Study of the Hydrate-Melt/Li4Ti5O12 Interphase by Scanning Electron Microscopy-Based Spectroscopy
Study of the Hydrate-Melt/Li4Ti5O12 Interphase by Scanning Electron Microscopy-Based Spectroscopy
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DOI：
10.1021/acs.langmuir.7b03066
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发表时间：
2017-12-12
期刊：
影响因子：
3.9
通讯作者：
Kohyama, Masanori
中科院分区：
文献类型：
--
作者：
Kitta, Mitsunori;Taguchi, Noboru;Kohyama, Masanori
To develop safe and low-cost Li-ion batteries (LIBs), recently, an aqueous-based electrolyte so-called "hydrate-melt" (HDM) electrolyte is proposed. Li4Ti5O12 is a promising negative electrode material for a LIB with such a HDM electrolyte because of its unexpected reversible Li insertion and extraction properties without usually inevitable water reduction. The solid-electrolyte interphase formation is one of the reasons for this stable reaction, although a detailed analysis is not yet performed. Here, a Li4Ti5O12 electrode surface reacted in a HDM electrolyte is investigated by scanning electron microscopy-based analysis. Surface reaction products are clearly observed on the Li4Ti5O12 surface after the Li insertion reaction in a HDM electrolyte. Energy-dispersive X-ray spectroscopy and Auger electron spectroscopy indicated that the products do not contain any components originated from Li salts, whereas anion-derived passivation films seem to cover a bare surface below the products. Further, the surface products are identified as Li2O by the feature of Li-K-edge reflection electron energy-loss spectrum. The Li2O formation would be one of the key issues for stable Li insertion and extraction of a Li4Ti5O12 electrode in a HDM electrolyte.
