One-step synthesis of hierarchically porous carbons for high-performance electric double layer supercapacitors

摘要

With plenty of unique porous structure at micro-ano scale, hierarchically porous carbons (HPCs) are promising for usage in advanced electric double layer supercapacitors (EDLCs) as the electrode materials. However, wide-range adoption of HPC for practical application is largely shadowed by its extremely complex synthesis process with considerably low production efficiency. Herein we reported a simple template-free, one-step sintering method, to massively produce the HPCs for high-performance EDLCs. Resorting to the 3D structure modification of the wide pore size distribution, high surface area of HPCs (up to 3000 m(2) g(-1)) was achieved. By using 1 M Na2SO4 as electrolyte, the as-fabricated HPCs based EDLCs can be operated reversibly over a wide voltage window of 1.6 V with superior specific capacitance of 240 F g(-1) under a current density of 0.5 A g(-1). In the meanwhile, the EDLCs exhibit excellent rate capability (high power density of 16 kW kg(-1) at 10.2 Wh kg(-1)) and long-term cycling stability with 9% loss of its initial capacitance after 2000 cycles. This output performance distinguished itself among most of the carbon-based EDLCs with neutral aqueous electrolyte. Thus, the template-free one-step sintering method produced HPCs for EDLCs represents a new approach for high-performance energy storage. (C) 2016 Elsevier B.V. All rights reserved.