Multinuclear NMR Study of the Solid Electrolyte Interface on the Li-FeSn2 Negative Electrodes for Li-Ion Batteries

详细信息    查看全文

• 作者：Hua Huo ; Mohamad Chamas ; Pierre-Emmanuel Lippens ; Michel M茅n茅trier
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：January 26, 2012
• 年：2012
• 卷：116
• 期：3
• 页码：2390-2398
• 全文大小：462K
• 年卷期：v.116,no.3(January 26, 2012)
• ISSN：1932-7455

文摘

The composition of the solid electrolyte interface (SEI) layer on the Li-FeSn₂ negative electrode has been determined by a multinuclear solid state NMR study. The strong e-nuclear dipolar and contact interactions between the as-formed superparamagnetic Fe nanoparticles and the SEI layer allows a layer wise observation highly depending on the proximity. Li⁺ from LiPF₆, which is traditionally considered as a postdeposited product from the electrolyte solution,has been observed as presenting different solvation states by ¹⁹F 鈫?⁷Li cross polarization magic angle spinning (CPMAS) NMR. Direct contact between LiOH and Li_xSn or Fe nanoparticles is suggested by Fermi-Contact shifts of 鈭?1 and 鈭? ppm observed in ⁷Li and ¹H NMR spectra, respectively. The Li_xSn alloy signal remains invisible to ⁷Li NMR due to the close proximity to the Fe nanoparticles. Effects of different discharging rates and aging at the discharge state are discussed as well.