Progress and prospect for NASICON-type Na3V2(PO4)3 for electrochemical energy storage

Sodium-ion batteries (SIBs) have attracted increasing attention in the past decades, because of high overall abundance of precursors, their even geographical distribution, and low cost. Na3V2(PO4)3 (NVP), a typical sodium super ion conductor (NASICON)-based electrode material, exhibits pronounced structural stability, exceptionally high ion conductivity, rendering it a most promising electrode for sodium storage. However, the comparatively low electronic conductivity makes the theoretical capacity of NVP cannot be fully accessible even at comparatively low rates, presenting a major drawback for further practical applications, especially when high rate capability is especially important. Thus, many endeavors have been conformed to increase the surface and intrinsic electrical conductivity of NVP by coating the active materials with a conductive carbon layer, downsizing the NVP particles, combining the NVP particle with various carbon materials and ion doping strategy. In this review, to get a better understanding on the sodium storage in NVP, we firstly present 4 distinct crystal structures in the temperature range of − 30°C∼225°C namely α-NVP, β-NVP, β′-NVP and γ-NVP. Moreover, we give an overview of recent approaches to enhance the surface electrical conductivity and intrinsic electrical conductivity of NVP. Finally, some potential applications of NVP such as in all-climate environment and PHEV, EV fields have been prospected.