Preparation method of ferrophosphorus sodium ore type ferric phosphate sodium composite material

The invention provides a preparation method of a ferro-phosphorus sodium ore type sodium iron phosphate composite material, which comprises the following steps: uniformly mixing iron phosphate, a sodium source, a boron source, a magnesium source, a solvent and a dispersing agent according to a certain proportion, carrying out spray drying treatment, uniformly mixing with a carbon source in a mixer, and sintering under the protection of nitrogen atmosphere to obtain the ferro-phosphorus sodium ore type sodium iron phosphate composite material. And crushing and screening to obtain the sodium iron phosphate composite material. B doping is carried out on the P site of polyanions of sodium ferric phosphate, so that the unit cell volume is reduced, meanwhile, a proper amount of Mg is introduced to balance charges, the diffusion path of sodium ions is shortened, oxygen defects are effectively improved, the transmission rate of the sodium ions is higher, and the specific discharge capacity is improved. And then surfa