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Asymmetric Supercapacitors Based on Graphene/MnO 2 and Activated Carbon Nanofiber Electrodes with High Power and Energy Density
Author(s) -
Fan Zhuangjun,
Yan Jun,
Wei Tong,
Zhi Linjie,
Ning Guoqing,
Li Tianyou,
Wei Fei
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201100058
Subject(s) - supercapacitor , materials science , graphene , capacitance , power density , electrode , electrolyte , electrochemistry , carbon nanofiber , energy storage , chemical engineering , nanotechnology , horizontal scan rate , nanofiber , carbon fibers , composite number , composite material , carbon nanotube , power (physics) , cyclic voltammetry , chemistry , physics , quantum mechanics , engineering
Asymmetric supercapacitor with high energy density has been developed successfully using graphene/MnO 2 composite as positive electrode and activated carbon nanofibers (ACN) as negative electrode in a neutral aqueous Na 2 SO 4 electrolyte. Due to the high capacitances and excellent rate performances of graphene/MnO 2 and ACN, as well as the synergistic effects of the two electrodes, such asymmetric cell exhibits superior electrochemical performances. An optimized asymmetric supercapacitor can be cycled reversibly in the voltage range of 0–1.8 V, and exhibits maximum energy density of 51.1 Wh kg −1 , which is much higher than that of MnO 2 //DWNT cell (29.1 Wh kg −1 ). Additionally, graphene/MnO 2 //ACN asymmetric supercapacitor exhibits excellent cycling durability, with 97% specific capacitance retained even after 1000 cycles. These encouraging results show great potential in developing energy storage devices with high energy and power densities for practical applications.