Department of Electronic Chemistry, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8502, Japan.
Phys Chem Chem Phys. 2010 Apr 21;12(15):3815-23. doi: 10.1039/b920271d. Epub 2010 Feb 24.
Surface and bulk structural changes of LiNi(0.5)Mn(0.5)O(2) were investigated during electrochemical reaction using synchrotron X-ray scattering and a restricted reaction plane consisting of two-dimensional epitaxial-film electrodes. The changes in bulk structure confirmed lithium diffusion through the (110) surface, which was perpendicular to the two-dimensional (2D) edges of the layered structure. No (de)intercalation reaction was observed through the (003) surface at voltages of 3.0-5.0 V. However, intercalation did proceed through the (003) plane below 3.0 V, indicating unusual three-dimensional (3D) lithium diffusion in the over-lithiated 2D structure. During the electrochemical process, the surface of the electrode showed different structure changes from those of the bulk structure. The reaction mechanism of the intercalation electrodes for lithium batteries is discussed on the basis of surface and bulk structural changes.
采用同步辐射 X 射线散射和二维外延薄膜电极组成的受限反应面研究了 LiNi(0.5)Mn(0.5)O(2) 在电化学过程中的表面和体相结构变化。体相结构的变化证实了锂离子通过垂直于层状结构二维（2D）边缘的（110）表面扩散。在 3.0-5.0 V 的电压下，未观察到通过（003）表面的（脱）插层反应。然而，在 3.0 V 以下，插层确实通过（003）平面进行，表明在过锂化的 2D 结构中存在异常的三维（3D）锂离子扩散。在电化学过程中，电极的表面表现出与体相结构不同的结构变化。根据表面和体相结构变化，讨论了锂离子电池插层电极的反应机制。
