Understanding the effect of Nb substitution on Li-Mn-rich layered oxides
Understanding the effect of Nb substitution on Li-Mn-rich layered oxides
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DOI：
10.1016/j.electacta.2021.138801
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发表时间：
2021-07-04
影响因子：
6.6
通讯作者：
Li, Jie
中科院分区：
文献类型：
--
作者：
Brinkmann, Jan-Paul;Rodehorst, Uta;Li, Jie
用4d/5d-元素取代最近已被确立为用于抑制锂离子电池的富含Li-Mn的层状氧化物阴极中的容量和电压衰减的有前景的解决方案。本研究旨在通过对一种无Nb取代Co的材料Li（1.2）ZNi0.2Mn0.6O2的系统研究来理解这一概念的基本工作原理。通过XRD证实Nb位于复合材料的C/2 m相的过渡金属层中Li的位置，从而显著增加活化动力学。由于取代，该材料经历了更大程度的可逆阴离子氧化还原活性，同时它还获得了增加的热稳定性，并且在循环期间显示出比原始材料更少的氧损失。此外，取代还通过提高材料的能量效率来改善电化学性能。这项研究提供了深入了解Nb替代的影响，并可能是一个有用的指导研究的其他替代元素和正在进行的改进，富锂锰层状氧化物阴极。(C)2021爱思唯尔有限公司保留所有权利。
Substitution with 4d/5d-elements has been recently established as promising solution for suppressing capacity and voltage fading in Li-Mn-rich layered oxide cathodes for lithium ion batteries. This study aims at understanding of the underlying working principles of this concept through a systematic study on an Nb substituted Co-free material, i.e. Li(1.2)Z Ni0.2Mn0.6O2. Nb is confirmed by XRD to be located at the position of Li in the transition metal layer of the C/2 m phase of the composite material thereby increasing the kinetics of activation significantly. Due to substitution, the material experiences a lager extent of reversible anionic redox activity while it also gains an increased thermal stability and shows less oxygen loss than the pristine material during cycling. In addition, substitution also improves the electrochemical performance by increasing the energy efficiency of the material. This study provides insights into the effects of Nb substitution and could be a useful guide for the study of other substitution elements and the ongoing improvement of Li-Mn-rich layered oxide cathodes. (C) 2021 Elsevier Ltd. All rights reserved.