A high pressure x-ray photoelectron spectroscopy experimental method for characterization of solid-liquid interfaces demonstrated with a Li-ion battery system.
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.
Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala, Sweden.
Julia
J
Maibach
Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala, Sweden.
Chao
C
Xu
Department of Chemistry-Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala, Sweden.
Susanna K
SK
Eriksson
VG Scienta AB, Box 15120, SE-750 15 Uppsala, Sweden.
John
J
Åhlund
Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala, Sweden.
Torbjörn
T
Gustafsson
Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
Hans
H
Siegbahn
Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
Håkan
H
Rensmo
Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala, Sweden.
Kristina
K
Edström
Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
Maria
M
Hahlin