Abnormal Inverse Current during Anion Deintercalation from Graphite Electrode

Abstract

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