Hexafluorophosphate intercalation into graphite electrode from gamma-butyrolactone solutions in activated carbon/graphite capacitors

In our recent work, the solvent of ethylene carbonate (EC) has been found to retard the intercalation of anions into graphite electrodes. Here we demonstrate that gamma-butyrolactone (GBL) also exhibits suppressive effect on the intercalation of PF6− into the interlayer space between the graphene planes. The intercalation process of PF6− into graphite electrode from GBL has been investigated by in situ XRD, in situ Raman and EQCM. Furthermore, the effect of GBL has been compared with those of EC and propylene carbonate (PC).