Treatment dependent sodium-rich Prussian blue as a cathode material for sodium-ion batteries.

In the preparation of Prussian blue analogs (PBAs), Na + loss and Fe 2+ oxidation take place when washing with water. Sodium-rich PBAs were prepared with sodium ascorbate aqueous solution as the washing solution, which can suppress the Na + loss and Fe 2+ oxidation. As the cathode of sodium-ion batteries, it exhibited excellent electrochemical performance.