An integrated radiative cooling coating for flexible thermoelectric power generator

Thermoelectric generators (TEGs) play a significant role in the utilization of low-grade heat, especially for human body heat harvesting. Radiative cooling coating has been combined with the TEGs to increase the temperature difference between the hot and cold side, thereby enhancing power generation efficiency. However, radiative cooling coating is usually simply attached to the cold side of the TEGs with adhesives, which introduces extra thermal contact resistance that limits the cooling capacity available to the cold side of TEGs. Furthermore, each layer is separated in the structure, struggling to accommodate the bending and folding motions of the human body and may easily detach with prolonged use. Here, we report an integrated radiative cooling coating for flexible TEG. The output voltage density of the TEG utilizing this design can reach up to 4.78 mV/cm² during outdoor testing. In peel tests conducted for mechanical consistency and stability validation, the proposed structure demonstrated performance improvements by a factor of up to 4.4 compared to existing adhesive bonding methods. These results demonstrate an alternative approach to integrating radiative cooling coatings with TEGs, as well as their application in wearable power generation.