Li1.20Mn0.54Co0.13Ni0.13O2 with Different Particle Sizes as Attractive Positive Electrode Materials for Lithium-Ion Batteries: Insights into Thei

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• 作者：Hideyuki Koga ; Laurence Croguennec ; Philippe Mannessiez ; Michel M茅n茅trier ; Fran莽ois Weill ; Lydie Bourgeois ; Mathieu Duttine ; Emmanuelle Suard ; Claude Delmas
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：June 28, 2012
• 年：2012
• 卷：116
• 期：25
• 页码：13497-13506
• 全文大小：512K
• 年卷期：v.116,no.25(June 28, 2012)
• ISSN：1932-7455

文摘

The effect of the synthesis temperature on the chemical composition of 鈥淟i_1.20Mn_0.54Co_0.13Ni_0.13O₂鈥?was considered using thermogravimetric analyses (TGA) and in situ X-ray diffraction (XRD) during thermal treatment. A continuous and small weight loss is observed above 800 掳C because of Li evaporation, and the lamellar phase disappears to the benefit of a spinel-type phase formed above 940 掳C. The layered structure is recovered upon cooling under air. 鈥淟i_1.20Mn_0.54Co_0.13Ni_0.13O₂鈥?materials synthesized at 800, 900, and 1000 掳C show very similar compositions, structures, and electrochemical properties despite very different crystallization states. Their average structure is 伪-NaFeO₂-type and described in the R3̅m space group, with less than 0.02 Ni²⁺ ions in the Li site. This peculiar composition 鈥淟i_1.20Mn_0.54Co_0.13Ni_0.13O₂鈥? with one-third of large cations (Li⁺, Ni²⁺) and two-thirds of small cations (Mn⁴⁺, Co³⁺) promotes the extension of the cation ordering in the slabs as revealed by the 鈭?a_hex. 脳 鈭?a_hex. superstructure, but without full correlation between the ordered slabs along the c_hex. stacking axis. Neutron and electron diffraction associated with NMR and Raman spectroscopies are shown to be efficient tools to get more insights into the average and local structures of these complex layered materials.