(Invited) Electrochemical Structure Evolution and Electronic Interactions in NaxVO2

Abstract

Vanadium oxides have been highly attractive for over half a century since the discovery of the metal insulator transition near room temperatures. Here NaxVO2 is studied through a systematic comparison with other layered sodium metal oxides with early 3d transition metals. The unique trimer structure in NaxVO2 first reported by Claude Delmas is here shown to be a delicate balance between strong electronic correlations and orbital effects that can be precisely modulated by both Na compositions and atomic stackings. This unveils an opportunity to design strongly correlated materials with tailored electronic transitions through electrochemical modulations and crystallographic designs, to elegantly balance various competition effects. We think the understanding will also help further elucidate complicated electronic behaviors in other vanadium oxide systems.