Three-dimensional scaffolding framework of porous carbon nanosheets derived from plant wastes for high-performance supercapacitors. (September 2016)

• Record Type: Journal Article
• Authors: Chen, Chong; Yu, Dengfeng; Zhao, Gongyuan; Du, Baosheng; Tang, Wei; Sun, Lei; Sun, Ye; Besenbacher, Flemming; Yu, Miao
• Is Part Of: Nano energy. Volume 27(2016:Sep.)
• Page Start: 377
• Page End: 389
• Publication Date: 2016-09
• Subjects: Porous carbon materials -- Supercapacitor -- Biomass -- Plant waste -- 3-D framework; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2016.07.020
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Utilizing carbon materials derived from sustainable biomass on supercapacitors has become particularly attractive recently. High-performance activated carbons (ACs) based on inexpensive, abundant but unwanted natural wastes are highly preferred. In this work, using dry elm samara as the prototype, we demonstrate that three-dimensional (3-D) scaffolding frameworks of highly porous carbon nanosheets (PCNSs) can be derived from plant wastes having specific natural morphology, i.e. half-transparent thin flakes, through a facile carbonization and activation treatment. The products possess a high accessible surface area induced by the 3-D framework, and a high density of micro-pores, which benefit large ion storage and high-rate ion transfer. In addition to the electric double-layer capacitor, the heteroatom doping evokes the faradic contribution. PCNS activated by 6 mol L −1 KOH (PCNS-6) exhibited a rather high specific capacitance of 470 F g −1 and 310 F g −1 at a current density of 1.0 A g −1 respectively in a three- and two-electrode system using 6 mol L −1 KOH electrolyte, among the highest ever reported for carbon materials derived from biomass. Furthermore, the high rate capability (72% and 64% capacitance retention at 200 mV s −1 and 20 A g −1, respectively) as well as the high cycling stability (2% loss over 50, 000 cycles) significantly potentiate the supercapacitor properties of the product. Additionally, an energy density as high as 25.4 Wh kg −1 at the power density of 15 kW kg −1 was verified in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4 ) electrolyte. Most importantly, it is demonstrated that 3-D scaffolding PCNS frameworks can be easily achieved from different plant wastes sharing common features. This work provides a clear strategy on how to select promising plant-waste candidates for high-performance ACs applied on energy storage. Graphical abstract: Highlights: 3D scaffolding PCNSs are fabricated from plant wastes sharing specific features. The product presents excellent capacitive performance. The assembled supercapacitors show high energy density. A clear strategy of plant waste selection for energy storage is provided.