In-Situ Studies on the Electrochemical Intercalation of Hexafluorophosphate Anion in Graphite with Selective Cointercalation of Solvent

• DOI: 10.1021/jp5115465
• Publication Date: 2015-04-02T02:42:53Z
• Authors: Jeffrey A. Read
• Keywords: Propylene carbonate; Hexafluorophosphate

Electrochemical cells utilizing graphite intercalation compounds at both electrodes have been proposed as an energy storage technology where the electrolyte salt is split and stored in on charge reformed discharge. The anion of cathodes these systems studied electrolytes that are resistant to oxidation 5 V but incompatible with anodes. Recent work has demonstrated based monofluoroethylene carbonate (FEC) ethylmethyl (EMC) superior oxidative stability over previously form a stable solid interphase (SEI) anodes allow for full dual-graphite be evaluated applications. There still limited understanding structure intercalate formed effect solvent cointercalation cathode performance. This effort was undertaken using number situ techniques better characterize fully intercalated composition well investigate process cointercalation. It shown series stages C24PF6 until, upon reaching charge, approaches C20PF6 stage I PF6– close contact layers 0.7 molecules cointercalated solvent. For first time, we move during intercalation/deintercalation while analysis crystals there unusually strong preference EMC FEC cointercalate this compound.