Flexible p-n segmented thermoelectric wires based textile using bismuth telluride-based inks

Thermoelectric (TE) materials hold great promise for waste heat recovery; however, the practical application of current commercial TE technologies based on conventional bulk materials, such as inorganic bismuth telluride and its derivatives, is hindered owing to their inherent brittleness, high thermal conductivity (κ), and geometric constraints. Ink-based printing enables shape adaptability, while the incorporation of organic binders degrades TE performance. Meanwhile, thermal drawing techniques fail to produce alternating p-n structures required for TE devices. Here, we develop bismuth telluride-based TE inks using antimony telluride chalcogenidometalate (ChaM) nanoparticles as densification enhancers. During sintering, they effectively fill grain boundaries, leading to an electrical conductivity (~ 940 ± 6 S cm− 1 of n-type) and, owing to a size-matching effect, suppress the κ to ~ 0.31–0.39 W m− 1 K− 1. This yields zT values of ~ 1.12 (p-type) and ~ 1.38 (n-type) at 300 K, representing a threefold enhancement compared to ChaM-free samples. By integrating simulation-optimized p-n segmented TE wires (fabricated via mold-forming method) into a crocheted textile, we fabricate a flexible thermoelectric textile (TET) with a power output of 97.4 µW at ∆T = 59.8 K. This strategy merges inorganic material performance with textile-process compatibility, potentially enabling conformal energy harvesting from irregular heat sources.