Scalable Fabrication of Supercapacitors by Nozzle-free Electrospinning

Nozzle-free electrospinning was investigated as a facile technique for producing nanoscale materials for supercapacitors. MnO2 nanofibers and their composites with multiwalled carbon nanotubes (MWCNTs) were synthesized in a single step, using polyvinylpyrrolidone (PVP) and Mn(CH_3COO)_2·4H_2O as starting materials, followed up by heat treatment in ambient air. Nanofibers of relatively uniform diameter were produced at high rates. The nanofibers exhibited good electrical contact between MnO_2 and MWCNT without degradation, which was attributed to the improved stability of MWCNTs in PVP solutions. Electrochemical testing of the composites demonstrated a high capacitance of 1.43 F cm^(–2) at a scan rate of 100 mV s^(–1) in the three-electrode tests. Electrodes and devices produced by nozzle-free electrospinning are promising for practical energy storage applications.