N-type core-shell heterostructured Bi₂S₃@Bi nanorods/polyaniline hybrids for stretchable thermoelectric generator

With the growing need on distributed power supply for portable electronics, energy harvesting from environment becomes a promising solution. Organic thermoelectric (TE) materials have advantages in intrinsic flexibility and low thermal conductivity, thus hold great prospect in applications as a flexible power generator from dissipated heat. Nevertheless, the weak electrical transport behaviors of organic TE materials have severely impeded their development. Moreover, compared with p-type organic TE materials, stable and high-performance n-type counterparts are more difficult to obtain. Here, we developed a n-type polyaniline-based hybrid with core-shell heterostructured Bi 2 S 3 @Bi nanorods as fillers, showing a Seebeck coefficient –159.4 μV/K at room temperature. Further, a couple of n/p legs from the PANI-based hybrids were integrated into an elastomer substrate forming a stretchable thermoelectric generator (TEG), whose function to output stable voltages responding to temperature differences has been demonstrated. The in situ output performance of the TEG under stretching could withstand up to 75% elongation, and stability test showed little degradation over a one-month period in the air. This study provides a promising strategy to develop stable and high thermopower organic TEGs harvesting heat from environment as long-term power supply.