title: Hindered Glymes for Graphite-Compatible Electrolytes.
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.
authors.affiliation: CIC Energigune, Parque Tecnologico de Álava, Albert Einstein 48-ED.CIC, 01510 Miñano (Spain).
authors.forename: Devaraj
authors.initials: D
authors.lastname: Shanmukaraj
authors.affiliation: Laboratoire de Réactivité et Chimie des Solides, CNRS UMR 7314, Université de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens (France).|Réseau sur le Stockage Electrochimique de l'Energie, CNRS RS2E FR3459, 33 rue Saint Leu, 80039 Amiens (France).
authors.forename: Sylvie
authors.initials: S
authors.lastname: Grugeon
authors.affiliation: Laboratoire de Réactivité et Chimie des Solides, CNRS UMR 7314, Université de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens (France).|Réseau sur le Stockage Electrochimique de l'Energie, CNRS RS2E FR3459, 33 rue Saint Leu, 80039 Amiens (France).
authors.forename: Stephane
authors.initials: S
authors.lastname: Laruelle
authors.affiliation: CIC Energigune, Parque Tecnologico de Álava, Albert Einstein 48-ED.CIC, 01510 Miñano (Spain). michel.armand@gmail.com.|Laboratoire de Réactivité et Chimie des Solides, CNRS UMR 7314, Université de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens (France). michel.armand@gmail.com.
authors.forename: Michel
authors.initials: M
authors.lastname: Armand
mesh_terms: D004553:Electric Conductivity; D004566:Electrodes; D004573:Electrolytes; D006108:Graphite / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*
chemical_list: D004573:Electrolytes; D010710:Phosphates; D006108:Graphite; D008094:Lithium; D007501:Iron
keywords: batteries; electrolytes; exfoliation; glymes; graphite