Flexible carbon nanofiber yarn electrodes for self-standing fiber supercapacitors

Abstract

In this study, polyacrylonitrile (PAN) nanofiber yarns were obtained by twisting the nanofiber mat strips produced in the electrospinning device. On the drum collector, the nanofibers are produced in such a way that the diameter change can be controlled. Through stabilization and carbonization processes, PAN nanofiber yarns were converted to carbon nanofiber (CNF) yarns. The stabilization process stabilized the yarn structure, which was previously unstable, due to thermal treatments. The obtained CNF yarn had a diameter of approximately 360 μm and an average nanofiber diameter of 123 ± 20 nm. On a three-electrode system, the electrochemical performance of CNF yarn in 1 m H2SO4 electrolyte was determined using cyclic voltammetry and galvanostatic charge/discharge test methods. The specific capacitance of the CNF yarn electrode was determined to be 145 F/g at a current density of 0.2 A/g. Up to 500 charge/discharge cycles, the specific capacitance increased by approximately 20% and remained constant thereafter. Due to their superior properties such as high surface area, lightweight, and flexibility, CNF yarn electrodes can be used in a wide variety of electronic applications, including energy harvesting, energy storage (supercapacitors, batteries, etc.), and sensors.