掺杂元素La、F对尖晶石LiMn2O4材料结构及性能的影响

采用X-射线衍射仪(XRK)、扫描电子显微镜(SEM)、电池测试系统等研究了掺杂元素La、F对高温固相合成尖晶石型LiMn2O4材料的相结构、貌、活化性能、循环稳定性能的影响.结果表明:掺杂元素La、F可有效地提高LiMn2O4样品的充放电效率、循环稳定性能:随着掺杂元素F含量的增加,LiMn2O4-xFx样品的初始容量降低、循环稳定性能呈现出先增后减的变化规律;当掺杂元素La、F的含量较少时,LiLay,Mn2-yO4-xFx样品具有纯的尖晶石LMn2O4结构,样品呈球形或近球形,粒径范围为0.5～2.5 μm,LiLa0.02Mn1.98O3.95F0.05样品的初始放电容量为123.6mAh/g,经30次循环充放电后的容量为114.6mAh/g,容量保持率为92.7%,具有较好的活化性能和循环稳定性能.

Effects of Doping Elements Lanthanum and Fluorine on Structure and Electrochemical Performance of Spinel LiMn2O4 Cathode Material

The effects of the doping elements such as La and F on the phase structure, the morphology, the activate and electrochemical properties of the spinel LiMn2O4 cathode material prepared by high temperature solid state reaction were investigated by means of the X-ray diffraction (XRD), scanning electron microscope (SEM) and battery testing system this paper. The results showed that the initial discharge capacity of the LiMn2O4-xFx sample decreased, and the cyclic stability of the specimen increased and then de...