Aramid nanofiber-reinforced MXene/PEDOT:PSS hybrid fibers for high-performance fiber-shaped supercapacitors

In recent years, a great deal attention has been paid to one-dimensional fiber-shaped wearable energy storage devices, but further exploration is still needed to obtain fiber-shaped devices with high mechanical and electrochemical performance to meet the requirements of stretching, twisting and squeezing deformation in daily use. Herein, high-performance aramid nanofiber-reinforced (ANF) MXene/PEDOT:PSS hybrid fibers were fabricated by a simple and tractable wet spinning strategy. In this strategy, ANF played the role of fiber reinforcement and barrier for the MXene layer, not only greatly enhancing the mechanical properties of fibers, but also effectively preventing the re-stacking of MXene layers. As a kind of spinnable conductive polymer, PEDOT:PSS can effectively improve the spinnability of fibers. The obtained hybrid fiber exhibited high tensile strength and high conductivity. Meanwhile, the assembled all solid-state fiber-shaped supercapacitor (FSC) showed a high energy density of 9.8 mWh cm−3 at the power density of 250.7 mW cm−3. Besides, the assembled FSC displayed outstanding cycle performance (86.9% capacitance retention after 10 000 cycles) and excellent flexibility. It is worth noting that the FSC could be extended in series to meet the needs of different equipment. This work provides a good reference for the manufacture of wearable high-performance fiber-shaped devices by facile wet spinning.