Ions Transfer Behavior during water washing for LiNi0.815Co0.15Al0.035O2: Role of Excess Lithium
Ions Transfer Behavior during water washing for LiNi0.815Co0.15Al0.035O2: Role of Excess Lithium
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DOI：
10.1016/j.mtener.2020.100440
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发表时间：
2020-09
影响因子：
9.3
通讯作者：
X. Huang;J. Duan;J. He;H. Shi;Y. Li;Y. Zhang;D. Wang;P. Dong
中科院分区：
文献类型：
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作者：
X. Huang;J. Duan;J. He;H. Shi;Y. Li;Y. Zhang;D. Wang;P. Dong
富镍材料中的快速水分和二氧化碳吸收会劣化其加工性能、热稳定性和电化学性能。水洗是一种广泛使用的方法，可以有效地从这些材料中去除锂基残留物。本文对LiNi_（0.815）Co_（0.15）Al_（0.035）O_2（NCA）在洗涤过程中的离子行为进行了详细的研究。电感耦合等离子体原子发射光谱（ICP-AES）、扫描电子显微镜（SEM）和X射线光电子能谱（XPS）深度分布等表征表明，在铅洗过程中，NCA近表面有一定量的Li+和Al 3+流失，这是铅洗样品电化学性能和结构稳定性差的关键原因之一。NCA合成过程中混合和高温烧结时过量的LiOH·H2O比例对Al 3+的溶解率有显着影响，当锂过量比例达到10at.%时，Al 3+的损失率高达23.14%。对样品的电化学性能、结构、形貌和元素化学状态的表征分析表明，Li+和Al 3+从NCA中的溶出降低了材料的循环性能、结构稳定性和热稳定性。
Rapid moisture and carbon dioxide uptake in Ni-rich materials deteriorates their processing properties, thermal stability and electrochemical performance. Water washing is a widely used method to efficiently remove Li-based residues from these materials. In this paper, a detailed investigation of ion behavior during washing was carried out for LiNi0.815Co0.15Al0.035O2(NCA). Multiple characterizations including inductive coupled plasma atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) depth profiles show that certain amount of Li+and Al3+are lost from the near-surface of NCA during washing process, which is one of the key issues that lead washed samples suffer from poor electrochemical performance and structural stability. The excess LiOH·H2O ratio in mixing and high temperature sintering during NCA synthesis has a remarkable effect on the Al3+dissolution ratio, and the loss rate of Al3+is as high as 23.14% for lithium excess ratio up to 10 at.%. Characterization analyses of the electrochemical performance, structure, morphology and elemental chemical state of the samples demonstrate that the dissolution of Li+and Al3+from NCA deteriorates the cyclic performance, structural stability and thermal stability.