Prussian blue positive electrode material, preparation method thereof and sodium ion battery

The invention relates to the technical field of battery materials, and discloses a Prussian blue positive electrode material, a preparation method thereof and a sodium ion battery. The Prussian blue positive electrode material comprises an inner core and a coating layer. The inner core comprises a compound with a chemical formula of NaxM [Fe (CN) 6] y, and the coating layer comprises a compound with a chemical formula of Na3V2-ZMgZ (PO4) 3. Wherein x is more than or equal to 0 and less than or equal to 2, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 2, and M is at least one of Fe, Mn, Co, Ni, Cu and Zn. The preparation method of the Prussian blue type positive electrode material comprises the following steps: (I) preparing the inner core; (II) preparing coating liquid; and (III) preparing the coating type material. The Prussian blue type positive electrode material and the Prussian blue type positive electrode material prepared by adopting th