Manganese dioxide nanowires on carbon nanofiber frameworks for efficient electrochemical device electrodes
Manganese dioxide nanowires on carbon nanofiber frameworks for efficient electrochemical device electrodes
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DOI：
10.1039/c6ra28789a
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发表时间：
2017-01-01
期刊：
影响因子：
3.9
通讯作者：
Matsumoto, H.
中科院分区：
文献类型：
--
作者：
Saito, Y.;Meguro, M.;Matsumoto, H.
通过在直径为250和650 nm的静电纺碳纤维（CNF）上电沉积直径为5-20 nm的二氧化锰纳米线（MnO 2 NWs），制备了多级纳米结构复合电极。研究了碳纳米纤维直径和MnO 2纳米线质量负载量对多级纳米结构形成和复合电极性能的影响。复合电极的内部结构取决于CNF直径和MnO 2 NW的质量负载。基于较薄的CNF和较高质量负载的MnO 2纳米线的电极显示出较高的重量和体积电容值。这可能是由于MnO 2纳米线在较薄的三维CNF框架中形成了致密的网络。此外，具有MnO 2 NW/CNF复合电极作为正极和活性炭作为负极的非对称超级电容器分别显示出8.9 W h kg（-1）和4.9 kW kg（-1）的高能量和功率密度。这些结果清楚地表明，由活性材料和电荷收集器组成的分级网络纳米结构可以被认为是用于各种电化学装置的有前途的电极。
Hierarchically nanostructured composite electrodes were prepared by the electrodeposition of manganese dioxide nanowires (MnO2 NWs) with 5-20 nm diameters on electrospun carbon nanofiber (CNF) webs with diameters of 250 and 650 nm. The effects of CNF diameters and mass loading of MnO2 NWs on the hierarchical nanostructure formation and the performance of the composite electrodes were investigated. The internal structure of the composite electrode depended on CNF diameter and mass loading of MnO2 NW. The electrodes based on thinner CNFs and higher mass loadings of MnO2 NWs showed higher values of gravimetric and volumetric capacitances. This would be due to MnO2 NWs forming a dense network in the thinner three-dimensional CNF framework. In addition, asymmetric supercapacitors with the MnO2 NW/CNF composite electrode as the positive electrode and activated carbon as the negative electrode showed high energy and power densities of 8.9 W h kg(-1) and 4.9 kW kg(-1), respectively. These results clearly indicate that the hierarchical network nanostructure composed of an active material and a charge collector can be considered a promising electrode for various electrochemical devices.