Comparative study of Li[Co1−zAlz]O2 prepared by solid-state and co-precipitation methods
Comparative study of Li[Co1−zAlz]O2 prepared by solid-state and co-precipitation methods
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DOI：
10.1016/j.electacta.2009.03.068
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发表时间：
2009-08
影响因子：
6.6
通讯作者：
Wenbin Luo;J. Dahn
中科院分区：
文献类型：
--
作者：
Wenbin Luo;J. Dahn
采用共沉淀法和固相法制备了Li[Co 1 −zAlz]O2（0≤z≤0.5）样品。对于共沉淀样品，晶格常数随z平滑地变化，但对于高于z=0.2的固态样品，晶格常数偏离。当铝含量大或当加热持续时间太短时，固态方法可能不能产生具有均匀阳离子分布的材料。采用共沉淀法合成了不同名义组成x=Li/（Co+Al）=0.95，1.0，1.1，1.2，1.3的非化学计量比Lix[Co0.9Al0.1] O2样品。Lix[Co0.9Al0.1] O2样品的XRD图谱表明固溶极限在Li/（Co+Al）=1.1和1.2之间。Li[Co 1 −zAlz] O2样品的电化学研究用于测量容量随Al含量的降低速率，发现约为−250±30（mAh/g）/（z=1）。关于Li[Ni 1/3 Mn 1/3Co 1/3−zAlz]O2、Li[Ni 1 −zAlz] O2和Li[Mn 2 −yAly] O 4的文献工作证明了容量随Al/（Al+M）比率的降低率相同。这些研究作为样品的基线表征，用于确定铝含量对电解质中脱锂Li[Co 1 −zAlz] O2热稳定性的影响。
Li[Co1−zAlz]O2(0≤z≤0.5) samples were prepared by co-precipitation and solid-state methods. The lattice constants varied smoothly with z for the co-precipitated samples but deviated for the solid-state samples above z=0.2. The solid-state method may not produce materials with a uniform cation distribution when the aluminum content is large or when the duration of heating is too brief. Non-stoichiometric Lix[Co0.9Al0.1]O2samples were synthesized by the co-precipitation method at various nominal compositions x=Li/(Co+Al)=0.95, 1.0, 1.1, 1.2, 1.3. XRD patterns of the Lix[Co0.9Al0.1]O2samples suggest the solid solution limit is between Li/(Co+Al)=1.1 and 1.2. Electrochemical studies of the Li[Co1−zAlz]O2samples were used to measure the rate of capacity reduction with Al content, found to be about −250±30 (mAh/g)/(z=1). Literature work on Li[Ni1/3Mn1/3Co1/3−zAlz]O2, Li[Ni1−zAlz]O2and Li[Mn2−yAly]O4demonstrates the same rate of capacity reduction with Al/(Al+M) ratio. These studies serve as baseline characterization of samples to be used to determine the impact of Al content on the thermal stability of delithiated Li[Co1−zAlz]O2in electrolyte.