Details

Autor(en) / Beteiligte

• Veith, Gabriel M
• Doucet, Mathieu
• Sacci, Robert L
• Vacaliuc, Bogdan
• Baldwin, J Kevin
• Browning, James F

Titel

Determination of the Solid Electrolyte Interphase Structure Grown on a Silicon Electrode Using a Fluoroethylene Carbonate Additive

Ist Teil von

• Scientific reports, 2017-07, Vol.7 (1), p.6326-15, Article 6326

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2017

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• In this work we explore how an electrolyte additive (fluorinated ethylene carbonate - FEC) mediates the thickness and composition of the solid electrolyte interphase formed over a silicon anode in situ as a function of state-of-charge and cycle. We show the FEC condenses on the surface at open circuit voltage then is reduced to C-O containing polymeric species around 0.9 V (vs. Li/Li ). The resulting film is about 50 Å thick. Upon lithiation the SEI thickens to 70 Å and becomes more organic-like. With delithiation the SEI thins by 13 Å and becomes more inorganic in nature, consistent with the formation of LiF. This thickening/thinning is reversible with cycling and shows the SEI is a dynamic structure. We compare the SEI chemistry and thickness to 280 Å thick SEI layers produced without FEC and provide a mechanism for SEI formation using FEC additives.