Confined construction of porous conductive framework Na3V2(PO4)3 nanocrystals and their ultrahigh rate and microtherm sodium storage performance

Sodium-ion batteries have been extensively studied due to their high safety and high natural abundance characteristics. Na 3 V 2 (PO 4 ) 3 (NVP) cathode materials, which have extraordinary rate performance and cycle stability, have become among the most promising cathode materials for commercialization. However, due to their low conductivity problem, it is still a serious challenge to develop a nanocrystalline and uniform conductive frame structure. This work reports a confinement reaction strategy derived from the chelation reaction, which can successfully realize electrode materials with adjustable internal NVP grains. The obtained ultrasmall grained carbon frame material showed to have ultrahigh rate performance, and it could reach 101 mAh g −1 at 100C and 100 mA h g −1 after 1800 cycles at 10C rate (capacity retention rate 99%). Moreover, it showed the characteristics of excellent low-temperature performance, and no capacity degradation at − 20 °C after 1000 cycles.