高温固相法合成尖晶石型Li_xMn_2O_4的结构及电化学性能

Structure and electrochemical performance of the spinel Li_xMn_2O_4 prepared by high-temperature solid-state synthesis

采用X射线衍射仪、扫描电子显微镜、电池测试系统等研究了Li／Mn（摩尔比）、合成温度、合成时间等工艺因素对LixMn2O4正极材料的相组成、形貌及电化学性能的影响。结果表明，当合成温度为1023～1223K，合成时间为12～36h时，所合成的LixMn2O4（x=0．98～1．05）样品具有单一的尖晶石型LiMn2O4结构，样品呈规则的球形或近球形，粒径为1～3μm。样品具有较好的室温活化特性，首次活化即达到最大放电容量118．0mAh／g，样品的放电容量随合成时间的延长而增加、随合成温度的升高呈先增后减的规律。

The effects of the process parameter such as the lithium to manganese molar ratio, the synthetical temperature and time on the phase structure, micrograph and electrochemical properties of the LixMn2O4 anode material were investigated by means of XRD,SEM and battery testing system. The results show that the LixMn2O4（x =0. 98-1. 05） sample is composed of the single-phase spinel LiMn2O4 when the synthetic temperature and time were 1023 - 1223 K and 12 - 36 h, respectively. The particles of the LixMn2O4 specimen are spheroid or sphere,and the size of the particles are 1-3 μm The sample reaches its maximum discharge-capacity（ 118.0 mAh/g）after the first charge/discharge cycling at room temperature. The discharge-capacity of the specimen increases with prolonging the synthetic time, and increases firstly and then decreases with increasing the synthetic temperature.