One-step wet-spinning process of CB/CNT/MnO2 nanotubes hybrid flexible fibres as electrodes for wearable supercapacitors

Fibres made from different nanostructured carbons (carbon black (CB)), carbon nanotubes (CNT) and CB/CNT were successfully developed by wet-spinning. The variation of dispersion conditions (carbon nanomaterial concentration, dispersant/Carbon nanomaterial concentration ratio, CB/CNT concentration ratio, pH) resulted in different electrochemical performance for each type of fibres. Fibres with the best capacitance values (10 F g -1 ) and good cycling stability (89%) were obtained from fibres containing 10% carbon black and 90% carbon nanotubes. A solid-state supercapacitor was fabricated by assembling the CB/CNT fibres resulting in 9.2 F g -1 electrode capacitance. Incorporation of 0.2 wt.% birnessite-type potassium manganese oxide nanotubes dramatically increased the capacitance of the fibres up to 246 F g -1 due to the high specific capacitance of birnessite phase and the tubular nature of the nanomaterial.