High energy supercapacitors based on interconnected porous carbon nanosheets with ionic liquid electrolyte

Future development of electrochemical energy storage systems requires low-cost supercapacitors with not only an outstanding power performance but also the high energy. Herein, interconnected porous carbon nanosheets are prepared via a simple hydrothermal process combined with chemical activation route by using reed as the precursor and KOH as the activating agent. The as-prepared carbon nanosheets exhibits a high specific surface area (up to 2183 m(2) g(-1)), and a hierarchical porous structure containing combined macroporous scaffolds and meso/microporous textures. When tested as electrode materials for ionic liquid-based supercapacitors, the carbon nanosheet exhibits a high capacitance of 147 F g(-1) and a good capacitance retention ratio of 48.3% at 100 A g(-1), with a high cycling life stability (10% loss after 10000 cycles). Moreover, the assembled supercapacitor yields a maximum energy and power density of 11.4 Wh kg(-1) and 98 kW kg(-1) based on the all components of the packaged device. The remarkable characteristics of the produced carbon materials indicate that the novel precursor-synthesis route offers promising potential for low-cost production for supercapacitors. (C) 2017 Elsevier Inc. All rights reserved.