A facilely-synthesized polyanionic cathode with impressive long-term cycling stability for sodium-ion batteries

In this work, nanoflower-like Na 0.5 VOPO 4 ·2H 2 O with a large interlayer distance of 6.5295 Å is synthesized via a simple chemical precipitation method at room temperature. It is the first time that the potential of the Na 0.5 VOPO 4 ·2H 2 O electrode as a cathode material for SIBs has been investigated, and it exhibits a high specific capacity (127 mA h g −1 at 0.2C), outstanding long-term cycling stability and superior reaction kinetics. Nanoflower-like Na 0.5 VOPO 4 ·2H 2 O exhibits excellent cycling performance, superior reaction kinetics and highly reversible evolution as a cathode material for sodium-ion batteries.