Intercalation Behavior of Hexafluorophosphate into Graphite Electrode from Propylene/Ethylmethyl Carbonates

The electrochemical manner of hexafluorophosphate anion into a graphite electrode has been studied in mixed solvents of propylene carbonate (PC) and ethylmethyl carbonate (EMC). The successful electrochemical intercalation of PF6- has been gained in PC/EMC-based electrolyte solutions and the effect of PC and EMC on PF6- insertion into graphite in these electrolyte solutions has been studied by electrochemical tests, ex situ XRD and in situ Raman. Moreover, the interaction between anions and solvents in electrolyte solutions was investigated by nuclear magnetic resonance. Furthermore, Li/graphite cells based on these solutions cycled well. (C) 2017 The Electrochemical Society. All rights reserved.