New Thermoelectric Material--With a Higher Thermoelectric Conversion Rate

wallpapers Innovation 2020-07-17

Working Principle of Thermoelectric

Electricity is a natural phenomenon, but in the 21st century today, it is widely used in the human world, because of it, our world has become colorful, watching TV, playing network games, cooking, washing clothes, lighting and so on. In order to get electricity, scientists use a variety of methods, such as traditional thermal power generation, nuclear power generation, solar power generation and geothermal power generation, which works by converting heat into electricity, namely Seebeck effect.
Thermoelectric materials are known to convert heat into electricity, due to the so-called Seebeck effect, where the difference in temperature between the two ends creates a voltage, thermoelectric materials can be used for thermoelectric power generation or thermal energy exchange to achieve refrigeration, so as to make a variety of thermoelectric devices, is a new functional environmental protection material. Thermoelectric devices have many advantages in work, such as small size, light weight, high efficiency, safety and environmental protection, long service life, noiseless work, maintenance free, etc. Its unique refrigeration and power generation functions have been widely used in military, medical, industrial, civil products, laboratory, photoelectric, communication and other fields. Heat, however, consumes a lot of energy when it is converted into electricity, so for the past few decades scientists have been trying to come up with an ideal thermoelectric material that could greatly improve the efficiency of the conversion process. Recently, scientists have made a breakthrough in this field, with the creation of a new material, which has greatly improved the conversion rate of electricity into electricity.

The Newly Discovered

Using theoretical calculations to predict the progress of new material properties, a new class of semi-Hessler thermoelectric compounds has been discovered, one of which has reached an all-time high in value. In January of last year, the director of the Texas Superconductor Center at the University of Houston, Ren Zhifeng said in an interview at any temperature it has maintained a high advantage, so it can be very important in the future, Ren Zhifeng is corresponding author of the study, its research papers published in Nature Communications (Nature Communications).Thermoelectric materials have attracted the interest of a growing number of research groups as a potential "clean" energy source. This energy is generated by converting waste heat from power plants or other industrial processes into electricity. While most of the materials cannot meet all the requirements for a wide range of commercial applications, Mr Ren says some promising materials have been found. The researchers said they had found semi-hessler compounds made of tantalum, iron and antimony, and the results were "very promising for thermoelectric power generation". The conversion efficiency of one compound was measured at 11.4%, meaning that for every 100 watts of heat absorbed by the material, 11.4 watts of electricity was generated. Theoretical calculations suggest an efficiency of up to 14%. Previously, many thermoelectric devices would have a practical conversion efficiency of 10%.
In the Seebeck effect, the value that measures the efficiency of thermoelectric conversion is called the ZT value, and the higher the ZT value of a thermoelectric material, the better its thermoelectric performance. In the past, scientists have developed the best thermoelectric materials with a ZT value as low as 2.8.Recently, scientists from the University of Vienna in Austria have successfully developed a new thermoelectric material with a ZT value of 6, leading to a major breakthrough in thermoelectric conversion. The new material is made of thin layers of silicon, iron, vanadium, tungsten and aluminum.
So this is a very efficient new material, and although it's not yet widely used, scientists have a blueprint for how it could be used not only for thermoelectric conversion, but also to power sensors and even minicomputers. In search of a new generation of thermoelectric materials, Ernst Bauer of the Institute at the University of Vienna began studying a variety of different thermoelectric materials six years ago in 2013. After thousands of tests, he found that a proportional combination of silicon, iron, vanadium, tungsten and aluminum was the best.
New thermoelectric materials of iron atoms arranged with strict rules in the so-called face-centered cubic lattice, the distance between the two iron atoms are the same, but when they are applied to silicon, some surprising happens immediately, two iron atoms may be adjacent to each other, which changes the electronic structure, means that electrons can move freely in the material, get very low resistance, and thermal conductivity is unchanged.

The Application Prospect of This Thermoelectric Material

Ernst Bauer said the new material could have wide applications in the future. The new study is in the journal Nature.

Tag: silicon   iron   Thermoelectric