Low-Temperature Synthesis, Structural Characterization, and Electrochemistry of Ni-Rich Spinel-like LiNi2鈥搚MnyO4 (0.4 鈮?y 鈮?1)

详细信息    查看全文

• 作者：Wang Hay Kan ; Ashfia Huq ; Arumugam Manthiram
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：November 24, 2015
• 年：2015
• 卷：27
• 期：22
• 页码：7729-7733
• 全文大小：447K
• ISSN：1520-5002

文摘

The thermal conversion of chemically delithiated layered Li_0.5Ni_1鈥?i>yMn_yO₂ (0.2 鈮?y 鈮?0.5) into spinel-like LiNi_2鈥?i>yMn_yO₄ (0.4 鈮?y 鈮?1) has been systematically investigated. The formed spinel-like phases are metastable and cannot be accessed by a conventional high-temperature solid-state method. The layered-to-spinel transformation mechanism has been studied by the Rietveld refinement of in situ neutron diffraction as a function of temperature (25鈥?00 掳C). In particular, the ionic diffusion of Li and M ions is quantified at different temperatures. Electrochemistry of the metastable spinel-like phases obtained has been studied in lithium-ion cells. A bond valence sum map has been performed to understand the ionic diffusion of lithium ions in the Ni-rich layered, spinel, and rock-salt structures. The study can aid the understanding of the possible phases that could be formed during the cycling of Ni-rich layered oxide cathodes.