High-capacitance MnO₂ nanoflakes on preformed C/TiO₂ shell/core nanowire arrays for electrochemical energy storage

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• 作者：SainanYang ; Kui Cheng ; Jichun Huang ; Ke Ye ; Yang Xu ; Dianxue Cao ; Xingmei Zhang Guiling Wang ; ^{wangguiling@hrbeu.edu.cn" class="auth_mail}
• 关键词：Manganese dioxide ; Electrodeposition ; Nanoflakes ; Core/shell ; Supercapacitors
• 刊名：Electrochimica Acta
• 出版年：20 February, 2014
• 年：2014
• 卷：120
• 期：Complete
• 页码：416-422
• 全文大小：2218 K

文摘

In this work, MnO₂ nanoflakes are electrochemically deposited on preformed C/TiO₂ shell/core nanowire arrays to form a shell/shell/core arrays electrode (MnO₂/C/TiO₂). Their structure and surface morphology are studied by using X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The results suggest that MnO₂ nanoflakes have well-distributed covered on the surface of C/TiO₂ shell/core nanowire arrays. The MnO₂/C/TiO₂ shell/shell/core arrays are evaluated as a supercapacitor electrode material, which exhibits high specific capacitance of 639 F g^鈭? at a charge/discharge current density of 1 A g^鈭? and 78.7% specific capacitance retained after 1000 cycles. The superior pseudo-capacitive properties are attributed to the unique shell/shell/core structure for easy access of electrolyte ions, large surface to volume and high electrochemical activity. Our result shows that three-dimensional hierarchical nanostructures are being regarded advantageous for electrochemical energy applications.