Effect of different vanadium sources on the electrochemical performance of sodium vanadium phosphate cathodes for sodium-ion batteries

Sodium-ion batteries (NIBs) have recently attracted considerable attention as an alternative to lithium-ion batteries because of their low cost, the abundance of their raw materials, and stable performance. In this paper, we report the effect of different vanadium sources on the electrochemical performance of sodium vanadium phosphate (NVP) for NIB. All samples prepared using different vanadium sources were successfully synthesized using the solid-state reaction method. Carbon was coated on the surface of the NVP to improve its electrochemical performance. A thermogravimetric analysis revealed that the amount of carbon in the NVP was 3 wt% and transmission electron microscopy revealed that the thickness of the carbon film was approximately 15 nm. The capacity cycling results indicated that the NVP / C prepared using V2O3 had a distinguished discharge capacity of 89 mAh / g at 0.1 C, which was higher than that of the NVP prepared using V2O5 (76 mAh / g). Both NVP / C samples prepared using V2O3 and V2O5 exhibited excellent capacity retention (95% after 100 cycles). These results suggested that the NVP / C is a major potential cathode material for NIB.