Hollow activated carbon with unique through-pore structure derived from reed straw for high-performance supercapacitors

•Hollow activated carbons (HACs) with unique through-pore structure derived from reed straw were prepared with KOH activation.•The specific capacitance of the assembled electrodes is up to 290Fg−1 even at a very high current density of 30Ag−1.•The HACs possess a high specific surface area of 2387m2g−1 and a large pore volume of 1.01cm3g−1. Hollow activated carbons (HACs) with unique through-pore structure derived from reed straw were prepared with KOH activation. The amount of activating agent greatly affected the properties of the HACs. When the KOH content was three times that of the carbonized reed straw, the HACs exhibited a large specific surface area of 2387m2g−1 and outstanding electrochemical performance. The specific capacitance of the assembled electrodes reached 355Fg−1 at 1Ag−1. Moreover, a high specific capacitance of 290Fg−1 was retained even at a high current density of 30Ag−1, implying excellent rate performance. These results clearly demonstrate the potential of reed straw-based HACs for use in supercapacitor electrode materials.