Prof. Jeong Min Baik’s Research Team (Dept. of Advanced Materials Science and Engineering) 

Suggests Fundamental Solution to Thermoelectric Energy Harvesting

- Achieved World’s best Output Voltage with Frictional charge and Thermoelectric Carrier Coupling effect

- Published in Energy field International Journal, Advanced Energy Materials

Prof. Jeong Min Baik’s Research Team (Dept. of Advanced Materials Science and Engineering) joined with Prof. Jae Sung Son’s (Dept. of Materials Science and Engineering, UNIST) research team, developed a technology that semi-permanently improves the performance of thermoelectric energy harvester through frictional charge and thermoelectric carrier coupling effect.

Thermoelectric energy harvesting technology is a technology that produces energy with potential difference created by the temperature difference of a material’s bisection during external heating and is assessed to be a suitable solution to converting waste heat produced in the industrial field to sustainable energy production, having a simple structure, low maintenance cost, and high reliability as its strength.

Until now, the energy conversion efficiency was minute due to contact resistance between the heat source and thermoelectric elements and the internal resistance of the elements. Moreover, optimization of the output could not be achieved because of the limits set by the material’s power factor and thus output level for commercialization was not accomplished.

* Power factor: Performance index used when assessing electricity power density produced by the thermoelectric module, calculated by multiplying the square of the materials’ Seebeck coefficient by the electrical conductivity

* Seebeck coefficient: Coefficients that correlate the voltage differences generated inside the material per unit temperature. Materials with a high Seebeck coefficient are known to be thermally conductive.

To break through the limit mentioned above, Prof. Baik’s research team developed and attached polyimide-based material which can contain high negative charge semi-permanently at lower temperature part of BiSbTe-based thermoelectric element which has the highest ZT value (thermal conduction performance index) at room temperature and induced fusion effect with carriers inside the thermoelectric elements. Through this, they yielded 4 times the output increment compared to the existing models and achieved the world’s best output voltage (2 times the existing one).

The benefit of this research is that this technology does not require external physical friction effects to create a negative charge so it can work semi-permanently.

Prof. Baik said, “This study presents a new direction to improve the low output voltage and energy conversion efficiency, which are the limitations of conventional thermoelectric energy harvesting, and shows excellent performance not only for energy harvesting but also for thermoelectric cooling.”

This research's result was published in December, in the energy field international academic journal ‘Advanced Energy Materials (IF: 29.698). Prof. Baik’s research team has applied for two patents related to this research and is continuing to research how to apply thermoelectric energy harvesting in various fields.

This research was supported by Mid-sized Research Projects and BRIDGE R&D Projects of the Korea Research Foundation.

※ Paper Title: Boosted Output Voltage of BiSbTe-Based Thermoelectric Generators via Coupled Effect between Thermoelectric Carriers and Triboelectric Charges

※ DOI: 10.1002/aenm.202202987