化学学报 ›› 2002, Vol. 60 ›› Issue (1): 87-92. 上一篇    下一篇

研究论文

PbO~2纳米粉体的固相合成及其对MnO~2电极材料的改性作用

夏熙;龚良玉   

  1. 新疆大学应用化学研究所
  • 发布日期:2002-01-15

Synthesis of nanophase PbO~2 by solid state reaction and its influence on MnO~2 electrode

XIA XI;GONG LIANGYU   

  • Published:2002-01-15

利用固相氧化反应制备了PbO~2纳米粉体样品,借助XRD,TEM以及循环伏安测试对其性质进行了表征。同时,对反应条件的选择进行了讨论。将所得样品用于改性MnO~2电极,恒流放电测试结果表明,样品掺杂量在1.25%~5.00%间对MnO~2有良好的改性效果,可使改性MnO~2的放电容量得到极大提高。循环伏安测试结果表明,铅的掺入改变了MnO~2的放电机理。在循环扫描过程中,掺杂物与MnO~2均不再以单纯氧化物的形式存在,而是形成了一系列Pb(X)(X=0,Ⅱ)Mn(Y)(Y=Ⅳ,Ⅲ,Ⅱ)复合物的共氧化与共还原,抑制了电化学惰性物质Mn~3O~4的生成和积累,从而有望改善MnO~2的可充性能。纳米PbO~2与常粒径PbO~2与常粒径PbO~2(标记为S)对MnO~2的改性机理类似。但前者对MnO~2的改性效果明显优于后者,当恒流放电至-1.0V时,其放电容量较S样改性MnO~2的放电容量平均高出约30%。

关键词: 氧化铅, 纳米相材料, 氧化锰, 电极材料, 改性, 放电容量, X射线衍射分析, 透射电子显微镜, 循环伏安法

Nanophase PbO~2 was prepared successfully by solid-phase redox reaction and characterized by XRD, TEM and CV techniques. The synthesis conditions of nanophase materials were discussed. PbO~2 modified MnO~2 electrodes were fabricated and their electrochemical properties were studied by means of constant current discharge and CV experiments. The results indicated that the optimum ratio of PbO~2 additives were 1.25%~5.00%. The charge-discharge mechanism of MnO~2 changed because the Pb(X)(X=0, Ⅱ) and Mn(Y)(Y=Ⅳ,Ⅲ,Ⅱ) atoms formed stable complexes. These complexes could be cooxidized and coreduced and thus restrained the formation of electrochemically inactive Mn~3O~4. The rechargeability of the MnO~2 electrode could be improved. Discharge mechanism of MnO~2 doped with nanophase sample was similar to that doped with conventional sample(S). But the nanophase sample was more effective in modifying MnO~2 electrode than the conventional sample. The discharge capacity of the nanophase PbO~2 modified MnO~2 electrodes were in average 30% higher than that of the conventional PbO~2 modified ones.

Key words: LEAD OXIDE, NANOPHASE MATERIALS, MANGANESE OXIDE, MODIFICATION, X-RAY DIFFRACTION ANALYSIS, CYCLOVOLTAMGRAPH

中图分类号: