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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (15): 1473-1480. 上一篇    下一篇

研究论文

薄层晶状α-MnO2/活性炭复合电极材料的制备和电化学性质

温祖标1,2，刘亚菲1，胡中华*,1，吴宇平3，刘爱芳1，王晨晨1，徐鑫1   

  1. (1同济大学化学系 上海 200092)
    (2江西师范大学化学化工学院 南昌 330022)
    (3复旦大学化学系 上海 200433)
  • 投稿日期:2009-10-27 修回日期:2010-03-14 发布日期:2010-04-09
  • 通讯作者: 胡中华 E-mail:huzh@tongji.edu.cn
  • 基金资助:

    国家“863”计划（No. 2008AA06Z329)和国家“973” 计划（ No: 2007CB209700)资助项目

Preparation and Electrochemical Performance of Thin Layer Crystal α-MnO2/AC Composite Electrode Materials

Wen Zubiao1,2 Liu Yafei1 Hu Zhonghua*,1 Wu Yuping3 Liu Aifang1 Wang Chenchen1 Xu Xin1   

  1. (1 Department of Chemistry, Tongji University, Shanghai 200092)
    (2 College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022)
    (3 Department of Chemistry, Fudan University, Shanghai 200433)
  • Received:2009-10-27 Revised:2010-03-14 Published:2010-04-09

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以自制活性炭(AC)为载体, (NH4)2S2O8为氧化剂、MnSO4为还原剂和锰源、(NH4)2SO4为模板试剂, 通过原位水热沉积法制备了α-MnO2/AC系列复合电极材料. 分别采用X 射线衍射、扫描电子显微镜、N2吸附/脱附等方法对试样的晶型结构、形貌、比表面积和孔结构进行了表征; 用循环伏安、恒流充放电和交流阻抗等电化学方法研究了材料的电化学性质. 结果表明, 在MnSO4浓度为0.075 mol•L－1的水热条件下, 获得了薄层晶状α-MnO2/AC复合材料. 在电流密度为3 mA•cm－2时, 该材料电化学性能优异, 比电容为374.5 F•g－1, 较沉积前AC的252.7 F•g－1有显著提高, 增幅为48.2%; α-MnO2/AC复合电极有良好的充放电特性和循环稳定性, 经 1000 次恒流充放电测试, 容量保持率达到 95%.

关键词: 原位水热沉积法, 活性炭, α-MnO2, 电极材料, 电化学电容器

The composite electrode materials of α-MnO2/activated carbon (α-MnO2/AC) were prepared by in-situ hydrothermal deposition using ammonium persulfate as oxidants, manganese sulfate as precursors, ammonium sulfate as templates and self-made activated carbon as supports. X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption at 77 K were used to investigate the crystal structure, morphology, specific surface area and porosity of the composites, respectively. Their electrochemical properties were evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results showed that crystalline α-MnO2 was well deposited on the AC to produce thin layer crystal α-MnO2/AC composite material at the optimal MnSO4 concentration of 0.075 mol• L－1 in the synthetic process. The specific capacitance of the composite could be as high as 374.5 F•g－1, 48.2% higher than that of pure AC electrode. The α-MnO2/AC composite electrode had high stability and the capacity retention was of 95% after a 1000-cycle charge-discharge.

Key words: in-situ hydrothermal deposition, activated carbon, α-MnO2, electrode material, electrochemical capacitors