Ultrathin carbon gauze for high-rate supercapacitor

Further increasing the output power is important to develop next-generation supercapacitor. In recent years, many papers focus on the design of pore structure to improve high-rate performance of supercapacitor, but few reports devote attention to reducing the nanoscale size of carbon framework to reach an optimal ion transfer. In the present paper, a novel ultrathin carbon gauze was fabricated by a simple boiling-induced volume expansion method. This carbon gauze shows foam-like morphology that is composed of 7 nm-thick carbon sheets. In addition, owing to the loose stack of carbon sheets, lots of meso-/macropores are created. When used as electrode in supercapacitor, the ultrathin carbon sheets can effectively minimize the electrolyte transfer distance and meso-/macropores can accelerate ion transfer speed, and then carbon gauze exhibits an impressive high-rate supercapacitive performance. While the scan rate is raised from 0.02 to 0.5 V s (1), the capacitance only reduces from 190 to 173 F g (1), implying a retention of 91%, and even under an extremely high scan rate of 2.0 V s (1), the cyclic voltammogram of carbon gauze still presents a symmetrically rectangular shape, revealing a considerable capacitance of 142 F g (1) (75% of the capacitance at 0.02 V s (1)). (C) 2016 Elsevier Ltd. All rights reserved.