Hollow, Spherical Nitrogen-Rich Porous Carbon Shells Obtained from a Porous Organic Framework for the Supercapacitor

Hollow, spherical nitrogen-rich porous carbon shells were prepared as supercapacitor electrode materials through the carbonization of structure-controlled porous organic frameworks at high temperature. The structure and electrochemical properties of the resulting carbonized materials were systematically characterized. Experimental results revealed that the nitrogen. rich hollow carbon spheres obtained at 800 C were a kind of amorphous carbon with micropores on the shell frame and with specific surface areas as high as 525 m(2) g(-1). The prepared porous carbon possessed a specific capacitance of 230 F g(-1) at a current density of 0.5 A g(-1) and could retain similar to 98% of the initial capacitance after 1500 successive charge-discharge cycles. Electrochemical impedance spectroscopy indicated that the material has a small equivalent series resistance (0.62 Omega). All of these values demonstrated that the prepared porous carbon is a promising supercapacitor material. The proposed method represents a simple approach towards the preparation of unique structures of nitrogen-containing porous carbon that exhibit the advantages of having a simple preparation process, a wide availability of precursors, flexible control of the structure, and an easier adjustment of the amount of heteroatoms.