Identification of Li-Ion Battery SEI Compounds through 7Li and 13C Solid-State MAS NMR Spectroscopy and MALDI-TOF Mass Spectrometry

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• 作者：Laura A. Huff ; Hadi Tavassol ; Jennifer L. Esbenshade ; Wenting Xing ; Yet-Ming Chiang ; Andrew A. Gewirth
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：January 13, 2016
• 年：2016
• 卷：8
• 期：1
• 页码：371-380
• 全文大小：476K
• ISSN：1944-8252

文摘

Solid-state ⁷Li and ¹³C MAS NMR spectra of cycled graphitic Li-ion anodes demonstrate SEI compound formation upon lithiation that is followed by changes in the SEI upon delithiation. Solid-state ¹³C DPMAS NMR shows changes in peaks associated with organic solvent compounds (ethylene carbonate and dimethyl carbonate, EC/DMC) upon electrochemical cycling due to the formation of and subsequent changes in the SEI compounds. Solid-state ¹³C NMR spin–lattice (T₁) relaxation time measurements of lithiated Li-ion anodes and reference poly(ethylene oxide) (PEO) powders, along with MALDI-TOF mass spectrometry results, indicate that large-molecular-weight polymers are formed in the SEI layers of the discharged anodes. MALDI-TOF MS and NMR spectroscopy results additionally indicate that delithiated anodes exhibit a larger number of SEI products than is found in lithiated anodes.