Preparation method of multiple carbon-coated high-compaction lithium iron manganese phosphate

A preparation method of multiple carbon-coated high-compaction lithium iron manganese phosphate, comprising the following steps:

• S1 mixing an iron source, a manganese source, a phosphorus source, a carbon source and an additive, and then synthesizing a carbon and vanadium co-doped ferromanganese phosphate precursor through a co-precipitation;
• and sintering the obtained carbon and vanadium co-doped ferromanganese phosphate precursor, and removing all crystal water to obtain an anhydrous ferromanganese phosphate precursor;
• S2 adding lithium phosphate, a supplemental phosphorus source, an organic carbon source, a dopant and deionized water into the anhydrous ferromanganese phosphate precursor obtained in step S1 and performing ball milling, wet sanding, spray drying and sintering to obtain an intermediate product;
• and
• S3 adding deionized water and the organic carbon source into the intermediate product obtained in step S2 again, performing ball milling, sanding, spray drying, sintering and air jet pulverization to finally obtain the multiple carbon-coated high-compaction lithium iron manganese phosphate material.