Three-dimensionally Hierarchical Porous Carbon Creating High-performance Electrochemical Capacitors

Three-dimensionally (3D) hierarchical porous carbon has been prepared through a simple and efficient hydrothermal treatment on colloidal silica as template. Nitrogen adsorption-desorption isotherms and transmission electron microscope images reveal that the porous carbon has a unique 3D interconnected micro-, meso- and macroporous network. The observed 3D interconnected meso/macroporous network originates from the cores of carbon hollow-spheres and the aggregation of crosslinked carbon hollow-spheres, and the micropores exist from the 3D interconnected network inside the shells of carbon hollow-spheres. The electrochemical capacitive tests indicate that the porous carbons exhibit large specific capacitance of about 300 F g−1 at 1 A g−1 in 6 M KOH aqueous electrolyte as well as high capacitance retention of 71% when the current density increased by 10 times.