An all-solid-state yarn supercapacitor using cotton yarn electrodes coated with polypyrrole nanotubes

A novel all-solid-state yarn supercapacitor (YSC) has been fabricated by using the cotton yarns coated with polypyrrole (PPy) nanotubes. The interconnected network structure of PPy can increase the surface area as well as the electrode/electrolyte interface area, thus resulting in improved electrochemical performance. For the proposed YSC, a high areal-specific capacitance of 74.0mFcm-2 and a desirable energy density of 7.5μWhcm-2 are achieved. The flexibility of the YSC demonstrates that it is suitable for the integration as flexible power sources in wearable electronic textiles.