Microwave synthesis of Sb2Se3/polyacrylonitrile-based carbon fiber mat electrodes for high-performance flexible capacitors and hydrogen evolution reaction

Abstract

The development of bifunctional electrodes with good capacitive performance and efficient hydrogen evolution reaction activity is one of the potential solutions to combat energy depletion. In this study, flexible polyacrylonitrile-based carbon fiber mat with nitrogen doping and oxygen-containing functional group carbon structure was selected as the flexible substrate, and binder-free flexible Sb2Se3/polyacrylonitrile-based carbon fiber mat composite electrode was successfully prepared within 120 s using microwave synthesis. The electrode not only has a capacitance of 478.0C g−1 and retains 97.4% of the initial capacitance after 50,000 charge–discharge tests but also exhibits good HER activity of low overpotential (152 mV) and Tafel slope (78.4 mV/dec) in alkaline electrolyte. The performance of the assembled flexible asymmetric supercapacitor is almost unaffected by bending up to 180°. The device has an energy density of 21.3 Wh kg−1 at a power density of 800.0 W kg−1, indicating that the electrode has good prospects for portable energy storage applications.