Method for reusing active material using positive electrode scrap

Patent metadata

Field	Value
Publication number	US-2023183836-A1
Application number	US-202117919718-A
Country	US
Kind code	A1
Filing date	Aug 30, 2021
Priority date	Oct 16, 2020
Publication date	Jun 15, 2023
Grant date	—

Abstract

There is provided a method of collecting and reusing an active material from a positive electrode scrap. The method of reusing a positive electrode active material according to the present disclosure includes (a-1) dry-milling a positive electrode scrap comprising an active material layer on a current collector to form the active material layer into a powdered state and separate the current collector, (a-2) thermally treating the active material layer in powder form in air for thermal decomposition of a binder and a conductive material in the active material layer, to collect an active material, (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 an addition of a lithium precursor to obtain a reusable active material.

First claim

1 . A method for of reusing a positive electrode active material, comprising:
(a-1) dry-milling a positive electrode scrap comprising an active material layer on a current collector to form the active material layer into a powdered state and separate the current collector; (a-2) thermally treating the active material layer in powder form in air for thermal decomposition of a binder and a conductive material in the active material layer, to collect an active material; (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 an addition of a lithium precursor to obtain a reusable active material.

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

3 . The method of claim 1 , wherein the dry-milling is performed by using a pin mill, a disc mill, a cutting mill or a hammer mill.

4 . The method of claim 1 , further comprising:
shredding or cutting the positive electrode scrap before the dry-milling step (a-1).

5 . The method of claim 1 , wherein the thermal treatment is performed at 300 to 1000° C.

6 . The method of claim 1 , wherein the lithium compound solution contains a lithium precursor in an amount of more than 0% and 15% or less, and the washing step (b) is performed within 1 hour.

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

8 . The method of claim 1 , wherein the lithium precursor is one or more selected from the group consisting of LiOH, Li 2 CO 3 , LiNO 3 and Li 2 O.

9 . The method of claim 1 , wherein the lithium precursor is added in an amount of lithium at a ratio of lost lithium to a ratio between lithium and other metal in a raw active material used in the active material layer.

10 . The method of claim 91 , wherein 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 the active material before the dry-milling step (a-1).

11 . The method of claim 10 , wherein an additional 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 active material before the dry-milling step (a-1).

12 . The method of claim 1 , wherein the annealing step (c) is performed in air at 400 to 1000° C.

13 . The method of claim 1 , wherein a temperature of the annealing step (c) exceeds a melting point of the lithium precursor.

14 . The method of claim 2 , wherein the surface-coating step (d) includes coating at least one of a metal, an organic metal or a carbon material on the surface of the active material annealed from the step (c) by a solid or liquid phase process, and then thermally treating at 100 to 1200° C.

15 . The method of 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]
wherein 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, and x+y+z+w=1.

16 . The method of claim 1 , wherein the lithium precursor is added in an amount corresponding to an amount of lithium depleted during the steps (a-1) to (b).

Assignees

• Lg Energy Solution Ltd

Inventors

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

Classifications

• C22B1/24

  Binding; Briquetting {; Granulating} · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• C01G53/50 Primary

  of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 · CPC title

• C22B7/001

  Dry processes · CPC title

• Y02P10/20

  Recycling · CPC title