Measurement of three-dimensional microstructure in a LiCoO2 positive electrode
Measurement of three-dimensional microstructure in a LiCoO2 positive electrode
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DOI：
10.1016/j.jpowsour.2010.04.066
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发表时间：
2011-04-01
影响因子：
9.2
通讯作者：
Harris, Stephen J.
中科院分区：
文献类型：
--
作者：
Wilson, James R.;Cronin, J. Scott;Harris, Stephen J.
在这项工作中，我们利用聚焦离子束扫描电子显微镜阐明了新的商用锂离子电池正极中LiCoO2相的三维微观结构。颗粒具有高度不规则的形状，包括明显的内部裂纹。这些裂缝为锂电荷的转移提供了更高的表面积，并为锂在粒子内的传输提供了替代途径。此外，裂纹会极大地改变li插入过程中颗粒内部的应力分布，使颗粒更容易破裂。颗粒通常由多个颗粒组成，其边界也可能影响颗粒内锂离子传输和断裂强度。当颗粒相互接触时，接触的横截面积非常小，强调了粘合剂和导电碳对提供电极结构完整性的重要性。(C) 2010 Elsevier B.V.版权所有
In this work we elucidate the 3D microstructure of the LiCoO2 phase in a fresh commercial Li-ion battery positive electrode using a focused ion beam-scanning electron microscope. The particles have a highly irregular shape that includes significant internal cracking. These cracks provide a higher surface area for Li charge transfer, and they provide alternate pathways for Li transport within particles. In addition, the cracks would substantially alter the stress distributions within particles during Li-insertion and make the particles more susceptible to fracture. The particles were typically made up of multiple grains whose boundaries may also affect intraparticle Li-ion transport and fracture strength. While the particles do contact each other, the cross-sectional area of contact is quite small, emphasizing the importance of binder and conductive carbon for providing structural integrity to the electrode. (C) 2010 Elsevier B.V. All rights reserved.