Green Synthesis of Continuous Wet-Spun PEDOT: PSS/MXene Composite Fibers for Highly Efficient Microsupercapacitors

With the rapid development of wearable, portable electronic devices, there is an increasing demand for advanced flexible energy storage devices. Fiber-shaped supercapacitors (FSCs) have been seen as effective energy storage solutions for miniature wearable electronics. Herein, a green and cost-effective coagulation bath was developed for fabricating PEDOT: PSS/MXene composite fibers by the wet-spinning technique. Results revealed that aqueous solution with small amount of Zn2+ ions and HCl could greatly improve the solidification of PEDOT: PSS/MXene composite fibers, even the Ti3C2Tx-MXene content, up to 80%. Additionally, PEDOT: PSS not only effectively prevented the restacking of MXene layers and then greatly improve the spinnability but also enhanced the mechanical properties of composite fibers. The fabricated M4P1 composite fibers displayed good flexibility and high conductivity (162.9 S·cm–1). Furthermore, the M4P1-LS composite fibers can be applied as flexible electrodes for the FSCs. The volume specific capacitance of assembled FSCs was up to 654.8 F·cm–3 at a current density of 0.5 A·g–1. Meanwhile, the energy density and powder density were 69.6 mW h·cm–3 and 3010.0 mW·cm–3 at a current density of 3 A·g–1. Moreover, a capacitance retention of 80.9% after 5000 cycles confirmed the outstanding cycle performance and excellent flexible. Based on these results, this work provides a green and cost-effective coagulation bath for wet-spinning the PEDOT/PSS/MXene composite fibers, which demonstrated the great potential application as highly efficient microsupercapacitors.