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

Synthesis of Nanostructured LiNi_(1/3)Co_(1/3)Mn-(1/3)O-2 by AmmoniaEvaporation-Induced Synthesis and Its Electrochemical Properties as a Cathode Material for a High-Power Li-Ion Battery

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131.23mAh?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）, highresolution transmission electron microscopy （HRTEM）, energydispersive X-ray spectroscopy （EDS）, Brunauer-Emmett-Teller nitrogen sorption, and galvanostatic chargedischarge 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 wellordered layered α-NaFeO2 with little cation mixing. Awalnut- 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,1 C, 3C, 5C and 100 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 will 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.