Fabrication of Core-shell Structured CNT(Carbon Nanotubes)/PEDOT:PSS(Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)) Microyarns for Energy Storage Devices

Abstract

CNT(carbon nanotubes) fibers are the most commonly used electrodes for power sources of fiber-type energy storage devices as they have intrinsic flexibility, light weight, excellent electrical conductivity, mechanical strength, and thermal/chemical stability. However, CNT fibers have low capacitance as they have electrical double layer capacitance only. Hence, many researchers have developed hybrid fiber structures of CNT fibers and pseudocapacitive materials such as conducting polymers and metal oxides. Unfortunately, CNT fibers have a property of ultra-hydrophobicity of their surface, it is difficult to fabricate the hybrid structures with other materials. Herein, we fabricated the core-shell structured CNT/PEDOT:PSS(poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)) microyarns and it was applied to energy storage electrodes with excellent electrical conductivity and high specific capacitance. The core-shell yarns were fabricated by core-shell yarning with wettability enhanced CNT fibers and PEDOT:PSS microfibers with the self-fusion property. The resultant core-shell yarns showed stable charge/discharge behavior without voltage drop and capacitance degradation as well as high electrical conductivity and enhanced specific capacitance.