▎ 摘　　要

NOVELTY - A carbon-coated sodium-rich sodium iron pyrophosphate composite positive electrode material comprises reduced graphene oxide-doped carbon-coated sodium-iron-metal-based pyrophosphate. USE - Carbon-coated sodium-rich sodium iron pyrophosphate composite material used in preparation of positive electrode sheet of sodium-ion battery (all claimed). DETAILED DESCRIPTION - A carbon-coated sodium-rich sodium iron pyrophosphate composite positive electrode material comprises reduced graphene oxide-doped carbon-coated sodium-iron-metal-based pyrophosphate of formula: Na4+xFe3-yMy(PO4)2P2O7Fx/C-rGO, where x is 0-0.1 (excluding 0), y is 0-3 (excluding 3), and M is manganese, cobalt, nickel, titanium, magnesium and/or aluminum. INDEPENDENT CLAIMS are included for the following: (1) preparation of the positive electrode material, which involves (s1) ultrasonically treating a reduced graphene oxide (rGO) dispersion, (s2) dissolving phosphate, iron salt, sodium salt, fluoride, metal (M) salt and carbon source in the dispersion, (s3) drying the obtained solution to obtain powder-shaped mixed precursor, and (s4) heat-treating the precursor under an inert reducing atmosphere; and (2) usage method of the positive electrode material in preparation of positive electrode sheet of sodium-ion battery, which involves weighing 80 parts mass carbon-coated sodium-rich sodium iron pyrophosphate composite positive electrode material, 10 parts mass acetylene black and 10 parts mass binder, dissolving the positive electrode material, acetylene black and binder in N-methyl pyrrolidone, coating on a processed aluminum foil, and drying.