Repair and regeneration method of lithium iron phosphate cathode material in waste batteries

Abstract

The invention discloses a method for repairing and regenerating lithium iron phosphate positive electrode materials in waste batteries. In the method, waste lithium iron phosphate is obtained by calcining the disassembled lithium iron phosphate positive pole pieces; dispersing the waste lithium iron phosphate in In deionized water, add surfactant, soluble iron salt and hydrogen peroxide, stir to obtain a solution containing lithium iron phosphate; then add ammonium dihydrogen phosphate solution to the solution containing lithium iron phosphate, stir and dry to obtain iron phosphate coated Lithium iron phosphate powder; mix iron phosphate coated lithium iron phosphate powder with lithium salt, and calcinate to obtain repaired and regenerated lithium iron phosphate positive electrode material; thus, the present invention adopts coating technology to coat a layer of the material on the surface of the material Lithium iron phosphate, and finally the repaired and regenerated lithium iron phosphate cathode material is obtained by high-temperature calcination with lithium supplementation, which achieves the purpose of coating while repairing and regenerating, thereby improving the cycle performance of the recovered lithium iron phosphate cathode material.

Description

technical field [0001] The invention belongs to the technical field of waste battery recycling, and in particular relates to a method for repairing and regenerating lithium iron phosphate cathode materials in waste batteries. Background technique [0002] The recycling of common lithium iron phosphate cathode materials mainly includes the extraction of valuable metals and repair and regeneration. [0003] In the prior art, the extraction of valuable metals usually adopts acid leaching to dissolve positive electrode materials to obtain a solution of valuable metal ions, and finally obtain inorganic salts of valuable metals through removal of impurities and precipitation; this extraction of valuable metals The method is simple and easy, and is currently the most common method for recycling waste batteries. However, this extraction method has high processing costs, requires a large amount of acid and alkali consumption, and produces a large amount of three wastes, causing serio...

AI Technical Summary

Problems solved by technology

[0003] In the prior art, the extraction of valuable metals usually adopts acid leaching to dissolve positive electrode materials to obtain a solution of valuable metal ions, and finally obtain inorganic salts of valuable metals through removal of impurities and precipitation; this extraction of valuable metals The method is simple and easy, and it is the most common method of recycling waste batteries at present. However, the extraction method has high processing costs, requires a large amount of acid and alkali consumption, and will produce a large amount of three wastes, causing serious pollution to the environment.

[0004] Restoration and regeneration is to restore the physical and chemical indicators of the separated positive electrode material through lithium supplementation, so as to achieve the purpose of repair and regeneration; as an emerging technology, repair and regeneration technology is currently under research and development in the laboratory. , which can realize the repair and regeneration of materials. However, compared with the directly prepared battery materials, due to the presence of some impurities in the materials of the repaired and regenerated battery materials, the impurities in the materials will interact with the electrolyte during the charging and discharging process. side reactions, thus affecting the cycle performance of the material, therefore, the electrochemical performance of the battery material obtained by this method is quite different, and it is difficult to compare with commercial materials