Hierarchical porous carbon prepared by NaOH activation of nano-CaCO3 templated carbon for high rate supercapacitors

Hierarchical porous carbon is prepared from sucrose by the nano-CaCO3 template method followed by NaOH activation for supercapacitors. As evidenced by SEM, TEM, nitrogen sorption and Hg porosimetry analysis, the carbon possesses a highly developed hierarchical porous texture containing interconnected micro-, meso-, and macropores. The surface area and pore volume of the carbon reach up to 2032 m(2) g(-1) and 2.602 cm(3) g(-1), respectively. Galvanostatic charge-discharge and cyclic voltammetry measurements indicate that the carbon shows high capacitance and excellent rate capability in both mol(-1) KOH aqueous electrolyte, it can afford a capacitance of 245 F g(-1) at 0.05 A g(-1), which remains at 188 F g(-1) as the current density increases up to 50 A g(-1), while the value reaches 144 F g(-1) at 0.05 A g(-1) and remains at 103 F g(-1) at 10 A g(-1) in the 1 mol L-1 Et4NBF4/PC non-aqueous electrolyte.