Hierarchical porous carbon with high nitrogen content derived from plant waste (pomelo peel) for supercapacitor

• Published in: Journal of materials science. Materials in electronics 2018-05, Vol.29 (9), p.7707-7717
• Main Authors: Fu, Guangsheng, Li, Qiang, Ye, Jianglin, Han, JunJian, Wang, Jiaqi, Zhai, Lei, Zhu, Yanwu
• Format: Article
• Language: English
• Subjects: Atomic structure; Capacitance; Carbon; Characterization and Evaluation of Materials; Chemistry and Materials Science; Density; Electrochemical analysis; Electrolytes; Flux density; Gravimetry; Materials Science; Nitrogen; Nitrogen atoms; Optical and Electronic Materials; Roasting; Sulfuric acid; Supercapacitors
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-8766-0

The plant waste pomelo peels are used as carbon precursors to fabricate nitrogen-doped hierarchical porous carbon. The sample PC600 is fabricated at mild calcination temperature of 600 °C, which has nitrogen content of as high as 4.47% and hierarchical pores with a BET surface area of 1104 m 2  g −1 . The symmetric supercapacitor based on PC600//PC600 electrodes exhibits excellent electrochemical performance benefiting from both the electric double-layer capacitance and pseudocapacitance of PC600. In 1 M H 2 SO 4 electrolyte, this supercapacitor delivers gravimetric capacitance of 208.7 F g −1 , volumetric capacitance of 219.3 F cm −3 , and energy density of 7.3 Wh kg −1 at a current density of 1 A g −1 . Furthermore, the extraordinary energy density of 21.6 Wh kg −1 at 1 A g −1 and 17.1 Wh kg −1 at 20 A g −1 are obtained in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF 4 ) electrolyte. The suitable calcination process can make the contents of nitrogen atoms and pores structures in PC600 to achieve an optimal combination, leading to improved electrochemical performance.