In-Depth Interfacial Chemistry and Reactivity Focused Investigation of Lithium–Imide- and Lithium–Imidazole-Based Electrolytes

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• 作者：Gebrekidan Gebresilassie Eshetu ; Thomas Diemant ; Sylvie Grugeon ; R. Jürgen Behm ; Stephane Laruelle ; Michel Armand ; Stefano Passerini
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：June 29, 2016
• 年：2016
• 卷：8
• 期：25
• 页码：16087-16100
• 全文大小：867K
• 年卷期：0
• ISSN：1944-8252

文摘

A comparative and in-depth investigation on the reactivity of various Li-based electrolytes and of the solid electrolyte interface (SEI) formed at graphite electrode is carried out using X-ray photoelectron spectroscopy (XPS), chemical simulation test, and differential scanning calorimetry (DSC). The electrolytes investigated include LiX (X = PF₆, TFSI, TDI, FSI, and FTFSI), dissolved in EC-DMC. The reactivity and SEI nature of electrolytes containing the relatively new imide (LiFSI and LiFTFSI) and imidazole (LiTDI) salts are evaluated and compared to those of well-researched LiPF₆⁻ and LiTFSI-based electrolytes. The thermal reactivity of Li_xC₆ in the various electrolytes is found to be in the order of LiFSI > LiTDI > LiTFSI > LiFTFSI > LiPF₆ and LiFSI > LiFTFSI > LiPF₆ > LiTFSI > LiTDI in terms of onset exothermic temperature and total heat generated, respectively. Surface and depth-profiling XPS analysis of the SEI formed with the diverse electrolyte formulations provide insight into the differences and similarities (composition, thickness, and evolution, etc.) emanating from the structure of the various salt anions.