Three-dimensional graphitized carbon nanovesicles for high-performance supercapacitors based on ionic liquids.
Three-dimensional nanoporous carbon with interconnected vesicle-like pores (1.5-4.2 nm) has been prepared through a low-cost, template-free approach from petroleum coke precursor by KOH activation. It is found that the thin pore walls are highly graphitized and consist of only three to four layers of graphene, which endows the material with an unusually high specific surface area (2933 m(2)  g(-1) ) and good conductivity. With such unique structural characteristics, if used as supercapacitor electrodes in ionic liquid (IL) electrolytes, the graphitized carbon nanovesicle (GCNV) material displays superior performance, such as high energy densities up to 145.9 Wh kg(-1) and a high combined energy-power delivery, and an energy density of 97.6 Wh kg(-1) can be charged in 47 s at 60 °C. This demonstrates that the energy output of the GCNV-based supercapacitors is comparable to that of batteries, and the power output is one order of magnitude higher. Moreover, the synergistic effect of the GCNVs and the IL electrolyte on the extraordinary performance of the GCNV supercapacitors has been analyzed and discussed.
Department of Chemistry, Institute for Biomedical Engineering & Nano Science, Tongji University, Shanghai 200092 (P.R. China), Fax: (+86) 21-65983706.
Chengxin
C
Peng
Zubiao
Z
Wen
Yao
Y
Qin
Lukas
L
Schmidt-Mende
Chongzhong
C
Li
Shihe
S
Yang
Donglu
D
Shi
Jinhu
J
Yang
D025802:Electric Capacitance; D004553:Electric Conductivity; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry*; D016062:Porosity
D052578:Ionic Liquids; D006108:Graphite
capacitors; carbon; electrochemistry; ionic liquids; nanostructures