镁含量对LiNi_(1/3)Co_(1/3)Mn_(1/3-x)Mg_xO_2正极材料物理性能的影响

Effect of Mg content on physical performance of LiNi_(1/3)Co_(1/3)Mn_(1/3-x)Mg_xO_2 cathode materials

采用共沉淀法和固相烧结法制得锂离子电池正极材料LiNi1/3Co1/3Mn1/3-xMgxO2（x为0、0.05和0.1）.用X射线衍射光谱法（XRD）、扫描电子显微镜法（SEM）研究了镁离子对材料结构和形貌的影响.SEM结果显示最终产物形貌随镁含量增加,晶粒尺寸变大,粒径分布变化小,类球形;研究发现LiNi1/3Co1/3Mn1/3O2的XRD图中在30°～40°有微量第二相,镁掺杂第二相消失,当掺杂5％（摩尔分数）镁离子时,有序性最好.随着Mg离子替代Mn离子量的增加,晶胞参数发生变化：a先减小后增大,c逐渐增大,c/a和I003/I104先增大后减小.

LiNi1/3Co1/3 Mn1/3-xgxO2 （x =0,0.5 and 0.1） cathode materials were prepared through co-precipitation and solid state sintering.The effect of Mg content on the structure and morphology of LiNi1/3Co1/3Mn1/3-xMgxO2 cathode materials was studied by XRD and SEM.SEM micrographs show the final product has the increasing particle size,spherical morphology and narrow particle size distribution with the increasing Mg content.XRD pattern of LiNi1/3Co1/3Mn1/3O2 shows that there is a bit of the second phase at 30°-40°,but the Mg-doping second phase disappears.The compound with 5％ Mg-doping has the best crystallinity.With the amount increase of Mg substituting for Mn,the lattice parameter changes：a firstly decreases and then increases; c dramatically increases; c/a and I003/I104 firstly increase and then decrease.