1. Boosting the performance of supercapacitors based hierarchically porous carbon from natural Juncus effuses by incorporation of MnO2.
- Author
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Ping, Yunjie, Liu, Zhe, Li, Jingjing, Han, Jinzhao, Yang, Yanpeng, Xiong, Bangyun, Fang, Pengfei, and He, Chunqing
- Subjects
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SUPERCAPACITORS , *SUPERCAPACITOR performance , *ENERGY conversion , *AQUEOUS electrolytes , *ENERGY density , *ENERGY storage - Abstract
Porous carbons have recently drawn extensive attention in energy conversion and storage devices. Boosting energy densities of carbon family is still a challenge due to their limited surface area and accessible active sites. In this work, porous carbons with hierarchically structures were prepared from natural Juncus effuses (CJE) and homogeneous MnO 2 layer was successfully incorporated on their surfaces without changing their original porous structure. The CJE/MnO 2 composite showed large specific capacitance (283 F/g at 1 A/g), which was on account of high specific surface area (1283 m2/g) and abundant active sites for pseudocapacitance, particularly, resulted from the introduction of MnO 2. Significantly, the assembled symmetric supercapacitor from CJE/MnO 2 in Na 2 SO 4 aqueous electrolyte delivered high energy/power densities (19.13 Wh/kg at 225 W/kg and 13.73 Wh/kg at 8984 W/kg) and good cyclic performance (86.2% capacitance retention over 5000 cycles at 10.0 A/g). These results demonstrate the CJE/MnO 2 composite can be a potential candidate for supercapacitors. • The surfaces of porous carbons from Juncus effuses are functioned. • Oxygen-containing functional groups facilitate the formation of MnO 2 layer. • Prepared CJE/MnO 2 composites show high specific surface area and capacitance. • The supercapacitor from CJE/MnO 2 delivers excellent energy-power output. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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