Preparation method of modified ferric phosphate sodium composite material

The invention belongs to the field of sodium ion battery positive electrode materials, and particularly relates to a preparation method of a modified sodium iron phosphate composite material. The invention provides a preparation method of a modified sodium iron phosphate composite material, which comprises the following steps: (1) uniformly mixing a sodium source and graphene oxide in a mixer, adding iron phosphate and a carbon source into the mixture, and uniformly mixing in the mixer; (2) performing primary sintering on the product obtained in the step (1) in a nitrogen atmosphere to obtain a primary sintering material; (3) crushing and sieving the primarily sintered material obtained in the step (2); (4) uniformly mixing the sodium iron phosphate composite material obtained in the step (3) with a titanium source and a tungsten source in a mixer; and (5) carrying out secondary sintering, and screening to obtain the positive electrode material. According to the invention, the problems of poor electronic cond