Hierarchically Porous Carbon Nanosheets from Waste Coffee Grounds for Supercapacitors

作者：Yun Young Soo; Park Min Hong; Hong Sung Ju; Lee Min Eui; Park Yung Woo; Jin Hyoung Joon^*

来源：ACS Applied Materials & Interfaces, 2015, 7(6): 3684-3690.

DOI：10.1021/am5081919

• waste coffee grounds
• carbon nanosheet
• porous carbon
• supercapacitor

he 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 (similar to 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 (0.510 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.

• 出版日期2015-2-18