Lithium recovery method

Abstract

A lithium recovery method from a used lithium-ion secondary battery including an electrode body having a positive electrode, a sulfide solid electrolyte, and a negative electrode, the method including: dissolving a solid electrolyte and a lithium compound contained in a deactivated lithium-ion secondary battery in pure water to obtain a dispersion liquid; recovering a separation solution by performing solid-liquid separation on the dispersion liquid; performing an oxidation treatment on the separation solution to generate an acidic component in the separation solution and adjusting a pH of the separation solution; recovering a recovery stock solution by performing solid-liquid separation on the separation solution after the oxidation treatment; and extracting a lithium hydroxide aqueous solution from the recovery stock solution through electrodialysis using a cation exchange membrane.

Dependencies are inferred from the claim text.