An Innovative Separation Process for Spent Lithium-Ion Battery Using Three-Stage Electrodialysis

An innovative electrochemical process to separate lithium, nickel, manganese, and cobalt using a three-stage electrodialysis with the addition of ethylenediaminetetraacetic acid (EDTA) is proposed. Before the electrodialysis experiment, ultraviolet–visible spectroscopy is used to study the complexation behavior of EDTA with four different metals. During the electrodialysis experiment, a synthetic solution mixed with a stoichiometric ratio of EDTA to the target metal is supplied to a lab-scale electrodialysis stack, in which nickel is separated in the first stage, cobalt is separated in the second stage, and manganese is separated from lithium in the third stage. The results reveal that the concept of separating four different metals in a multi-metallic system using the three-stage electrodialysis is feasible, which could be potentially implemented in other industries that involve the waste valorization of critical metals.