Method for reusing active material using positive electrode scrap

Patent metadata

Field	Value
Publication number	US-12494522-B2
Application number	US-202117792688-A
Country	US
Kind code	B2
Filing date	Jan 14, 2021
Priority date	Jun 4, 2020
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

There is provided a method for collecting and reusing an active material from positive electrode scrap. The method of reusing a positive electrode active material of the present disclosure includes (a-1) immersing a positive electrode scrap comprising an active material layer on a current collector into a basic solution to separate the active material layer from the current collector, (a-2) thermally treating the active material layer in air for thermal decomposition of a binder and a conductive material in the active material layer, and collecting an active material in the active material layer, (b) washing the active material collected from the step (a-2) with a lithium compound solution which is basic in an aqueous solution and drying, and (c) annealing the active material washed from the step (b) with a lithium precursor to obtain a reusable active material.

First claim

What is claimed is:

1 . A method for reusing a positive electrode active material, comprising:
(a-1) immersing a positive electrode scrap comprising an active material layer on a current collector into a basic solution to separate the active material layer from the current collector; (a-2) thermally treating the active material layer in air for thermal decomposition of a binder and a conductive material in the active material layer, and collecting an active material in the active material layer; (b) washing the active material collected from the step (a-2) with a lithium compound solution which is basic in an aqueous solution and drying; and (c) annealing the active material washed from the step (b) with a lithium precursor to obtain a reusable active material.

2 . The method according to claim 1 , wherein the basic solution comprises LiOH or NaOH.

3 . The method according to claim 1 , further comprising:
(d) surface-coating the active material annealed from the step (c).

4 . The method according to claim 1 , wherein the thermal treatment in the step (a-2) is performed at 300 to 800° C.

5 . The method according to claim 1 , wherein the lithium compound solution contains a lithium compound in an amount of more than 0% and 15% or less, and the washing is performed within 1 hour.

6 . The method according to claim 1 , wherein the washing in the step (b) is performed by stirring the active material collected from the step (a-2) at the same time with immersing into the lithium compound solution.

7 . The method according to claim 1 , wherein the lithium precursor used in the annealing step (c) is one or more selected from the group consisting of LiOH, Li 2 CO 3 , LiNO 3 and Li 2 O.

8 . The method according to claim 1 , wherein, in the annealing step (c), the lithium precursor is added in an amount that satisfies a ratio of lithium to other metals in a raw active material used in the active material layer.

9 . The method according to claim 1 , wherein, in the annealing step (c), the lithium precursor is added in an amount corresponding to an amount of lithium at a molar ratio of 0.001 to 0.4 relative to an amount of lithium in a raw active material used in the active material layer.

10 . The method according to claim 8 , wherein, in the annealing step (c), the lithium precursor is further added in an amount corresponding to an amount of lithium at a molar ratio of 0.0001 to 0.1 relative to an amount of lithium in the raw active material used in the active material layer.

11 . The method according to claim 1 , wherein the annealing is performed in air at 400 to 1000° C.

12 . The method according to claim 1 , wherein a temperature of the annealing step exceeds a melting point of the lithium precursor.

13 . The method according to claim 1 , wherein the active material in the active material layer is collected in a form of powder, and carbon produced by carbonization of the binder or the conductive material does not remain on a surface of the powder.

14 . The method according to claim 3 , wherein the surface-coating step (d) includes coating at least one of a metal, an organic metal or a carbon material on a surface of the active material annealed from the step (c) by a solid or liquid phase process, and thermally treating at 100 to 1200° C.

15 . The method according to claim 1 , wherein the reusable active material is represented by the following Formula 1:
Li a Ni x Mn y Co z M w O 2+δ   [Formula 1]
where M comprises at least one selected from the group consisting of B, W, Al, Ti and Mg, 1<a≤1.1, 0≤x<0.95, 0≤y<0.8, 0≤z<1.0, 0≤w≤0.1, −0.02≤δ≤0.02, x+y+z+w=1.

16 . The method according to claim 1 , wherein the reusable active material has a fluorine (F) content of 150 ppm or less.

17 . The method according to claim 1 , wherein the positive electrode scrap comprises a residual electrolyte solution, and the residual electrolyte solution is removed in the step (a-1), and
wherein the step (a-1) further comprises filtration and washing after the immersion.

18 . The method according to claim 1 , wherein, in the annealing step (c), the lithium precursor is added in an amount corresponding to an amount of lithium depleted during the steps (a-2) and (b).

Assignees

• Lg Energy Solution Ltd

Inventors

• Kim Min-Seo
• Park Se-Ho
• Yang Doo-Kyung

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• C01P2006/80

  Compositional purity · CPC title

• C01P2006/40

  Electric properties · CPC title