4861. The mechanism of Li2S activation in lithium-sulfur batteries: Can we avoid the polysulfide formation?Alen Vižintin, Laurent Chabanne, Elena Tchernychova, Iztok Arčon, Lorenzo Stievano, Giuliana Aquilanti, Markus Antonietti, Tim-Patric Fellinger, Robert Dominko, 2017, original scientific article Abstract: Electrochemical reactions in the LieS batteries are considered as a multistep reaction process with at least
2e3 equilibrium states. Here we report a possibility of having a conversion of Li2S into sulfur without
detectible formation of polysulfides. That was confirmed by using a novel material system consisting of
carbon coated Li2S particles prepared by carbothermal reduction of Li2SO4. Two independent in operando
measurements showed direct oxidation of Li2S into sulfur for this system, with almost negligible formation
of polysulfides at potentials above 2.5 V vs. Li/Liþ. Our results link the diversity of first charge profiles in the
literature to the Li2S oxidation mechanism and show the importance of ionic wiring within the material.
Furthermore, we demonstrate that the Li2S oxidation mechanism depends on the relative amount of
soluble sulfur in the electrolyte. By controlling the type and the amount of electrolyte within the encapsulating
carbon shell, it is thereby possible to control the reaction mechanism of Li2S activation. Keywords: Lithium-sulfur batteries
Li2S active material
XAS
UV/Vis spectroscopy
Li2S activation Published in RUNG: 03.03.2017; Views: 5238; Downloads: 0 This document has many files! More... |
4862. Operando characterization of batteries using x-ray absorption spectroscopy: advances at the beamline XAFS at synchrotron ElettraGiuliana Aquilanti, marco Giorgetti, Robert Dominko, Lorenzo Stievano, Iztok Arčon, Nicola Novello, Luca Ivanc Olivieri, 2017, original scientific article Abstract: X-ray absorption spectroscopy is a synchrotron radiation based technique that is able to
provide information on both local structure and electronic properties in a chemically selective
manner. It can be used to characterize the dynamic processes that govern the electrochemical
energy storage in batteries, and to shed light on the redox chemistry and changes in structure
during galvanostatic cycling to design cathode materials with improved properties. Operando
XAS studies have been performed at beamline XAFS at Elettra on different systems. For
Li-ion batteries, a multiedge approach revealed the role of the different cathode components
during the charge and discharge of the battery. In addition, Li-S batteries for automotive
applications were studied. Operando sulfur K-edge XANES and EXAFS analysis was used to
characterize the redox chemistry of sulfur, and to relate the electrochemical mechanism to its
local structure. Keywords: operando studies, x-ray absorption spectroscopy, Li-ion batteries, Li-S batteries Published in RUNG: 03.03.2017; Views: 6214; Downloads: 0 This document has many files! More... |
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4864. Construction of a Medium-Sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array: Implementation of the Cherenkov-Camera Data Acquisition SystemM. Santander, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2015, published scientific conference contribution Keywords: Cherenkov Telescope Array (CTA), double-mirror Schwarzschild-Couder medium-size telescopes
(MST-2M) for CTA, data acquisition system Published in RUNG: 02.03.2017; Views: 3998; Downloads: 197 Full text (533,75 KB) |
4865. Software design for the control system for Small-Size Telescopes with single-mirror of the Cherenkov Telescope ArrayA. Porcelli, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2015, published scientific conference contribution Keywords: Cherenkov Telescope Array (CTA), single-mirror Small-Size Telescopes (SST-1M) for CTA, SST-1M control system, software design Published in RUNG: 02.03.2017; Views: 4157; Downloads: 177 Full text (666,06 KB) |
4866. The Instrument Response Function Format for the Cherenkov Telescope ArrayJohn E. Ward, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2015, published scientific conference contribution Keywords: Cherenkov Telescope Array (CTA), public observatory, instrument response functions Published in RUNG: 02.03.2017; Views: 3648; Downloads: 177 Full text (357,42 KB) |
4867. |
4868. Data model issues in the Cherenkov Telescope Array projectJ.L. Contreras, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2015, published scientific conference contribution Keywords: Cherenkov Telescope Array (CTA), public observatory, data model Published in RUNG: 02.03.2017; Views: 3701; Downloads: 217 Full text (1,20 MB) |
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