One-step synthesis of high-performance porous carbon from corn starch for supercapacitor

The novel route for preparation of high-performance porous carbon from corn starch by a one-step process of chemical activation with H₃PO₄ was studied in this paper. The resulting porous carbon showed a high specific surface area of 1167 m² g⁻¹ and a large pore volume of 1.80 cm³ g⁻¹. The maximum specific capacitance was up to 162 F g⁻¹ at a current density of 0.625 A g⁻¹, which was higher than commercial carbon (100 F g⁻¹). Meanwhile, the electrode exhibited larger energy density (22.5 Wh kg⁻¹ at a power density of 313 W kg⁻¹) and longer cycle stability with above 93% capacitance retention after 5000 cycles. The better capacitive behavior was ascribed to unique pore structure, which indicated the porous carbon will be an ideal electrode material for supercapacitor.