Naslov
Fingerprinting Mean Composition of Lithium Polysulfide Standard Solutions by Applying High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy

Autori
Robba, A. ; Barchasz, C. ; Bučar, K. ; Petric, M. ; Žitnik, M. ; Kvashnina, K. ; Vaughan, G. B. M. ; Bouchet, R. ; Alloin, F. ; Kavčič, M.

Izvornik
The Journal of Physical Chemistry Letters (1948-7185) 11 (2020), 14; 5446-5450

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Energy, Sulfur, Batteries, Absorption, Lithium

Sažetak
In a lithium/sulfur (Li/S) battery, the reduction of sulfur during discharge involves a particular mechanism, where the active material successively dissolves into the electrolyte to form lithium polysulfide intermediate species (Li2Sx), with x being a function of the state of charge. In this work, sulfur K-edge resonant inelastic X-ray scattering measurements were performed for the characterization of different Li2Sx polysulfide standard solutions. High-energy resolution fluorescence detected X-ray absorption spectroscopy allowed clear separation the pre-edge absorption peak corresponding to terminal sulfur atoms from the main absorption peak due to internal atoms and allowed quantitative evaluation of the evolution of the peak area ratio as a function of the polysulfide chain length. Results of this experimental work demonstrate that the normalized area of the pre-edge is a reliable fingerprint of the Li2Sx mean chain length in agreement with recent theoretical predictions. As a perspective, this work confirms that operando HERFD XAS can be used to differentiate mean polysulfide composition, which is key issue in the characterization of Li/S cells.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA