Method for preparing battery-grade lithium carbonate from recycled lithium ion battery material

The invention discloses a method for preparing battery-grade lithium carbonate from a recycled lithium ion battery material. The method comprises the following steps: 1, preparing lithium-containing fluorine residue; 2, preparing the lithium-containing fluorine residue and water into slurry, adding a leaching agent so that lithium in the lithium-containing fluorine residue can be dissolved in water, and filtering to obtain a rough lithium solution; 3, regulating the pH value by an alkaline reagent, and removing impurities such as magnesium, nickel and cobalt out of the rough lithium solution to obtain a purified lithium solution; 4, adding carbonate to the purified lithium solution to form precipitate which is rough lithium carbonate; and 5, washing the obtained rough lithium carbonate, and drying to obtain the battery-grade lithium carbonate product. The method can be used for simultaneously recycling lithium and precious metals such as cobalt, nickel and magnesium from the lithium battery, and the prepared battery-grade lithium carbonate product can be directly applied to production of the lithium battery; therefore, the product value is high and the comprehensive recycling rate of resources is improved.