At the Seoul National University, a research group under the guidance of Professor In Chung has reported the development of the latest record-breaking thermoelectric material made of affordable and less-toxic elements.
Over 65% of the global energy production is lost as waste heat. Electric energy is mainly produced from fossil fuels. Hence, retrieving such a vast amount of universal energy loss into usable forms of energy can help resolve the energy and environmental crisis humans face.
At the same time, thermoelectric technology can play a major part in resolving such issues. It helps convert heat into electric energy directly without discharging any environmentally unwanted chemical residues such as greenhouse gases.
But high-performance thermoelectric materials available at present essentially include harmful lead and/or rare tellurium elements and exhibit low power generation efficiencies, thereby making it hard to commercialize this technology.
Designing a new ultrahigh performance polycrystalline thermoelectric material made of selenium and tin elements helped resolve all these issues associated with the technology. Professor Chung’s research group developed the material.
Tin selenide-based material gained widespread academic attention in 2014 due to the remarkably high thermoelectric figure of merit (ZT) of 2.6 observed in its single crystal form.
But until now, the reproducibility of such high-performance material has been under debate. Moreover, the performance of equivalent polycrystalline materials has been far worse. Single crystal forms are not apt for commercial applications and mass production because of the expensiveness, mechanical brittleness, and prolonged and laborious production.
Professor Chung’s team unraveled the source of poor performance of polycrystalline tin selenide materials and came up with a new synthesis process to resolve all the issues. Consequently, the new polycrystalline material displayed a thermoelectric figure of merit higher than 3.1 in bulk form for the first time in history. The record-breaking thermoelectric power generation efficiency of the material surpasses 20%.
Our new material open an era of the commercialization of ultra-high performance practical thermoelectrics.
In Chung, Professor, College of Engineering, Seoul National University
Also, he had developed all-solid-state solar cells based on perovskite materials in 2012 for the first time.
This study was financially supported by the Nano Material Technology Development and Mid-Career Research Programs through the National Research Foundation of Korea Grant funded by the Korean Government.
Iversen, B. B., (2021) Breaking thermoelectric performance limits. Nature Materials. doi.org/10.1038/s41563-021-01065-5.