Ivanov Svetlozar, Mai Sebastian, Himmerlich Marcel, Dimitrova Anna, Krischok Stefan, Bund Andreas
Electrochemistry and Electroplating Group, Technische Universität Ilmenau, Ilmenau, 98693, Germany.
CERN, European Organization for Nuclear Research, Geneva, 1211, Switzerland.
Chemphyschem. 2019 Mar 4;20(5):655-664. doi: 10.1002/cphc.201801001. Epub 2019 Feb 12.
Electrochemical quartz crystal microbalance (EQCM) with damping monitoring is applied for real-time analysis of solid-electrolyte interphase (SEI) formation in diphenyl octyl phosphate (DPOP) and vinylene carbonate (VC) modified electrolytes. Fast SEI formation is observed for the DPOP containing electrolyte, whereas slow growth is detected in VC-modified and reference electrolytes. QCM measurements in a dry state show considerable reduction of the mass quantity for DPOP and reference samples and minor mass decrease for the SEI layer formed in the presence of VC. The results indicate that VC enhances SEI stability, whereas the addition of DPOP or no additive results in incorporation of loosely attached species, leadubg to SEI instability. Resonance frequency damping, Δw, and dissipation factor, D, are used for analyzing mechanical properties of the SEI layers. The apparent increase of Δw and D during SEI formation in presence of DPOP suggests a pronounced viscoelasticity of the layer. QCM results are compared with surface morphology and chemical composition, revealing excellent agreement of the applied characterization approaches.
采用带有阻尼监测的电化学石英晶体微天平（EQCM）对磷酸二苯辛酯（DPOP）和碳酸亚乙烯酯（VC）改性电解质中固体电解质界面（SEI）的形成进行实时分析。含DPOP的电解质中观察到快速的SEI形成，而在VC改性电解质和参比电解质中检测到缓慢生长。在干燥状态下的QCM测量表明，DPOP和参比样品的质量有显著减少，而在VC存在下形成的SEI层质量有轻微下降。结果表明，VC增强了SEI的稳定性，而添加DPOP或不添加添加剂会导致掺入松散附着的物种，导致SEI不稳定。共振频率阻尼Δw和耗散因子D用于分析SEI层的机械性能。在DPOP存在下SEI形成过程中Δw和D的明显增加表明该层具有明显的粘弹性。将QCM结果与表面形貌和化学成分进行比较，显示所应用的表征方法具有极好的一致性。
