Method for preparing positive electrode active material

Patent metadata

Field	Value
Publication number	US-12288866-B2
Application number	US-201816614233-A
Country	US
Kind code	B2
Filing date	Nov 23, 2018
Priority date	Nov 24, 2017
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

A method for preparing a positive electrode active material includes: a step for adding a reaction mixture containing a lithium-raw material and a nickel-manganese-cobalt precursor into a first crucible and performing a first heat treatment at a temperature of 500-800° C. to form a pre-sintered mixture; a step for extracting the pre-sintered mixture from the first crucible and pulverizing or classifying the same; and a step for adding the pulverized or classified pre-sintered mixture into a second crucible and performing a second heat treatment at a temperature of 700-1000° C. under an atmosphere in which an oxygen partial pressure is 20% or less to form a lithium nickel-manganese-cobalt-based positive electrode active material, wherein a volume of the pre-sintered mixture formed after the first heat treatment is reduced to a volume that is 20-50% of a volume of the reaction mixture added into the first crucible.

First claim

The invention claimed is:

1. A method for preparing a positive electrode active material comprising:
adding a reaction mixture containing a lithium-raw material and a nickel-manganese-cobalt precursor into a first crucible and performing a first heat treatment at a temperature of 500-800° C. under an oxygen atmosphere to form a pre-sintered mixture;
extracting the pre-sintered mixture from the first crucible and pulverizing or classifying the pre-sintered mixture; and
directly after the pulverizing or classifying of the pre-sintered mixture, adding the pulverized or classified pre-sintered mixture into a second crucible and performing a second heat treatment at a temperature of 700-1000° C. under an atmosphere in which an oxygen partial pressure is 20% or less to form a lithium nickel-manganese-cobalt-based positive electrode active material,
wherein during the first heat treatment a volume of the pre-sintered mixture is reduced to a volume that is 20-50% of a volume of the reaction mixture added into the first crucible, wherein the oxygen partial pressure of the second heat treatment is lower than that of the first heat treatment, and
wherein the lithium nickel-manganese-cobalt-based positive electrode active material is represented by Formula 1 below:
Li 1+x [Ni a Mn b CO c M 1 1-a-b-c ] 1-x O 2   [Formula 1]

wherein,
0.2≤x≤0.2, 0.6≤a≤0.98, 0.01≤b≤0.39 and 0.01≤c≤0.39, and
M 1 is at least one selected from the group consisting of Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, In, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo.

2. The method of claim 1 , wherein the second heat treatment is performed under a nitrogen atmosphere, a vacuum atmosphere, or a non-fluid atmosphere.

3. The method of claim 1 , wherein the lithium-raw material is at least one selected from the group consisting of lithium hydroxide and lithium carbonate.

4. The method of claim 1 , wherein the nickel-manganese-cobalt precursor is at least one selected from the group consisting of nickel-manganese-cobalt hydroxide, nickel-manganese-cobalt oxyhydroxide, nickel-manganese-cobalt carbonate, and a nickel-manganese-cobalt organic complex.

5. The method of claim 1 , wherein the reaction mixture further comprises a doping raw material.

6. The method of claim 5 , wherein the doping raw material is oxide, hydroxide, sulfide, oxyhydroxide, halide, or a mixture thereof comprising Cu, Fe, V, Cr, Ti, Zr, Zn, Al, In, Ta, Y, In, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, Mo or combination thereof.

7. The method of claim 1 , wherein the first crucible is a crucible formed of stainless steel, a crucible formed of nickel, or an alloy crucible.

8. The method of claim 1 , wherein the first heat treatment is performed for 1 hour to 12 hours.

9. The method of claim 1 , wherein a content of the sintered mixture added into the second crucible is 2-10 times a content of the sintered mixture formed from the first crucible.

10. The method of claim 1 , wherein the second crucible is a crucible formed of aluminum.

11. The method of claim 1 , further comprising adding a doping raw material to the second crucible before the second heat treatment.

12. The method of claim 1 , wherein the second heat treatment is performed for 2 hours to 20 hours.

Assignees

• Lg Chemical Ltd

Inventors

• Choi Sang Soon
• Cho Seung Beom
• Lim Jung Ho
• Jung Won Sig

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

• C01P2006/40

  Electric properties · CPC title

• H01M10/052

  Li-accumulators · CPC title