An international team of researchers has unveiled a new material and an efficient way to convert excess heat into electricity. They can be applied to dozens of devices.
A group of scientists from Northwestern University and Seoul National University in Korea presented a highly efficient thermoelectric material that can be used in the development of dozens of devices. It is purified tin selenide in polycrystalline form – it outperforms monocrystalline form in converting heat to electricity, making it the most efficient thermoelectric system in history. The researchers were able to achieve high conversion rates after identifying and fixing an oxidation problem that had reduced efficiency in previous studies.
Polycrystalline tin selenide can be developed for use in solid state thermoelectric devices in a variety of industries with potentially large energy savings. The key application is to capture industrial waste heat – for example in power plants, the automotive industry, glass and brick factories – and convert it into electricity. More than 65% of the energy generated worldwide from fossil fuels is lost as waste heat.
The researchers note that this material can be applied to dozens of scenarios. For example, on Mars, the source of heat is the radioactive decay of plutonium, and the conversion efficiency of the device is 4-5%. This is enough to power the Perseverence, but this is a poor result on Earth.
“Thermoelectric devices are used, but only in niche devices. However, they have not gained the same popularity as solar panels, and there are significant difficulties in creating good devices. We focused on developing a material that would be inexpensive and highly efficient and would facilitate wider use of thermoelectric devices, ”the researchers noted.