Title: Synthetic Control of Kinetic Reaction Pathway and Cationic Ordering in High-Ni Layered Oxide Cathodes
Author: Dawei Wang, Ronghui Kou, Yang Ren, Cheng-Jun Sun, Hu Zhao, Ming-Jian Zhang, Yan Li, Ashifia Huq, J. Y. Peter Ko, Feng Pan, Yang-Kook Sun, Yong Yang*, Khalil Amine*, Jianming Bai*, Zonghai Chen, Feng Wang*
Summary:
Nickel-rich layered transition metal oxides, LiNi1−x(MnCo)xO2 (1−x ≥ 0.5), are appealing candidates for cathodes in next-generation lithium-ion batteries (LIBs) for electric vehicles and other large-scale applications, due to their high capacity and low cost. However, synthetic control of the structural ordering in such a complex quaternary system has been a great challenge, especially in the presence of high Ni content. Herein, synthesis reactions for preparing layered LiNi0.7Mn0.15Co0.15O2 (NMC71515) by solid-state methods are investigated through a combination of time-resolved in situ high-energy X-ray diffraction and absorption spectroscopy measurements. The real-time observation reveals a strong temperature dependence of the kinetics of cationic ordering in NMC71515 as a result of thermal-driven oxidation of transition metals and lithium/oxygen loss that concomitantly occur during heat treatment. Through synthetic control of the kinetic reaction pathway, a layered NMC71515 with low cationic disordering and a high reversible capacity is prepared in air. The findings may help to pave the way for designing high-Ni layered oxide cathodes for LIBs.
Full Link: http://onlinelibrary.wiley.com/doi/10.1002/adma.201606715/full
