Maibach Julia, Källquist Ida, Andersson Margit, Urpelainen Samuli, Edström Kristina, Rensmo Håkan, Siegbahn Hans, Hahlin Maria
Department of Chemistry - Ångström Laboratory, Uppsala University, Box 538, 751 21, Uppsala, Sweden.
Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
Nat Commun. 2019 Jul 12;10(1):3080. doi: 10.1038/s41467-019-10803-y.
Operando ambient pressure photoelectron spectroscopy in realistic battery environments is a key development towards probing the functionality of the electrode/electrolyte interface in lithium-ion batteries that is not possible with conventional photoelectron spectroscopy. Here, we present the ambient pressure photoelectron spectroscopy characterization of a model electrolyte based on 1M bis(trifluoromethane)sulfonimide lithium salt in propylene carbonate. For the first time, we show ambient pressure photoelectron spectroscopy data of propylene carbonate in the liquid phase by using solvent vapor as the stabilizing environment. This enables us to separate effects from salt and solvent, and to characterize changes in electrolyte composition as a function of probing depth. While the bulk electrolyte meets the expected composition, clear accumulation of ionic species is found at the electrolyte surface. Our results show that it is possible to measure directly complex liquids such as battery electrolytes, which is an important accomplishment towards true operando studies.
在实际电池环境中进行的常压光电子能谱分析是朝着探究锂离子电池中电极/电解质界面功能迈出的关键一步，而这是传统光电子能谱无法实现的。在此，我们展示了基于碳酸丙烯酯中1M双（三氟甲烷）磺酰亚胺锂盐的模型电解质的常压光电子能谱表征。首次通过使用溶剂蒸汽作为稳定环境，展示了液相中碳酸丙烯酯的常压光电子能谱数据。这使我们能够区分盐和溶剂的影响，并表征电解质组成随探测深度的变化。虽然本体电解质符合预期组成，但在电解质表面发现了离子物种的明显积累。我们的结果表明，可以直接测量诸如电池电解质之类的复杂液体，这是朝着真正的原位研究取得的一项重要成果。
