Magnetic and structural approach for understanding the electrochemical behavior of LiNi0.33Co0.33Mn0.33O2 positive electrode material
Magnetic and structural approach for understanding the electrochemical behavior of LiNi0.33Co0.33Mn0.33O2 positive electrode material
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DOI：
10.1016/j.electacta.2013.08.051
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发表时间：
2013-11
影响因子：
6.6
通讯作者：
M. Labrini;I. Saadoune;F. Scheiba;A. Almaggoussi;Jamal Elhaskouri;P. Amorós;H. Ehrenberg;J. Brötz-J.-Bröt
中科院分区：
文献类型：
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作者：
M. Labrini;I. Saadoune;F. Scheiba;A. Almaggoussi;Jamal Elhaskouri;P. Amorós;H. Ehrenberg;J. Brötz-J.-Bröt
系统研究了LiNiyMnyCo 1 - 2 yO 2系列化合物LiNi0.33Mn0.33Co0.33O2化学脱嵌锂后的结构和磁性变化。化学脱锂LixNi0.33Mn0.33Co0.33O2样品的结构表征表明，在整个0.3 ≤x≤ 1.0组成范围内，初始菱面体对称性（α-NaFeO 2型结构）保持不变。六边形晶胞体积的变化小于1%，表明该样品具有良好的结构稳定性。脱锂相的SEM照片证实了这种稳定性。结果表明，在x = 0.3时，LixNi_（0.33）Mn_（0.33）Co_（0.33）O_2的平均粒径从180 nm减小到130 nm.在去除锂后，观察到Ni 2+经由Ni 3+氧化成Ni 4+和Co 3+氧化成Co 4+的同时。EPR信号登记在100 K，再加上SQUID测量，揭示了强烈的反铁磁相互作用的结构内的这个样品变得更加明显的脱锂过程。
A systematic study has been performed to investigate the structural and magnetic changes in LiNi0.33Mn0.33Co0.33O2, a member of the LiNiyMnyCo1–2yO2series, upon chemical lithium deintercalation. Structural characterization of the chemically delithiated LixNi0.33Mn0.33Co0.33O2samples indicates that the initial rhombohedral symmetry (α-NaFeO2type structure) is maintained in the whole 0.3 ≤x≤ 1.0 composition range. Less than 1% variation in the hexagonal unit cell volume was evidenced showing a good structural stability of this sample. SEM pictures of the delithiated phases confirm this stability. Indeed, the particle size average undergoes a small decrease (from 180 nm atx= 1.0–130 nm forx= 0.3).The magnetic properties (SQUID and EPR) of LixNi0.33Mn0.33Co0.33O2compounds were also investigated. A simultaneous oxidation of Ni2+to Ni4+via Ni3+and Co3+to Co4+was observed upon lithium removal. EPR signals registered at 100 K, coupled to SQUID measurements, revealed strong antiferromagnetic interactions within the structure of this sample which became more pronounced by the delithiation process.