Characterization of Li–S Batteries Using Laboratory Sulfur X-ray Emission Spectroscopy

Abstract

Application of laboratory-based X-ray analytical techniques that are capable of a reliable characterization of the chemical state of sulfur within bulk battery cathode in parallel with electrochemical characterization is essential for further development of lithium–sulfur batteries. In this work, MeV proton-induced X-ray emission (XES) sulfur measurements were performed in ex situ mode on laboratory-synthesized sulfur standards and precycled battery cathodes. The average sulfur charge was determined from the energy shift of the Kα emission line and from the spectral shape of the Kβ emission spectrum. Finally, operando Kα XES measurements were performed to monitor reduction of sulfur within battery cathode during discharge. The experimental approach presented here provides an important step toward more routine laboratory analysis of sulfur-based battery systems and also other sulfur-neighboring low- Z bulk materials with emission energies in the tender X-ray range.

Operando Radiography and Multimodal Analysis of Lithium–Sulfur Pouch Cells—Electrolyte Dependent Morphology Evolution at the Cathode

“…Although a certain number of Li/S pouch cell studies [15,38,39] already exist, operando measurements with this cell type are rather the exception. Typically, applied methods cover UV-vis, [40,41] XRD, [42] XES, [43] and calorimetry. [44] To obtain a complete and more realistic picture of the relevant processes in a Li/S battery, we have developed a setup for pouch cells that allows simultaneous measurement of temperature distribution, pouch cell stack pressure, electrochemical impedance spectroscopy (EIS), and X-ray imaging during (dis-) charging.…”

“…Although a certain number of Li/S pouch cell studies [ 15,38,39 ] already exist, operando measurements with this cell type are rather the exception. Typically, applied methods cover UV–vis, [ 40,41 ] XRD, [ 42 ] XES, [ 43 ] and calorimetry. [ 44 ]…”

Characterization of Electrochemical Processes in Metal–Organic Batteries by X-ray Raman Spectroscopy

“…In the case of Li and Mg batteries, the cathodes were enclosed in a Swagelok type cells used in our previous studies on Li–S and Mg–S batteries. 19 , 20 A foil, composed of 120 μm polyethylene and 8 μm of Al to prevent outgassing, was used as an entrance/exit window for the beam, separating the cathode from ambient atmosphere. The Swagelok cell allowed for a relatively easy positioning and alignment of the sample relative to the incident beam by the motorized sample holder.…”

A parallel-beam wavelength-dispersive X-ray emission spectrometer for high energy resolution in-air micro-PIXE analysis

“…11 In our laboratory, a crystal spectrometer in Johansson geometry has been used for high energy resolution PIXE analysis with an energy resolution below the natural core-hole broadening, 12 and chemical speciation studies of low-Z elements in different materials have been performed. [13][14][15][16][17][18] Apart from their moderate efficiency, such spectrometers are also quite large, and require a complex alignment procedure and a xed beam spot, which is usually not compatible with ion microprobes. A compact at crystal WDS spectrometer coupled to an ion microprobe has been introduced recently, 19,20 mainly to perform chemical state analysis with focused ion beams and has not been used for PIXE mapping.…”