With the rapid development of new energy vehicles, miniature electronic devices and energy storage, lithium iron phosphate batteries (LFPBs) have been widely used. However, with the promotion of electric vehicles for many years, there will be a climax of retirement, and it is expected that 9,400 tons of lithium iron phosphate will be retired in 2021. If decommissioned lithium iron phosphate batteries are not properly disposed of, it will bring about problems of environmental pollution and waste of resources. Therefore, the recovery, harmless treatment and resource reuse of decommissioned lithium iron phosphate batteries have become hot topics.
The resource reuse of decommissioned lithium iron phosphate materials can not only alleviate the environmental pressure caused by waste batteries, but also turn waste into treasures. It is common to see the overall recycling and reuse process of decommissioned lithium iron phosphate batteries, and various recycling and reuse of decommissioned lithium iron phosphate materials. The reuse method provides a new type of lithium battery processing equipment for the large-scale reuse of retired lithium iron phosphate materials.
Separation of decommissioned lithium iron phosphate materials from current collectors
The cathode current collector in the lithium iron phosphate battery is aluminum foil, and the current collector should be separated from the retired lithium iron phosphate material first during the recycling process. At present, the methods for separating decommissioned lithium iron phosphate materials and current collectors mainly include organic solvent dissolution, thermal separation and mechanical pulverization.
mechanical crushing
The mechanical pulverization method mainly pulverizes the positive electrode sheet, and utilizes the difference in density and particle size between the current collector and the retired lithium iron phosphate material, and realizes the separation of the current collector and the retired lithium iron phosphate material through flotation and other screening methods.
The decommissioned lithium iron phosphate battery pack was immersed in saturated NaCl solution for discharge, and then disassembled to separate out the plastic casing, diaphragm, positive electrode and negative electrode, and mechanically pulverized the lithium iron phosphate material from the surface of the aluminum foil. Separate collection of aluminum foil and decommissioned lithium iron phosphate material.
The mechanical pulverization method can separate the decommissioned lithium iron phosphate and the current collector. Although the fines of the current collector will be partially mixed into the decommissioned lithium iron phosphate during the pulverization process, the impurity content can be increased, but the impurity content can be effectively controlled through equipment optimization and refined control. Using acid-base reagents, no waste is generated, no environmental pollution is caused, and it meets the development requirements of green chemistry.