Direct visualization of solid electrolyte interphase on Li4Ti5O12 by in situ AFM
Direct visualization of solid electrolyte interphase on Li4Ti5O12 by in situ AFM
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DOI：
10.1039/c6ra16208h
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发表时间：
2016-08
期刊：
影响因子：
3.9
通讯作者：
Shuwei Wang;Kai Yang;Fei Gao;Deyu Wang;Cai Shen
中科院分区：
文献类型：
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作者：
Shuwei Wang;Kai Yang;Fei Gao;Deyu Wang;Cai Shen
由于该SEI层的脆弱性以及缺乏可靠的表征工具，Li4Ti5O12电极表面是否具有固体电解质中间相（SEI）层长期以来一直是争论的话题。在本文中，我们报告了通过电势控制下的原位原子力显微镜直接可视化 LTO 电极表面上的 SEI 层形成。我们的结果表明，在 2.5-1.0 V 的电势范围内，基于 EC/DMC 的电解质不会形成 SEI 层。然而，通过将还原电势降低至零，可以在 LTO 表面上生长 SEI 层。通过在第一个循环中将 LTO 阳极放电至 0 V，然后在 2.5-1.0 V 的正常范围内运行电池来形成 SEI 层的策略可能是提高 LTO 电池性能的简便方法。使用各种添加剂如碳酸亚乙烯酯(VC)、硫酸乙烯酯(ES)和氟代碳酸亚乙酯(FEC)作为添加剂来评价它们对SEI层形成的影响。
Whether Li4Ti5O12 has a solid electrolyte interphase (SEI) layer on the electrode surface has been the subject of controversy for a long time due to the delicate nature of this SEI layer and the lack of reliable characterization tools. In this paper, we report direct visualization of SEI layer formation on an LTO electrode surface by in situ atomic force microscopy under potential control. Our results showed that no SEI layer formed from EC/DMC based electrolyte in the potential range of 2.5–1.0 V. However, by extending the reduction potential down to zero, it is possible to grow a SEI layer on the LTO surface. The strategy of forming an SEI layer by discharging an LTO anode down to 0 V in the first cycle and then operating the battery in the normal range of 2.5–1.0 V might be a facile method to improve LTO battery performance. Various additives such as Vinylene Carbonate (VC), ethylene sulfate (ES) and fluoroethylene carbonate (FEC) were used as additives to evaluate their effect on SEI layer formation.