Search results for "thermoelectric generator"
showing 10 items of 25 documents
Tailoring of the electrical and thermal properties using ultra-short period non-symmetric superlattices
2016
Thermoelectric modules based on half-Heusler compounds offer a cheap and clean way to create eco-friendly electrical energy from waste heat. Here we study the impact of the period composition on the electrical and thermal properties in non-symmetric superlattices, where the ratio of components varies according to (TiNiSn)���:(HfNiSn)���������, and 0 ��� n ��� 6 unit cells. The thermal conductivity (��) showed a strong dependence on the material content achieving a minimum value for n = 3, whereas the highest value of the figure of merit ZT was achieved for n = 4. The measured �� can be well modeled using non-symmetric strain relaxation applied to the model of the series of thermal resistanc…
High Electron Mobility and Disorder Induced by Silver Ion Migration Lead to Good Thermoelectric Performance in the Argyrodite Ag8SiSe6
2017
Superionic chalcopyrites have recently attracted interest in their use as potential thermoelectric materials because of extraordinary low thermal conductivities. To overcome long-term stability issues in thermoelectric generators using superionic materials at evaluated temperatures, materials need to be found that show good thermoelectric performance at moderate temperatures. Here, we present the structural and thermoelectric properties of the argyrodite Ag8SiSe6, which exhibits promising thermoelectric performance close to room temperature.
La 1−xCaxMnO3 semiconducting nanostructures: morphology and thermoelectric properties
2014
Semiconducting metallic oxides, especially perosvkite materials, are great candidates for thermoelectric applications due to several advantages over traditionally metallic alloys such as low production costs and high chemical stability at high temperatures. Nanostructuration can be the key to develop highly efficient thermoelectric materials. In this work, La 1−xCa x MnO3 perosvkite nanostructures with Ca as a dopant have been synthesized by the hydrothermal method to be used in thermoelectric applications at room temperature. Several heat treatments have been made in all samples, leading to a change in their morphology and thermoelectric properties. The best thermoelectric efficiency has b…
Thin Film Organic Thermoelectric Generator Based on Tetrathiotetracene
2017
This is the peer reviewed version of the following article: K. Pudzs, A. Vembris, M. Rutkis, S. Woodward, Adv. Electron. Mater. 2017, 1600429, which has been published in final form at http://onlinelibrary.wi...002/aelm.201600429/full This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
Growth mechanisms and related thermoelectric properties of innovative hybrid networks fabricated by direct deposition of Bi2Se3 and Sb2Te3 on multiwa…
2020
Abstract Flexible thermoelectric generators are an emerging trend in the field of waste heat conversion, as well as wearable and autonomous devices. However, the energy conversion efficiency of the state-of-the-art flexible thermoelectric devices is too low for their wide application and commercialization. In this work, n- and p-type multiwalled carbon nanotube (MWCNT)-thermoelectric material hybrid networks that may become a promising building block for the fabrication of flexible thermoelectric devices are presented. The hybrid networks were fabricated by direct deposition of thermoelectric material (Bi2Se3, Sb2Te3) on the MWCNT networks using physical vapor deposition technique. Growth m…
Thermal potential of ion-exchange membranes and its application to thermoelectric power generation
2016
The low efficiency and high price of thermoelectric semiconductors has generated interest in unconventional forms of thermoelectric materials. In this article, ionic thermoelectricity has been studied with commercial ion-exchange membranes for different aqueous 1:1 electrolytes. The theory of thermal membrane potential has been derived taking into account the ionic heats of transport, the non-isothermal Donnan potentials, the temperature polarization, and the thermally-induced concentration polarization of the electrolyte. Also the generated thermoelectric power has been experimentally studied. The experiments show good agreement with the theory, and suggest ways for systematic improvement …
Thermo-elektrische Verbindungen. Strom aus Abwärme
2011
Thermoelektrische Materialien bieten die Moglichkeit, thermische Gradienten in elektrische Energie umzuwandeln um somit Abwarme aus verschiedensten Prozessen zur Energieerzeugung zu nutzen. In diesem Artikel werden die physikalischen Hintergrunde der thermoelektrischen Effekte beschrieben sowie Aufbau und Wirkungsgrad thermoelektrischer Generatoren erlautert. Um eine Brucke zwischen der Physik und Chemie in Festkorpern zu schlagen, werden die unterschiedlichen physikalischen Transportprozesse in Festkorpern mit Hilfe chemischer Konzepte erlautert. Anhand von Beispielen fur thermoelektrische Materialien werden die Ansatze zur Maximierung des thermoelektrischen Wirkungsgrades und der Einfluss…
DESIGN, MODELING, AND FABRICATION OF THERMOELECTRIC GENERATOR FOR WASTE HEAT RECOVERY IN LOCAL PROCESS INDUSTRY
2017
Master's thesis Renewable Energy ENE500 - University of Agder 2017 The waste heat from energy company consumption sectors, when rejected into atmosphere, are useless and it contributes to global warming. Nowadays industrial activities and energy sectors (power stations, oil refineries, coke ovens, etc.) are the most energy consuming sectors worldwide and, consequently, the responsible for the release of large quantities of industrial waste heat to the environment by means of hot exhaust gases, cooling media and heat lost from hot equipment surfaces and heated products. Recovering and reusing these waste heats would provide an attractive opportunity for a low-carbon and less costly energy re…
Subamorphous thermal conductivity of crystalline half-Heusler superlattices
2021
The quest to improve the thermoelectric figure of merit has mainly followed the roadmap of lowering the thermal conductivity while keeping unaltered the power factor of the material. Ideally an electron-crystal phonon-glass system is desired. In this work, we report an extraordinary reduction of the cross-plane thermal conductivity in crystalline (TiNiSn):(HfNiSn) half-Heusler superlattices (SLs). We create SLs with thermal conductivities below the effective amorphous limit, which is kept in a large temperature range (120–300 K). We measured thermal conductivity at room temperature values as low as 0.75 W m−1 K−1, the lowest thermal conductivity value reported so far for half-Heusler compou…
Thermoelectrics: From history, a window to the future
2019
Thermoelectricity offers a sustainable path to recover and convert waste heat into readily available electric energy, and has been studied for more than two centuries. From the controversy between Galvani and Volta on the Animal Electricity, dating back to the end of the XVIII century and anticipating Seebeck’s observations, the understanding of the physical mechanisms evolved along with the development of the technology. In the XIX century Ørsted clarified some of the earliest observations of the thermoelectric phenomenon and proposed the first thermoelectric pile, while it was only after the studies on thermodynamics by Thomson, and Rayleigh’s suggestion to exploit the Seebeck effect for …