Direct production of porous carbon nanosheets/particle composites from wasted litchi shell for supercapacitors

Various carbon-based materials with tunable porous structure, high surface area and good conductivity were widely used in energy storage devices. In this work, porous carbon nanosheets/particle composites were pyrolyzed directly from abundant and inexpensive waste litchi shell via a simple KOH activation method. High specific capacitance of 222.0 F g(-1) at current density of 0.1 A/g and excellent rate performance were obtained when the prepared porous carbon nanosheets/particle composites served as supercapacitor electrode. In addition, the composites material exhibits favorable cycling stability of 97.3% after 5000 cycles at current density of 1 A/g, suggesting the promising application for high-performance supercapacitors. The presented method may provide an easy, economical and scalable strategy in synthesizing of 2D based carbon materials derived from biomass for energy storage devices. (C) 2019 Elsevier B.V. All rights reserved.