熔融盐法制备LiMn2O4材料的合成条件研究

Synthesis Conditions of LiMn_2O_4 Prepared by Molten Salt Method

采用熔融盐法制备锂离子电池正极材料LiMn2O4,对制备过程中熔融盐种类、焙烧时间和焙烧温度等影响因素进行了系统研究。通过XRD、SEM和充放电测试,研究了产物的组成结构、形貌及电化学性能。研究结果表明,合成的LiMn2O4样品具有完整的尖晶石结构;样品的粒径分布范围小,平均粒径为几百纳米;优化实验条件之后制备得到的材料,在电压范围3.3～4.3V,充放电电流值为60mA.g-1(0.5C)时,初始放电比容量约125mAh·g-1,最初50次0.5C充放电循环的比容量保持率约为95%,在后续50次1C循环中,比容量保持率为96%左右,循环性能优良。

Cathode material LiMn2O4 for lithium-ion batteries was prepared by molten salt method. The effects from the species of molten salt, sintering time and sintering temperature during preparation were studied. XRD, SEM and charge-discharge tests were used to analyze the composition, structure, surface morphology and electrochemical properties of the cathode material. XRD results showed the structure of sample was pure spinel. SEM results showed the size of particle was uniform with the average diameter of several hundreds nanometers.The LiMn2O4 cathode material prepared under optimized conditions had an initial capacity of 125 mAh·g^-1 at 0.5C （60 mA·g^-1 ） with a voltage window of 3.3-4.3 V. It showed good cyclic ability with capacity retention about 95% during the first 50 cycles at 0.5C, and about 96% between the 51^th and 100^th cycles at 1C.