球磨促进高温固相反应合成尖晶石相LiMn_2O_4

Synthesis of spinel LiMn_2O_4 by ball-milling promoted solid state reaction

利用球磨促进高温固相反应方法进行了LiMn2 O4的合成 ,研究了球磨时间对原料颗粒大小和反应温度的影响 ,并利用热重分析 (TG)、扫描电镜 (SEM )、X射线衍射 (XRD)等手段对反应过程及产物形貌和物相结构进行了分析。实验结果表明球磨大大地降低了LiMn2 O4的合成温度 ,缩短了合成时间 ,并且晶粒的粒径要比没球磨的样品小。电化学测试结果表明用此种方法合成的尖晶石结构LiMn2 O4其初始放电容量能达到 1 2 0mAh/g 。

Spinel phase LiMn 2O 4 was synthesized by ball milling promoted solid state reaction. The effects of different ball milling time on the grain size of raw materials and the synthesis temperature were studied. In this process, scanning electric microscopy (SEM), thermogravimetry (TG) and X ray diffraction (XRD) were used to analyze the reaction process and the appearance and phase structure of synthesized sample. The results show that raw materials of LiMn 2O 4 treated by ball milling have much smaller size than those untreated and their synthesis temperature and synthesis time decreased greatly. The electrochemical properties of synthesized sample were also tested and the results show that the initial capacity of the sample is over 120 mAh/g and its high rate discharge capability is improved.