Method for removing copper and aluminum from an electrode material, and process for recycling electrode material from waste lithium-ion batteries
The present invention provides a method for removing copper and aluminum from an electrode material and a process for recycling electrode material from waste lithium-ion batteries. The method for removing copper and aluminum from the electrode material comprises: subjecting the electrode material containing electrode active material, copper and aluminum to reaction with an aqueous solution, wherein the aqueous solution has a pH value of higher than 10, and comprises base, oxidizing agent and complexing agent. The process for recycling electrode material from waste lithium-ion batteries comprises: a) harvesting an electrode material containing electrode active material, copper and aluminum from waste lithium-ion batteries; b) removing copper and aluminum from the electrode material according to the foresaid method; and c) further purifying and regenerating the electrode active material for reuse in new lithium-ion batteries. The present invention thus provides a practical and efficient method for recycling active materials from waste lithium-ion batteries.
1. A method for removing copper and aluminum from an electrode material, comprising: subjecting the electrode material containing electrode active material, copper, and aluminum, to reaction with an aqueous solution, wherein the aqueous solution has a pH value higher than 10, and comprises base, oxidizing agent and complexing agent.
2. The method of claim 1 , in which the base in the aqueous solution is one or more selected from the group consisting of inorganic bases with a pKb less than <1.
3. The method of claim 2 , in which the base in the aqueous solution is one or more selected from the group consisting of lithium hydroxide (LiOH), sodium hydroxide (NaOH), and potassium hydroxide (KOH).
4. The method of claim 1 , in which the pH value of the aqueous solution is higher than 11.
5. The method of claim 1 , in which the oxidizing agent is dissolved oxygen.
6. The method of claim 5 , in which the dissolved oxygen is provided by aerating oxygen gas into the aqueous solution.
7. The method of claim 1 , in which the complexing agent is ammonium hydroxide (NH 4 OH).
8. The method of claim 1 , in which the concentration of the complexing agent is between 1 mol/L to 10 mol/L.
9. The method of claim 1 , in which the reaction temperature is between 20° C. to 90° C., and the reaction time is between 0.5 hour and 100 hours.
10. The method of claim 1 , in which the electrode active material is one or more selected from the group consisting of LiCoO 2 , LiMn 2 O 4 , LiNiO 2 , LiNiCoO 2 , Li(LiNiCoMn)O 2 , LiNiCoMnO 2 , and LiFePO 4 .
11. The method of claim 1 , in which the electrode material is powder or slurry.
12. The method of claim 1 , in which the electrode material is derived from waste lithium-ion batteries.
13. A process for recycling electrode material from waste lithium-ion batteries, comprising:
a) harvesting an electrode material containing electrode active material, and which may contain copper and aluminum, from waste lithium-ion batteries;
b) removing copper and aluminum from the electrode material according to the method of claim 1 ; and
c) further purifying and regenerating the electrode active material obtained in operation b) for reuse in new lithium-ion batteries.