Lithium recovery process from spent lithium batteries and in-situ coordination leaching solution

Abstract

This application provides an in-situ coordination lithium extraction leaching solution and a method for lithium recovery from retired lithium batteries. The in-situ coordination lithium extraction leaching solution provided in this application comprises a polycyclic compound and a solution agent. The polycyclic compound includes a primary polycyclic compound and an auxiliary polycyclic compound, with a mass ratio of 7:3 to 9:1. The primary polycyclic compound is selected from at least one of biphenyl, 4-methylbiphenyl, and naphthalene, while the auxiliary polycyclic compound is selected from at least one of phenanthrene, pyrene, and perylene. This application utilizes the nucleophilicity between the primary polycyclic compound and lithium atoms to rapidly combine with lithium metal in lithium-containing graphite anode sheets, improving lithium extraction efficiency. The chemical coordination between the auxiliary polycyclic compound and lithium atoms regulates the redox potential during the lithium extraction process. Therefore, by using a specific mass ratio of primary and auxiliary polycyclic compounds to synergistically leach lithium-containing graphite anode sheets in situ, the purpose of recovering lithium from retired lithium batteries can be achieved.

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