Temperature dependence of the passivation layer on graphite
Temperature dependence of the passivation layer on graphite
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DOI：
10.1016/s0378-7753(99)00202-5
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发表时间：
1999-09-01
影响因子：
9.2
通讯作者：
Wendsjö, Å
中科院分区：
文献类型：
--
作者：
Andersson, AM;Edström, K;Wendsjö, Å
研究了第一次充放电循环中在石墨表面形成的固体电解质界面(SEI)的高温稳定性。这样做是为了确定它在C/LiMn2O4锂离子电池中发生的高温降解过程中的作用。用X射线光电子能谱(XPS)研究了不同热处理条件下石墨电极的表面层生长和元素组成。当储存在60摄氏度以下时，循环电极的表面被认为与未储存电极的表面非常相似。储存在60摄氏度下的电极显示出氧化的碳和氧的量显著增加。Ar溅射分析表明，石墨电极表面覆盖了一层厚厚的宏观层，但没有覆盖分离的石墨颗粒；这与观察到的容量迅速下降和储存后循环此类电池的大电池电阻是一致的。在RT和40℃下储存的细胞没有观察到这种容量下降。(C)1999 Elsevier Science S.A.保留所有权利。
The elevated temperature stability of the Solid Electrolyte Interface (SEI) formed on graphite during the first charge/discharge cycle has been investigated. This was done in order to determine its role in the high-temperature degradation process which occurs in a C/LiMn2O4 Li-ion cell. X-ray photoelectron spectroscopy (XPS) is used to probe the surface-layer growth and elemental composition of graphite electrodes exposed to different thermal treatment. The surfaces of cycled electrodes, when stored below 60 degrees C, were seen to resemble closely those of unstored electrodes. An electrode stored at 60 degrees C exhibited a significant increase in the amount of oxidized carbon and oxygen. Analysis by Ar sputtering suggests that a thick 'macroscopic' layer coats the graphite electrode surface, but not the separate graphite grains; this is consistent with the observed rapid decrease in capacity and large cell-resistance on cycling such cells after storage. This capacity decrease was not observed for the cells stored at RT and 40 degrees C. (C) 1999 Elsevier Science S.A. All rights reserved.