Nanostructured Strontium Titanate as High Efficiency Thermoelectric Ceramic

Thermoelectrics, which can generate electricity from waste heat or act as heat pump, could play an important role in global sustainable energy production or for solid-state refrigerator devices. Although thermoelectric devices are increasingly used, they have not yet made a breakthrough as waste heat recovery system due to their limited efficiency. However, theoretical predictions which have yet been experimentally confirmed show that nanostructured thermoelectrics possess superior properties compared to their bulk counterparts, what has lead to a resurgence of interest in thermoelectric materials. At this moment, most research is focussed on metallic thermoelectrics, such as BiSbTe, but these alloys are not suited for high temperature applications due to their relatively low melting temperature. This is where the ceramic materials come in to the picture as they can withstand high temperatures and are chemical resistant. Unfortunately, they are not that efficient in comparison with the metal alloys. In this research we want to proof that low dimensional nanostructures can also be incorporated into an industrially useful bulk material, leading to an unusual enhancement of the thermoelectric conversion efficiency. A novel approach to synthesize bulk nanostructured thermoelectric material is being developed here.

The thermoelectric ceramic SrTiO₃ is investigated in our group as it is environmentally friendly, chemically and thermally stable and it has a fairly high conversion efficiency. The research focuses on the synthesis of nanostructured SrTiO₃ via a templating approach. The influence of the morphology, the dimensions and the orientation of the nanustructures on the thermoelectric properties are the main focus of this investigation.

For more information: Prof. dr. Klaartje De Buysser.