Abnormal\nInverse Current during Anion Deintercalation\nfrom Graphite Electrode

Abstract

It\nwas taken for granted that the charge and discharge processes\ncorrespond with distinctly opposite directions of ionic flow when\nthe energy storage mechanism of dual-ion battery was concerned. This\ncommon sense is challenged as we find a remarkable countercurrent\nin the cyclic voltammetric curve during the deintercalation of tetrafluoroborate\nanions from graphite electrode using ethylene carbonate solution.\nBy electrochemical analysis, there is believed to be backflow of anions\nduring the deintercalation process. The cause of this abnormal ionic\nflow relates to both the desolvation and resolvation of the intercalated\nanions inside the graphite electrode. Supportive evidence is provided.