尖晶石型锰酸锂的复合掺杂改性

以固相烧结法制备的尖晶石型锰酸锂为基础,对其结构中掺杂复合非金属元素B和F,合成了B、F掺杂的尖晶石。通过X射线衍射、扫描电镜、电化学分析方法对试样的晶体结构、表面形貌及电化学性能进行表征。结果表明,采用B、F包覆的锰酸锂与纯锰酸锂的X射线衍射结果相似,波峰尖锐且峰值高;随着B的掺入,尖晶石作为正极材料充放电的循环性能得到了提高,但是其初始容量较低,仅为102.3mA·h/g。随着加入复合非金属元素B和F,样品的初始容量提高到了110.9mA·h/g,50次循环后的容量保持率为83.14%。实验结果表明,复合掺杂有效提高了锰酸锂的电化学性能。

Research on the spinel-type lithium manganese oxide doped with nonmetal elements

In this experiment,the spinel-type lithium manganese oxide(LiMn2O4)was prepared via solid-phase sintering method,and the spinel was synthesized by doped with nonmetal elements B and F.The prepared sample was characterized by X ray diffraction,scanning electron microscopy and electrochemical analysis.The LiMn2O4 doped with nonmetal elements B and F was similar to the pure LiMn2O4,and both showed sharp and high peaks.The cycle ability of LiBxMn2-xO4 was enhanced by doping B,but the first discharge capacity can reach only 102.3mA·h/g.First discharge capacity of the spinel increased to 110.9mA·h/g with the capacity retentions of 83.14%after fifty cycles.B and F doping can enhance the stability and cycling behavior of LiMn2O4 and showed good electrochemical performance.