Method of recycling positive electrode active material and recycled positive electrode active material prepared by the same

Patent metadata

Field	Value
Publication number	US-2024039070-A1
Application number	US-202218265906-A
Country	US
Kind code	A1
Filing date	Jul 22, 2022
Priority date	Sep 9, 2021
Publication date	Feb 1, 2024
Grant date	—

Abstract

The present disclosure relates to a method of recycling a positive electrode active material and a recycled positive electrode active material prepared by the same. More particularly, the present disclosure relates to a method of recycling a positive electrode active material, the method including step A of recovering a positive electrode active material by heat-treating a waste positive electrode including a current collector and a positive electrode active material layer coated thereon at 300 to 650° C. in air; step B of precipitating the recovered positive electrode active material in a basic aqueous lithium compound solution for 10 to 40 minutes; step C of removing a supernatant after the precipitation step and obtaining a precipitate; and step D of adding a lithium precursor to the obtained precipitate and performing annealing at 400 to 1,000° C. in air and a recycled positive electrode active material prepared by the method.

First claim

1 . A method of recycling a positive electrode active material, comprising:
step A of recovering a positive electrode active material by heat-treating a waste positive electrode comprising a current collector and a positive electrode active material layer coated thereon at 300 to 650° C. in air; step B of precipitating the positive electrode active material recovered from step A in a basic aqueous lithium compound solution for 10 to 40 minutes; step C of removing a supernatant after step B and obtaining a precipitate; and step D of adding a lithium precursor to the precipitate and performing annealing at 400 to 1,000° C. in air.

2 . The method according to claim 1 , wherein the positive electrode active material layer of step A comprises the positive electrode active material, a binder, and a conductive material.

3 . The method according to claim 1 , wherein the positive electrode active material is represented by Chemical Formula 1:
Li a Ni x Mn y Co z M w O 2+δ   [Chemical Formula 1]
wherein M comprises one or more 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.

4 . The method according to claim 1 , wherein, in step B, the positive electrode active material is precipitated by adding 0.1 g to 100 g of the positive electrode active material recovered from Step A per 100 ml of the basic aqueous lithium compound solution.

5 . The method according to claim 1 , wherein the basic aqueous lithium compound solution of step B comprises a basic lithium compound in an amount of greater than 0% by weight and less than or equal to 15% by weight.

6 . The method according to claim 1 , wherein, in step B, before the positive electrode active material recovered from Step A is precipitated, the positive electrode active material and the basic aqueous lithium compound solution are stirred to wash the positive electrode active material.

7 . The method according to claim 6 , wherein the stirring is performed within a week.

8 . The method according to claim 1 , wherein a particle size distribution of the precipitate of step C exhibits a bimodal or multimodal pattern,
wherein, in the multimodal pattern, a peak corresponding to a particle having a first size is lower than a peak corresponding to a particle having a second size which is larger than the first size.

9 . The method according to claim 1 , wherein, in the precipitate of step C, a total amount of particles having a particle size of 1 μm or less is 5% by volume or less.

10 . The method according to claim 1 , wherein step C further comprises a step of drying the obtained precipitate.

11 . The method according to claim 1 , wherein the lithium precursor of step D comprises one or more selected from the group consisting of LiOH, Li 2 CO 3 , LiNO 3 , and Li 2 O.

12 . The method according to claim 1 , wherein the lithium precursor of step D is added in an amount corresponding to a difference in lithium content between a molar ratio of lithium in the positive electrode active material of step A and a molar ratio of lithium in the precipitate in which an amount of lithium is reduced.

13 . The method according to claim 1 , wherein the lithium precursor of step D is added in an amount capable of providing 1 to 40 mol % of lithium based on 100 mol % in total of lithium in the positive electrode active material of step A.

14 . The method according to claim 1 , wherein, in step D, the annealing temperature is a temperature exceeding a melting point of the lithium precursor.

15 . The method according to claim 1 , further comprising:
step F of coating the annealed precipitate of step D with a coating agent containing metal or carbon, and then heat-treating the precipitate at 100 to 1,200° C.

16 . A recycled positive electrode active material prepared by the method according to claim 1 .

17 . A recycled positive electrode active material, comprising:
a compound represented by Chemical Formula 1:
Li a Ni x Mn y Co z M w O 2+δ   [Chemical Formula 1]

wherein M comprises one or more 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; wherein a particle size distribution of the recycled positive electrode active material exhibits a bimodal or multimodal pattern, wherein, in the multimodal pattern, a peak corresponding to a particle having a first size is lower than a peak corresponding to a particle having a second size which is larger than the first size; and wherein a content of fluorine (F) in the recycled positive electrode active material is 5,000 ppm or less.

18 . The recycled positive electrode active material according to claim 17 , wherein the recycled positive electrode active material has a surface coated with a coating agent containing metals or carbon.

Assignees

• Lg Energy Solution Ltd

Inventors

• Park Se Ho
• Seo Yongsik
• Yang Doo Kyung
• Kim Min Seo
• Lee Jeongbae
• Seong Eunkyu

Classifications

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · 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

• H01M4/38

  of elements or alloys · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title