High-performance hierarchical N-doped porous carbons from hydrothermally carbonized bamboo shoot shells for symmetric supercapacitors

摘要

Biomass-derived porous carbons have become the most competitive electrode materials for supercapacitor due to their renewability and sustainability. Here we report a facile method to synthesize N-doped hierarchical carbons from hydrothermal carbonization followed by a mild KOH activation, using agricultural biowastes of bamboo shoot shells as raw materials and melamine as nitrogen source. The pore structure and surface-doping chemistry of carbons can be easily adjusted by changing activation temperature, showing surface areas of similar to 3300 m(2)/g with main mesopores centering at similar to 2.8 nm. The carbons used as electrodes for supercapacitor showed excellent capacitive performance with capacitance of 209 F/g in 6 M KOH electrolytes at 0.5 A/g, and remained to be 188 F/g even at high current density of 10 A/g. In addition, the as-assembled supercapacitor also exhibited superior cycling stability with capacity retention of 95% at 10 A/g even after 10,000 cycles. The effective carbon conversion from the discarded biowastes exhibits great potential in resources recycles for energy storage supercapacitors. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.