Lithium iron phosphate composite positive electrode material with surface coated with titanium nitride and graphene as well as preparation method and application of material

The invention provides a lithium iron phosphate composite positive electrode material with a surface coated with titanium nitride and graphene, a preparation method of the material and an application of the material in preparation of a lithium ion battery. According to the lithium iron phosphate composite positive electrode material, a lithium iron phosphate material is used as an inner core; the surface of the lithium iron phosphate material is coated with a conductive network film which consists of titanium nitride and graphene; and the mass of the conductive network film is 0.2%-10% of the mass of the lithium iron phosphate material. The preparation method of the material comprises the following steps: uniformly mixing the lithium iron phosphate material with graphene, a nitride source and a titanium-containing compound in a dispersion medium to prepare a mixed material, drying the mixed material, subsequently sintering the mixed material at 400 DEG C to 900 DEG C for 6-24 hours in the presence of inert protective atmosphere so as to prepare the lithium iron phosphate composite positive electrode material with the surface coated with titanium nitride and graphene. The lithium iron phosphate composite positive electrode material is relatively high in conductivity and tap density and relatively good in rate capability and cycle performance; and the preparation method is simple in steps, low in cost and simple to operate.