Preparation method for lithium iron phosphate cathode material and application thereof

A preparation method for a lithium iron phosphate cathode material, comprising the following steps:

• (1) dry mixing an iron source, a phosphorus source, a lithium source, a carbon source and an additive, and refining to obtain a mixed material;
• (2) subjecting the mixed material to first calcination, followed by pulverizing to obtain a pulverized material;
• in step (2), the first calcination is carried out at a temperature of 600° C.-800° C. with a heating rate of 1-10° C./min under an inert atmosphere, the temperature is held for 4-15 h;
• the pulverized material has a median particle size of 0.5 μm-10 μm;
• (3) subjecting the pulverized material to second calcination, during which a gasifiable organic carbon source is introduced for coating;
• cooling to obtain the lithium iron phosphate cathode material;
• the gasifiable organic carbon source is one or more selected from the group consisting of acetylene, methane, ethane, propane, methanol, ethanol, ethylene glycol, isopropanol, glycerol, acetone, butanone and 2-pentanone.