Method for recovering lithium from waste lithium ion battery and waste pole piece

The invention discloses a method for recovering lithium from a waste lithium ion battery and a waste pole piece. The method comprises the following steps of: (1) crushing the waste lithium ion battery or the waste pole piece by using a crusher, placing the crushed material in a high-temperature furnace and removing an adhesive from the crushed material by thermal processing to obtain powder; (2) removing aluminum from the powder by dissolving the aluminum in sodium hydroxide solution and filtering the solution to obtain low-aluminum filter mud; (3) leaching the low-aluminum filter mud with acid and a reducing agent to obtain lixivium; (4) removing impurities such as iron, copper, aluminum and the like from the lixivium by a chemical method; (5) precipitating lithium in the lixivium with fluorine salt to obtain a lithium fluoride rough product; (6) washing the lithium fluoride rough product, filtering and drying to obtain a lithium fluoride product; and (7) returning filtrate obtained after the lithium fluorid