where the use of bulk inorganic materials is precluded by their inherent rigidity. The purpose of this paper is to review the research progress on flexible thermoelectric materials and generators, including theoretical principles for TEGs, conducting polymer TE materials, nanocomposites comprised of inorganic nanostructures in polymer matrices and fully inorganic flexible TE materials in nanostructured thin films. Approaches for flexible TEGs and components are reviewed, and remaining challenges discussed. (C) 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
|
|
| 5. |
- Du, Yong, et al.
(författare)
-
Preparation and Thermoelectric Properties of Graphite/poly(3,4-ethyenedioxythiophene) Nanocomposites
- 2018
-
Ingår i: Energies. - : MDPI. - 1996-1073. ; 11:10
-
Tidskriftsartikel (refereegranskat)abstract
- Graphite/poly(3,4-ethyenedioxythiophene) (PEDOT) nanocomposites were prepared by an in-situ oxidative polymerization process. The electrical conductivity and Seebeck coefficient of the graphite/PEDOT nanocomposites with different content of graphite were measured in the temperature range from 300 K to 380 K. The results show that as the content of graphite increased from 0 to 37.2 wt %, the electrical conductivity of the nanocomposites increased sharply from 3.6 S/cm to 80.1 S/cm, while the Seebeck coefficient kept almost the same value (in the range between 12.0 V/K to 15.1 V/K) at 300 K, which lead to an increased power factor. The Seebeck coefficient of the nanocomposites increased from 300 K to 380 K, while the electrical conductivity did not substantially depend on the measurement temperature. As a result, a power factor of 3.2 Wm(-1) K-2 at 380 K was obtained for the nanocomposites with 37.2 wt % graphite.
|
|
| 6. |
- Du, Yong, et al.
(författare)
-
Thermoelectric Properties of Reduced Graphene Oxide/Bi2Te3 Nanocomposites
- 2019
-
Ingår i: Energies. - : MDPI. - 1996-1073. ; 12:12
-
Tidskriftsartikel (refereegranskat)abstract
- Reduced graphene oxide (rGO)/Bi2Te3 nanocomposite powders with different contents of rGO have been synthesized by a one-step in-situ reductive method. Then, rGO/Bi2Te3 nanocomposite bulk materials were fabricated by a hot-pressing process. The effect of rGO contents on the composition, microstructure, TE properties, and carrier transportation of the nanocomposite bulk materials has been investigated. All the composite bulk materials show negative Seebeck coefficient, indicating n-type conduction. The electrical conductivity for all the rGO/Bi2Te3 nanocomposite bulk materials decreased with increasing measurement temperature from 25 degrees C to 300 degrees C, while the absolute value of Seebeck coefficient first increased and then decreased. As a result, the power factor of the bulk materials first increased and then decreased, and a power factor of 1340 mu Wm(-1)K(-2) was achieved for the nanocomposite bulk materials with 0.25 wt% rGO at 150 degrees C.
|
|
