Wet Nanoindentation of the Solid Electrolyte Interphase on Thin Film Si Electrodes

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• 作者：Volodymyr Kuznetsov ; Arndt-Hendrik Zinn ; Giorgia Zampardi ; Sara Borhani-Haghighi ; Fabio La Mantia ; Alfred Ludwig ; Wolfgang Schuhmann ; Edgar Ventosa
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：October 28, 2015
• 年：2015
• 卷：7
• 期：42
• 页码：23554-23563
• 全文大小：594K
• ISSN：1944-8252

文摘

The solid electrolyte interphase (SEI) film formed at the surface of negative electrodes strongly affects the performance of a Li-ion battery. The mechanical properties of the SEI are of special importance for Si electrodes due to the large volumetric changes of Si upon (de)insertion of Li ions. This manuscript reports the careful determination of the Young鈥檚 modulus of the SEI formed on a sputtered Si electrode using wet atomic force microscopy (AFM)-nanoindentation. Several key parameters in the determination of the Young鈥檚 modulus are considered and discussed, e.g., wetness and roughness鈥搕hickness ratio of the film and the shape of a nanoindenter. The values of the Young鈥檚 modulus were determined to be 0.5鈥?0 MPa under the investigated conditions which are in the lower range of those previously reported, i.e., 1 MPa to 10 GPa, pointing out the importance of the conditions of its determination. After multiple electrochemical cycles, the polymeric deposits formed on the surface of the SEI are revealed, by force-volume mapping in liquid using colloidal probes, to extend up to 300 nm into bulk solution.