SnO2 Model Electrode Cycled in Li-Ion Battery Reveals the Formation of Li2SnO3 and Li8SnO6 Phases through Conversion Reactions
Autor: | Mario El Kazzi, Giulio Ferraresi, Michael Horisberger, Claire Villevieille, Petr Novák, Izabela Czekaj |
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Přispěvatelé: | Paul Scherrer Institute, Electrochemistry Laboratory |
Rok vydání: | 2018 |
Předmět: |
Materials science
Scanning electron microscope [SPI.NRJ]Engineering Sciences [physics]/Electric power Analytical chemistry [CHIM.MATE]Chemical Sciences/Material chemistry 02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology 7. Clean energy 01 natural sciences 0104 chemical sciences Ion Amorphous solid chemistry.chemical_compound X-ray photoelectron spectroscopy chemistry Electrode [CHIM]Chemical Sciences General Materials Science Graphite 0210 nano-technology Ethylene carbonate |
Zdroj: | ACS Applied Materials & Interfaces ACS Applied Materials & Interfaces, Washington, D.C. : American Chemical Society, 2018, 10 (10), pp.8712-8720. ⟨10.1021/acsami.7b19481⟩ |
ISSN: | 1944-8252 1944-8244 |
DOI: | 10.1021/acsami.7b19481 |
Popis: | International audience; SnO2 is an attractive negative electrode for Li-ion battery owing to its high specific charge compared to commercial graphite. However, the various intermediate conversion and alloy reactions taking place during lithiation/delithiation, as well as the electrolyte stability, have not been fully elucidated, and many ambiguities remain. An amorphous SnO2 thin film was investigated for use as a model electrode by a combination of postmortem X-ray photoelectron spectroscopy supported by density functional theory calculations and scanning electron microscopy to shed light on these different processes. The early stages of lithiation reveal the presence of multiple overlapping reactions leading to the formation of Li2SnO3 and Sn0 phases between 2 and 0.8 V vs Li+/Li. Between 0.45 V and 5 mV vs Li+/Li Li8SnO6, Li2O and LixSn phases are formed. Electrolyte reduction occurs simultaneously in two steps, at 1.4 and 1 V vs Li+/Li, corresponding to the decomposition of the LiPF6 salt and ethylene carbonate/dimethyl carbonate solvents, respectively. Most of the reactions during delithiation are reversible up to 1.5 V vs Li+/Li, with the reappearance of Sn0 accompanied by the decomposition of Li2O. Above 1.5 V vs Li+/Li, Sn0 is partially reoxidized to SnOx. This process tends to limit the conversion reactions in favor of the alloy reaction, as also confirmed by the long-term cycling samples. |
Databáze: | OpenAIRE |
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