Operando soft x-ray emission spectroscopy of LiMn2O4 thin film involving Li-ion extraction/insertion reaction
Operando soft x-ray emission spectroscopy of LiMn2O4 thin film involving Li-ion extraction/insertion reaction
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DOI：
10.1016/j.elecom.2014.09.015
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发表时间：
2015-01-01
影响因子：
5.4
通讯作者：
Harada, Yoshihisa
中科院分区：
文献类型：
--
作者：
Asakura, Daisuke;Hosono, Eiji;Harada, Yoshihisa
为了准确研究锂离子电池正极材料中过渡金属的氧化还原反应和电子结构，研制了一种用于软X射线发射光谱（XES）的电化学原位电池。原位电池由Li金属对电极、有机电解质溶液和膜窗口上的阴极组成，该膜窗口将液体电解质与高真空分开，并且可以使入射和发射的光子通过。在这项研究中，Mn的3d电子结构的LiMn 204薄膜电极是明确的操作数XES。在充电状态下，XES光谱从开路电压（OCV）状态显著改变，表明通过Li离子提取的Mn 3+组分的氧化。在放电至相对于Li/Li+的3.0V时，XES光谱几乎返回到其在OCV状态下的曲线，具有小的差异，表明Mn的价态变化：Mn 3.6 + -> Mn 4 + -> Mn 33+对应于OCV、充电和放电状态。(C)2014爱思唯尔有限公司版权所有。
We developed an electrochemical in situ cell for soft x-ray emission spectroscopy (XES) to accurately investigate the redox reaction and electronic structure of transition metals in the cathode materials for Li-ion battery. The in situ cell consists of a Li-metal counter electrode, an organic electrolyte solution, and a cathode on a membrane window which separates the liquid electrolyte from high vacuum and can pass the incoming and emitted photons. In this study, the Mn 3d electronic structure of LiMn204 thin-film electrode was clarified by the operand XES. At the charged state, the XES spectrum changed significantly from the open-circuit-voltage (OCV) state, suggesting oxidation of the Mn3+ component through Li-ion extraction. Upon discharge up to 3.0 V vs. Li/Li+, the XES spectrum almost returned to its profile at the OCV state with small difference, indicating the valence change of Mn: Mn3.6+ -> Mn4+ -> Mn33+ corresponding to the OCV, charged, and discharged states. (C) 2014 Elsevier B.V. All rights reserved.