物理化学学报 >> 2015, Vol. 31 >> Issue (4): 693-699.doi: 10.3866/PKU.WHXB201502021

电化学和新能源 上一篇    下一篇

水热合成制备Al掺杂α-MnO2纳米管及其超级电容器电化学性能

黎阳, 谢华清, 李靖   

  1. 上海第二工业大学城市建设与环境工程学院, 上海201209
  • 收稿日期:2014-09-09 修回日期:2015-01-29 发布日期:2015-04-03
  • 通讯作者: 黎阳 E-mail:liyang@sspu.edu.cn
  • 基金资助:

    上海市教委创新重点项目(13ZZ139), 上海第二工业大学校级重点培育学科(材料科学)建设(XXKPY1302)及上海市高校“东方学者”岗位计划资助

Hydrothermal Synthesis of Al-Doped α-MnO2 Nanotubes and Their Electrochemical Performance for Supercapacitors

LI Yang, XIE Hua-Qing, LI Jing   

  1. School of Urban Development and Environmental Engineering, Shanghai Second Polytechnic University, Shanghai 201209, P. R. China
  • Received:2014-09-09 Revised:2015-01-29 Published:2015-04-03
  • Contact: LI Yang E-mail:liyang@sspu.edu.cn
  • Supported by:

    The project was supported by the Key Innovation Foundation of Shanghai Education Commission, China (13ZZ139), Key Discipline Construction (Materials Science) of Shanghai Second Polytechnic University, China (XXKPY1302), and Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, China.

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摘要：

通过水热法制备了未掺杂α-MnO2和Al 掺杂α-MnO2, 对产物的形貌、结构和电化学性能进行了研究. 扫描电镜(SEM)和高分辨透射电镜(HRTEM)观察表明制备产物呈纳米管形态. 紫外-可见光谱分析计算了产物的能带间隙: 随着Al 的掺杂, α-MnO2的能带间隙值降低. 以未掺杂α-MnO2与Al 掺杂α-MnO2作为电极材料, 通过循环伏安(CV)和恒流充放电测试电极的超级电容器性能. 在50 mA·g-1电流密度下, 未掺杂α-MnO2与Al 掺杂α-MnO2电极的比电容分别达到了204.8 和228.8 F·g-1. 电化学阻抗谱(EIS)分析表明Al 的掺杂降低了α-MnO2在电解液中的阻抗, 有利于提高其电化学比电容. 增强的比电容及在1000个循环后仍具有良好的容量保持率,使Al 掺杂α-MnO2在超级电容器中具有较好的应用前景.

关键词: α-MnO2, Al 掺杂, 纳米管, 超级电容器, 电化学电容器

Abstract:

α-MnO2 and Al-doped α-MnO2 were synthesized via a hydrothermal method. The morphologies, structures, and electrochemical performances of as-synthesized un-doped and doped α-MnO2 were studied. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) show that these un-doped and doped α-MnO2 are nanotube shaped. The band gaps of α-MnO2 are investigated by ultraviolet-visible absorption spectroscopy, which indicates that the band gap of α-MnO2 decreases upon Al doping. The electrochemical performances of un-doped and doped α-MnO2 as electrode materials for supercapacitors were measured by cyclic voltammetry (CV) and galvanostatical charge/discharge tests. The specific capacitances of un-doped and Al-doped α-MnO2 respectively reach 204.8 and 228.8 F·g-1under a current density of 50 mA·g-1. It was discovered that the electrochemical impedance of Al-doped α-MnO2 was decreased by Al doping analyzed using electrochemical impedance spectra (EIS), which provides a beneficial increase to its electrochemical specific capacitance. Enhanced specific capacitance and preferable cycling stability (up to 1000 cycles) for Al-doped α-MnO2 mean that these systems are favorable prospects for application in supercapacitors.

Key words: α-MnO2, Al doping, Nanotube, Supercapacitor, Electrochemical capacitor