Facile Preparation of Novel Hierarchically Porous Carbon at the Molecular Level for Supercapacitor Electrode Application

Hierarchically porous carbons are obtained by a facile process of carbonizing the precursor of diblock copolymer xPS-b-polymethylmethacrylate (PMMA). In the diblock copolymer, there is a carbon source of cross-linked polystyrene (xPS) and a sacrificial block of PMMA. The atom transfer radical polymerization was used to synthesize the diblock copolymer with controlled molecular weight and narrow polydispersity in dimethylformamide at 120 degrees C. The obtained hierarchically porous carbons (HPCs) exhibit remarkable electrochemical properties, such as higher specific capacitance of 204 F g(-1) at the current density of 0.5 A g(-1) in 6 mol L-1 aqueous KOH electrolyte. In addition, it also presents an excellent rate performance of 64% capacitance retention as the current density increases to 10 A g(-1) and a superior cycling stability of 98% capacitance retention after 5000 cycles at the current density of 1 A g(-1).