Kinetics Tuning of Li-Ion Diffusion in Layered Li(NixMnyCoz)O2

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• 作者：Yi Wei ; Jiaxin Zheng ; Suihan Cui ; Xiaohe Song ; Yantao Su ; Wenjun Deng ; Zhongzhen Wu ; Xinwei Wang ; Weidong Wang ; Mumin Rao ; Yuan Lin ; Chongmin Wang ; Khalil Amine ; Feng Pan
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：July 8, 2015
• 年：2015
• 卷：137
• 期：26
• 页码：8364-8367
• 全文大小：284K
• ISSN：1520-5126

文摘

Using ab initio calculations combined with experiments, we clarified how the kinetics of Li-ion diffusion can be tuned in LiNi_xMn_yCo_zO₂ (NMC, x + y + z = 1) materials. It is found that Li-ions tend to choose oxygen dumbbell hopping (ODH) at the early stage of charging (delithiation), and tetrahedral site hopping (TSH) begins to dominate when more than 1/3 Li-ions are extracted. In both ODH and TSH, the Li-ions surrounded by nickel (especially with low valence state) are more likely to diffuse with low activation energy and form an advantageous path. The Li slab space, which also contributes to the effective diffusion barriers, is found to be closely associated with the delithiation process (Ni oxidation) and the contents of Ni, Co, and Mn.