纳米级锂离子电池正极材料LiCoO2的制备及表征

摘要

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 different wet-chemistry methods: sol-gel process (Method B) and improved sol-gel process (Method C). And for comparison: solidstate reaction (Method A) at low temperature was applied. Precursors and powders of nanosized LiCoO2 were characterized with Differential Thermal Analysis, Infrared, X-ray Diffraction, and Transmission Electron Microscope, respectively. The results showed that good crystalline, nano-scale LiCoO2 were obtained when fired at 600℃. 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.%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℃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50 nm.电化学测试表明方法C得到的产物具有最好的性能.