高等学校化学学报 ›› 2023, Vol. 44 ›› Issue (4): 20220658.doi: 10.7503/cjcu20220658

• 物理化学 • 上一篇    下一篇

Al3+离子掺杂 δ-MnO2的制备和电化学性能

夏傲(), 曾啸雄, 李佳萌, 陈军, 谈国强   

  1. 陕西科技大学材料科学与工程学院, 西安 710021
  • 收稿日期:2022-10-06 出版日期:2023-04-10 发布日期:2023-01-08
  • 通讯作者: 夏傲 E-mail:xiaao@sust.edu.cn
  • 基金资助:
    中国博士后科学基金(2016M592746);陕西科技大学博士科研启动基金(BJ15-04);陕西高校青年创新团队项目(2022-70)

Preparation and Electrochemical Properties of Al3+-Doped δ -MnO2

XIA Ao(), ZENG Xiaoxiong, LI Jiameng, CHEN Jun, TAN Guoqiang   

  1. School of Materials Science and Engineering,Shaanxi University of Science & Technology,Xi’an 710021,China
  • Received:2022-10-06 Online:2023-04-10 Published:2023-01-08
  • Contact: XIA Ao E-mail:xiaao@sust.edu.cn
  • Supported by:
    the China Postdoctoral Science Foundation(2016M592746);the Doctoral Research Launch Fund of Shaanxi University of Science and Technology, China(BJ15-04);the Youth Innovation Team of Shaanxi Universities, China(2022-70)

摘要:

采用水热法合成了不同比例Al3+离子掺杂的δ-MnO2纳米粉体. 通过X射线衍射(XRD)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 X射线光电子能谱(XPS)、 循环伏安(CV)曲线、 电化学阻抗谱(EIS)和恒电流充放电(GCD)曲线等手段对材料的结构和电化学性能进行了表征. 结果表明, Al3+离子进入δ-MnO2的晶格替代部分Mn3+和Mn4+离子, 使得δ-MnO2电极的性能明显提升. 当反应物中Al3+/Mn2+摩尔比为0.45时, 所得样品(A0.45M)的性能最好; 其在1 A/g电流密度下的比电容为207.61 F/g, 是纯相δ-MnO2(A0M)的2.4倍; 其在10 A/g电流密度下循环10000次后的比电容为100.81 F/g, 容量保持率为81.33%.

关键词: δ-二氧化锰, 超级电容器, 铝掺杂, 水热法

Abstract:

Al3+-doped δ-MnO2 nano-powders with different doping ratios were synthesized by hydrothermal method. The influence of Al3+-doping on the δ-MnO2 crystal structure and electrochemical performance was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectro- scopy, cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge. The results suggested that Al3+ ions entered into the crystal lattice of δ-MnO2 to replace some Mn3+ and Mn4+ ions, which enhanced the electrical conductivity and structural stability of δ-MnO2, and thus significantly improved the electrochemical performance. When the molar ratio of Al3+/Mn2+ in the precursor was 0.45, the synthesized product (A0.45M) showed the best electrochemical performance. A0.45M delivered a specific capacitance of 207.61 F/g at a current density of 1 A/g, which was 2.4 times the capacitance of the pure δ-MnO2(A0M). Moreover, A0.45M could maintain a high specific capacitance of 100.81 F/g even after 10000 cycles at 10 A/g, with capacity retention ratio of 81.33%.

Key words: δ-MnO2, Supercapacitor, Al3+-Doped, Hydrothermal method

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