High–rate electrochemical capacitors from highly graphitic carbon–tipped manganese oxide/mesoporous carbon/manganese oxide hybrid nanowires

• Main Authors: Jiang, Hao, Yang, Liping, Li, Chunzhong, Yan, Chaoyi, Lee, Pooi See, Ma, Jan
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Chemistry::Physical chemistry::Electrochemistry; DRNTU::Engineering::Materials::Energy materials
• Online Access: https://hdl.handle.net/10356/93940; http://hdl.handle.net/10220/7257
• Institution: Nanyang Technological University

In this paper, using manganese oxide as an example, we report the successful design and synthesis of a novel one-dimensional highly graphitic carbon-tipped manganese oxide/mesoporous carbon/ manganese oxide hybrid nanowire. The unique structure significantly improves the conductivity of metal oxide materials, which is a key limitation in pseudocapacitors. The hybrid nanowire with optimal carbon content, when applied as an electrode, exhibits superior capacitive properties in 1 M Na2SO4 aqueous solution, such as high specific capacitance (266 F g 1 at 1 A g 1 ), excellent rate capability (56.4% capacity retention at 60 A g 1 ) and outstanding cycling stability (without degradation after 1200 cycles). The energy densities achieved can be as high as 20.8Wh kg 1 , at a power density of 30 kWkg 1 . The results demonstrated that the manganese oxide in our hybrid nanomaterial was efficiently utilized with the assistance of the highly conductive graphitic carbon-tipped mesoporous carbon shell. It is reckoned that the present low-cost novel hybrid nanowire can serve as a promising electrode material for supercapacitors and other electrochemical devices.