Method for preparing lithium iron phosphate material from waste lithium iron phosphate battery

The invention relates to the technical field of waste lithium iron phosphate material recovery, and discloses a method for preparing a lithium iron phosphate material from waste lithium iron phosphate batteries. The method comprises the following steps: discharging the waste lithium iron phosphate battery by using equipment, soaking the battery in saline water, fully discharging, and disassembling to obtain a positive plate; putting the positive plate into a sagger, and sintering in an inert atmosphere; taking out the positive plate, and carrying out ultrasonic vibration sieving to separate the lithium iron phosphate material, the foil and the tab; the lithium iron phosphate material is subjected to crushing, boiling water soaking, alcohol soaking and drying treatment; adding the treated lithium iron phosphate material and a carbon source into pure water, stirring, uniformly mixing, and drying to obtain a lithium iron phosphate precursor; and (6) sintering, crushing and sieving the lithium iron phosphate prec