Thermoelectric materials

Topic

Fig. Micro to Nanostructurisation.

Fig. Micro to Nanostructurisation.

Thermoelectric materials are applied in thermoelectric generators (TEG) to convert unused heating energy in electrical energy, for example, to enhance the energy balance of the process. TEGs work with less vibration, less emission and without maintenance. In contrast to turbines, TEGs directly transform the heating energy into electrical energy without using moveable components.

Up to now, thermoelectric materials mainly consist of expensive materials which are also toxic. Therefore, the development of ceramic, non-toxic thermoelectric materials synthesized by precursor routes are in the focus of research. The use of precursors allows one to vary the microstructure, by which the thermoelectric efficiency of the materials can be increased as compared to conventional powders (see figure). Simultaneously, the ceramic material improves the thermal stability. So, they can be used for high-temperature applications. Based on a suitable synthesis route it is possible, for example, to build up miniaturized thermoelectric generator modules which are suited to be used as wireless sensor.

As we have many years of experience and extensive knowledge in joining technology, system integration as well as material science we are able to realize and optimize complete module assemblies.


Services offered
 

  • Synthesis of precursors under inert atmosphere
  • Pyrolysis of metallo-organic precursors to inorganic materials 
  • Upscaling of synthesis up to semi-industrial scale
  • Production of nanopowder, nanostructured bulk materials and nanocomposites
  • Optimization of thermoelectric properties with regard to the application 
  • Improvement of thermoelectric efficiency by decreasing the thermal conductivity 
  • Material scientific and thermoelectric characterization of the materials 
  • Design and assembly of a miniaturized thermoelectric generator


Technical equipment
 

  • Fully equipped chemical laboratory
  • Glovebox with argon and nitrogen atmosphere, hotplate and attritor 
  • Pyrolysis furnace with controllable inert and reactive gas 
  • Heat and pressure treatment such as hot pressing and spark plasma sintering (SPS)


Application areas
 

  • Waste heat recovery
  • Self-sufficient energy supply of wireless mini-components
  • Sensor technology