Wet-spinning fabrication of multi-walled carbon nanotubes reinforced poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) hybrid fibers for high-performance fiber-shaped supercapacitor

Fiber-shaped supercapacitors with high energy density and power density are promising as energy storage device for flexible electronics because of their one-dimensional distinct structure, excellent flexibility and potential to be integrated. In this study, multi-walled carbon nanotubes (MWCNT)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) hybrid fibers with different fraction of MWCNT were fabricated via wet-spinning and post-treatment process. Due to the synergistic effects of two components, the designed hybrid fibers displayed excellent conductivity and mechanical property. Furthermore, the symmetric flexible supercapacitor based on our prepared hybrid fibers possessed an impressive specific capacitance (117.0 mF/cm2 at current density 0.1 mA/cm2), superior energy/power characteristics (16.3 μWh/cm2 at power density of 0.05 mW/cm2), as well as satisfactory cycle stability (90% capacitance retention after 2000 charge/discharge cycles) and flexibility (87% capacitance retention after 1000 bending cycles). Thus, MWCNT/PEDOT:PSS hybrid fibers are a promising candidate for constructing flexible electrochemical energy storage device.