Progress in the investigation and application of Na3V2(PO4)3 for electrochemical energy storage

Abstract

Lithium ion batteries (LiBs) have been widely utilized, but the limited lithium resource restricts development and application of LiBs in largescale energy storage. Sodium has similar physicochemical characteristics to that of lithium and is suitable to transfer between two electrodes as a cation in the “rocking chair” mechanism of LiBs. Na-containing compounds have been proposed as the electrodes to store sodium ions and provide channels for diffusion. Polyanion Na<inf>3</inf>V<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf> is a Na-super-ionic conductor (NASICON) with specific Na sites in its crystal structure and three-dimensional open channels. Recently, Na<inf>3</inf>V<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf> has been demonstrated as potential electrode material with promising properties for energy storage. In this review we systematically summarize the structure of Na<inf>3</inf>V<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf>, the application and mechanism in a specific energy system, and the recent development of Na<inf>3</inf>V<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf> structure for use as electrodes. The potential problems and trends of Na<inf>3</inf>V<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf> are also discussed.