纳米级锂离子电池正极材料LiCoO_2的制备及表征(英)

LiCoO2是锂离子电池中最有前途的正极材料之一;;近年来人们对它进行了广泛的研究.这里我们通过两种不同的湿化学方法首次合成了纳米级的LiCoO2:溶胶—凝胶法(方法B)和一种改进了的溶胶—凝胶法(方法C).为了便于比较;;我们也采用了固相反应法(方法A).用DTA;;IR;;XRD;;TEM等技术对前驱体和LiCoO2纳米颗粒进行了表征.结果表明在600?C煅烧时可以得到晶化程度较好的LiCoO2纳米颗粒.方法A和方法B得到了直径大约为100和40nm的球状颗粒;;而方法C主要得到球形颗粒;;同时伴有少量小棒形颗粒生成;;直径约为50nm.电化学测试表明方法C得到的产物具有最好的性能.

Preparation and characterization of nanosized LiCoO_2 with different methods

LiCoO2 is a promising positive electrode material in lithium-ion batteries, and it has been widely studied for many years. Here we prepared nanosized LiCoO2 with two di?erent wet-chemistry methods: sol-gel process (Method B) and improved sol-gel process (Method C). And for comparison: solid- state reaction (Method A) at low temperature was applied. Precursors and powders of nanosized LiCoO2 were characterized with Di?erential Thermal Analysis, Infrared, X-ray Di?raction, and Transmission Electron Microscope, respectively. The results showed that good crystalline, nano-scale LiCoO2 were obtained when ?red at 600?C. Method A and B produced spherical grain about 100 nm and 40 nm, while C mainly got spherical grain along with a small amount of particular stick grain, about 50 nm. Electrochemical tests showed the product of C has excellent characterization.