Nitrogen-Enriched Nanocarbons with a 3-D Continuous Mesopore Structure from Polyacrylonitrile for Supercapacitor Application

A kind of polyacrylonitrile-based carbon with a 3-D continuous mesopore structure was prepared by using silica gel as a template. Both the mesopore structure and the nitrogen content could be easily tailored by controlling the carbonization temperature. With decreasing the carbonization temperature, the porosity gradually decreased, while the nitrogen content increased. The sample carbonized at 800 degrees C and showed the highest specific capacitance of 210 F g(-1) at the current density of 0.1 A g(-1), which could still stay over 90% when the current density increased by 10 times. The good electrochemical properties could be ascribed to the following three factors: (1) the great pseudocapacitance of nitrogen functionalities, which is 28% of the total capacitance, (2) the 3-D continuous pore structure with a high mesoporosity of 92.5%, and (3) the enhanced wettability resulting from the nitrogen on the carbon skeleton.