Initiating a Stretchable, Compressible, and Wearable Thermoelectric Generator by a Spiral Architecture with Ternary Nanocomposites for Efficient Heat Harvesting

Abstract Thermoelectric generators (TEGs) based on organic/inorganic nanocomposites have made great achievements in recent years, while rational design of flexible TEGs to harvest energy via cross‐plane heat flux remains a great challenge. Herein, flexible poly(3,4‐ethylenedioxytiophene)‐tosylate/Te/single‐walled carbon nanotubes (PEDOT‐Tos/Te/SWCNTs) ternary nanocomposite films with unique layered structure are synthesized, exhibiting an optimized power factor of 131.9 ± 8.5 µW m –1 K –2 that is ≈120 times of that of the pristine PEDOT‐Tos. A spiral architecture is subsequently proposed to assemble the nanocomposite films into 3D TEGs, resulting in device‐level flexibility, stretchability, and compressibility. The spiral‐like TEGs can realize efficient heat‐to‐electricity conversion through cross‐plane heat flux, and large output powers of 7.04 and 9.59 µW are achieved for the TEG prototypes with 10 p‐type legs and 5 pairs of p‐n couples, respectively, under a temperature difference of 80 K, surpassing most reported TEGs using Te‐based composites. They can also provide stable energy output upon multiple stretching and compressing cycles. Furthermore, the spiral‐like TEGs are demonstrated versatile applications to harvest human body heat on wrist, and to generate electricity via the temperature difference induced by hot water or liquid nitrogen. This work offers a promising route to exploit thermoelectric composites for flexible and wearable applications.