Preparation method of high-capacity sodium ion battery positive electrode material

The invention relates to a preparation method of a high-capacity sodium ion battery positive electrode material. The preparation method comprises the following steps: 1) calculating and weighing all reaction raw materials according to a chemical formula of NaNi < 0.4 > Mn < 0.6-x > Ti < x > O < 2 >; 2) adding the raw materials weighed according to the proportion into a ball mill, and uniformly mixing the raw materials; 3) sintering the raw materials mixed in the step 2); 4) crushing the sintered raw materials; 5) mixing cobalt hydroxide with a corresponding addition amount with the intermediate product prepared in the step 4); (6) adding a ball milling medium into a ball mill, adding the mixture obtained in the step (5) into the ball mill, and uniformly mixing; 7) sintering the mixture in the step 6); and 8) crushing the sintered product. The product provided by the invention has specific chemical composition, good polycrystalline morphology and stable product structure, the defect of high surface PH of the s