Maibach Julia, Xu Chao, Eriksson Susanna K, Åhlund John, Gustafsson Torbjörn, Siegbahn Hans, Rensmo Håkan, Edström Kristina, Hahlin Maria
Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala, Sweden.
Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
Rev Sci Instrum. 2015 Apr;86(4):044101. doi: 10.1063/1.4916209.
We report a methodology for a direct investigation of the solid/liquid interface using high pressure x-ray photoelectron spectroscopy (HPXPS). The technique was demonstrated with an electrochemical system represented by a Li-ion battery using a silicon electrode and a liquid electrolyte of LiClO4 in propylene carbonate (PC) cycled versus metallic lithium. For the first time the presence of a liquid electrolyte was realized using a transfer procedure where the sample was introduced into a 2 mbar N2 environment in the analysis chamber without an intermediate ultrahigh vacuum (UHV) step in the load lock. The procedure was characterized in detail concerning lateral drop gradients as well as stability of measurement conditions over time. The X-ray photoelectron spectroscopy (XPS) measurements demonstrate that the solid substrate and the liquid electrolyte can be observed simultaneously. The results show that the solid electrolyte interphase (SEI) composition for the wet electrode is stable within the probing time and generally agrees well with traditional UHV studies. Since the methodology can easily be adjusted to various high pressure photoelectron spectroscopy systems, extending the approach towards operando solid/liquid interface studies using liquid electrolytes seems now feasible.
我们报道了一种使用高压X射线光电子能谱（HPXPS）直接研究固/液界面的方法。该技术通过一个以锂离子电池为代表的电化学系统进行了演示，该电池使用硅电极和碳酸丙烯酯（PC）中的LiClO4液体电解质与金属锂进行循环。首次通过一种转移程序实现了液体电解质的存在，即在分析室中将样品引入2毫巴的N2环境中，而在负载锁中没有中间的超高真空（UHV）步骤。该程序在横向液滴梯度以及测量条件随时间的稳定性方面进行了详细表征。X射线光电子能谱（XPS）测量表明，可以同时观察到固体基底和液体电解质。结果表明，湿电极的固体电解质界面（SEI）组成在探测时间内是稳定的，并且总体上与传统的超高真空研究结果吻合良好。由于该方法可以很容易地应用于各种高压光电子能谱系统，因此现在似乎可以将该方法扩展到使用液体电解质的原位固/液界面研究。
