METHOD FOR SELECTIVELY EXTRACTING LITHIUM FROM RETIRED BATTERY AND APPLICATION OF METHOD

Disclosed are a method for selectively extracting lithium from a retired battery and an application of the method. According to the method, on the basis of an ion exchange effect between a divalent manganese ion and a lithium ion, a positive electrode material and a divalent manganese salt are mixed according to a certain proportion and prepared into a slurry, and the divalent manganese salt and the positive electrode material are fully mixed by means of a ball milling process, such that a lattice structure of the positive electrode material is effectively damaged, thereby reducing activation energy of exchange of the divalent manganese ion and the lithium ion and greatly reducing reaction energy required by a subsequence lithium extraction process. A mixed material after ball milling is roasted at a lower temperature such that the bivalent manganese in the manganese salt occupies a lithium position in a layered structure, and manganese-lithium replacement is directly performed to obtain a pure lithium-containing leaching solution. The present method greatly improves the leaching rate and selectivity of lithium. The present invention uses a mode of first performing ball-mill mixing and then performing roasting, and thus has low power consumption, high safety, good leaching rate and selectivity of lithium, and wide application prospects.