(1) Physical method Physical method uses the physicochemical reaction process to treat the lithium ion iron phosphate battery. The common physical and chemical treatment methods are crushing flotation and mechanical grinding.

(2) Chemical method Chemical method is the use of chemical reaction process of lithium ion battery treatment method, generally divided into pyrometallurgical and hydrometallurgical two methods.

(3) Biometallurgy is also under study, which utilizes the metabolic process of microorganisms to achieve the selective leaching of cobalt, lithium and other metal elements. The biological method has low energy consumption and low cost, and the microorganism can be reused with little pollution. However, the culture of microorganisms requires harsh conditions, long incubation time, low leaching efficiency, and the process needs to be further improved. In the general treatment of iron phosphate lithium ion battery, the whole battery is mechanically crushed, and the aluminum is dissolved and separated by polar organic solvent NMP or strong alkali. The remaining material is a mixture of LiFePO4 and toner. By introducing Li, Fe and P into the mixture to adjust the molar ratio of these three elements in the material, LiFePO4 material can be synthesized again after ball milling and high temperature calcination in an inert atmosphere. However, compared with the cathode material of iron phosphate lithium ion battery synthesized for the first time, the electric capacity and charge and discharge performance of the material are decreased. The way to cure the symptoms and root causes is to oxidize and decompose the cathode materials of the failed iron phosphate lithium ion battery, recycle lithium, iron,