Sea urchin-like core/shell hierarchical porous carbon for supercapacitors

Abstract

We report a strategy to prepare sea urchin-like core-shell carbon spheres (SUCSs) by one-pot cooperative assembly process. The obtained SUCSs have sea urchin-like core with pores radially oriented from the center to the outer surface. By adjusting the amount of tetraethyl orthosilicate and resorcinol formaldehyde resins, the SUCSs with different diameters and shell thicknesses are obtained. After activated by KOH, the SUCSs with hierarchical pores are explored as electrode materials for supercapacitors. Due to hierarchical pores and sea urchin-like core-shell structure, the activated SUCSs show a reversible specific capacitance as high as 230 F g−1 at a current density of 0.5 A g−1. And the activated SUCSs also exhibit good electrochemical stability (95.02% of its initial capacity) at a current density of 2 A g−1 for up to 10000 cycles in 6 M KOH aqueous solution. These results reveal that the sea urchin-like core-shell carbon spheres with hierarchical pores are promising candidates for supercapacitor applications.