Abstract
In this study, we demonstrate that highly functionalized and porous carbons can be derived from palm-leaf waste using the template-free facile synthesis process. The derived carbons have high content of nitrogen dopant, high surface area, and various defects. Moreover, these carbons exhibit a high electrical conductivity (107 S m(-1)). Thanks to the high content of edge N (64.3%) and highly microporous nature (82% of microspores), these biomass-derived carbons show promising performance when used as supercapacitor electrodes. To be specific, these carbonaceous materials show a specific capacitance as high as 197 and 135 F g(-1) at 2 and 20 A g(-1) in three-electrode configuration, respectively. Furthermore, the symmetrical cells using palm-leaf-derived carbon show an energy density of 8.4 Wh Kg(-1) at a power density of 0.64 kW Kg(-1), with high cycling life stability (similar to 8% loss after 10,000 continuous charge-discharge cycles at 20 A g(-1)). Interestingly, as the power density increases from 4.4 kW kg(-1) to 36.8 kW kg(-1), the energy density drops slowly from 8.4 Wh kg(-1) to 3.4 Wh kg(-1). Getting such extremely high power density without significant loss of energy density indicates that these palm-leaf-derived carbons have excellent electrode performance as supercapacitor electrodes.