Continuous fabrication of flexible, high-performance PEDOT: PSS thermoelectric fiber without post-processing

Abstract

Organic thermoelectric fibers (OTEFs) are popular in wearable self-powered technology due to easy weaving and power generation. However, limitations include poor spinning capability, weak mechanical strength, low output power, and dangerous post-treatment. Here, we report the rapid preparation of flexible, high-performance OTEFs without post-treatment through introducing ionic liquid (IL) of 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (EMIM: TFSI) into the Poly (3,4-ethylene dioxythiophene): Poly (styrene sulfonate) (PEDOT: PSS) to enhance thermoelectric properties, and mechanical strength, with just 1 wt% of IL enabling continuous fabrication of the PEDOT: PSS fiber. The resulting fiber exhibits remarkable electrical, and thermoelectric performance of ∼2267.7 S cm−1, and ∼85 μW m−1 K−2, respectively. It also demonstrates excellent strength (∼289.72 MPa), with a resistance change of less than 8 % after 10,000 bending cycles. The fabricated five-legs devices achieve an impressive output power and output power density of ∼7.84 nW and ∼4.32 μW cm−2 at 49 K, and the fabric textile generates a significant voltage of ∼47.8 mV using human body heat. This work proposes a new design strategy for high-performance organic thermoelectric fibers without additional post-processing, and the ultra-high output power and flexibility exhibit excellent combined application potential in both organic and inorganic TE fields.