High-performance symmetric supercapacitors based on carbon nanosheets framework with graphene hydrogel architecture derived from cellulose acetate

• Published in: Journal of power sources 2017-01, Vol.337, p.45-53
• Main Authors: An, Yufeng, Yang, Yuying, Hu, Zhongai, Guo, Bingshu, Wang, Xiaotong, Yang, Xia, Zhang, Quancai, Wu, Hongying
• Format: Article
• Language: English
• Subjects: Carbon nanosheets framework; Cellulose acetate; Energy storage performance; High rate capability; Nitrogen-doping; Symmetric supercapacitor
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2016.10.112

Three-dimensional nitrogen-doped carbon nanosheets framework (N-CNF) has been obtained starting with cellulose acetate. The product is prepared through a so-called one-step method that carbonization, activation and nitrogen-doping occur simultaneously. The resultant N-CNF shows an architecture like graphene hydrogel with interconnected hierarchical porous structure, N-doping with high nitrogen content (8.7 wt%) and high specific surface area (1003.6 m2 g−1). The N-CNF electrode displays excellent electrochemical performances due to the unique architecture and pseudocapacitance contribution from heteroatoms. In the three-electrode configuration, the N-GNF achieves a high specific capacitance of 242 F g−1 at 1 A g−1 and displays ultrahigh rate capability (83.4% capacitance retention at 100 A g−1) in 6 mol L−1 KOH electrolyte. The symmetric supercapacitor (SSC) based N-CNF exhibits energy density as high as 60.4 Wh kg−1 (at a power density of 1750 W kg−1) and 17.9 Wh kg−1 (at 850 W kg−1) in ionic liquid and aqueous electrolytes, respectively. It is surprised that the single device filled by ionic liquid electrolyte is able to light easily 60 red light-emitting diodes (LEDs, 2.2 V) in parallel after charging for only 10 s, showing an excellent energy storage/release performance. [Display omitted] •N-doping carbon nanosheets framework (N-CNF) is fabricated from cellulose acetate.•The N-CNF shows an architecture like hydrogel with high specific surface area.•The N-CNF exhibits excellent rate capability and high specific capacitance.•A single symmetric supercapacitor easily lights 60 red light-emitting diodes.