Porous Carbon from Corn Flour Prepared by H<sub>3</sub>PO<sub>4</sub>Carbonization Combined with KOH Activation for Supercapacitors

Hierarchical porous activated carbon is a superior material in manufacturing supercapacitors. However, the hierarchical porous structure is hard to obtain from a single activation method. This work was carried out with the anticipation of producing activated carbon by reactivating corn flour with KOH. By employing the electrodes, the supercapacitor demonstrated a high discharge capacitance (151.2 F·g-1 at 1 A·g-1), and the specific capacitance is with 3.7 times more capacitance than the activated carbon only through H3PO4 activation. The mechanism of improving the electrical performance has been discussed through performing SEM, XRD, EIS, and Raman analysis. The hierarchical porous and disordered structure emerge smaller charge transfer resistance, and fast electron transfer.