▎ 摘　　要

NOVELTY - Sodium ion battery positive electrode material comprises polyanion phosphate and carbon composite that is supported on the polyanion phosphate. USE - Sodium ion battery positive electrode material. ADVANTAGE - The positive electrode material has iron defects on the iron site, and also has sodium vacancies on the sodium site. The combination of the two greatly improves the transmission rate of sodium ions, and also improves rate performance, cycle performance and capacity of the material. DETAILED DESCRIPTION - Sodium ion battery positive electrode material comprises polyanion phosphate and carbon composite that is supported on the polyanion phosphate. The molecular formula of the polyanionic phosphate is NaXFeY(PO4)2P2O7, where X=3-4;Y=2-3; and X/Y=1.25-1.32. An INDEPENDENT CLAIM is included for a method for preparing the positive electrode material of a sodium-ion battery, which involves: mixing materials containing sodium, iron and phosphorus and citric acid monohydrate, carbon source and water to prepare a mixed solution, and ball milling mixed solution, drying and calcining to obtain a positive electrode material for a sodium ion battery.