Hierarchically porous carbon nanosheets derived from Moringa oleifera stems as electrode material for high-performance electric double-layer capacitors

• Published in: Journal of power sources Vol. 353; pp. 260 - 269
• Main Authors: Cai, Yijin, Luo, Ying, Dong, Hanwu, Zhao, Xiao, Xiao, Yong, Liang, Yeru, Hu, Hang, Liu, Yingliang, Zheng, Mingtao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-06-2017
• Subjects: Electric double-layer capacitors; High specific surface area; Moringa oleifera; Porous carbon nanosheets; Electric double-layer capacitors; High specific surface area; Moringa oleifera; Porous carbon nanosheets
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2017.04.021

A facile one-step pyrolysis route for the synthesis of hierarchically porous carbon nanosheets (PCNSs) derived from Moringa oleifera stems (MOSs) is reported, in which no post-activation-process in needed. The as-prepared PCNSs possesses unique porous nanosheet morphology with high specific surface area of ca. 2250 m2 g−1, large pore volume of ca. 2.3 cm3 g−1, appropriate porosity as well as heteroatom doping (N and O), endowing outstanding electrochemical properties as electrode material for high-performance supercapacitors. The PCNS-based electrodes are investigated in various aqueous electrolytes including 1.0 M Na2SO4, 1.0 M H2SO4, and 6.0 M KOH. The PCNSs exhibit a maximum specific capacitance of ca. 283 F g−1 (0.5 A g−1), excellent rate capability (ca. 72% of capacitance retention even at an ultrahigh current density of 50 A g−1), and a tremendous long-term cycling stability in the three-electrode system. Moreover, the as-assembled PCNS-based symmetric supercapacitor shows a high energy density of ca. 25.8 Wh kg−1 (in 1.0 M Na2SO4 electrolyte) and remarkable long-term cycling stability (almost no capacitance fade in aqueous electrolytes), indicating the promising of the as-prepared PCNSs for electrochemical energy storage and conversion.
A facile one-step pyrolysis strategy is designed to synthesize hierarchically porous carbon nanosheets (PCNSs) with unique two-dimensional nanosheet structure, high specific surface area, and outstanding electrochemical properties for high-performance electric double-layer capacitors. [Display omitted]
•Porous carbon nanosheets (PCNSs) are prepared by a facile one-step method.•No post-activation-process is needed for PCNS synthesis.•The PCNSs presents large surface area and abundant nitrogen content.•The PCNSs exhibit excellent electrochemical performance in aqueous electrolytes.