Twisted yarns for fiber-shaped supercapacitors based on wetspun PEDOT:PSS fibers from aqueous coagulation

Recently, fiber-shaped yarn supercapacitors (YSCs) have attracted extensive attention due to their merits of small volume, high flexibility and potential to be woven in textiles for future wearable electronics. PEDOT:PSS possesses properties of high-redox capacitance, high conductivity and high intrinsic flexibility, so PEDOT: PSS yarn electrodes are quite promising in the field of YSCs. However, to the best of our knowledge, twisted yarns based on wetspun PEDOT: PSS fibers for fiber-shaped YSCs have not been reported. Herein, we develop a new coagulation bath with CaCl2 in aqueous solution for preparing meter-long PEDOT: PSS fibers. The PEDOT: PSS fibers with good mechanical properties can be easily woven, sewed, knotted and braided as the YSC electrode. The PEDOT: PSS fiber-based YSCs show a high areal capacitance of 119 mF cm(-2) and areal energy density of 4.13 mu W h cm(-2). Meanwhile, the all-solid-state YSCs are flexible and robust enough to tolerate the long-term and repeated bending without an obvious capacitance drop.