Hierarchically porous carbon nanosheets from waste coffee grounds for supercapacitors.
Hierarchically porous carbon nanosheets from waste coffee grounds for supercapacitors.
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DOI：
10.1021/am5081919
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发表时间：
2015-02
影响因子：
9.5
通讯作者：
Y. S. Yun;M. Park;S. J. Hong;Min Eui Lee;Y. Park;H. Jin
中科院分区：
文献类型：
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作者：
Y. S. Yun;M. Park;S. J. Hong;Min Eui Lee;Y. Park;H. Jin
多孔碳基电极材料的纳米结构设计是提高超级电容器电化学性能的关键。本研究以废咖啡渣为原料，采用原位碳化和氢氧化钾活化工艺制备了层状多孔碳纳米片(HP-CNS)。尽管合成工艺简单，但HP-∼具有高长径比纳米结构(厚度为20 nm，横向尺寸为几个微米)，高比表面积为1945.7 m(2)g(-1)，大量的杂原子，良好的电输运性能，以及分级多孔特性(尺寸为0.5-10 nm)。在比功率为30000 W kg(-1)、充放电电流比为3 S时，11250 W kg(-1)下的比能量为35.4Wh kg(-1)，23 Wh kg(-1)。此外，HP-CNS超级电容器在5000次循环中表现出良好的循环性能。
The nanostructure design of porous carbon-based electrode materials is key to improving the electrochemical performance of supercapacitors. In this study, hierarchically porous carbon nanosheets (HP-CNSs) were fabricated using waste coffee grounds by in situ carbonization and activation processes using KOH. Despite the simple synthesis process, the HP-CNSs had a high aspect ratio nanostructure (∼20 nm thickness to several micrometers in lateral size), a high specific surface area of 1945.7 m(2) g(-1), numerous heteroatoms, and good electrical transport properties, as well as hierarchically porous characteristics (0.5-10 nm in size). HP-CNS-based supercapacitors showed a specific energy of 35.4 Wh kg(-1) at 11250 W kg(-1) and of 23 Wh kg(-1) for a 3 s charge/discharge current rate corresponding to a specific power of 30000 W kg(-1). Additionally, the HP-CNS supercapacitors demonstrated good cyclic performance over 5000 cycles.