氨蒸发诱导法制备纳米结构LiNi1/3Co1/3Mn1/3O2及其作为高功率型锂离子电池正极材料的性能

摘要

采用氨蒸发诱导法成功制备出纳米结构LiNi1/3Co1/3Mn1/3O2正极材料，借助X射线衍射(XRD)分析、扫描电镜(SEM)、透射电镜(TEM)、高分辨率透射电镜(HRTEM)、能量分散谱(EDS)和比表面测试等表征手段及恒电流充放电测试研究了其晶体结构、微观形貌和电化学性能.研究表明该方法制备出的材料具有良好的α-NaFeO2层状结构，阳离子混排程度低.纳米片交错堆积而成核桃仁状形貌，片与片之间形成许多纳米孔，而且纳米片的侧面属于{010}活性面，能够提供较多的锂离子的脱嵌通道.在室温下及3.0-4.6 V充放电范围内，该材料在电流密度为0.5C、1C、3C、5C和10C时放电比容量分别为172.90、153.95、147.09、142.16和131.23 mAh∙g-1.说明其具有优异的电化学性能，非常有潜力用于动力汽车等高功率密度锂离子电池中.%We report on an ammonia-evaporation-induced synthetic method for nanostructured LiNi1/3Co1/3Mn1/3O2 cathode material. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Tel er nitrogen sorption, and galvanostatic charge-discharge tests were applied to analyze the crystal structure, micromorphology, and electrochemical properties of nanostructured LiNi1/3Co1/3Mn1/3O2. The results show that it has a wel-ordered layeredα-NaFeO2 with little cation mixing. A walnut-kernel-like morphology is formed by nanosheets, leading to a nanoporous material. The lateral plane of nanosheets are{010}-faceted, which could provide multiple channels for Li+-ion migration. The electrochemical properties of the lithium cells used this material as cathode are excellent:the specific discharge capacity at 0.5C, 1C, 3C, 5C and 10C is, respectively, up to 172.90, 153.95, 147.09, 142.16, and 131.23 mAh∙g-1 between 3.0 and 4.6 V at room temperature. These excellent features wil make the nanostructured LiNi1/3Co1/3Mn1/3O2 become a positive electrode material of potential interest for useful applications, such as in electric vehicles and hybrid electric vehicles.