Premium
Hindered Glymes for Graphite‐Compatible Electrolytes
Author(s) -
Shanmukaraj Devaraj,
Grugeon Sylvie,
Laruelle Stephane,
Armand Michel
Publication year - 2015
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201500502
Subject(s) - ethylene carbonate , electrolyte , dimethyl carbonate , diethyl carbonate , chemistry , intercalation (chemistry) , carbonate , inorganic chemistry , propylene carbonate , graphite , trimethyl phosphate , lithium (medication) , conductivity , alkyl , electrode , organic chemistry , catalysis , phosphate , medicine , endocrinology
Abstract Organic carbonate mixtures are used almost exclusively as lithium battery electrolyte solvents. The linear compounds (dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate) act mainly as thinner for the more viscous and high‐melting ethylene carbonate but are the least stable component and have low flash points; these are serious handicaps for lifetime and safety. Polyethers (glymes) are useful co‐solvents, but all formerly known representatives solvate Li + strongly enough to co‐intercalate in the graphite negative electrode and exfoliate it. We have put forward a new electrolyte composition comprising a polyether to which a bulky tert ‐butyl group is attached (“hindered glyme”), thus completely preventing co‐intercalation while maintaining good conductivity. This alkyl‐carbonate‐free electrolyte shows remarkable cycle efficiency of the graphite electrode, not only at room temperature, but also at 50 and 70 °C in the presence of lithium bis(fluorosulfonimide). The two‐ethylene‐bridge hindered glyme has a high boiling point and a flash point of 80 °C, a considerable advantage for safety.