Wet-spun PEDOT: PSS/ionic liquid composite fibers for wearable e-textiles

Wet-spinning technology plays an essential role in the development of wearable electronics. Poly(3,4-ethylene dioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) fibers have been widely investigated in this field due to their advantages of being environment-friendly and low-cost. They are mainly wet-spun from a coagulation bath containing ethanol and water with additional metal salts. However, the conductivity of PEDOT: PSS fibers spun by this method is low. Here, we propose a novel coagulation bath made of ionic liquid (IL), ethanol, and water, and the resultant PEDOT: PSS fibers could achieve a conductivity of 118.3 S·cm−1. Furthermore, the fiber-shaped supercapacitor prepared by such PEDOT: PSS/IL fibers reveals an optimal capacitance retention rate of 97 % even after 10,000 cycles, and the capacitance loss of the supercapacitor is only 7 % at −20 ℃. The sensor derived from the PEDOT: PSS/IL fibers has superb sensing capability, indicating their promising applications for wearable electronics.