Sodium-embedded lithium ion battery positive electrode material and preparation method thereof

The invention relates to a sodium-embedded lithium ion battery positive electrode material and a preparation method thereof. The preparation method comprises the following steps: obtaining a hydroxide or carbonate precursor containing metal nickel, iron and manganese; mixing the hydroxide or carbonate precursor, an oxidizing agent and a sodium-containing metal compound, and controlling the reaction conditions to be as follows: the reaction pressure is 0.1-3 MPa, the reaction temperature is 20-250 DEG C, the reaction time is 4-50 hours and the concentration of sodium metal ions in a reaction system is 0.5-10 mol/L, so that the sodium ions and the hydroxide or carbonate precursor are subjected to physicochemical reaction; carrying out solid-liquid separation on the reaction product to obtain a sodium-embedded metal oxide precursor; the sodium-embedded metal oxide precursor and a lithium source are mixed and calcined to obtain the sodium-embedded lithium ion battery positive electrode material, and the first dis