화학공학소재연구정보센터
Journal of Materials Science, Vol.54, No.18, 11959-11971, 2019
Modification of porous carbon with nitrogen elements to enhance the capacitance of supercapacitors
A porous carbon precursor is prepared by modifying polyvinylidene fluoride with nitrogen via a chemical polyreaction and then introducing mesopores using the soft-template method. After carbonization at the appropriate temperature, the obtained carbon material could be applied in supercapacitors without further treatment. The resulting material exhibits not only a comparatively stable nitrogen content that is very close to the nitrogen content of its precursor but also an effective hierarchical porous structure (similar to 0.68 and similar to 4nm). The large specific surface area of the carbon material (up to 1688m(2)g(-1)) is also an important factor influencing its excellent electrochemical performance. When tested using 6M KOH as an electrolyte in a three-electrode system, CN-900 exhibits a specific capacitance of 355.6Fg(-1) at 1Ag(-1). When tested using the same electrolyte in a two-electrode system, CN-900 shows a specific capacitance of 84.08Fg(-1) at 0.5Ag(-1). In addition, the carbon material can maintain 98.4% capacitance after 8000 charge/discharge cycles at a current density of 2Ag(-1). The performance of CN-900 is further tested in a two-electrode solid-state supercapacitor with sulfuric acid/polyvinyl alcohol as the electrolyte, and a specific capacitance of 90.31Fg(-1) is observed at 1Ag(-1). Therefore, the nitrogen-modified porous carbon is a very promising material with practical applications in supercapacitors.