合成温度对LiMn1.95Mg0．05O4结构与性能的影响

用柠檬酸辅助溶胶一凝胶法在不同温度下合成了LiMn1.95Mg0．05O4正极材料。用X射线衍射、充放电测试以及电化学阻抗谱分析技术研究了不同合成温度对LiMn1.95Mg0．05O4结构和电化学性能的影响。结果表明：合成温度对LiMn1.95Mg0．05O4正极材料的晶相结构、电化学性能有显著影响，LiMn1.95Mg0．05O4尖晶石相的生成和长大与其合成的温度有密切的关系，合成的最佳温度为750℃；在750℃条件下合成的LiMn1.95Mg0．05O4具有较高的电化学活性和较好的晶相结构；高温合成有利于提高LiMn1.95Mg0．05O4正极材料的放电容量，低温合成有利于提高其循环性能。

Effect of Synthesis Temperatures on Structure and Performance of LiMn1.95Mg0.05O4

LiMn1.95Mg0.05O4 cathode material has been prepared by citric acld-assisted sol-gel method at different temperatures. The ef- fects of different synthesized temperatures .qn structure and electrochemical performance of LiMn1.95Mg0.05O4 were investigated by X-ray diffraction （XRD）, galvanostatic charge-discharge test, and electrochemical impedance spectroscopy （EIS）, respectively. The results show that synthesis temperature has significant effects on the crystal structure and electrochemical performance of LiMn1.95Mg0.05O4 cathode material, and the formation and growth of spinel phase intimately relates to synthesis temperatures; the optimal synthesis temperature of LiMn1.95Mg0.05O4 is about 750 ℃. LiMn1.95Mg0.05O4 synthesized at 750℃ has higher electrochemical activity and crystal structure. It is propitious to improve discharge capacity of LiMn1.95Mg0.05O4 cathode materials at high synthesis temperature and increase its cycle performance at low synthesis temperature.