Preparation method and application of carbon-coated sodium ferric sulfate material

The invention provides a preparation method of a carbon-coated sodium ferric sulfate material, which comprises the following steps: preparing a mixed solution of ferrous sulfate and a sodium source according to a certain proportion, keeping the mixed solution in an inert gas atmosphere, heating and stirring the mixed solution to form sol, and drying and crushing the sol to obtain a precursor; performing first sintering on the precursor to obtain a first intermediate; dissolving a carbon source, and coating the surface of the first intermediate with the carbon source through spray drying to obtain a second intermediate; the carbon source comprises a reducing organic carbon source; the second intermediate is subjected to second sintering, and the carbon-coated sodium ferric sulfate material is obtained. The carbon-coated sodium ferric sulfate material prepared by the preparation method provided by the invention has pure-phase sodium ferric sulfate and a uniform carbon coating layer, and has good electrochemical