Adsorption of Dimethyl Sulfoxide on LiCoO2 Thin Films: Interface Formation Studied by Photoemission Spectroscopy
Adsorption of Dimethyl Sulfoxide on LiCoO2 Thin Films: Interface Formation Studied by Photoemission Spectroscopy
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DOI：
10.1021/acs.jpcc.6b05881
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发表时间：
2016-09
影响因子：
3.7
通讯作者：
Th Späth;M. Fingerle;N. Schulz;W. Jaegermann;R. Hausbrand
中科院分区：
文献类型：
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作者：
Th Späth;M. Fingerle;N. Schulz;W. Jaegermann;R. Hausbrand
电极-电解液界面的形成对锂离子电池的稳定性和性能至关重要。为了提高效率和寿命，有必要详细了解这些接口上的流程。两种化学反应都会导致界面层的形成和双层的形成，即带弯曲，这两种反应都会影响电池的性能。在这项贡献中，我们研究了薄膜LiCoO2正极材料和溶剂吸附物之间的界面形成。采用表面科学方法，以二甲基亚砜(DMSO，(CH3)2SO)为分子探针，在低温下逐步吸附在LiCoO2上。每一步后，用同步加速器软X射线光电子能谱(SXPS)分析界面。我们建立了LiCoO2DMSO界面的能级排列，表明正极材料中有一个向下弯曲的能带，这归因于锂离子进入吸附相。锂的输运导致了灰尘的形成。
The formation of electrode–electrolyte interfaces is of key importance for the stability and performance of lithium-ion batteries. To increase efficiency and lifetime, a detailed understanding of the processes at these interfaces is necessary. Both chemical reactions resulting in the formation of interface layers as well as double layer formation, i.e., band bending, influence the batteries’ properties. In this contribution, we investigate the interface formation between a thin film LiCoO2 cathode material and a solvent adsorbate. Using a surface-science approach, dimethyl sulfoxide (DMSO, (CH3)2SO) was used as molecular probe and adsorbed stepwise onto LiCoO2 at low temperature. After each step, the interface was analyzed by synchrotron-based soft X-ray photoemission spectroscopy (SXPS). We established the energy level alignment of the LiCoO2−DMSO interface, showing a band bending downward in the cathode material attributed to Li-ion transport into the adsorbate phase. Lithium transport results in the fo...