Characterization of Cast Iron Scrap Chips toward β-FeSi2 Thermoelectric Materials

2014 ◽  
Vol 804 ◽  
pp. 3-6 ◽  
Author(s):  
Assayidatul Laila ◽  
Makoto Nanko

The upgrade recycling process of cast-iron scrap chips toward β-FeSi2 is regarded as an eco-friendly and cost-effective production process. It is useful for reducing the material cost in fabricating β-FeSi2 by utilizing the waste that is obtained from the manufacturing process of cast-iron components. In this research, β-FeSi2 was successfully obtained from cast iron bscrap chips and showed good thermoelectric performance in Seebeck coefficient and electrical conductivity which is around 70% to almost 100% compared to β-FeSi2 that was prepared from pure Fe and other publications. The thermoelectric power factor was achieved 90% performance compared to other literatures and β-FeSi2 prepared from pure Fe.

RSC Advances ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 1593-1599 ◽  
Author(s):  
Jonna Hynynen ◽  
David Kiefer ◽  
Christian Müller

The crystallinity of P3HT strongly benefits the electrical conductivity but not Seebeck coefficient, leading to an increase in power factor by one order of magnitude.


2015 ◽  
Vol 819 ◽  
pp. 193-197 ◽  
Author(s):  
Arshad Hmood ◽  
Arej Kadhim ◽  
H.A. Hassan

In this paper we reported the electrical conductivity and thermoelectric characterization of silver (Ag) and antimony (Sb) co-doped lead telluride bulk materials, which have been synthesized using solid state microwave technique. The doping level has performed first-principle calculations for the AgPbmSbTem+2 (LAST-m) (m = 0, 2, 4, 6, 8 and 10) to clarify the effect of simultaneous doping of Ag and Sb on PbTe. The Hall effect and thermoelectric measurements have shown n-type conductivity in AgPbmSbTem+2 samples. The samples show large and negative values of the Seebeck coefficient and moderate electrical conductivity. The Seebeck coefficient increased with doping levels increases at m=0 to 10. The value of the Seebeck coefficient is −419.69 μVK−1 for AgPb8SbTe10 at 338 K. It has been found that AgPb8SbTe10 sample has a higher thermoelectric power factor 1.87 mW K-2 m-1 at 310 K.


Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 14
Author(s):  
Zhenhua Wu ◽  
Zhiyu Hu

In this paper, metals’ (Cu, Ag, Au)/Al2O3/Bi2Te3 heterostructures have been fabricated to synergistically optimize their carrier concentration and mobility, thereby enhancing their thermoelectric power factor. Metal can be alloyed with Bi2Te3 to reduce the electron concentration. The introduction of the oxide layer further reduces the electron concentration and leads to an increase in mobility. By adjusting the metal and oxide layer, it is possible to realize the simultaneous optimization of electric conductivity and the Seebeck coefficient. This work will enable the optimal and novel design of heterstructures for thermoelectric materials with further improved performance.


2014 ◽  
Vol 1 (1) ◽  
pp. 65-72
Author(s):  
D.M. Freik ◽  
I.K. Yurchyshyn ◽  
V.Yu. Potyak

On the basis of theoretical model of quantum well (QW) with infinitely high walls it was investigated thermoelectric parameters depending on the thickness of the layer of nanostructures IV-VI (PbS, PbSe, PbTe) in the approximation of changing Fermi energy. There have been shown that the dependences of the Seebeck coefficient, electrical conductivity and thermoelectric power factor on well width for lead chalcogenides nanofilms are in good agreement with the experimental data. So, that proves the correctness of used model.


2019 ◽  
Vol 798 ◽  
pp. 304-309 ◽  
Author(s):  
Chutima Oopathump ◽  
Direk Boonthuma ◽  
Siwaporn Meejoo Smith

Organic polymer composites are relatively simple to process and are therefore used in thermoelectric materials. The organic polymers are used as an adhesive agent between thermoelectric material grains. Thermoelectric effects of poly (vinyl alcohol) (PVA) composited with sodium cobalt oxide (NaxCoO2) were studied in this work. PVA is a low cost and an excellent biocompatibility polymer. High electrical conductivity, high Seebeck coefficient and low thermal conductivity are required in thermoelectric materials. As PVA is an insulating material, the PVA in between NaxCoO2 grain boundaries has an effect on the low electrical conductivity of NaxCoO2 composite. This results in a decrease in thermoelectric efficiency. However, PVA has been utilized to increase the Seebeck coefficient and also enhance thermoelectric efficiency. In order to improve the electrical conductivity of NaxCoO2 composite, PVA removal was produced by furnace heating at 500̊ C to eliminate PVA from NaxCoO2/PVA sample. The general thermoelectric parameters including the Seebeck coefficient, electrical conductivity and power factor of NaxCoO2/PVA and PVA removal sample were compared. X-ray diffraction patterns (XRD) and scanning electron microscope (SEM) images were used to identify the phase identification and morphology study, respectively. The results showed that the PVA removal sample had higher electrical conductivity than the NaxCoO2/PVA sample. However, NaxCoO2/PVA sample had higher thermoelectric performance than the PVA removal sample because the NaxCoO2/PVA sample showed higher Seebeck coefficient and power factor.


2017 ◽  
Vol 52 (5) ◽  
pp. 621-627 ◽  
Author(s):  
Endou Liu ◽  
Congcong Liu ◽  
Zhengyou Zhu ◽  
Jingkun Xu ◽  
Fengxing Jiang ◽  
...  

Herein, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/silicon dioxide nanoparticles (SiO2-NPs) composite films were prepared via a simple method by direct vacuum filtration technique. The effect of SiO2-NPs contents on the thermoelectric performance of PEDOT:PSS was investigated systematically. PEDOT:PSS nanofilm without SiO2-NPs exhibited a maximum electrical conductivity of 1487 S cm−1 and a Seebeck coefficient of 17.4 µV/K. When the SiO2-NPs were introduced, the Seebeck coefficient of PEDOT:PSS/SiO2-NPs nanocomposite films increased to a peak value of 24.2 µV/K at 20 wt% SiO2-NPs, and the corresponding electrical conductivity was 1132 S/cm. Although a compromise in electrical conductivity, a large optimized power factor up to be 66.29 µW/m K2 was achieved due to the contribution of improved Seebeck coefficient. The presence of SiO2-NPs in the composite films with small-size structure and abundant grain boundaries may cause the carrier scattering and filtering effect, which accounts for the enhanced Seebeck coefficient.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yijie Li ◽  
Nguyen Van Toan ◽  
Zhuqing Wang ◽  
Khairul Fadzli Bin Samat ◽  
Takahito Ono

AbstractPorous silicon (Si) is a low thermal conductivity material, which has high potential for thermoelectric devices. However, low output performance of porous Si hinders the development of thermoelectric performance due to low electrical conductivity. The large contact resistance from nonlinear contact between porous Si and metal is one reason for the reduction of electrical conductivity. In this paper, p- and n-type porous Si were formed on Si substrate by metal-assisted chemical etching. To decrease contact resistance, p- and n-type spin on dopants are employed to dope an impurity element into p- and n-type porous Si surface, respectively. Compared to the Si substrate with undoped porous samples, ohmic contact can be obtained, and the electrical conductivity of doped p- and n-type porous Si can be improved to 1160 and 1390 S/m, respectively. Compared with the Si substrate, the special contact resistances for the doped p- and n-type porous Si layer decreases to 1.35 and 1.16 mΩ/cm2, respectively, by increasing the carrier concentration. However, the increase of the carrier concentration induces the decline of the Seebeck coefficient for p- and n-type Si substrates with doped porous Si samples to 491 and 480 μV/K, respectively. Power factor is related to the Seebeck coefficient and electrical conductivity of thermoelectric material, which is one vital factor that evaluates its output performance. Therefore, even though the Seebeck coefficient values of Si substrates with doped porous Si samples decrease, the doped porous Si layer can improve the power factor compared to undoped samples due to the enhancement of electrical conductivity, which facilitates its development for thermoelectric application.


2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis

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).


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2849 ◽  
Author(s):  
Yong Du ◽  
Haixia Li ◽  
Xuechen Jia ◽  
Yunchen Dou ◽  
Jiayue Xu ◽  
...  

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 μV/K to 15.1 μV/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 μWm−1 K−2 at 380 K was obtained for the nanocomposites with 37.2 wt % graphite.


Sign in / Sign up

Export Citation Format

Share Document