微波合成LiMn2O4正极材料及其电化学性能的研究

本文以Li2CO3 、MnO2为原料,采用微波热处理合成锂离子电池正极材料LiMn2O4,研究了热处理温度,Li/Mn摩尔比对产物结构和电化学性能的影响,同时研究了微波热处理和传统热处理两种加热方式的差别.通过X射线衍射（XRD）、扫描电镜（SEM）、恒电流充放电测试分别对产物的结构、形貌及电化学性能进行表征,结果表明：采用微波法在750℃保温15 min,快速地制备出尖晶石型LiMn2O4,纯度高,尺寸分布均匀,约100-300 nm;于0.1C倍率下,以微波法制备的正极材料首次放电比容量可达112.38 mA·h/g,1C倍率充放电50次循环后,容量保持率为91.6％;以传统方法制备的正极材料0.1C倍率下首次放电比容量为94.07 mA·h/g,1C倍率充放电50次循环后,容量保持率为71.4％

Preparation of LiMn2O4 Anode Materials by Microwave Heating and Their Electrochemical Properties

In this paper, the anode material for lithium-ion battery of LiMn2 04 is prepared by microwave method u- sing Li2CO3 and MnO2 as starting materials. The influence of heating temperature and the mole ratio of Li/Mn on the structure and electrochemical properties of LiMn2Q is investigated. The differences between microwave and conventional heating are also studied. The structures, morphology and electrochemical properties are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, galvanostatic charge and discharge tests, re- spectively. The results indicate that, a high purity spinel LiMn2O4 with narrow size distribution （about 100-300 nm） are prepared fast within 15 minutes at 750C by microwave method. The first discharge capacity of LiMn2 04 sample synthesized by microwave sintering is 112.38 mA h/g at 0.1C rate. After 50th cycle at 1C, the ratio of discharge capacity retention is 91.6%. The first discharge capacity of LiMn2O4 sample obtained by traditional sin- tering is 94.07 mAh/g at 0.1C rate. After 50th cycle at 1C, the ratio of discharge capacity retention is 71.4%.