One-Step Solvothermal-Processed 3D Spinel-Type Manganese Oxide Microspheres and Their Improved Supercapacitive Properties

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• 作者：Wen-Yin Ko ; Lung-Jing Chen ; Yu-Hung Chen ; Wei-Hung Chen ; Ke-Ming Lu ; Jin-Ru Yang ; Yin-Cheng Yen ; Kuan-Jiuh Lin
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：August 15, 2013
• 年：2013
• 卷：117
• 期：32
• 页码：16290-16296
• 全文大小：450K
• 年卷期：v.117,no.32(August 15, 2013)
• ISSN：1932-7455

文摘

Three-dimensional (3D) spinel-type MnO₂ has attracted extensive interest as a potential electrode material for supercapacitors in order to meet cost/performance requirements of power supplies. In this study, MnO₂ microspheres (MS-MnO₂) with a 3D spinel phase and 0.5鈥?.0 渭m size were constructed from small MnO₂ nanoparticles by a rapid and facile solvothermal process in which tetraethylammonium (TEA) was used as the template. The properties of the synthesized spinel MS-MnO₂ for use in supercapacitors were investigated by cyclic voltammetry and galvanostatic charge/discharge measurements using a three-electrode system in a neutral 1 M Na₂SO₄ electrolyte. The synthesized spinel MS-MnO₂ exhibited faster charge/discharge rates and higher capacitance than commercial MnO₂ materials. The obtained results showed that the as-prepared spinel MS-MnO₂ possessed good specific capacitance (SC) of 190 F/g at 0.5 A/g. The spinel MS-MnO₂ also exhibited excellent SC retention and Coulombic efficiency of 100% and 95%, respectively, after 1000 cycles at 1 A/g, suggesting its potential application in supercapacitors. In addition, manganese oxides with large cavities were obtained through postannealing treatment and showed their potential for use in energy-storage devices, energy-conversion systems, catalysts, and sensors.