Depth-resolved X-ray absorption spectroscopic study on nanoscale observation of the electrode-solid electrolyte interface for all solid state lithium ion batteries
Depth-resolved X-ray absorption spectroscopic study on nanoscale observation of the electrode-solid electrolyte interface for all solid state lithium ion batteries
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DOI：
10.1039/c0jm04366d
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发表时间：
2011-01-01
影响因子：
--
通讯作者：
Ogumi, Zempachi
中科院分区：
文献类型：
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作者：
Okumura, Toyoki;Nakatsutsumi, Takayuki;Ogumi, Zempachi
利用深度分辨x射线吸收光谱（DR-XAS）直接观察LiCoO(2)电极-固体电解质模型界面的化学状态和局部结构，有助于提高所有固态锂电池的功率密度。交流阻抗谱法测定LiCoO(2)电极-固体电解质界面的电荷转移电阻随着NbO(2)中间层的加入而减小，而随着ZrO(2)和MoO(2)中间层的加入而增大。利用深度分辨率约为7 nm的DR-XAS，研究了LiCoO(2)电极的电子结构和局部结构的变化。DR-XAS的扩展x射线吸收精细结构表明，NbO(2)层的引入有效地限制了衰减过程中界面处Co-O键的大变化。该中间层减轻了氧化过程中LiCoO(2)体积变化引起的界面应力，降低了电荷转移过程的活化能。
Depth-resolved X-ray absorption spectroscopy (DR-XAS) measurements were performed for the direct observation of the chemical state and local structure at the LiCoO(2) electrode-solid electrolyte model interface, which can contribute towards the enhancement of the power density in all solid-state lithium batteries. The charge transfer resistance, measured by AC impedance spectroscopy, of the LiCoO(2) electrode-solid electrolyte interface decreased with the introduction of a NbO(2) interlayer at the interface, while the resistance increased with ZrO(2) and MoO(2) interlayers. Using DR-XAS with a depth resolution of about 7 nm, the changes in electronic structure and local structure of the LiCoO(2) electrode were clarified. The extended X-ray absorption fine structure of DR-XAS revealed that the introduction of the NbO(2) layer is effective for restricting the large Co-O bond change at the interface during delithiation. This interlayer relieved the stress at the interface due to the volume change of LiCoO(2) during delithiation and then decreased the activation energy for the charge transfer process.