Hydrothermal synthesis of 3D hierarchical ordered porous carbon from yam biowastes for enhanced supercapacitor performance

Through simple treatment of biowastes to obtain carbon materials with hierarchical ordered porous structure and prominent specific capacity has received increasing attention. Herein, novel uniform three-dimensional (3D) hierarchical porous carbon was generated by a low-cost and facile hydrothermal carbonization and chemical activation process from yam biowastes. Specially, the derived uniform 3D hierarchical carbon demonstrates an ultra-high specific capacity of 556.0 F·g−1 at 0.5 A·g−1 and a superior cycle stability with a capacitance retention of 94.7 % after 10,000 cycles at 10 A·g−1 in 6 M KOH. Moreover, the assembled symmetrical supercapacitor provides an outstanding energy density of 45.5 Wh·kg−1 if the specific power was 200.0 W·kg−1 in 1 M Na2SO4 electrolyte. The encouraging results presented herein make the 3D hierarchical ordered porous carbon immensely promising for supercapacitors with good property.