Asymmetric Supercapacitors Based on Graphene/MnO2 and Activated Carbon Nanofiber Electrodes with High Power and Energy Density |
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| Authors: | Zhuangjun Fan Jun Yan Tong Wei Linjie Zhi Guoqing Ning Tianyou Li Fei Wei |
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| Affiliation: | 1. Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China;2. National Center for Nanoscience and Technology of China, Zhongguancun, Beiyitiao 11, Beijing 100190, P. R. China;3. State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, P. R. China;4. Beijing Key Laboratory of Green Chemical Reaction, Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China |
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| Abstract: | Asymmetric supercapacitor with high energy density has been developed successfully using graphene/MnO2 composite as positive electrode and activated carbon nanofibers (ACN) as negative electrode in a neutral aqueous Na2SO4 electrolyte. Due to the high capacitances and excellent rate performances of graphene/MnO2 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 MnO2//DWNT cell (29.1 Wh kg?1). Additionally, graphene/MnO2//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. |
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| Keywords: | graphene/MnO2 activated carbon nanofibers asymmetric supercapacitor energy density |
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