▎ 摘　　要

NOVELTY - Micron-level porous sodium ferrous sulfate/carbon composite cathode material, is claimed. The particle size of the micron-level porous sodium ferrous sulfate/carbon composite cathode material is 2-30 mum. The particles have a porous structure, and are formed by close packing of primary nanoparticles of 80-200 nm. The primary nanoparticles are tightly covered by amorphous carbon, and the particle surface is covered by a thin layer of reduced graphene. In the micron-level porous sodium ferrous sulfate/carbon composite cathode material, the total mass of graphene/carbon is 4-18.5 wt.% of the mass of the sodium ferrous sulfate/carbon composite cathode material. USE - Used as micron-level porous sodium ferrous sulfate/carbon composite cathode material. ADVANTAGE - The cathode material: has high tap density, which helps to improve the volume energy density of the battery; has rich raw materials, economical, high working voltage, excellent rate performance and excellent cycle stability; has simple method; and has high energy density and broad market application prospects. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the cathode material, comprising (1) dispersing certain proportion of ethylene glycol and graphene oxide powder into deionized water, ultrasonicating for 15-120 minutes, then adding certain proportion of anhydrous sodium sulfate, ferrous sulfate heptahydrate, antioxidant, and organic carbon source, stirring for 30-120 minutes, adding organic alcohol dropwise, stirring for 10-120 minutes, centrifuging the obtained turbid solution, and freeze-drying to obtain the precursor, or dispersing certain proportion of ethylene glycol and graphene oxide powder into deionized water, ultrasonicating for 15-120 minutes, then adding certain proportion of anhydrous sodium sulfate, ferrous sulfate heptahydrate, antioxidant, organic carbon source and metal dopant, stirring for 30-120 minutes, adding organic alcohol dropwise, stirring for 10-120 minutes, centrifuging the obtained turbid solution and freeze-drying to obtain a precursor, and (2) uniformly grinding the precursor obtained in step (1), placing in a tube furnace of an inert atmosphere for pre-firing, then raising the temperature to 300-450degreesC and calcining for 8-48 hours to obtain the product; and (2) sodium ion battery or sodium battery prepared by the micron-level porous sodium ferrous sulfate/carbon composite cathode material.