Method for Preparing Positive Electrode Active Material

Patent metadata

Field	Value
Publication number	US-2020350554-A1
Application number	US-201816614233-A
Country	US
Kind code	A1
Filing date	Nov 23, 2018
Priority date	Nov 24, 2017
Publication date	Nov 5, 2020
Grant date	—

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-calcinated mixture; a step for extracting the pre-calcinated mixture from the first crucible and pulverizing or classifying the same; and a step for adding the pulverized or classified pre-calcinated 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-calcinated mixture formed after the first heat treatment is 20-50% with respect to a volume of the reaction mixture added into the first crucible.

First claim

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. to form a pre-calcinated mixture; extracting the pre-calcinated mixture from the first crucible and pulverizing or classifying the pre-calcinated mixture; and adding the pulverized or classified pre-calcinated 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-calcinated mixture formed after the first heat treatment is 20-50% with respect to a volume of the reaction mixture added into the first crucible.

2 . The method of claim 1 , wherein the first heat treatment is performed under an oxygen atmosphere or an air atmosphere.

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

4 . 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.

5 . 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.

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

7 . The method of claim 6 , wherein the doping raw material is oxide, hydroxide, sulfide, oxyhydroxide, halide, or a mixture thereof comprising W, 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.

8 . 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.

9 . The method of claim 1 , wherein the first heat treatment is performed for 1 hour or more.

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

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

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

13 . The method of claim 1 , wherein the second heat treatment is performed for 2 hours or more.

14 . The method of claim 1 , 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<a<1, 0<b<1, and 0<c<1, and M 1 is at least one selected from the group consisting of W, 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.

15 . The method of claim 9 , wherein the first heat treatment is performed for 1 to 12 hours.

16 . The method of claim 13 , wherein the second heat treatment is performed for 2 to 20 hours.

Assignees

• Lg Chemical Ltd

Inventors

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

Classifications

• 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

• C01P2006/40

  Electric properties · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• C01G53/44 Primary

  containing manganese · CPC title

• H01M10/052

  Li-accumulators · CPC title