Unusual interconnected graphitized carbon nanosheets as the electrode of high-rate ionic liquid-based supercapacitor. (August 2017)

• Record Type: Journal Article
• Authors: Tian, Weiqian; Gao, Qiuming; Tan, Yanli; Li, Zeyu
• Is Part Of: Carbon. Volume 119(2017)
• Page Start: 287
• Page End: 295
• Publication Date: 2017-08
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2017.04.050
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: A type of unusual interconnected graphitized carbon nanosheets (GCNS) was fabricated from biomass waste, i.e., inner shaddock skins using a facile combined method of simultaneous carbonization-activation and post-vacuum-annealing processes. The obtained GCNS has an optimized integration of a cage-like high-aspect-ratio nanosheet structure (∼8 nm thickness), a large surface area of 2327 m 2 g −1 and hierarchical meso/micropore systems (82.3% mesopore volume). Given the effect of post-vacuum-annealing process, enhanced graphitization degree and excellent electronic conductivity (7.9 S cm −1 ) were obtained for the GCNS. The enhanced graphitization degree not only effectively improves electronic/ionic-transport kinetics in favor of rate capability but also prevents electrolyte degradation thus benefitting cyclic life. The ionic liquid-based supercapacitors assembled with symmetric GCNS electrodes exhibited an ultrahigh rate capability of 87% at current density of 100 A g −1 (holding 132 F g −1 ) and a long cyclic life of 97.6% capacitance retention after 10, 000 cycles. The excellent rate capability resulted in an integrated high energy-power property at an energy density of 56 Wh kg −1 (29.2 Wh L −1 ), corresponding to a power density of 93 kW kg −1 (48.4 kW L −1 ). Graphical abstract: