锂过量层状有序/无序锂离子电池正极材料因具有出色的电化学性能而被人们广泛关注,并成为研究热点之一.所有该类型材料可以被表述为Li1+xM1-xO2(M是一种或一种以上的过渡金属元素,x≥0).但M通常是多个金属元素比如M=Ni1-x-yCoxMny,一些金属元素在材料中也可以具有多种价态形式例如Ni和Mn,而且可有不同的层间/层内阳离子有序.这种材料的成分、结构复杂性以及化合价多变性极容易引起读者理解上的混淆.目前文献中对此类材料的本质的理解仍不够清晰准确.在一些报道中甚至错误地翻译了一些材料的本质,而且已被报道的很多材料本质上可归结为同一类固溶体材料.本文在准确理解此类材料的结构定义基础上,首先用LiAO2-Li2BO3固溶体概念诠释此类材料的本质.结合我们的研究结果,进一步讨论怎样利用相图帮助理解和设计此类材料,并评述它们的最新研究进展.%Recently, Li excess (or Li-rich) layered ordered/disordered materials for Li-ion battery exhibited amazing electrochemical performances and thus received extensive attention. They all can be formulated as Li1 +x M1 -xO2 (M can be one or multi-metal ions, x ≥0). However, the complexity of composition and structure in most of Li1 +xM1-xO2 compounds ( M usually represents multi-metal ions such as M = Ni1 -x-yCoxMny and materials can present different interlayer/intralayer cations ordering in structure) and variability of valence in some metal ions (different valences in some metals ions such as Ni and Mn may form depending on conditions) easily make readers confused in understanding nature of those materials. The clear interpretation of those materials' nature in references is still not enough at present and even some materials were misinterpreted in some references. In this review, on the basis of their structure, the nature of Li excess ( or Li-rich) layered ordered/disordered materials was firstly described precisely according to LiAO2-Li2BO3 solid solution. In combination with our research results, it was further discussed how to utilize phase diagram to assist readers to understand those complicated Li1+x M1-x O2 materials and further design new compounds. Some recent important progress on these materials was also commented.
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